Add m-esr52 at 52.6.0

48 files changed, 27600 insertions, 0 deletions

diff --git a/netwerk/cache2/AppCacheStorage.cpp b/netwerk/cache2/AppCacheStorage.cpp
new file mode 100644
index 0000000000..c550b272d4
--- /dev/null
+++ b/netwerk/cache2/AppCacheStorage.cpp
@@ -0,0 +1,177 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "AppCacheStorage.h"
+#include "CacheStorageService.h"
+
+#include "OldWrappers.h"
+
+#include "nsICacheEntryDoomCallback.h"
+
+#include "nsCacheService.h"
+#include "nsIApplicationCache.h"
+#include "nsIApplicationCacheService.h"
+#include "nsIURI.h"
+#include "nsNetCID.h"
+#include "nsServiceManagerUtils.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS_INHERITED0(AppCacheStorage, CacheStorage)
+
+AppCacheStorage::AppCacheStorage(nsILoadContextInfo* aInfo,
+                                 nsIApplicationCache* aAppCache)
+: CacheStorage(aInfo, true /* disk */, false /* lookup app cache */, false /* skip size check */, false /* pin */)
+, mAppCache(aAppCache)
+{
+  MOZ_COUNT_CTOR(AppCacheStorage);
+}
+
+AppCacheStorage::~AppCacheStorage()
+{
+  ProxyReleaseMainThread(mAppCache);
+  MOZ_COUNT_DTOR(AppCacheStorage);
+}
+
+NS_IMETHODIMP AppCacheStorage::AsyncOpenURI(nsIURI *aURI,
+                                            const nsACString & aIdExtension,
+                                            uint32_t aFlags,
+                                            nsICacheEntryOpenCallback *aCallback)
+{
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  NS_ENSURE_ARG(aURI);
+  NS_ENSURE_ARG(aCallback);
+
+  nsresult rv;
+
+  nsCOMPtr<nsIApplicationCache> appCache = mAppCache;
+
+  if (!appCache) {
+    rv = ChooseApplicationCache(aURI, getter_AddRefs(appCache));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (!appCache) {
+    LOG(("AppCacheStorage::AsyncOpenURI entry not found in any appcache, giving up"));
+    aCallback->OnCacheEntryAvailable(nullptr, false, nullptr, NS_ERROR_CACHE_KEY_NOT_FOUND);
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIURI> noRefURI;
+  rv = aURI->CloneIgnoringRef(getter_AddRefs(noRefURI));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString cacheKey;
+  rv = noRefURI->GetAsciiSpec(cacheKey);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // This is the only way how to recognize appcache data by the anonymous
+  // flag.  There is no way to switch to e.g. a different session, because
+  // there is just a single session for an appcache version (identified
+  // by the client id).
+  if (LoadInfo()->IsAnonymous()) {
+    cacheKey = NS_LITERAL_CSTRING("anon&") + cacheKey;
+  }
+
+  nsAutoCString scheme;
+  rv = noRefURI->GetScheme(scheme);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<_OldCacheLoad> appCacheLoad =
+    new _OldCacheLoad(scheme, cacheKey, aCallback, appCache,
+                      LoadInfo(), WriteToDisk(), aFlags);
+  rv = appCacheLoad->Start();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP AppCacheStorage::OpenTruncate(nsIURI *aURI, const nsACString & aIdExtension,
+                                            nsICacheEntry **aCacheEntry)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP AppCacheStorage::Exists(nsIURI *aURI, const nsACString & aIdExtension,
+                                      bool *aResult)
+{
+  *aResult = false;
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP AppCacheStorage::AsyncDoomURI(nsIURI *aURI, const nsACString & aIdExtension,
+                                            nsICacheEntryDoomCallback* aCallback)
+{
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  if (!mAppCache) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  RefPtr<_OldStorage> old = new _OldStorage(
+    LoadInfo(), WriteToDisk(), LookupAppCache(), true, mAppCache);
+  return old->AsyncDoomURI(aURI, aIdExtension, aCallback);
+}
+
+NS_IMETHODIMP AppCacheStorage::AsyncEvictStorage(nsICacheEntryDoomCallback* aCallback)
+{
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  nsresult rv;
+
+  if (!mAppCache) {
+    // Discard everything under this storage context
+    nsCOMPtr<nsIApplicationCacheService> appCacheService =
+      do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = appCacheService->Evict(LoadInfo());
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    // Discard the group
+    RefPtr<_OldStorage> old = new _OldStorage(
+      LoadInfo(), WriteToDisk(), LookupAppCache(), true, mAppCache);
+    rv = old->AsyncEvictStorage(aCallback);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return NS_OK;
+  }
+
+  if (aCallback)
+    aCallback->OnCacheEntryDoomed(NS_OK);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP AppCacheStorage::AsyncVisitStorage(nsICacheStorageVisitor* aVisitor,
+                                                 bool aVisitEntries)
+{
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  LOG(("AppCacheStorage::AsyncVisitStorage [this=%p, cb=%p]", this, aVisitor));
+
+  nsresult rv;
+
+  nsCOMPtr<nsICacheService> serv =
+    do_GetService(NS_CACHESERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<_OldVisitCallbackWrapper> cb = new _OldVisitCallbackWrapper(
+    "offline", aVisitor, aVisitEntries, LoadInfo());
+  rv = nsCacheService::GlobalInstance()->VisitEntriesInternal(cb);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/AppCacheStorage.h b/netwerk/cache2/AppCacheStorage.h
new file mode 100644
index 0000000000..eef70dea08
--- /dev/null
+++ b/netwerk/cache2/AppCacheStorage.h
@@ -0,0 +1,37 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef AppCacheStorage__h__
+#define AppCacheStorage__h__
+
+#include "CacheStorage.h"
+
+#include "nsCOMPtr.h"
+#include "nsILoadContextInfo.h"
+#include "nsIApplicationCache.h"
+
+class nsIApplicationCache;
+
+namespace mozilla {
+namespace net {
+
+class AppCacheStorage : public CacheStorage
+{
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSICACHESTORAGE
+
+public:
+  AppCacheStorage(nsILoadContextInfo* aInfo,
+                  nsIApplicationCache* aAppCache);
+
+private:
+  virtual ~AppCacheStorage();
+
+  nsCOMPtr<nsIApplicationCache> mAppCache;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheEntry.cpp b/netwerk/cache2/CacheEntry.cpp
new file mode 100644
index 0000000000..b79bf73734
--- /dev/null
+++ b/netwerk/cache2/CacheEntry.cpp
@@ -0,0 +1,1920 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheEntry.h"
+#include "CacheStorageService.h"
+#include "CacheObserver.h"
+#include "CacheFileUtils.h"
+#include "CacheIndex.h"
+
+#include "nsIInputStream.h"
+#include "nsIOutputStream.h"
+#include "nsISeekableStream.h"
+#include "nsIURI.h"
+#include "nsICacheEntryOpenCallback.h"
+#include "nsICacheStorage.h"
+#include "nsISerializable.h"
+#include "nsIStreamTransportService.h"
+#include "nsISizeOf.h"
+
+#include "nsComponentManagerUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "nsString.h"
+#include "nsProxyRelease.h"
+#include "nsSerializationHelper.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Telemetry.h"
+#include <math.h>
+#include <algorithm>
+
+namespace mozilla {
+namespace net {
+
+static uint32_t const ENTRY_WANTED =
+  nsICacheEntryOpenCallback::ENTRY_WANTED;
+static uint32_t const RECHECK_AFTER_WRITE_FINISHED =
+  nsICacheEntryOpenCallback::RECHECK_AFTER_WRITE_FINISHED;
+static uint32_t const ENTRY_NEEDS_REVALIDATION =
+  nsICacheEntryOpenCallback::ENTRY_NEEDS_REVALIDATION;
+static uint32_t const ENTRY_NOT_WANTED =
+  nsICacheEntryOpenCallback::ENTRY_NOT_WANTED;
+
+NS_IMPL_ISUPPORTS(CacheEntryHandle, nsICacheEntry)
+
+// CacheEntryHandle
+
+CacheEntryHandle::CacheEntryHandle(CacheEntry* aEntry)
+: mEntry(aEntry)
+{
+  MOZ_COUNT_CTOR(CacheEntryHandle);
+
+#ifdef DEBUG
+  if (!mEntry->HandlesCount()) {
+    // CacheEntry.mHandlesCount must go from zero to one only under
+    // the service lock. Can access CacheStorageService::Self() w/o a check
+    // since CacheEntry hrefs it.
+    CacheStorageService::Self()->Lock().AssertCurrentThreadOwns();
+  }
+#endif
+
+  mEntry->AddHandleRef();
+
+  LOG(("New CacheEntryHandle %p for entry %p", this, aEntry));
+}
+
+CacheEntryHandle::~CacheEntryHandle()
+{
+  mEntry->ReleaseHandleRef();
+  mEntry->OnHandleClosed(this);
+
+  MOZ_COUNT_DTOR(CacheEntryHandle);
+}
+
+// CacheEntry::Callback
+
+CacheEntry::Callback::Callback(CacheEntry* aEntry,
+                               nsICacheEntryOpenCallback *aCallback,
+                               bool aReadOnly, bool aCheckOnAnyThread,
+                               bool aSecret)
+: mEntry(aEntry)
+, mCallback(aCallback)
+, mTargetThread(do_GetCurrentThread())
+, mReadOnly(aReadOnly)
+, mRevalidating(false)
+, mCheckOnAnyThread(aCheckOnAnyThread)
+, mRecheckAfterWrite(false)
+, mNotWanted(false)
+, mSecret(aSecret)
+, mDoomWhenFoundPinned(false)
+, mDoomWhenFoundNonPinned(false)
+{
+  MOZ_COUNT_CTOR(CacheEntry::Callback);
+
+  // The counter may go from zero to non-null only under the service lock
+  // but here we expect it to be already positive.
+  MOZ_ASSERT(mEntry->HandlesCount());
+  mEntry->AddHandleRef();
+}
+
+CacheEntry::Callback::Callback(CacheEntry* aEntry, bool aDoomWhenFoundInPinStatus)
+: mEntry(aEntry)
+, mReadOnly(false)
+, mRevalidating(false)
+, mCheckOnAnyThread(true)
+, mRecheckAfterWrite(false)
+, mNotWanted(false)
+, mSecret(false)
+, mDoomWhenFoundPinned(aDoomWhenFoundInPinStatus == true)
+, mDoomWhenFoundNonPinned(aDoomWhenFoundInPinStatus == false)
+{
+  MOZ_COUNT_CTOR(CacheEntry::Callback);
+  MOZ_ASSERT(mEntry->HandlesCount());
+  mEntry->AddHandleRef();
+}
+
+CacheEntry::Callback::Callback(CacheEntry::Callback const &aThat)
+: mEntry(aThat.mEntry)
+, mCallback(aThat.mCallback)
+, mTargetThread(aThat.mTargetThread)
+, mReadOnly(aThat.mReadOnly)
+, mRevalidating(aThat.mRevalidating)
+, mCheckOnAnyThread(aThat.mCheckOnAnyThread)
+, mRecheckAfterWrite(aThat.mRecheckAfterWrite)
+, mNotWanted(aThat.mNotWanted)
+, mSecret(aThat.mSecret)
+, mDoomWhenFoundPinned(aThat.mDoomWhenFoundPinned)
+, mDoomWhenFoundNonPinned(aThat.mDoomWhenFoundNonPinned)
+{
+  MOZ_COUNT_CTOR(CacheEntry::Callback);
+
+  // The counter may go from zero to non-null only under the service lock
+  // but here we expect it to be already positive.
+  MOZ_ASSERT(mEntry->HandlesCount());
+  mEntry->AddHandleRef();
+}
+
+CacheEntry::Callback::~Callback()
+{
+  ProxyRelease(mCallback, mTargetThread);
+
+  mEntry->ReleaseHandleRef();
+  MOZ_COUNT_DTOR(CacheEntry::Callback);
+}
+
+void CacheEntry::Callback::ExchangeEntry(CacheEntry* aEntry)
+{
+  if (mEntry == aEntry)
+    return;
+
+  // The counter may go from zero to non-null only under the service lock
+  // but here we expect it to be already positive.
+  MOZ_ASSERT(aEntry->HandlesCount());
+  aEntry->AddHandleRef();
+  mEntry->ReleaseHandleRef();
+  mEntry = aEntry;
+}
+
+bool CacheEntry::Callback::DeferDoom(bool *aDoom) const
+{
+  MOZ_ASSERT(mEntry->mPinningKnown);
+
+  if (MOZ_UNLIKELY(mDoomWhenFoundNonPinned) || MOZ_UNLIKELY(mDoomWhenFoundPinned)) {
+    *aDoom = (MOZ_UNLIKELY(mDoomWhenFoundNonPinned) && MOZ_LIKELY(!mEntry->mPinned)) ||
+             (MOZ_UNLIKELY(mDoomWhenFoundPinned) && MOZ_UNLIKELY(mEntry->mPinned));
+
+    return true;
+  }
+
+  return false;
+}
+
+nsresult CacheEntry::Callback::OnCheckThread(bool *aOnCheckThread) const
+{
+  if (!mCheckOnAnyThread) {
+    // Check we are on the target
+    return mTargetThread->IsOnCurrentThread(aOnCheckThread);
+  }
+
+  // We can invoke check anywhere
+  *aOnCheckThread = true;
+  return NS_OK;
+}
+
+nsresult CacheEntry::Callback::OnAvailThread(bool *aOnAvailThread) const
+{
+  return mTargetThread->IsOnCurrentThread(aOnAvailThread);
+}
+
+// CacheEntry
+
+NS_IMPL_ISUPPORTS(CacheEntry,
+                  nsICacheEntry,
+                  nsIRunnable,
+                  CacheFileListener)
+
+CacheEntry::CacheEntry(const nsACString& aStorageID,
+                       const nsACString& aURI,
+                       const nsACString& aEnhanceID,
+                       bool aUseDisk,
+                       bool aSkipSizeCheck,
+                       bool aPin)
+: mFrecency(0)
+, mSortingExpirationTime(uint32_t(-1))
+, mLock("CacheEntry")
+, mFileStatus(NS_ERROR_NOT_INITIALIZED)
+, mURI(aURI)
+, mEnhanceID(aEnhanceID)
+, mStorageID(aStorageID)
+, mUseDisk(aUseDisk)
+, mSkipSizeCheck(aSkipSizeCheck)
+, mIsDoomed(false)
+, mSecurityInfoLoaded(false)
+, mPreventCallbacks(false)
+, mHasData(false)
+, mPinned(aPin)
+, mPinningKnown(false)
+, mState(NOTLOADED)
+, mRegistration(NEVERREGISTERED)
+, mWriter(nullptr)
+, mPredictedDataSize(0)
+, mUseCount(0)
+{
+  LOG(("CacheEntry::CacheEntry [this=%p]", this));
+
+  mService = CacheStorageService::Self();
+
+  CacheStorageService::Self()->RecordMemoryOnlyEntry(
+    this, !aUseDisk, true /* overwrite */);
+}
+
+CacheEntry::~CacheEntry()
+{
+  LOG(("CacheEntry::~CacheEntry [this=%p]", this));
+}
+
+char const * CacheEntry::StateString(uint32_t aState)
+{
+  switch (aState) {
+  case NOTLOADED:     return "NOTLOADED";
+  case LOADING:       return "LOADING";
+  case EMPTY:         return "EMPTY";
+  case WRITING:       return "WRITING";
+  case READY:         return "READY";
+  case REVALIDATING:  return "REVALIDATING";
+  }
+
+  return "?";
+}
+
+nsresult CacheEntry::HashingKeyWithStorage(nsACString &aResult) const
+{
+  return HashingKey(mStorageID, mEnhanceID, mURI, aResult);
+}
+
+nsresult CacheEntry::HashingKey(nsACString &aResult) const
+{
+  return HashingKey(EmptyCString(), mEnhanceID, mURI, aResult);
+}
+
+// static
+nsresult CacheEntry::HashingKey(nsCSubstring const& aStorageID,
+                                nsCSubstring const& aEnhanceID,
+                                nsIURI* aURI,
+                                nsACString &aResult)
+{
+  nsAutoCString spec;
+  nsresult rv = aURI->GetAsciiSpec(spec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return HashingKey(aStorageID, aEnhanceID, spec, aResult);
+}
+
+// static
+nsresult CacheEntry::HashingKey(nsCSubstring const& aStorageID,
+                                nsCSubstring const& aEnhanceID,
+                                nsCSubstring const& aURISpec,
+                                nsACString &aResult)
+{
+  /**
+   * This key is used to salt hash that is a base for disk file name.
+   * Changing it will cause we will not be able to find files on disk.
+   */
+
+  aResult.Assign(aStorageID);
+
+  if (!aEnhanceID.IsEmpty()) {
+    CacheFileUtils::AppendTagWithValue(aResult, '~', aEnhanceID);
+  }
+
+  // Appending directly
+  aResult.Append(':');
+  aResult.Append(aURISpec);
+
+  return NS_OK;
+}
+
+void CacheEntry::AsyncOpen(nsICacheEntryOpenCallback* aCallback, uint32_t aFlags)
+{
+  LOG(("CacheEntry::AsyncOpen [this=%p, state=%s, flags=%d, callback=%p]",
+    this, StateString(mState), aFlags, aCallback));
+
+  bool readonly = aFlags & nsICacheStorage::OPEN_READONLY;
+  bool bypassIfBusy = aFlags & nsICacheStorage::OPEN_BYPASS_IF_BUSY;
+  bool truncate = aFlags & nsICacheStorage::OPEN_TRUNCATE;
+  bool priority = aFlags & nsICacheStorage::OPEN_PRIORITY;
+  bool multithread = aFlags & nsICacheStorage::CHECK_MULTITHREADED;
+  bool secret = aFlags & nsICacheStorage::OPEN_SECRETLY;
+
+  MOZ_ASSERT(!readonly || !truncate, "Bad flags combination");
+  MOZ_ASSERT(!(truncate && mState > LOADING), "Must not call truncate on already loaded entry");
+
+  Callback callback(this, aCallback, readonly, multithread, secret);
+
+  if (!Open(callback, truncate, priority, bypassIfBusy)) {
+    // We get here when the callback wants to bypass cache when it's busy.
+    LOG(("  writing or revalidating, callback wants to bypass cache"));
+    callback.mNotWanted = true;
+    InvokeAvailableCallback(callback);
+  }
+}
+
+bool CacheEntry::Open(Callback & aCallback, bool aTruncate,
+                      bool aPriority, bool aBypassIfBusy)
+{
+  mozilla::MutexAutoLock lock(mLock);
+
+  // Check state under the lock
+  if (aBypassIfBusy && (mState == WRITING || mState == REVALIDATING)) {
+    return false;
+  }
+
+  RememberCallback(aCallback);
+
+  // Load() opens the lock
+  if (Load(aTruncate, aPriority)) {
+    // Loading is in progress...
+    return true;
+  }
+
+  InvokeCallbacks();
+
+  return true;
+}
+
+bool CacheEntry::Load(bool aTruncate, bool aPriority)
+{
+  LOG(("CacheEntry::Load [this=%p, trunc=%d]", this, aTruncate));
+
+  mLock.AssertCurrentThreadOwns();
+
+  if (mState > LOADING) {
+    LOG(("  already loaded"));
+    return false;
+  }
+
+  if (mState == LOADING) {
+    LOG(("  already loading"));
+    return true;
+  }
+
+  mState = LOADING;
+
+  MOZ_ASSERT(!mFile);
+
+  nsresult rv;
+
+  nsAutoCString fileKey;
+  rv = HashingKeyWithStorage(fileKey);
+
+  bool reportMiss = false;
+
+  // Check the index under two conditions for two states and take appropriate action:
+  // 1. When this is a disk entry and not told to truncate, check there is a disk file.
+  //    If not, set the 'truncate' flag to true so that this entry will open instantly
+  //    as a new one.
+  // 2. When this is a memory-only entry, check there is a disk file.
+  //    If there is or could be, doom that file.
+  if ((!aTruncate || !mUseDisk) && NS_SUCCEEDED(rv)) {
+    // Check the index right now to know we have or have not the entry
+    // as soon as possible.
+    CacheIndex::EntryStatus status;
+    if (NS_SUCCEEDED(CacheIndex::HasEntry(fileKey, &status))) {
+      switch (status) {
+      case CacheIndex::DOES_NOT_EXIST:
+        // Doesn't apply to memory-only entries, Load() is called only once for them
+        // and never again for their session lifetime.
+        if (!aTruncate && mUseDisk) {
+          LOG(("  entry doesn't exist according information from the index, truncating"));
+          reportMiss = true;
+          aTruncate = true;
+        }
+        break;
+      case CacheIndex::EXISTS:
+      case CacheIndex::DO_NOT_KNOW:
+        if (!mUseDisk) {
+          LOG(("  entry open as memory-only, but there is a file, status=%d, dooming it", status));
+          CacheFileIOManager::DoomFileByKey(fileKey, nullptr);
+        }
+        break;
+      }
+    }
+  }
+
+  mFile = new CacheFile();
+
+  BackgroundOp(Ops::REGISTER);
+
+  bool directLoad = aTruncate || !mUseDisk;
+  if (directLoad) {
+    // mLoadStart will be used to calculate telemetry of life-time of this entry.
+    // Low resulution is then enough.
+    mLoadStart = TimeStamp::NowLoRes();
+    mPinningKnown = true;
+  } else {
+    mLoadStart = TimeStamp::Now();
+  }
+
+  {
+    mozilla::MutexAutoUnlock unlock(mLock);
+
+    if (reportMiss) {
+      CacheFileUtils::DetailedCacheHitTelemetry::AddRecord(
+        CacheFileUtils::DetailedCacheHitTelemetry::MISS, mLoadStart);
+    }
+
+    LOG(("  performing load, file=%p", mFile.get()));
+    if (NS_SUCCEEDED(rv)) {
+      rv = mFile->Init(fileKey,
+                       aTruncate,
+                       !mUseDisk,
+                       mSkipSizeCheck,
+                       aPriority,
+                       mPinned,
+                       directLoad ? nullptr : this);
+    }
+
+    if (NS_FAILED(rv)) {
+      mFileStatus = rv;
+      AsyncDoom(nullptr);
+      return false;
+    }
+  }
+
+  if (directLoad) {
+    // Just fake the load has already been done as "new".
+    mFileStatus = NS_OK;
+    mState = EMPTY;
+  }
+
+  return mState == LOADING;
+}
+
+NS_IMETHODIMP CacheEntry::OnFileReady(nsresult aResult, bool aIsNew)
+{
+  LOG(("CacheEntry::OnFileReady [this=%p, rv=0x%08x, new=%d]",
+      this, aResult, aIsNew));
+
+  MOZ_ASSERT(!mLoadStart.IsNull());
+
+  if (NS_SUCCEEDED(aResult)) {
+    if (aIsNew) {
+      CacheFileUtils::DetailedCacheHitTelemetry::AddRecord(
+        CacheFileUtils::DetailedCacheHitTelemetry::MISS, mLoadStart);
+    } else {
+      CacheFileUtils::DetailedCacheHitTelemetry::AddRecord(
+        CacheFileUtils::DetailedCacheHitTelemetry::HIT, mLoadStart);
+    }
+  }
+
+  // OnFileReady, that is the only code that can transit from LOADING
+  // to any follow-on state and can only be invoked ones on an entry.
+  // Until this moment there is no consumer that could manipulate
+  // the entry state.
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  MOZ_ASSERT(mState == LOADING);
+
+  mState = (aIsNew || NS_FAILED(aResult))
+    ? EMPTY
+    : READY;
+
+  mFileStatus = aResult;
+
+  mPinned = mFile->IsPinned();;
+  mPinningKnown = true;
+  LOG(("  pinning=%d", mPinned));
+
+  if (mState == READY) {
+    mHasData = true;
+
+    uint32_t frecency;
+    mFile->GetFrecency(&frecency);
+    // mFrecency is held in a double to increase computance precision.
+    // It is ok to persist frecency only as a uint32 with some math involved.
+    mFrecency = INT2FRECENCY(frecency);
+  }
+
+  InvokeCallbacks();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::OnFileDoomed(nsresult aResult)
+{
+  if (mDoomCallback) {
+    RefPtr<DoomCallbackRunnable> event =
+      new DoomCallbackRunnable(this, aResult);
+    NS_DispatchToMainThread(event);
+  }
+
+  return NS_OK;
+}
+
+already_AddRefed<CacheEntryHandle> CacheEntry::ReopenTruncated(bool aMemoryOnly,
+                                                               nsICacheEntryOpenCallback* aCallback)
+{
+  LOG(("CacheEntry::ReopenTruncated [this=%p]", this));
+
+  mLock.AssertCurrentThreadOwns();
+
+  // Hold callbacks invocation, AddStorageEntry would invoke from doom prematurly
+  mPreventCallbacks = true;
+
+  RefPtr<CacheEntryHandle> handle;
+  RefPtr<CacheEntry> newEntry;
+  {
+    if (mPinned) {
+      MOZ_ASSERT(mUseDisk);
+      // We want to pin even no-store entries (the case we recreate a disk entry as
+      // a memory-only entry.)
+      aMemoryOnly = false;
+    }
+
+    mozilla::MutexAutoUnlock unlock(mLock);
+
+    // The following call dooms this entry (calls DoomAlreadyRemoved on us)
+    nsresult rv = CacheStorageService::Self()->AddStorageEntry(
+      GetStorageID(), GetURI(), GetEnhanceID(),
+      mUseDisk && !aMemoryOnly,
+      mSkipSizeCheck,
+      mPinned,
+      true, // truncate existing (this one)
+      getter_AddRefs(handle));
+
+    if (NS_SUCCEEDED(rv)) {
+      newEntry = handle->Entry();
+      LOG(("  exchanged entry %p by entry %p, rv=0x%08x", this, newEntry.get(), rv));
+      newEntry->AsyncOpen(aCallback, nsICacheStorage::OPEN_TRUNCATE);
+    } else {
+      LOG(("  exchanged of entry %p failed, rv=0x%08x", this, rv));
+      AsyncDoom(nullptr);
+    }
+  }
+
+  mPreventCallbacks = false;
+
+  if (!newEntry)
+    return nullptr;
+
+  newEntry->TransferCallbacks(*this);
+  mCallbacks.Clear();
+
+  // Must return a new write handle, since the consumer is expected to
+  // write to this newly recreated entry.  The |handle| is only a common
+  // reference counter and doesn't revert entry state back when write
+  // fails and also doesn't update the entry frecency.  Not updating
+  // frecency causes entries to not be purged from our memory pools.
+  RefPtr<CacheEntryHandle> writeHandle =
+    newEntry->NewWriteHandle();
+  return writeHandle.forget();
+}
+
+void CacheEntry::TransferCallbacks(CacheEntry & aFromEntry)
+{
+  mozilla::MutexAutoLock lock(mLock);
+
+  LOG(("CacheEntry::TransferCallbacks [entry=%p, from=%p]",
+    this, &aFromEntry));
+
+  if (!mCallbacks.Length())
+    mCallbacks.SwapElements(aFromEntry.mCallbacks);
+  else
+    mCallbacks.AppendElements(aFromEntry.mCallbacks);
+
+  uint32_t callbacksLength = mCallbacks.Length();
+  if (callbacksLength) {
+    // Carry the entry reference (unfortunatelly, needs to be done manually...)
+    for (uint32_t i = 0; i < callbacksLength; ++i)
+      mCallbacks[i].ExchangeEntry(this);
+
+    BackgroundOp(Ops::CALLBACKS, true);
+  }
+}
+
+void CacheEntry::RememberCallback(Callback & aCallback)
+{
+  mLock.AssertCurrentThreadOwns();
+
+  LOG(("CacheEntry::RememberCallback [this=%p, cb=%p, state=%s]",
+    this, aCallback.mCallback.get(), StateString(mState)));
+
+  mCallbacks.AppendElement(aCallback);
+}
+
+void CacheEntry::InvokeCallbacksLock()
+{
+  mozilla::MutexAutoLock lock(mLock);
+  InvokeCallbacks();
+}
+
+void CacheEntry::InvokeCallbacks()
+{
+  mLock.AssertCurrentThreadOwns();
+
+  LOG(("CacheEntry::InvokeCallbacks BEGIN [this=%p]", this));
+
+  // Invoke first all r/w callbacks, then all r/o callbacks.
+  if (InvokeCallbacks(false))
+    InvokeCallbacks(true);
+
+  LOG(("CacheEntry::InvokeCallbacks END [this=%p]", this));
+}
+
+bool CacheEntry::InvokeCallbacks(bool aReadOnly)
+{
+  mLock.AssertCurrentThreadOwns();
+
+  RefPtr<CacheEntryHandle> recreatedHandle;
+
+  uint32_t i = 0;
+  while (i < mCallbacks.Length()) {
+    if (mPreventCallbacks) {
+      LOG(("  callbacks prevented!"));
+      return false;
+    }
+
+    if (!mIsDoomed && (mState == WRITING || mState == REVALIDATING)) {
+      LOG(("  entry is being written/revalidated"));
+      return false;
+    }
+
+    bool recreate;
+    if (mCallbacks[i].DeferDoom(&recreate)) {
+      mCallbacks.RemoveElementAt(i);
+      if (!recreate) {
+        continue;
+      }
+
+      LOG(("  defer doom marker callback hit positive, recreating"));
+      recreatedHandle = ReopenTruncated(!mUseDisk, nullptr);
+      break;
+    }
+
+    if (mCallbacks[i].mReadOnly != aReadOnly) {
+      // Callback is not r/w or r/o, go to another one in line
+      ++i;
+      continue;
+    }
+
+    bool onCheckThread;
+    nsresult rv = mCallbacks[i].OnCheckThread(&onCheckThread);
+
+    if (NS_SUCCEEDED(rv) && !onCheckThread) {
+      // Redispatch to the target thread
+      rv = mCallbacks[i].mTargetThread->Dispatch(NewRunnableMethod(this,
+								   &CacheEntry::InvokeCallbacksLock),
+						 nsIEventTarget::DISPATCH_NORMAL);
+      if (NS_SUCCEEDED(rv)) {
+        LOG(("  re-dispatching to target thread"));
+        return false;
+      }
+    }
+
+    Callback callback = mCallbacks[i];
+    mCallbacks.RemoveElementAt(i);
+
+    if (NS_SUCCEEDED(rv) && !InvokeCallback(callback)) {
+      // Callback didn't fire, put it back and go to another one in line.
+      // Only reason InvokeCallback returns false is that onCacheEntryCheck
+      // returns RECHECK_AFTER_WRITE_FINISHED.  If we would stop the loop, other
+      // readers or potential writers would be unnecessarily kept from being
+      // invoked.
+      size_t pos = std::min(mCallbacks.Length(), static_cast<size_t>(i));
+      mCallbacks.InsertElementAt(pos, callback);
+      ++i;
+    }
+  }
+
+  if (recreatedHandle) {
+    // Must be released outside of the lock, enters InvokeCallback on the new entry
+    mozilla::MutexAutoUnlock unlock(mLock);
+    recreatedHandle = nullptr;
+  }
+
+  return true;
+}
+
+bool CacheEntry::InvokeCallback(Callback & aCallback)
+{
+  LOG(("CacheEntry::InvokeCallback [this=%p, state=%s, cb=%p]",
+    this, StateString(mState), aCallback.mCallback.get()));
+
+  mLock.AssertCurrentThreadOwns();
+
+  // When this entry is doomed we want to notify the callback any time
+  if (!mIsDoomed) {
+    // When we are here, the entry must be loaded from disk
+    MOZ_ASSERT(mState > LOADING);
+
+    if (mState == WRITING || mState == REVALIDATING) {
+      // Prevent invoking other callbacks since one of them is now writing
+      // or revalidating this entry.  No consumers should get this entry
+      // until metadata are filled with values downloaded from the server
+      // or the entry revalidated and output stream has been opened.
+      LOG(("  entry is being written/revalidated, callback bypassed"));
+      return false;
+    }
+
+    // mRecheckAfterWrite flag already set means the callback has already passed
+    // the onCacheEntryCheck call. Until the current write is not finished this
+    // callback will be bypassed.
+    if (!aCallback.mRecheckAfterWrite) {
+
+      if (!aCallback.mReadOnly) {
+        if (mState == EMPTY) {
+          // Advance to writing state, we expect to invoke the callback and let
+          // it fill content of this entry.  Must set and check the state here
+          // to prevent more then one
+          mState = WRITING;
+          LOG(("  advancing to WRITING state"));
+        }
+
+        if (!aCallback.mCallback) {
+          // We can be given no callback only in case of recreate, it is ok
+          // to advance to WRITING state since the caller of recreate is expected
+          // to write this entry now.
+          return true;
+        }
+      }
+
+      if (mState == READY) {
+        // Metadata present, validate the entry
+        uint32_t checkResult;
+        {
+          // mayhemer: TODO check and solve any potential races of concurent OnCacheEntryCheck
+          mozilla::MutexAutoUnlock unlock(mLock);
+
+          nsresult rv = aCallback.mCallback->OnCacheEntryCheck(
+            this, nullptr, &checkResult);
+          LOG(("  OnCacheEntryCheck: rv=0x%08x, result=%d", rv, checkResult));
+
+          if (NS_FAILED(rv))
+            checkResult = ENTRY_NOT_WANTED;
+        }
+
+        aCallback.mRevalidating = checkResult == ENTRY_NEEDS_REVALIDATION;
+
+        switch (checkResult) {
+        case ENTRY_WANTED:
+          // Nothing more to do here, the consumer is responsible to handle
+          // the result of OnCacheEntryCheck it self.
+          // Proceed to callback...
+          break;
+
+        case RECHECK_AFTER_WRITE_FINISHED:
+          LOG(("  consumer will check on the entry again after write is done"));
+          // The consumer wants the entry to complete first.
+          aCallback.mRecheckAfterWrite = true;
+          break;
+
+        case ENTRY_NEEDS_REVALIDATION:
+          LOG(("  will be holding callbacks until entry is revalidated"));
+          // State is READY now and from that state entry cannot transit to any other
+          // state then REVALIDATING for which cocurrency is not an issue.  Potentially
+          // no need to lock here.
+          mState = REVALIDATING;
+          break;
+
+        case ENTRY_NOT_WANTED:
+          LOG(("  consumer not interested in the entry"));
+          // Do not give this entry to the consumer, it is not interested in us.
+          aCallback.mNotWanted = true;
+          break;
+        }
+      }
+    }
+  }
+
+  if (aCallback.mCallback) {
+    if (!mIsDoomed && aCallback.mRecheckAfterWrite) {
+      // If we don't have data and the callback wants a complete entry,
+      // don't invoke now.
+      bool bypass = !mHasData;
+      if (!bypass && NS_SUCCEEDED(mFileStatus)) {
+        int64_t _unused;
+        bypass = !mFile->DataSize(&_unused);
+      }
+
+      if (bypass) {
+        LOG(("  bypassing, entry data still being written"));
+        return false;
+      }
+
+      // Entry is complete now, do the check+avail call again
+      aCallback.mRecheckAfterWrite = false;
+      return InvokeCallback(aCallback);
+    }
+
+    mozilla::MutexAutoUnlock unlock(mLock);
+    InvokeAvailableCallback(aCallback);
+  }
+
+  return true;
+}
+
+void CacheEntry::InvokeAvailableCallback(Callback const & aCallback)
+{
+  LOG(("CacheEntry::InvokeAvailableCallback [this=%p, state=%s, cb=%p, r/o=%d, n/w=%d]",
+    this, StateString(mState), aCallback.mCallback.get(), aCallback.mReadOnly, aCallback.mNotWanted));
+
+  nsresult rv;
+
+  uint32_t const state = mState;
+
+  // When we are here, the entry must be loaded from disk
+  MOZ_ASSERT(state > LOADING || mIsDoomed);
+
+  bool onAvailThread;
+  rv = aCallback.OnAvailThread(&onAvailThread);
+  if (NS_FAILED(rv)) {
+    LOG(("  target thread dead?"));
+    return;
+  }
+
+  if (!onAvailThread) {
+    // Dispatch to the right thread
+    RefPtr<AvailableCallbackRunnable> event =
+      new AvailableCallbackRunnable(this, aCallback);
+
+    rv = aCallback.mTargetThread->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+    LOG(("  redispatched, (rv = 0x%08x)", rv));
+    return;
+  }
+
+  if (mIsDoomed || aCallback.mNotWanted) {
+    LOG(("  doomed or not wanted, notifying OCEA with NS_ERROR_CACHE_KEY_NOT_FOUND"));
+    aCallback.mCallback->OnCacheEntryAvailable(
+      nullptr, false, nullptr, NS_ERROR_CACHE_KEY_NOT_FOUND);
+    return;
+  }
+
+  if (state == READY) {
+    LOG(("  ready/has-meta, notifying OCEA with entry and NS_OK"));
+
+    if (!aCallback.mSecret)
+    {
+      mozilla::MutexAutoLock lock(mLock);
+      BackgroundOp(Ops::FRECENCYUPDATE);
+    }
+
+    OnFetched(aCallback);
+
+    RefPtr<CacheEntryHandle> handle = NewHandle();
+    aCallback.mCallback->OnCacheEntryAvailable(
+      handle, false, nullptr, NS_OK);
+    return;
+  }
+
+  // R/O callbacks may do revalidation, let them fall through
+  if (aCallback.mReadOnly && !aCallback.mRevalidating) {
+    LOG(("  r/o and not ready, notifying OCEA with NS_ERROR_CACHE_KEY_NOT_FOUND"));
+    aCallback.mCallback->OnCacheEntryAvailable(
+      nullptr, false, nullptr, NS_ERROR_CACHE_KEY_NOT_FOUND);
+    return;
+  }
+
+  // This is a new or potentially non-valid entry and needs to be fetched first.
+  // The CacheEntryHandle blocks other consumers until the channel
+  // either releases the entry or marks metadata as filled or whole entry valid,
+  // i.e. until MetaDataReady() or SetValid() on the entry is called respectively.
+
+  // Consumer will be responsible to fill or validate the entry metadata and data.
+
+  OnFetched(aCallback);
+
+  RefPtr<CacheEntryHandle> handle = NewWriteHandle();
+  rv = aCallback.mCallback->OnCacheEntryAvailable(
+    handle, state == WRITING, nullptr, NS_OK);
+
+  if (NS_FAILED(rv)) {
+    LOG(("  writing/revalidating failed (0x%08x)", rv));
+
+    // Consumer given a new entry failed to take care of the entry.
+    OnHandleClosed(handle);
+    return;
+  }
+
+  LOG(("  writing/revalidating"));
+}
+
+void CacheEntry::OnFetched(Callback const & aCallback)
+{
+  if (NS_SUCCEEDED(mFileStatus) && !aCallback.mSecret) {
+    // Let the last-fetched and fetch-count properties be updated.
+    mFile->OnFetched();
+  }
+}
+
+CacheEntryHandle* CacheEntry::NewHandle()
+{
+  return new CacheEntryHandle(this);
+}
+
+CacheEntryHandle* CacheEntry::NewWriteHandle()
+{
+  mozilla::MutexAutoLock lock(mLock);
+
+  // Ignore the OPEN_SECRETLY flag on purpose here, which should actually be
+  // used only along with OPEN_READONLY, but there is no need to enforce that.
+  BackgroundOp(Ops::FRECENCYUPDATE);
+
+  return (mWriter = NewHandle());
+}
+
+void CacheEntry::OnHandleClosed(CacheEntryHandle const* aHandle)
+{
+  LOG(("CacheEntry::OnHandleClosed [this=%p, state=%s, handle=%p]", this, StateString(mState), aHandle));
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (IsDoomed() && NS_SUCCEEDED(mFileStatus) &&
+      // Note: mHandlesCount is dropped before this method is called
+      (mHandlesCount == 0 ||
+       (mHandlesCount == 1 && mWriter && mWriter != aHandle))
+      ) {
+    // This entry is no longer referenced from outside and is doomed.
+    // We can do this also when there is just reference from the writer,
+    // no one else could ever reach the written data.
+    // Tell the file to kill the handle, i.e. bypass any I/O operations
+    // on it except removing the file.
+    mFile->Kill();
+  }
+
+  if (mWriter != aHandle) {
+    LOG(("  not the writer"));
+    return;
+  }
+
+  if (mOutputStream) {
+    LOG(("  abandoning phantom output stream"));
+    // No one took our internal output stream, so there are no data
+    // and output stream has to be open symultaneously with input stream
+    // on this entry again.
+    mHasData = false;
+    // This asynchronously ends up invoking callbacks on this entry
+    // through OnOutputClosed() call.
+    mOutputStream->Close();
+    mOutputStream = nullptr;
+  } else {
+    // We must always redispatch, otherwise there is a risk of stack
+    // overflow.  This code can recurse deeply.  It won't execute sooner
+    // than we release mLock.
+    BackgroundOp(Ops::CALLBACKS, true);
+  }
+
+  mWriter = nullptr;
+
+  if (mState == WRITING) {
+    LOG(("  reverting to state EMPTY - write failed"));
+    mState = EMPTY;
+  }
+  else if (mState == REVALIDATING) {
+    LOG(("  reverting to state READY - reval failed"));
+    mState = READY;
+  }
+
+  if (mState == READY && !mHasData) {
+    // We may get to this state when following steps happen:
+    // 1. a new entry is given to a consumer
+    // 2. the consumer calls MetaDataReady(), we transit to READY
+    // 3. abandons the entry w/o opening the output stream, mHasData left false
+    //
+    // In this case any following consumer will get a ready entry (with metadata)
+    // but in state like the entry data write was still happening (was in progress)
+    // and will indefinitely wait for the entry data or even the entry itself when
+    // RECHECK_AFTER_WRITE is returned from onCacheEntryCheck.
+    LOG(("  we are in READY state, pretend we have data regardless it"
+          " has actully been never touched"));
+    mHasData = true;
+  }
+}
+
+void CacheEntry::OnOutputClosed()
+{
+  // Called when the file's output stream is closed.  Invoke any callbacks
+  // waiting for complete entry.
+
+  mozilla::MutexAutoLock lock(mLock);
+  InvokeCallbacks();
+}
+
+bool CacheEntry::IsReferenced() const
+{
+  CacheStorageService::Self()->Lock().AssertCurrentThreadOwns();
+
+  // Increasing this counter from 0 to non-null and this check both happen only
+  // under the service lock.
+  return mHandlesCount > 0;
+}
+
+bool CacheEntry::IsFileDoomed()
+{
+  if (NS_SUCCEEDED(mFileStatus)) {
+    return mFile->IsDoomed();
+  }
+
+  return false;
+}
+
+uint32_t CacheEntry::GetMetadataMemoryConsumption()
+{
+  NS_ENSURE_SUCCESS(mFileStatus, 0);
+
+  uint32_t size;
+  if (NS_FAILED(mFile->ElementsSize(&size)))
+    return 0;
+
+  return size;
+}
+
+// nsICacheEntry
+
+NS_IMETHODIMP CacheEntry::GetPersistent(bool *aPersistToDisk)
+{
+  // No need to sync when only reading.
+  // When consumer needs to be consistent with state of the memory storage entries
+  // table, then let it use GetUseDisk getter that must be called under the service lock.
+  *aPersistToDisk = mUseDisk;
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::GetKey(nsACString & aKey)
+{
+  aKey.Assign(mURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::GetFetchCount(int32_t *aFetchCount)
+{
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  return mFile->GetFetchCount(reinterpret_cast<uint32_t*>(aFetchCount));
+}
+
+NS_IMETHODIMP CacheEntry::GetLastFetched(uint32_t *aLastFetched)
+{
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  return mFile->GetLastFetched(aLastFetched);
+}
+
+NS_IMETHODIMP CacheEntry::GetLastModified(uint32_t *aLastModified)
+{
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  return mFile->GetLastModified(aLastModified);
+}
+
+NS_IMETHODIMP CacheEntry::GetExpirationTime(uint32_t *aExpirationTime)
+{
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  return mFile->GetExpirationTime(aExpirationTime);
+}
+
+NS_IMETHODIMP CacheEntry::GetIsForcedValid(bool *aIsForcedValid)
+{
+  NS_ENSURE_ARG(aIsForcedValid);
+
+  MOZ_ASSERT(mState > LOADING);
+
+  if (mPinned) {
+    *aIsForcedValid = true;
+    return NS_OK;
+  }
+
+  nsAutoCString key;
+  nsresult rv = HashingKey(key);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  *aIsForcedValid = CacheStorageService::Self()->IsForcedValidEntry(mStorageID, key);
+  LOG(("CacheEntry::GetIsForcedValid [this=%p, IsForcedValid=%d]", this, *aIsForcedValid));
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::ForceValidFor(uint32_t aSecondsToTheFuture)
+{
+  LOG(("CacheEntry::ForceValidFor [this=%p, aSecondsToTheFuture=%d]", this, aSecondsToTheFuture));
+
+  nsAutoCString key;
+  nsresult rv = HashingKey(key);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  CacheStorageService::Self()->ForceEntryValidFor(mStorageID, key, aSecondsToTheFuture);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::SetExpirationTime(uint32_t aExpirationTime)
+{
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  nsresult rv = mFile->SetExpirationTime(aExpirationTime);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Aligned assignment, thus atomic.
+  mSortingExpirationTime = aExpirationTime;
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::OpenInputStream(int64_t offset, nsIInputStream * *_retval)
+{
+  LOG(("CacheEntry::OpenInputStream [this=%p]", this));
+  return OpenInputStreamInternal(offset, nullptr, _retval);
+}
+
+NS_IMETHODIMP CacheEntry::OpenAlternativeInputStream(const nsACString & type, nsIInputStream * *_retval)
+{
+  LOG(("CacheEntry::OpenAlternativeInputStream [this=%p, type=%s]", this,
+       PromiseFlatCString(type).get()));
+  return OpenInputStreamInternal(0, PromiseFlatCString(type).get(), _retval);
+}
+
+nsresult CacheEntry::OpenInputStreamInternal(int64_t offset, const char *aAltDataType, nsIInputStream * *_retval)
+{
+  LOG(("CacheEntry::OpenInputStreamInternal [this=%p]", this));
+
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  nsresult rv;
+
+  RefPtr<CacheEntryHandle> selfHandle = NewHandle();
+
+  nsCOMPtr<nsIInputStream> stream;
+  if (aAltDataType) {
+    rv = mFile->OpenAlternativeInputStream(selfHandle, aAltDataType,
+                                           getter_AddRefs(stream));
+    if (NS_FAILED(rv)) {
+      // Failure of this method may be legal when the alternative data requested
+      // is not avaialble or of a different type.  Console error logs are ensured
+      // by CacheFile::OpenAlternativeInputStream.
+      return rv;
+    }
+  } else {
+    rv = mFile->OpenInputStream(selfHandle, getter_AddRefs(stream));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  nsCOMPtr<nsISeekableStream> seekable =
+    do_QueryInterface(stream, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = seekable->Seek(nsISeekableStream::NS_SEEK_SET, offset);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (!mHasData) {
+    // So far output stream on this new entry not opened, do it now.
+    LOG(("  creating phantom output stream"));
+    rv = OpenOutputStreamInternal(0, getter_AddRefs(mOutputStream));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  stream.forget(_retval);
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::OpenOutputStream(int64_t offset, nsIOutputStream * *_retval)
+{
+  LOG(("CacheEntry::OpenOutputStream [this=%p]", this));
+
+  nsresult rv;
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  MOZ_ASSERT(mState > EMPTY);
+
+  if (mOutputStream && !mIsDoomed) {
+    LOG(("  giving phantom output stream"));
+    mOutputStream.forget(_retval);
+  }
+  else {
+    rv = OpenOutputStreamInternal(offset, _retval);
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  // Entry considered ready when writer opens output stream.
+  if (mState < READY)
+    mState = READY;
+
+  // Invoke any pending readers now.
+  InvokeCallbacks();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::OpenAlternativeOutputStream(const nsACString & type, nsIOutputStream * *_retval)
+{
+  LOG(("CacheEntry::OpenAlternativeOutputStream [this=%p, type=%s]", this,
+       PromiseFlatCString(type).get()));
+
+  nsresult rv;
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (!mHasData || mState < READY || mOutputStream || mIsDoomed) {
+    LOG(("  entry not in state to write alt-data"));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsCOMPtr<nsIOutputStream> stream;
+  rv = mFile->OpenAlternativeOutputStream(nullptr,
+                                          PromiseFlatCString(type).get(),
+                                          getter_AddRefs(stream));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  stream.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult CacheEntry::OpenOutputStreamInternal(int64_t offset, nsIOutputStream * *_retval)
+{
+  LOG(("CacheEntry::OpenOutputStreamInternal [this=%p]", this));
+
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  mLock.AssertCurrentThreadOwns();
+
+  if (mIsDoomed) {
+    LOG(("  doomed..."));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  MOZ_ASSERT(mState > LOADING);
+
+  nsresult rv;
+
+  // No need to sync on mUseDisk here, we don't need to be consistent
+  // with content of the memory storage entries hash table.
+  if (!mUseDisk) {
+    rv = mFile->SetMemoryOnly();
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  RefPtr<CacheOutputCloseListener> listener =
+    new CacheOutputCloseListener(this);
+
+  nsCOMPtr<nsIOutputStream> stream;
+  rv = mFile->OpenOutputStream(listener, getter_AddRefs(stream));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsISeekableStream> seekable =
+    do_QueryInterface(stream, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = seekable->Seek(nsISeekableStream::NS_SEEK_SET, offset);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Prevent opening output stream again.
+  mHasData = true;
+
+  stream.swap(*_retval);
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::GetPredictedDataSize(int64_t *aPredictedDataSize)
+{
+  *aPredictedDataSize = mPredictedDataSize;
+  return NS_OK;
+}
+NS_IMETHODIMP CacheEntry::SetPredictedDataSize(int64_t aPredictedDataSize)
+{
+  mPredictedDataSize = aPredictedDataSize;
+
+  if (!mSkipSizeCheck && CacheObserver::EntryIsTooBig(mPredictedDataSize, mUseDisk)) {
+    LOG(("CacheEntry::SetPredictedDataSize [this=%p] too big, dooming", this));
+    AsyncDoom(nullptr);
+
+    return NS_ERROR_FILE_TOO_BIG;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::GetSecurityInfo(nsISupports * *aSecurityInfo)
+{
+  {
+    mozilla::MutexAutoLock lock(mLock);
+    if (mSecurityInfoLoaded) {
+      NS_IF_ADDREF(*aSecurityInfo = mSecurityInfo);
+      return NS_OK;
+    }
+  }
+
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  nsXPIDLCString info;
+  nsCOMPtr<nsISupports> secInfo;
+  nsresult rv;
+
+  rv = mFile->GetElement("security-info", getter_Copies(info));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (info) {
+    rv = NS_DeserializeObject(info, getter_AddRefs(secInfo));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    mSecurityInfo.swap(secInfo);
+    mSecurityInfoLoaded = true;
+
+    NS_IF_ADDREF(*aSecurityInfo = mSecurityInfo);
+  }
+
+  return NS_OK;
+}
+NS_IMETHODIMP CacheEntry::SetSecurityInfo(nsISupports *aSecurityInfo)
+{
+  nsresult rv;
+
+  NS_ENSURE_SUCCESS(mFileStatus, mFileStatus);
+
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    mSecurityInfo = aSecurityInfo;
+    mSecurityInfoLoaded = true;
+  }
+
+  nsCOMPtr<nsISerializable> serializable =
+    do_QueryInterface(aSecurityInfo);
+  if (aSecurityInfo && !serializable)
+    return NS_ERROR_UNEXPECTED;
+
+  nsCString info;
+  if (serializable) {
+    rv = NS_SerializeToString(serializable, info);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  rv = mFile->SetElement("security-info", info.Length() ? info.get() : nullptr);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::GetStorageDataSize(uint32_t *aStorageDataSize)
+{
+  NS_ENSURE_ARG(aStorageDataSize);
+
+  int64_t dataSize;
+  nsresult rv = GetDataSize(&dataSize);
+  if (NS_FAILED(rv))
+    return rv;
+
+  *aStorageDataSize = (uint32_t)std::min(int64_t(uint32_t(-1)), dataSize);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::AsyncDoom(nsICacheEntryDoomCallback *aCallback)
+{
+  LOG(("CacheEntry::AsyncDoom [this=%p]", this));
+
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    if (mIsDoomed || mDoomCallback)
+      return NS_ERROR_IN_PROGRESS; // to aggregate have DOOMING state
+
+    RemoveForcedValidity();
+
+    mIsDoomed = true;
+    mDoomCallback = aCallback;
+  }
+
+  // This immediately removes the entry from the master hashtable and also
+  // immediately dooms the file.  This way we make sure that any consumer
+  // after this point asking for the same entry won't get
+  //   a) this entry
+  //   b) a new entry with the same file
+  PurgeAndDoom();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::GetMetaDataElement(const char * aKey, char * *aRetval)
+{
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  return mFile->GetElement(aKey, aRetval);
+}
+
+NS_IMETHODIMP CacheEntry::SetMetaDataElement(const char * aKey, const char * aValue)
+{
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  return mFile->SetElement(aKey, aValue);
+}
+
+NS_IMETHODIMP CacheEntry::VisitMetaData(nsICacheEntryMetaDataVisitor *aVisitor)
+{
+  NS_ENSURE_SUCCESS(mFileStatus, NS_ERROR_NOT_AVAILABLE);
+
+  return mFile->VisitMetaData(aVisitor);
+}
+
+NS_IMETHODIMP CacheEntry::MetaDataReady()
+{
+  mozilla::MutexAutoLock lock(mLock);
+
+  LOG(("CacheEntry::MetaDataReady [this=%p, state=%s]", this, StateString(mState)));
+
+  MOZ_ASSERT(mState > EMPTY);
+
+  if (mState == WRITING)
+    mState = READY;
+
+  InvokeCallbacks();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::SetValid()
+{
+  LOG(("CacheEntry::SetValid [this=%p, state=%s]", this, StateString(mState)));
+
+  nsCOMPtr<nsIOutputStream> outputStream;
+
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    MOZ_ASSERT(mState > EMPTY);
+
+    mState = READY;
+    mHasData = true;
+
+    InvokeCallbacks();
+
+    outputStream.swap(mOutputStream);
+  }
+
+  if (outputStream) {
+    LOG(("  abandoning phantom output stream"));
+    outputStream->Close();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::Recreate(bool aMemoryOnly,
+                                   nsICacheEntry **_retval)
+{
+  LOG(("CacheEntry::Recreate [this=%p, state=%s]", this, StateString(mState)));
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  RefPtr<CacheEntryHandle> handle = ReopenTruncated(aMemoryOnly, nullptr);
+  if (handle) {
+    handle.forget(_retval);
+    return NS_OK;
+  }
+
+  BackgroundOp(Ops::CALLBACKS, true);
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP CacheEntry::GetDataSize(int64_t *aDataSize)
+{
+  LOG(("CacheEntry::GetDataSize [this=%p]", this));
+  *aDataSize = 0;
+
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    if (!mHasData) {
+      LOG(("  write in progress (no data)"));
+      return NS_ERROR_IN_PROGRESS;
+    }
+  }
+
+  NS_ENSURE_SUCCESS(mFileStatus, mFileStatus);
+
+  // mayhemer: TODO Problem with compression?
+  if (!mFile->DataSize(aDataSize)) {
+    LOG(("  write in progress (stream active)"));
+    return NS_ERROR_IN_PROGRESS;
+  }
+
+  LOG(("  size=%lld", *aDataSize));
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP CacheEntry::GetAltDataSize(int64_t *aDataSize)
+{
+  LOG(("CacheEntry::GetAltDataSize [this=%p]", this));
+  if (NS_FAILED(mFileStatus)) {
+    return mFileStatus;
+  }
+  return mFile->GetAltDataSize(aDataSize);
+}
+
+
+NS_IMETHODIMP CacheEntry::MarkValid()
+{
+  // NOT IMPLEMENTED ACTUALLY
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::MaybeMarkValid()
+{
+  // NOT IMPLEMENTED ACTUALLY
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::HasWriteAccess(bool aWriteAllowed, bool *aWriteAccess)
+{
+  *aWriteAccess = aWriteAllowed;
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::Close()
+{
+  // NOT IMPLEMENTED ACTUALLY
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntry::GetDiskStorageSizeInKB(uint32_t *aDiskStorageSize)
+{
+  if (NS_FAILED(mFileStatus)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  return mFile->GetDiskStorageSizeInKB(aDiskStorageSize);
+}
+
+// nsIRunnable
+
+NS_IMETHODIMP CacheEntry::Run()
+{
+  MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  BackgroundOp(mBackgroundOperations.Grab());
+  return NS_OK;
+}
+
+// Management methods
+
+double CacheEntry::GetFrecency() const
+{
+  MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+  return mFrecency;
+}
+
+uint32_t CacheEntry::GetExpirationTime() const
+{
+  MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+  return mSortingExpirationTime;
+}
+
+bool CacheEntry::IsRegistered() const
+{
+  MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+  return mRegistration == REGISTERED;
+}
+
+bool CacheEntry::CanRegister() const
+{
+  MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+  return mRegistration == NEVERREGISTERED;
+}
+
+void CacheEntry::SetRegistered(bool aRegistered)
+{
+  MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+
+  if (aRegistered) {
+    MOZ_ASSERT(mRegistration == NEVERREGISTERED);
+    mRegistration = REGISTERED;
+  }
+  else {
+    MOZ_ASSERT(mRegistration == REGISTERED);
+    mRegistration = DEREGISTERED;
+  }
+}
+
+bool CacheEntry::DeferOrBypassRemovalOnPinStatus(bool aPinned)
+{
+  LOG(("CacheEntry::DeferOrBypassRemovalOnPinStatus [this=%p]", this));
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (mPinningKnown) {
+    LOG(("  pinned=%d, caller=%d", mPinned, aPinned));
+    // Bypass when the pin status of this entry doesn't match the pin status
+    // caller wants to remove
+    return mPinned != aPinned;
+  }
+
+  LOG(("  pinning unknown, caller=%d", aPinned));
+  // Oterwise, remember to doom after the status is determined for any
+  // callback opening the entry after this point...
+  Callback c(this, aPinned);
+  RememberCallback(c);
+  // ...and always bypass
+  return true;
+}
+
+bool CacheEntry::Purge(uint32_t aWhat)
+{
+  LOG(("CacheEntry::Purge [this=%p, what=%d]", this, aWhat));
+
+  MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+
+  switch (aWhat) {
+  case PURGE_DATA_ONLY_DISK_BACKED:
+  case PURGE_WHOLE_ONLY_DISK_BACKED:
+    // This is an in-memory only entry, don't purge it
+    if (!mUseDisk) {
+      LOG(("  not using disk"));
+      return false;
+    }
+  }
+
+  if (mState == WRITING || mState == LOADING || mFrecency == 0) {
+    // In-progress (write or load) entries should (at least for consistency and from
+    // the logical point of view) stay in memory.
+    // Zero-frecency entries are those which have never been given to any consumer, those
+    // are actually very fresh and should not go just because frecency had not been set
+    // so far.
+    LOG(("  state=%s, frecency=%1.10f", StateString(mState), mFrecency));
+    return false;
+  }
+
+  if (NS_SUCCEEDED(mFileStatus) && mFile->IsWriteInProgress()) {
+    // The file is used when there are open streams or chunks/metadata still waiting for
+    // write.  In this case, this entry cannot be purged, otherwise reopenned entry
+    // would may not even find the data on disk - CacheFile is not shared and cannot be
+    // left orphan when its job is not done, hence keep the whole entry.
+    LOG(("  file still under use"));
+    return false;
+  }
+
+  switch (aWhat) {
+  case PURGE_WHOLE_ONLY_DISK_BACKED:
+  case PURGE_WHOLE:
+    {
+      if (!CacheStorageService::Self()->RemoveEntry(this, true)) {
+        LOG(("  not purging, still referenced"));
+        return false;
+      }
+
+      CacheStorageService::Self()->UnregisterEntry(this);
+
+      // Entry removed it self from control arrays, return true
+      return true;
+    }
+
+  case PURGE_DATA_ONLY_DISK_BACKED:
+    {
+      NS_ENSURE_SUCCESS(mFileStatus, false);
+
+      mFile->ThrowMemoryCachedData();
+
+      // Entry has been left in control arrays, return false (not purged)
+      return false;
+    }
+  }
+
+  LOG(("  ?"));
+  return false;
+}
+
+void CacheEntry::PurgeAndDoom()
+{
+  LOG(("CacheEntry::PurgeAndDoom [this=%p]", this));
+
+  CacheStorageService::Self()->RemoveEntry(this);
+  DoomAlreadyRemoved();
+}
+
+void CacheEntry::DoomAlreadyRemoved()
+{
+  LOG(("CacheEntry::DoomAlreadyRemoved [this=%p]", this));
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  RemoveForcedValidity();
+
+  mIsDoomed = true;
+
+  // Pretend pinning is know.  This entry is now doomed for good, so don't
+  // bother with defering doom because of unknown pinning state any more.
+  mPinningKnown = true;
+
+  // This schedules dooming of the file, dooming is ensured to happen
+  // sooner than demand to open the same file made after this point
+  // so that we don't get this file for any newer opened entry(s).
+  DoomFile();
+
+  // Must force post here since may be indirectly called from
+  // InvokeCallbacks of this entry and we don't want reentrancy here.
+  BackgroundOp(Ops::CALLBACKS, true);
+  // Process immediately when on the management thread.
+  BackgroundOp(Ops::UNREGISTER);
+}
+
+void CacheEntry::DoomFile()
+{
+  nsresult rv = NS_ERROR_NOT_AVAILABLE;
+
+  if (NS_SUCCEEDED(mFileStatus)) {
+    if (mHandlesCount == 0 ||
+        (mHandlesCount == 1 && mWriter)) {
+      // We kill the file also when there is just reference from the writer,
+      // no one else could ever reach the written data.  Obvisouly also
+      // when there is no reference at all (should we ever end up here
+      // in that case.)
+      // Tell the file to kill the handle, i.e. bypass any I/O operations
+      // on it except removing the file.
+      mFile->Kill();
+    }
+
+    // Always calls the callback asynchronously.
+    rv = mFile->Doom(mDoomCallback ? this : nullptr);
+    if (NS_SUCCEEDED(rv)) {
+      LOG(("  file doomed"));
+      return;
+    }
+    
+    if (NS_ERROR_FILE_NOT_FOUND == rv) {
+      // File is set to be just memory-only, notify the callbacks
+      // and pretend dooming has succeeded.  From point of view of
+      // the entry it actually did - the data is gone and cannot be
+      // reused.
+      rv = NS_OK;
+    }
+  }
+
+  // Always posts to the main thread.
+  OnFileDoomed(rv);
+}
+
+void CacheEntry::RemoveForcedValidity()
+{
+  mLock.AssertCurrentThreadOwns();
+
+  nsresult rv;
+
+  if (mIsDoomed) {
+    return;
+  }
+
+  nsAutoCString entryKey;
+  rv = HashingKey(entryKey);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return;
+  }
+
+  CacheStorageService::Self()->RemoveEntryForceValid(mStorageID, entryKey);
+}
+
+void CacheEntry::BackgroundOp(uint32_t aOperations, bool aForceAsync)
+{
+  mLock.AssertCurrentThreadOwns();
+
+  if (!CacheStorageService::IsOnManagementThread() || aForceAsync) {
+    if (mBackgroundOperations.Set(aOperations))
+      CacheStorageService::Self()->Dispatch(this);
+
+    LOG(("CacheEntry::BackgroundOp this=%p dipatch of %x", this, aOperations));
+    return;
+  }
+
+  {
+    mozilla::MutexAutoUnlock unlock(mLock);
+
+    MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+
+    if (aOperations & Ops::FRECENCYUPDATE) {
+      ++mUseCount;
+
+      #ifndef M_LN2
+      #define M_LN2 0.69314718055994530942
+      #endif
+
+      // Half-life is dynamic, in seconds.
+      static double half_life = CacheObserver::HalfLifeSeconds();
+      // Must convert from seconds to milliseconds since PR_Now() gives usecs.
+      static double const decay = (M_LN2 / half_life) / static_cast<double>(PR_USEC_PER_SEC);
+
+      double now_decay = static_cast<double>(PR_Now()) * decay;
+
+      if (mFrecency == 0) {
+        mFrecency = now_decay;
+      }
+      else {
+        // TODO: when C++11 enabled, use std::log1p(n) which is equal to log(n + 1) but
+        // more precise.
+        mFrecency = log(exp(mFrecency - now_decay) + 1) + now_decay;
+      }
+      LOG(("CacheEntry FRECENCYUPDATE [this=%p, frecency=%1.10f]", this, mFrecency));
+
+      // Because CacheFile::Set*() are not thread-safe to use (uses WeakReference that
+      // is not thread-safe) we must post to the main thread...
+      NS_DispatchToMainThread(NewRunnableMethod<double>(this, &CacheEntry::StoreFrecency, mFrecency));
+    }
+
+    if (aOperations & Ops::REGISTER) {
+      LOG(("CacheEntry REGISTER [this=%p]", this));
+
+      CacheStorageService::Self()->RegisterEntry(this);
+    }
+
+    if (aOperations & Ops::UNREGISTER) {
+      LOG(("CacheEntry UNREGISTER [this=%p]", this));
+
+      CacheStorageService::Self()->UnregisterEntry(this);
+    }
+  } // unlock
+
+  if (aOperations & Ops::CALLBACKS) {
+    LOG(("CacheEntry CALLBACKS (invoke) [this=%p]", this));
+
+    InvokeCallbacks();
+  }
+}
+
+void CacheEntry::StoreFrecency(double aFrecency)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (NS_SUCCEEDED(mFileStatus)) {
+    mFile->SetFrecency(FRECENCY2INT(aFrecency));
+  }
+}
+
+// CacheOutputCloseListener
+
+CacheOutputCloseListener::CacheOutputCloseListener(CacheEntry* aEntry)
+: mEntry(aEntry)
+{
+  MOZ_COUNT_CTOR(CacheOutputCloseListener);
+}
+
+CacheOutputCloseListener::~CacheOutputCloseListener()
+{
+  MOZ_COUNT_DTOR(CacheOutputCloseListener);
+}
+
+void CacheOutputCloseListener::OnOutputClosed()
+{
+  // We need this class and to redispatch since this callback is invoked
+  // under the file's lock and to do the job we need to enter the entry's
+  // lock too.  That would lead to potential deadlocks.
+  NS_DispatchToCurrentThread(this);
+}
+
+NS_IMETHODIMP CacheOutputCloseListener::Run()
+{
+  mEntry->OnOutputClosed();
+  return NS_OK;
+}
+
+// Memory reporting
+
+size_t CacheEntry::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  size_t n = 0;
+
+  n += mCallbacks.ShallowSizeOfExcludingThis(mallocSizeOf);
+  if (mFile) {
+    n += mFile->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  n += mURI.SizeOfExcludingThisIfUnshared(mallocSizeOf);
+  n += mEnhanceID.SizeOfExcludingThisIfUnshared(mallocSizeOf);
+  n += mStorageID.SizeOfExcludingThisIfUnshared(mallocSizeOf);
+
+  // mDoomCallback is an arbitrary class that is probably reported elsewhere.
+  // mOutputStream is reported in mFile.
+  // mWriter is one of many handles we create, but (intentionally) not keep
+  // any reference to, so those unfortunatelly cannot be reported.  Handles are
+  // small, though.
+  // mSecurityInfo doesn't impl nsISizeOf.
+
+  return n;
+}
+
+size_t CacheEntry::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheEntry.h b/netwerk/cache2/CacheEntry.h
new file mode 100644
index 0000000000..7331be2a4f
--- /dev/null
+++ b/netwerk/cache2/CacheEntry.h
@@ -0,0 +1,418 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheEntry__h__
+#define CacheEntry__h__
+
+#include "nsICacheEntry.h"
+#include "CacheFile.h"
+
+#include "nsIRunnable.h"
+#include "nsIOutputStream.h"
+#include "nsICacheEntryOpenCallback.h"
+#include "nsICacheEntryDoomCallback.h"
+
+#include "nsCOMPtr.h"
+#include "nsRefPtrHashtable.h"
+#include "nsDataHashtable.h"
+#include "nsHashKeys.h"
+#include "nsString.h"
+#include "nsCOMArray.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/TimeStamp.h"
+
+static inline uint32_t
+PRTimeToSeconds(PRTime t_usec)
+{
+  PRTime usec_per_sec = PR_USEC_PER_SEC;
+  return uint32_t(t_usec /= usec_per_sec);
+}
+
+#define NowInSeconds() PRTimeToSeconds(PR_Now())
+
+class nsIOutputStream;
+class nsIURI;
+class nsIThread;
+
+namespace mozilla {
+namespace net {
+
+class CacheStorageService;
+class CacheStorage;
+class CacheOutputCloseListener;
+class CacheEntryHandle;
+
+class CacheEntry final : public nsICacheEntry
+                       , public nsIRunnable
+                       , public CacheFileListener
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSICACHEENTRY
+  NS_DECL_NSIRUNNABLE
+
+  CacheEntry(const nsACString& aStorageID, const nsACString& aURI, const nsACString& aEnhanceID,
+             bool aUseDisk, bool aSkipSizeCheck, bool aPin);
+
+  void AsyncOpen(nsICacheEntryOpenCallback* aCallback, uint32_t aFlags);
+
+  CacheEntryHandle* NewHandle();
+  // For a new and recreated entry w/o a callback, we need to wrap it
+  // with a handle to detect writing consumer is gone.
+  CacheEntryHandle* NewWriteHandle();
+
+public:
+  uint32_t GetMetadataMemoryConsumption();
+  nsCString const &GetStorageID() const { return mStorageID; }
+  nsCString const &GetEnhanceID() const { return mEnhanceID; }
+  nsCString const &GetURI() const { return mURI; }
+  // Accessible at any time
+  bool IsUsingDisk() const { return mUseDisk; }
+  bool IsReferenced() const;
+  bool IsFileDoomed();
+  bool IsDoomed() const { return mIsDoomed; }
+  bool IsPinned() const { return mPinned; }
+
+  // Methods for entry management (eviction from memory),
+  // called only on the management thread.
+
+  // TODO make these inline
+  double GetFrecency() const;
+  uint32_t GetExpirationTime() const;
+  uint32_t UseCount() const { return mUseCount; }
+
+  bool IsRegistered() const;
+  bool CanRegister() const;
+  void SetRegistered(bool aRegistered);
+
+  TimeStamp const& LoadStart() const { return mLoadStart; }
+
+  enum EPurge {
+    PURGE_DATA_ONLY_DISK_BACKED,
+    PURGE_WHOLE_ONLY_DISK_BACKED,
+    PURGE_WHOLE,
+  };
+
+  bool DeferOrBypassRemovalOnPinStatus(bool aPinned);
+  bool Purge(uint32_t aWhat);
+  void PurgeAndDoom();
+  void DoomAlreadyRemoved();
+
+  nsresult HashingKeyWithStorage(nsACString &aResult) const;
+  nsresult HashingKey(nsACString &aResult) const;
+
+  static nsresult HashingKey(nsCSubstring const& aStorageID,
+                             nsCSubstring const& aEnhanceID,
+                             nsIURI* aURI,
+                             nsACString &aResult);
+
+  static nsresult HashingKey(nsCSubstring const& aStorageID,
+                             nsCSubstring const& aEnhanceID,
+                             nsCSubstring const& aURISpec,
+                             nsACString &aResult);
+
+  // Accessed only on the service management thread
+  double mFrecency;
+  ::mozilla::Atomic<uint32_t, ::mozilla::Relaxed> mSortingExpirationTime;
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+private:
+  virtual ~CacheEntry();
+
+  // CacheFileListener
+  NS_IMETHOD OnFileReady(nsresult aResult, bool aIsNew) override;
+  NS_IMETHOD OnFileDoomed(nsresult aResult) override;
+
+  // Keep the service alive during life-time of an entry
+  RefPtr<CacheStorageService> mService;
+
+  // We must monitor when a cache entry whose consumer is responsible
+  // for writing it the first time gets released.  We must then invoke
+  // waiting callbacks to not break the chain.
+  class Callback
+  {
+  public:
+    Callback(CacheEntry* aEntry,
+             nsICacheEntryOpenCallback *aCallback,
+             bool aReadOnly, bool aCheckOnAnyThread, bool aSecret);
+    // Special constructor for Callback objects added to the chain
+    // just to ensure proper defer dooming (recreation) of this entry.
+    Callback(CacheEntry* aEntry, bool aDoomWhenFoundInPinStatus);
+    Callback(Callback const &aThat);
+    ~Callback();
+
+    // Called when this callback record changes it's owning entry,
+    // mainly during recreation.
+    void ExchangeEntry(CacheEntry* aEntry);
+
+    // Returns true when an entry is about to be "defer" doomed and this is
+    // a "defer" callback.
+    bool DeferDoom(bool *aDoom) const;
+
+    // We are raising reference count here to take into account the pending
+    // callback (that virtually holds a ref to this entry before it gets
+    // it's pointer).
+    RefPtr<CacheEntry> mEntry;
+    nsCOMPtr<nsICacheEntryOpenCallback> mCallback;
+    nsCOMPtr<nsIThread> mTargetThread;
+    bool mReadOnly : 1;
+    bool mRevalidating : 1;
+    bool mCheckOnAnyThread : 1;
+    bool mRecheckAfterWrite : 1;
+    bool mNotWanted : 1;
+    bool mSecret : 1;
+
+    // These are set only for the defer-doomer Callback instance inserted
+    // to the callback chain.  When any of these is set and also any of
+    // the corressponding flags on the entry is set, this callback will
+    // indicate (via DeferDoom()) the entry have to be recreated/doomed.
+    bool mDoomWhenFoundPinned : 1;
+    bool mDoomWhenFoundNonPinned : 1;
+
+    nsresult OnCheckThread(bool *aOnCheckThread) const;
+    nsresult OnAvailThread(bool *aOnAvailThread) const;
+  };
+
+  // Since OnCacheEntryAvailable must be invoked on the main thread
+  // we need a runnable for it...
+  class AvailableCallbackRunnable : public Runnable
+  {
+  public:
+    AvailableCallbackRunnable(CacheEntry* aEntry,
+                              Callback const &aCallback)
+      : mEntry(aEntry)
+      , mCallback(aCallback)
+    {}
+
+  private:
+    NS_IMETHOD Run() override
+    {
+      mEntry->InvokeAvailableCallback(mCallback);
+      return NS_OK;
+    }
+
+    RefPtr<CacheEntry> mEntry;
+    Callback mCallback;
+  };
+
+  // Since OnCacheEntryDoomed must be invoked on the main thread
+  // we need a runnable for it...
+  class DoomCallbackRunnable : public Runnable
+  {
+  public:
+    DoomCallbackRunnable(CacheEntry* aEntry, nsresult aRv)
+      : mEntry(aEntry), mRv(aRv) {}
+
+  private:
+    NS_IMETHOD Run() override
+    {
+      nsCOMPtr<nsICacheEntryDoomCallback> callback;
+      {
+        mozilla::MutexAutoLock lock(mEntry->mLock);
+        mEntry->mDoomCallback.swap(callback);
+      }
+
+      if (callback)
+        callback->OnCacheEntryDoomed(mRv);
+      return NS_OK;
+    }
+
+    RefPtr<CacheEntry> mEntry;
+    nsresult mRv;
+  };
+
+  // Starts the load or just invokes the callback, bypasses (when required)
+  // if busy.  Returns true on job done, false on bypass.
+  bool Open(Callback & aCallback, bool aTruncate, bool aPriority, bool aBypassIfBusy);
+  // Loads from disk asynchronously
+  bool Load(bool aTruncate, bool aPriority);
+
+  void RememberCallback(Callback & aCallback);
+  void InvokeCallbacksLock();
+  void InvokeCallbacks();
+  bool InvokeCallbacks(bool aReadOnly);
+  bool InvokeCallback(Callback & aCallback);
+  void InvokeAvailableCallback(Callback const & aCallback);
+  void OnFetched(Callback const & aCallback);
+
+  nsresult OpenOutputStreamInternal(int64_t offset, nsIOutputStream * *_retval);
+  nsresult OpenInputStreamInternal(int64_t offset, const char *aAltDataType, nsIInputStream * *_retval);
+
+  void OnHandleClosed(CacheEntryHandle const* aHandle);
+
+private:
+  friend class CacheEntryHandle;
+  // Increment/decrements the number of handles keeping this entry.
+  void AddHandleRef() { ++mHandlesCount; }
+  void ReleaseHandleRef() { --mHandlesCount; }
+  // Current number of handles keeping this entry.
+  uint32_t HandlesCount() const { return mHandlesCount; }
+
+private:
+  friend class CacheOutputCloseListener;
+  void OnOutputClosed();
+
+private:
+  // Schedules a background operation on the management thread.
+  // When executed on the management thread directly, the operation(s)
+  // is (are) executed immediately.
+  void BackgroundOp(uint32_t aOperation, bool aForceAsync = false);
+  void StoreFrecency(double aFrecency);
+
+  // Called only from DoomAlreadyRemoved()
+  void DoomFile();
+  // When this entry is doomed the first time, this method removes
+  // any force-valid timing info for this entry.
+  void RemoveForcedValidity();
+
+  already_AddRefed<CacheEntryHandle> ReopenTruncated(bool aMemoryOnly,
+                                                     nsICacheEntryOpenCallback* aCallback);
+  void TransferCallbacks(CacheEntry & aFromEntry);
+
+  mozilla::Mutex mLock;
+
+  // Reflects the number of existing handles for this entry
+  ::mozilla::ThreadSafeAutoRefCnt mHandlesCount;
+
+  nsTArray<Callback> mCallbacks;
+  nsCOMPtr<nsICacheEntryDoomCallback> mDoomCallback;
+
+  RefPtr<CacheFile> mFile;
+
+  // Using ReleaseAcquire since we only control access to mFile with this.
+  // When mFileStatus is read and found success it is ensured there is mFile and
+  // that it is after a successful call to Init().
+  ::mozilla::Atomic<nsresult, ::mozilla::ReleaseAcquire> mFileStatus;
+  nsCString mURI;
+  nsCString mEnhanceID;
+  nsCString mStorageID;
+
+  // mUseDisk, mSkipSizeCheck, mIsDoomed are plain "bool", not "bool:1",
+  // so as to avoid bitfield races with the byte containing
+  // mSecurityInfoLoaded et al.  See bug 1278524.
+  //
+  // Whether it's allowed to persist the data to disk
+  bool const mUseDisk;
+  // Whether it should skip max size check.
+  bool const mSkipSizeCheck;
+  // Set when entry is doomed with AsyncDoom() or DoomAlreadyRemoved().
+  bool mIsDoomed;
+
+  // Following flags are all synchronized with the cache entry lock.
+
+  // Whether security info has already been looked up in metadata.
+  bool mSecurityInfoLoaded : 1;
+  // Prevents any callback invocation
+  bool mPreventCallbacks : 1;
+  // true: after load and an existing file, or after output stream has been opened.
+  //       note - when opening an input stream, and this flag is false, output stream
+  //       is open along ; this makes input streams on new entries behave correctly
+  //       when EOF is reached (WOULD_BLOCK is returned).
+  // false: after load and a new file, or dropped to back to false when a writer
+  //        fails to open an output stream.
+  bool mHasData : 1;
+  // The indication of pinning this entry was open with
+  bool mPinned : 1;
+  // Whether the pinning state of the entry is known (equals to the actual state
+  // of the cache file)
+  bool mPinningKnown : 1;
+
+  static char const * StateString(uint32_t aState);
+
+  enum EState {      // transiting to:
+    NOTLOADED = 0,   // -> LOADING | EMPTY
+    LOADING = 1,     // -> EMPTY | READY
+    EMPTY = 2,       // -> WRITING
+    WRITING = 3,     // -> EMPTY | READY
+    READY = 4,       // -> REVALIDATING
+    REVALIDATING = 5 // -> READY
+  };
+
+  // State of this entry.
+  EState mState;
+
+  enum ERegistration {
+    NEVERREGISTERED = 0, // The entry has never been registered
+    REGISTERED = 1,      // The entry is stored in the memory pool index
+    DEREGISTERED = 2     // The entry has been removed from the pool
+  };
+
+  // Accessed only on the management thread.  Records the state of registration
+  // this entry in the memory pool intermediate cache.
+  ERegistration mRegistration;
+
+  // If a new (empty) entry is requested to open an input stream before
+  // output stream has been opened, we must open output stream internally
+  // on CacheFile and hold until writer releases the entry or opens the output
+  // stream for read (then we trade him mOutputStream).
+  nsCOMPtr<nsIOutputStream> mOutputStream;
+
+  // Weak reference to the current writter.  There can be more then one
+  // writer at a time and OnHandleClosed() must be processed only for the
+  // current one.
+  CacheEntryHandle* mWriter;
+
+  // Background thread scheduled operation.  Set (under the lock) one
+  // of this flags to tell the background thread what to do.
+  class Ops {
+  public:
+    static uint32_t const REGISTER =          1 << 0;
+    static uint32_t const FRECENCYUPDATE =    1 << 1;
+    static uint32_t const CALLBACKS =         1 << 2;
+    static uint32_t const UNREGISTER =        1 << 3;
+
+    Ops() : mFlags(0) { }
+    uint32_t Grab() { uint32_t flags = mFlags; mFlags = 0; return flags; }
+    bool Set(uint32_t aFlags) { if (mFlags & aFlags) return false; mFlags |= aFlags; return true; }
+  private:
+    uint32_t mFlags;
+  } mBackgroundOperations;
+
+  nsCOMPtr<nsISupports> mSecurityInfo;
+  int64_t mPredictedDataSize;
+  mozilla::TimeStamp mLoadStart;
+  uint32_t mUseCount;
+};
+
+
+class CacheEntryHandle : public nsICacheEntry
+{
+public:
+  explicit CacheEntryHandle(CacheEntry* aEntry);
+  CacheEntry* Entry() const { return mEntry; }
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_FORWARD_NSICACHEENTRY(mEntry->)
+private:
+  virtual ~CacheEntryHandle();
+  RefPtr<CacheEntry> mEntry;
+};
+
+
+class CacheOutputCloseListener final : public Runnable
+{
+public:
+  void OnOutputClosed();
+
+private:
+  friend class CacheEntry;
+
+  virtual ~CacheOutputCloseListener();
+
+  NS_DECL_NSIRUNNABLE
+  explicit CacheOutputCloseListener(CacheEntry* aEntry);
+
+private:
+  RefPtr<CacheEntry> mEntry;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheFile.cpp b/netwerk/cache2/CacheFile.cpp
new file mode 100644
index 0000000000..fa0a893823
--- /dev/null
+++ b/netwerk/cache2/CacheFile.cpp
@@ -0,0 +1,2377 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheFile.h"
+
+#include "CacheFileChunk.h"
+#include "CacheFileInputStream.h"
+#include "CacheFileOutputStream.h"
+#include "nsThreadUtils.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Move.h"
+#include <algorithm>
+#include "nsComponentManagerUtils.h"
+#include "nsProxyRelease.h"
+#include "mozilla/Telemetry.h"
+
+// When CACHE_CHUNKS is defined we always cache unused chunks in mCacheChunks.
+// When it is not defined, we always release the chunks ASAP, i.e. we cache
+// unused chunks only when:
+//  - CacheFile is memory-only
+//  - CacheFile is still waiting for the handle
+//  - the chunk is preloaded
+
+//#define CACHE_CHUNKS
+
+namespace mozilla {
+namespace net {
+
+class NotifyCacheFileListenerEvent : public Runnable {
+public:
+  NotifyCacheFileListenerEvent(CacheFileListener *aCallback,
+                               nsresult aResult,
+                               bool aIsNew)
+    : mCallback(aCallback)
+    , mRV(aResult)
+    , mIsNew(aIsNew)
+  {
+    LOG(("NotifyCacheFileListenerEvent::NotifyCacheFileListenerEvent() "
+         "[this=%p]", this));
+    MOZ_COUNT_CTOR(NotifyCacheFileListenerEvent);
+  }
+
+protected:
+  ~NotifyCacheFileListenerEvent()
+  {
+    LOG(("NotifyCacheFileListenerEvent::~NotifyCacheFileListenerEvent() "
+         "[this=%p]", this));
+    MOZ_COUNT_DTOR(NotifyCacheFileListenerEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    LOG(("NotifyCacheFileListenerEvent::Run() [this=%p]", this));
+
+    mCallback->OnFileReady(mRV, mIsNew);
+    return NS_OK;
+  }
+
+protected:
+  nsCOMPtr<CacheFileListener> mCallback;
+  nsresult                    mRV;
+  bool                        mIsNew;
+};
+
+class NotifyChunkListenerEvent : public Runnable {
+public:
+  NotifyChunkListenerEvent(CacheFileChunkListener *aCallback,
+                           nsresult aResult,
+                           uint32_t aChunkIdx,
+                           CacheFileChunk *aChunk)
+    : mCallback(aCallback)
+    , mRV(aResult)
+    , mChunkIdx(aChunkIdx)
+    , mChunk(aChunk)
+  {
+    LOG(("NotifyChunkListenerEvent::NotifyChunkListenerEvent() [this=%p]",
+         this));
+    MOZ_COUNT_CTOR(NotifyChunkListenerEvent);
+  }
+
+protected:
+  ~NotifyChunkListenerEvent()
+  {
+    LOG(("NotifyChunkListenerEvent::~NotifyChunkListenerEvent() [this=%p]",
+         this));
+    MOZ_COUNT_DTOR(NotifyChunkListenerEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    LOG(("NotifyChunkListenerEvent::Run() [this=%p]", this));
+
+    mCallback->OnChunkAvailable(mRV, mChunkIdx, mChunk);
+    return NS_OK;
+  }
+
+protected:
+  nsCOMPtr<CacheFileChunkListener> mCallback;
+  nsresult                         mRV;
+  uint32_t                         mChunkIdx;
+  RefPtr<CacheFileChunk>           mChunk;
+};
+
+
+class DoomFileHelper : public CacheFileIOListener
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  explicit DoomFileHelper(CacheFileListener *aListener)
+    : mListener(aListener)
+  {
+    MOZ_COUNT_CTOR(DoomFileHelper);
+  }
+
+
+  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) override
+  {
+    MOZ_CRASH("DoomFileHelper::OnFileOpened should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                           nsresult aResult) override
+  {
+    MOZ_CRASH("DoomFileHelper::OnDataWritten should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult) override
+  {
+    MOZ_CRASH("DoomFileHelper::OnDataRead should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) override
+  {
+    if (mListener)
+      mListener->OnFileDoomed(aResult);
+    return NS_OK;
+  }
+
+  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) override
+  {
+    MOZ_CRASH("DoomFileHelper::OnEOFSet should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) override
+  {
+    MOZ_CRASH("DoomFileHelper::OnFileRenamed should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+private:
+  virtual ~DoomFileHelper()
+  {
+    MOZ_COUNT_DTOR(DoomFileHelper);
+  }
+
+  nsCOMPtr<CacheFileListener>  mListener;
+};
+
+NS_IMPL_ISUPPORTS(DoomFileHelper, CacheFileIOListener)
+
+
+NS_IMPL_ADDREF(CacheFile)
+NS_IMPL_RELEASE(CacheFile)
+NS_INTERFACE_MAP_BEGIN(CacheFile)
+  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileChunkListener)
+  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileIOListener)
+  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileMetadataListener)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports,
+                                   mozilla::net::CacheFileChunkListener)
+NS_INTERFACE_MAP_END_THREADSAFE
+
+CacheFile::CacheFile()
+  : mLock("CacheFile.mLock")
+  , mOpeningFile(false)
+  , mReady(false)
+  , mMemoryOnly(false)
+  , mSkipSizeCheck(false)
+  , mOpenAsMemoryOnly(false)
+  , mPinned(false)
+  , mPriority(false)
+  , mDataAccessed(false)
+  , mDataIsDirty(false)
+  , mWritingMetadata(false)
+  , mPreloadWithoutInputStreams(true)
+  , mPreloadChunkCount(0)
+  , mStatus(NS_OK)
+  , mDataSize(-1)
+  , mAltDataOffset(-1)
+  , mKill(false)
+  , mOutput(nullptr)
+{
+  LOG(("CacheFile::CacheFile() [this=%p]", this));
+}
+
+CacheFile::~CacheFile()
+{
+  LOG(("CacheFile::~CacheFile() [this=%p]", this));
+
+  MutexAutoLock lock(mLock);
+  if (!mMemoryOnly && mReady && !mKill) {
+    // mReady flag indicates we have metadata plus in a valid state.
+    WriteMetadataIfNeededLocked(true);
+  }
+}
+
+nsresult
+CacheFile::Init(const nsACString &aKey,
+                bool aCreateNew,
+                bool aMemoryOnly,
+                bool aSkipSizeCheck,
+                bool aPriority,
+                bool aPinned,
+                CacheFileListener *aCallback)
+{
+  MOZ_ASSERT(!mListener);
+  MOZ_ASSERT(!mHandle);
+
+  MOZ_ASSERT(!(aMemoryOnly && aPinned));
+
+  nsresult rv;
+
+  mKey = aKey;
+  mOpenAsMemoryOnly = mMemoryOnly = aMemoryOnly;
+  mSkipSizeCheck = aSkipSizeCheck;
+  mPriority = aPriority;
+  mPinned = aPinned;
+
+  // Some consumers (at least nsHTTPCompressConv) assume that Read() can read
+  // such amount of data that was announced by Available().
+  // CacheFileInputStream::Available() uses also preloaded chunks to compute
+  // number of available bytes in the input stream, so we have to make sure the
+  // preloadChunkCount won't change during CacheFile's lifetime since otherwise
+  // we could potentially release some cached chunks that was used to calculate
+  // available bytes but would not be available later during call to
+  // CacheFileInputStream::Read().
+  mPreloadChunkCount = CacheObserver::PreloadChunkCount();
+
+  LOG(("CacheFile::Init() [this=%p, key=%s, createNew=%d, memoryOnly=%d, "
+       "priority=%d, listener=%p]", this, mKey.get(), aCreateNew, aMemoryOnly,
+       aPriority, aCallback));
+
+  if (mMemoryOnly) {
+    MOZ_ASSERT(!aCallback);
+
+    mMetadata = new CacheFileMetadata(mOpenAsMemoryOnly, false, mKey);
+    mReady = true;
+    mDataSize = mMetadata->Offset();
+    return NS_OK;
+  }
+  else {
+    uint32_t flags;
+    if (aCreateNew) {
+      MOZ_ASSERT(!aCallback);
+      flags = CacheFileIOManager::CREATE_NEW;
+
+      // make sure we can use this entry immediately
+      mMetadata = new CacheFileMetadata(mOpenAsMemoryOnly, mPinned, mKey);
+      mReady = true;
+      mDataSize = mMetadata->Offset();
+    } else {
+      flags = CacheFileIOManager::CREATE;
+    }
+
+    if (mPriority) {
+      flags |= CacheFileIOManager::PRIORITY;
+    }
+
+    if (mPinned) {
+      flags |= CacheFileIOManager::PINNED;
+    }
+
+    mOpeningFile = true;
+    mListener = aCallback;
+    rv = CacheFileIOManager::OpenFile(mKey, flags, this);
+    if (NS_FAILED(rv)) {
+      mListener = nullptr;
+      mOpeningFile = false;
+
+      if (mPinned) {
+        LOG(("CacheFile::Init() - CacheFileIOManager::OpenFile() failed "
+             "but we want to pin, fail the file opening. [this=%p]", this));
+        return NS_ERROR_NOT_AVAILABLE;
+      }
+
+      if (aCreateNew) {
+        NS_WARNING("Forcing memory-only entry since OpenFile failed");
+        LOG(("CacheFile::Init() - CacheFileIOManager::OpenFile() failed "
+             "synchronously. We can continue in memory-only mode since "
+             "aCreateNew == true. [this=%p]", this));
+
+        mMemoryOnly = true;
+      }
+      else if (rv == NS_ERROR_NOT_INITIALIZED) {
+        NS_WARNING("Forcing memory-only entry since CacheIOManager isn't "
+                   "initialized.");
+        LOG(("CacheFile::Init() - CacheFileIOManager isn't initialized, "
+             "initializing entry as memory-only. [this=%p]", this));
+
+        mMemoryOnly = true;
+        mMetadata = new CacheFileMetadata(mOpenAsMemoryOnly, mPinned, mKey);
+        mReady = true;
+        mDataSize = mMetadata->Offset();
+
+        RefPtr<NotifyCacheFileListenerEvent> ev;
+        ev = new NotifyCacheFileListenerEvent(aCallback, NS_OK, true);
+        rv = NS_DispatchToCurrentThread(ev);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+      else {
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OnChunkRead(nsresult aResult, CacheFileChunk *aChunk)
+{
+  CacheFileAutoLock lock(this);
+
+  nsresult rv;
+
+  uint32_t index = aChunk->Index();
+
+  LOG(("CacheFile::OnChunkRead() [this=%p, rv=0x%08x, chunk=%p, idx=%u]",
+       this, aResult, aChunk, index));
+
+  if (NS_FAILED(aResult)) {
+    SetError(aResult);
+  }
+
+  if (HaveChunkListeners(index)) {
+    rv = NotifyChunkListeners(index, aResult, aChunk);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk)
+{
+  // In case the chunk was reused, made dirty and released between calls to
+  // CacheFileChunk::Write() and CacheFile::OnChunkWritten(), we must write
+  // the chunk to the disk again. When the chunk is unused and is dirty simply
+  // addref and release (outside the lock) the chunk which ensures that
+  // CacheFile::DeactivateChunk() will be called again.
+  RefPtr<CacheFileChunk> deactivateChunkAgain;
+
+  CacheFileAutoLock lock(this);
+
+  nsresult rv;
+
+  LOG(("CacheFile::OnChunkWritten() [this=%p, rv=0x%08x, chunk=%p, idx=%u]",
+       this, aResult, aChunk, aChunk->Index()));
+
+  MOZ_ASSERT(!mMemoryOnly);
+  MOZ_ASSERT(!mOpeningFile);
+  MOZ_ASSERT(mHandle);
+
+  if (NS_FAILED(aResult)) {
+    SetError(aResult);
+  }
+
+  if (NS_SUCCEEDED(aResult) && !aChunk->IsDirty()) {
+    // update hash value in metadata
+    mMetadata->SetHash(aChunk->Index(), aChunk->Hash());
+  }
+
+  // notify listeners if there is any
+  if (HaveChunkListeners(aChunk->Index())) {
+    // don't release the chunk since there are some listeners queued
+    rv = NotifyChunkListeners(aChunk->Index(), aResult, aChunk);
+    if (NS_SUCCEEDED(rv)) {
+      MOZ_ASSERT(aChunk->mRefCnt != 2);
+      return NS_OK;
+    }
+  }
+
+  if (aChunk->mRefCnt != 2) {
+    LOG(("CacheFile::OnChunkWritten() - Chunk is still used [this=%p, chunk=%p,"
+         " refcnt=%d]", this, aChunk, aChunk->mRefCnt.get()));
+
+    return NS_OK;
+  }
+
+  if (aChunk->IsDirty()) {
+    LOG(("CacheFile::OnChunkWritten() - Unused chunk is dirty. We must go "
+         "through deactivation again. [this=%p, chunk=%p]", this, aChunk));
+
+    deactivateChunkAgain = aChunk;
+    return NS_OK;
+  }
+
+  bool keepChunk = false;
+  if (NS_SUCCEEDED(aResult)) {
+    keepChunk = ShouldCacheChunk(aChunk->Index());
+    LOG(("CacheFile::OnChunkWritten() - %s unused chunk [this=%p, chunk=%p]",
+         keepChunk ? "Caching" : "Releasing", this, aChunk));
+  } else {
+    LOG(("CacheFile::OnChunkWritten() - Releasing failed chunk [this=%p, "
+         "chunk=%p]", this, aChunk));
+  }
+
+  RemoveChunkInternal(aChunk, keepChunk);
+
+  WriteMetadataIfNeededLocked();
+
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OnChunkAvailable(nsresult aResult, uint32_t aChunkIdx,
+                            CacheFileChunk *aChunk)
+{
+  MOZ_CRASH("CacheFile::OnChunkAvailable should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFile::OnChunkUpdated(CacheFileChunk *aChunk)
+{
+  MOZ_CRASH("CacheFile::OnChunkUpdated should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFile::OnFileOpened(CacheFileHandle *aHandle, nsresult aResult)
+{
+  nsresult rv;
+
+  // Using an 'auto' class to perform doom or fail the listener
+  // outside the CacheFile's lock.
+  class AutoFailDoomListener
+  {
+  public:
+    explicit AutoFailDoomListener(CacheFileHandle *aHandle)
+      : mHandle(aHandle)
+      , mAlreadyDoomed(false)
+    {}
+    ~AutoFailDoomListener()
+    {
+      if (!mListener)
+        return;
+
+      if (mHandle) {
+        if (mAlreadyDoomed) {
+          mListener->OnFileDoomed(mHandle, NS_OK);
+        } else {
+          CacheFileIOManager::DoomFile(mHandle, mListener);
+        }
+      } else {
+        mListener->OnFileDoomed(nullptr, NS_ERROR_NOT_AVAILABLE);
+      }
+    }
+
+    CacheFileHandle* mHandle;
+    nsCOMPtr<CacheFileIOListener> mListener;
+    bool mAlreadyDoomed;
+  } autoDoom(aHandle);
+
+  nsCOMPtr<CacheFileListener> listener;
+  bool isNew = false;
+  nsresult retval = NS_OK;
+
+  {
+    CacheFileAutoLock lock(this);
+
+    MOZ_ASSERT(mOpeningFile);
+    MOZ_ASSERT((NS_SUCCEEDED(aResult) && aHandle) ||
+               (NS_FAILED(aResult) && !aHandle));
+    MOZ_ASSERT((mListener && !mMetadata) || // !createNew
+               (!mListener && mMetadata));  // createNew
+    MOZ_ASSERT(!mMemoryOnly || mMetadata); // memory-only was set on new entry
+
+    LOG(("CacheFile::OnFileOpened() [this=%p, rv=0x%08x, handle=%p]",
+         this, aResult, aHandle));
+
+    mOpeningFile = false;
+
+    autoDoom.mListener.swap(mDoomAfterOpenListener);
+
+    if (mMemoryOnly) {
+      // We can be here only in case the entry was initilized as createNew and
+      // SetMemoryOnly() was called.
+
+      // Just don't store the handle into mHandle and exit
+      autoDoom.mAlreadyDoomed = true;
+      return NS_OK;
+    }
+
+    if (NS_FAILED(aResult)) {
+      if (mMetadata) {
+        // This entry was initialized as createNew, just switch to memory-only
+        // mode.
+        NS_WARNING("Forcing memory-only entry since OpenFile failed");
+        LOG(("CacheFile::OnFileOpened() - CacheFileIOManager::OpenFile() "
+             "failed asynchronously. We can continue in memory-only mode since "
+             "aCreateNew == true. [this=%p]", this));
+
+        mMemoryOnly = true;
+        return NS_OK;
+      }
+
+      if (aResult == NS_ERROR_FILE_INVALID_PATH) {
+        // CacheFileIOManager doesn't have mCacheDirectory, switch to
+        // memory-only mode.
+        NS_WARNING("Forcing memory-only entry since CacheFileIOManager doesn't "
+                   "have mCacheDirectory.");
+        LOG(("CacheFile::OnFileOpened() - CacheFileIOManager doesn't have "
+             "mCacheDirectory, initializing entry as memory-only. [this=%p]",
+             this));
+
+        mMemoryOnly = true;
+        mMetadata = new CacheFileMetadata(mOpenAsMemoryOnly, mPinned, mKey);
+        mReady = true;
+        mDataSize = mMetadata->Offset();
+
+        isNew = true;
+        retval = NS_OK;
+      } else {
+        // CacheFileIOManager::OpenFile() failed for another reason.
+        isNew = false;
+        retval = aResult;
+      }
+
+      mListener.swap(listener);
+    } else {
+      mHandle = aHandle;
+      if (NS_FAILED(mStatus)) {
+        CacheFileIOManager::DoomFile(mHandle, nullptr);
+      }
+
+      if (mMetadata) {
+        InitIndexEntry();
+
+        // The entry was initialized as createNew, don't try to read metadata.
+        mMetadata->SetHandle(mHandle);
+
+        // Write all cached chunks, otherwise they may stay unwritten.
+        for (auto iter = mCachedChunks.Iter(); !iter.Done(); iter.Next()) {
+          uint32_t idx = iter.Key();
+          const RefPtr<CacheFileChunk>& chunk = iter.Data();
+
+          LOG(("CacheFile::OnFileOpened() - write [this=%p, idx=%u, chunk=%p]",
+               this, idx, chunk.get()));
+
+          mChunks.Put(idx, chunk);
+          chunk->mFile = this;
+          chunk->mActiveChunk = true;
+
+          MOZ_ASSERT(chunk->IsReady());
+
+          // This would be cleaner if we had an nsRefPtr constructor that took
+          // a RefPtr<Derived>.
+          ReleaseOutsideLock(RefPtr<nsISupports>(chunk));
+
+          iter.Remove();
+        }
+
+        return NS_OK;
+      }
+    }
+  }
+
+  if (listener) {
+    listener->OnFileReady(retval, isNew);
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(NS_SUCCEEDED(aResult));
+  MOZ_ASSERT(!mMetadata);
+  MOZ_ASSERT(mListener);
+
+  mMetadata = new CacheFileMetadata(mHandle, mKey);
+
+  rv = mMetadata->ReadMetadata(this);
+  if (NS_FAILED(rv)) {
+    mListener.swap(listener);
+    listener->OnFileReady(rv, false);
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                         nsresult aResult)
+{
+  MOZ_CRASH("CacheFile::OnDataWritten should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFile::OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult)
+{
+  MOZ_CRASH("CacheFile::OnDataRead should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFile::OnMetadataRead(nsresult aResult)
+{
+  MOZ_ASSERT(mListener);
+
+  LOG(("CacheFile::OnMetadataRead() [this=%p, rv=0x%08x]", this, aResult));
+
+  bool isNew = false;
+  if (NS_SUCCEEDED(aResult)) {
+    mPinned = mMetadata->Pinned();
+    mReady = true;
+    mDataSize = mMetadata->Offset();
+    if (mDataSize == 0 && mMetadata->ElementsSize() == 0) {
+      isNew = true;
+      mMetadata->MarkDirty();
+    } else {
+      const char *altData = mMetadata->GetElement(CacheFileUtils::kAltDataKey);
+      if (altData &&
+          (NS_FAILED(CacheFileUtils::ParseAlternativeDataInfo(
+            altData, &mAltDataOffset, nullptr)) ||
+          (mAltDataOffset > mDataSize))) {
+        // alt-metadata cannot be parsed or alt-data offset is invalid
+        mMetadata->InitEmptyMetadata();
+        isNew = true;
+        mAltDataOffset = -1;
+        mDataSize = 0;
+      } else {
+        CacheFileAutoLock lock(this);
+        PreloadChunks(0);
+      }
+    }
+
+    InitIndexEntry();
+  }
+
+  nsCOMPtr<CacheFileListener> listener;
+  mListener.swap(listener);
+  listener->OnFileReady(aResult, isNew);
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OnMetadataWritten(nsresult aResult)
+{
+  CacheFileAutoLock lock(this);
+
+  LOG(("CacheFile::OnMetadataWritten() [this=%p, rv=0x%08x]", this, aResult));
+
+  MOZ_ASSERT(mWritingMetadata);
+  mWritingMetadata = false;
+
+  MOZ_ASSERT(!mMemoryOnly);
+  MOZ_ASSERT(!mOpeningFile);
+
+  if (NS_WARN_IF(NS_FAILED(aResult))) {
+    // TODO close streams with an error ???
+    SetError(aResult);
+  }
+
+  if (mOutput || mInputs.Length() || mChunks.Count())
+    return NS_OK;
+
+  if (IsDirty())
+    WriteMetadataIfNeededLocked();
+
+  if (!mWritingMetadata) {
+    LOG(("CacheFile::OnMetadataWritten() - Releasing file handle [this=%p]",
+         this));
+    CacheFileIOManager::ReleaseNSPRHandle(mHandle);
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult)
+{
+  nsCOMPtr<CacheFileListener> listener;
+
+  {
+    CacheFileAutoLock lock(this);
+
+    MOZ_ASSERT(mListener);
+
+    LOG(("CacheFile::OnFileDoomed() [this=%p, rv=0x%08x, handle=%p]",
+         this, aResult, aHandle));
+
+    mListener.swap(listener);
+  }
+
+  listener->OnFileDoomed(aResult);
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OnEOFSet(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFile::OnEOFSet should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFile::OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFile::OnFileRenamed should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+bool CacheFile::IsKilled()
+{
+  bool killed = mKill;
+  if (killed) {
+    LOG(("CacheFile is killed, this=%p", this));
+  }
+
+  return killed;
+}
+
+nsresult
+CacheFile::OpenInputStream(nsICacheEntry *aEntryHandle, nsIInputStream **_retval)
+{
+  CacheFileAutoLock lock(this);
+
+  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);
+
+  if (!mReady) {
+    LOG(("CacheFile::OpenInputStream() - CacheFile is not ready [this=%p]",
+         this));
+
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (NS_FAILED(mStatus)) {
+    LOG(("CacheFile::OpenInputStream() - CacheFile is in a failure state "
+         "[this=%p, status=0x%08x]", this, mStatus));
+
+    // Don't allow opening the input stream when this CacheFile is in
+    // a failed state.  This is the only way to protect consumers correctly
+    // from reading a broken entry.  When the file is in the failed state,
+    // it's also doomed, so reopening the entry won't make any difference -
+    // data will still be inaccessible anymore.  Note that for just doomed 
+    // files, we must allow reading the data.
+    return mStatus;
+  }
+
+  // Once we open input stream we no longer allow preloading of chunks without
+  // input stream, i.e. we will no longer keep first few chunks preloaded when
+  // the last input stream is closed.
+  mPreloadWithoutInputStreams = false;
+
+  CacheFileInputStream *input = new CacheFileInputStream(this, aEntryHandle,
+                                                         false);
+  LOG(("CacheFile::OpenInputStream() - Creating new input stream %p [this=%p]",
+       input, this));
+
+  mInputs.AppendElement(input);
+  NS_ADDREF(input);
+
+  mDataAccessed = true;
+  NS_ADDREF(*_retval = input);
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OpenAlternativeInputStream(nsICacheEntry *aEntryHandle,
+                                      const char *aAltDataType,
+                                      nsIInputStream **_retval)
+{
+  CacheFileAutoLock lock(this);
+
+  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);
+
+  nsresult rv;
+
+  if (NS_WARN_IF(!mReady)) {
+    LOG(("CacheFile::OpenAlternativeInputStream() - CacheFile is not ready "
+         "[this=%p]", this));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (mAltDataOffset == -1) {
+    LOG(("CacheFile::OpenAlternativeInputStream() - Alternative data is not "
+         "available [this=%p]", this));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (NS_FAILED(mStatus)) {
+    LOG(("CacheFile::OpenAlternativeInputStream() - CacheFile is in a failure "
+         "state [this=%p, status=0x%08x]", this, mStatus));
+
+    // Don't allow opening the input stream when this CacheFile is in
+    // a failed state.  This is the only way to protect consumers correctly
+    // from reading a broken entry.  When the file is in the failed state,
+    // it's also doomed, so reopening the entry won't make any difference -
+    // data will still be inaccessible anymore.  Note that for just doomed 
+    // files, we must allow reading the data.
+    return mStatus;
+  }
+
+  const char *altData = mMetadata->GetElement(CacheFileUtils::kAltDataKey);
+  MOZ_ASSERT(altData, "alt-metadata should exist but was not found!");
+  if (NS_WARN_IF(!altData)) {
+    LOG(("CacheFile::OpenAlternativeInputStream() - alt-metadata not found but "
+         "alt-data exists according to mAltDataOffset! [this=%p, ]", this));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  int64_t offset;
+  nsCString availableAltData;
+  rv = CacheFileUtils::ParseAlternativeDataInfo(altData, &offset,
+                                                &availableAltData);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    MOZ_ASSERT(false, "alt-metadata unexpectedly failed to parse");
+    LOG(("CacheFile::OpenAlternativeInputStream() - Cannot parse alternative "
+         "metadata! [this=%p]", this));
+    return rv;
+  }
+
+  if (availableAltData != aAltDataType) {
+    LOG(("CacheFile::OpenAlternativeInputStream() - Alternative data is of a "
+         "different type than requested [this=%p, availableType=%s, "
+         "requestedType=%s]", this, availableAltData.get(), aAltDataType));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // mAltDataOffset must be in sync with what is stored in metadata
+  MOZ_ASSERT(mAltDataOffset == offset);
+
+  // Once we open input stream we no longer allow preloading of chunks without
+  // input stream, i.e. we will no longer keep first few chunks preloaded when
+  // the last input stream is closed.
+  mPreloadWithoutInputStreams = false;
+
+  CacheFileInputStream *input = new CacheFileInputStream(this, aEntryHandle, true);
+
+  LOG(("CacheFile::OpenAlternativeInputStream() - Creating new input stream %p "
+       "[this=%p]", input, this));
+
+  mInputs.AppendElement(input);
+  NS_ADDREF(input);
+
+  mDataAccessed = true;
+  NS_ADDREF(*_retval = input);
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OpenOutputStream(CacheOutputCloseListener *aCloseListener, nsIOutputStream **_retval)
+{
+  CacheFileAutoLock lock(this);
+
+  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);
+
+  nsresult rv;
+
+  if (!mReady) {
+    LOG(("CacheFile::OpenOutputStream() - CacheFile is not ready [this=%p]",
+         this));
+
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (mOutput) {
+    LOG(("CacheFile::OpenOutputStream() - We already have output stream %p "
+         "[this=%p]", mOutput, this));
+
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Fail if there is any input stream opened for alternative data
+  for (uint32_t i = 0; i < mInputs.Length(); ++i) {
+    if (mInputs[i]->IsAlternativeData()) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+
+  if (mAltDataOffset != -1) {
+    // Remove alt-data
+    rv = Truncate(mAltDataOffset);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    mMetadata->SetElement(CacheFileUtils::kAltDataKey, nullptr);
+    mAltDataOffset = -1;
+  }
+
+  // Once we open output stream we no longer allow preloading of chunks without
+  // input stream. There is no reason to believe that some input stream will be
+  // opened soon. Otherwise we would cache unused chunks of all newly created
+  // entries until the CacheFile is destroyed.
+  mPreloadWithoutInputStreams = false;
+
+  mOutput = new CacheFileOutputStream(this, aCloseListener, false);
+
+  LOG(("CacheFile::OpenOutputStream() - Creating new output stream %p "
+       "[this=%p]", mOutput, this));
+
+  mDataAccessed = true;
+  NS_ADDREF(*_retval = mOutput);
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OpenAlternativeOutputStream(CacheOutputCloseListener *aCloseListener,
+                                       const char *aAltDataType,
+                                       nsIOutputStream **_retval)
+{
+  CacheFileAutoLock lock(this);
+
+  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);
+
+  nsresult rv;
+
+  if (!mReady) {
+    LOG(("CacheFile::OpenAlternativeOutputStream() - CacheFile is not ready "
+         "[this=%p]", this));
+
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (mOutput) {
+    LOG(("CacheFile::OpenAlternativeOutputStream() - We already have output "
+         "stream %p [this=%p]", mOutput, this));
+
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Fail if there is any input stream opened for alternative data
+  for (uint32_t i = 0; i < mInputs.Length(); ++i) {
+    if (mInputs[i]->IsAlternativeData()) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+
+  if (mAltDataOffset != -1) {
+    // Truncate old alt-data
+    rv = Truncate(mAltDataOffset);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  } else {
+    mAltDataOffset = mDataSize;
+  }
+
+  nsAutoCString altMetadata;
+  CacheFileUtils::BuildAlternativeDataInfo(aAltDataType, mAltDataOffset,
+                                           altMetadata);
+  rv = mMetadata->SetElement(CacheFileUtils::kAltDataKey, altMetadata.get());
+  if (NS_FAILED(rv)) {
+    // Removing element shouldn't fail because it doesn't allocate memory.
+    mMetadata->SetElement(CacheFileUtils::kAltDataKey, nullptr);
+
+    mAltDataOffset = -1;
+    return rv;
+  }
+
+  // Once we open output stream we no longer allow preloading of chunks without
+  // input stream. There is no reason to believe that some input stream will be
+  // opened soon. Otherwise we would cache unused chunks of all newly created
+  // entries until the CacheFile is destroyed.
+  mPreloadWithoutInputStreams = false;
+
+  mOutput = new CacheFileOutputStream(this, aCloseListener, true);
+
+  LOG(("CacheFile::OpenAlternativeOutputStream() - Creating new output stream "
+       "%p [this=%p]", mOutput, this));
+
+  mDataAccessed = true;
+  NS_ADDREF(*_retval = mOutput);
+  return NS_OK;
+}
+
+nsresult
+CacheFile::SetMemoryOnly()
+{
+  LOG(("CacheFile::SetMemoryOnly() mMemoryOnly=%d [this=%p]",
+       mMemoryOnly, this));
+
+  if (mMemoryOnly)
+    return NS_OK;
+
+  MOZ_ASSERT(mReady);
+
+  if (!mReady) {
+    LOG(("CacheFile::SetMemoryOnly() - CacheFile is not ready [this=%p]",
+         this));
+
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (mDataAccessed) {
+    LOG(("CacheFile::SetMemoryOnly() - Data was already accessed [this=%p]", this));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // TODO what to do when this isn't a new entry and has an existing metadata???
+  mMemoryOnly = true;
+  return NS_OK;
+}
+
+nsresult
+CacheFile::Doom(CacheFileListener *aCallback)
+{
+  LOG(("CacheFile::Doom() [this=%p, listener=%p]", this, aCallback));
+
+  CacheFileAutoLock lock(this);
+
+  return DoomLocked(aCallback);
+}
+
+nsresult
+CacheFile::DoomLocked(CacheFileListener *aCallback)
+{
+  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);
+
+  LOG(("CacheFile::DoomLocked() [this=%p, listener=%p]", this, aCallback));
+
+  nsresult rv = NS_OK;
+
+  if (mMemoryOnly) {
+    return NS_ERROR_FILE_NOT_FOUND;
+  }
+
+  if (mHandle && mHandle->IsDoomed()) {
+    return NS_ERROR_FILE_NOT_FOUND;
+  }
+
+  nsCOMPtr<CacheFileIOListener> listener;
+  if (aCallback || !mHandle) {
+    listener = new DoomFileHelper(aCallback);
+  }
+  if (mHandle) {
+    rv = CacheFileIOManager::DoomFile(mHandle, listener);
+  } else if (mOpeningFile) {
+    mDoomAfterOpenListener = listener;
+  }
+
+  return rv;
+}
+
+nsresult
+CacheFile::ThrowMemoryCachedData()
+{
+  CacheFileAutoLock lock(this);
+
+  LOG(("CacheFile::ThrowMemoryCachedData() [this=%p]", this));
+
+  if (mMemoryOnly) {
+    // This method should not be called when the CacheFile was initialized as
+    // memory-only, but it can be called when CacheFile end up as memory-only
+    // due to e.g. IO failure since CacheEntry doesn't know it.
+    LOG(("CacheFile::ThrowMemoryCachedData() - Ignoring request because the "
+         "entry is memory-only. [this=%p]", this));
+
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (mOpeningFile) {
+    // mayhemer, note: we shouldn't get here, since CacheEntry prevents loading
+    // entries from being purged.
+
+    LOG(("CacheFile::ThrowMemoryCachedData() - Ignoring request because the "
+         "entry is still opening the file [this=%p]", this));
+
+    return NS_ERROR_ABORT;
+  }
+
+  // We cannot release all cached chunks since we need to keep preloaded chunks
+  // in memory. See initialization of mPreloadChunkCount for explanation.
+  CleanUpCachedChunks();
+
+  return NS_OK;
+}
+
+nsresult
+CacheFile::GetElement(const char *aKey, char **_retval)
+{
+  CacheFileAutoLock lock(this);
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  const char *value;
+  value = mMetadata->GetElement(aKey);
+  if (!value)
+    return NS_ERROR_NOT_AVAILABLE;
+
+  *_retval = NS_strdup(value);
+  return NS_OK;
+}
+
+nsresult
+CacheFile::SetElement(const char *aKey, const char *aValue)
+{
+  CacheFileAutoLock lock(this);
+
+  LOG(("CacheFile::SetElement() this=%p", this));
+
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  if (!strcmp(aKey, CacheFileUtils::kAltDataKey)) {
+    NS_ERROR("alt-data element is reserved for internal use and must not be "
+             "changed via CacheFile::SetElement()");
+    return NS_ERROR_FAILURE;
+  }
+
+  PostWriteTimer();
+  return mMetadata->SetElement(aKey, aValue);
+}
+
+nsresult
+CacheFile::VisitMetaData(nsICacheEntryMetaDataVisitor *aVisitor)
+{
+  CacheFileAutoLock lock(this);
+  MOZ_ASSERT(mMetadata);
+  MOZ_ASSERT(mReady);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  return mMetadata->Visit(aVisitor);
+}
+
+nsresult
+CacheFile::ElementsSize(uint32_t *_retval)
+{
+  CacheFileAutoLock lock(this);
+
+  if (!mMetadata)
+    return NS_ERROR_NOT_AVAILABLE;
+
+  *_retval = mMetadata->ElementsSize();
+  return NS_OK;
+}
+
+nsresult
+CacheFile::SetExpirationTime(uint32_t aExpirationTime)
+{
+  CacheFileAutoLock lock(this);
+
+  LOG(("CacheFile::SetExpirationTime() this=%p, expiration=%u",
+       this, aExpirationTime));
+
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  PostWriteTimer();
+
+  if (mHandle && !mHandle->IsDoomed())
+    CacheFileIOManager::UpdateIndexEntry(mHandle, nullptr, &aExpirationTime);
+
+  return mMetadata->SetExpirationTime(aExpirationTime);
+}
+
+nsresult
+CacheFile::GetExpirationTime(uint32_t *_retval)
+{
+  CacheFileAutoLock lock(this);
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  return mMetadata->GetExpirationTime(_retval);
+}
+
+nsresult
+CacheFile::SetFrecency(uint32_t aFrecency)
+{
+  CacheFileAutoLock lock(this);
+
+  LOG(("CacheFile::SetFrecency() this=%p, frecency=%u",
+       this, aFrecency));
+
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  PostWriteTimer();
+
+  if (mHandle && !mHandle->IsDoomed())
+    CacheFileIOManager::UpdateIndexEntry(mHandle, &aFrecency, nullptr);
+
+  return mMetadata->SetFrecency(aFrecency);
+}
+
+nsresult
+CacheFile::GetFrecency(uint32_t *_retval)
+{
+  CacheFileAutoLock lock(this);
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  return mMetadata->GetFrecency(_retval);
+}
+
+nsresult
+CacheFile::GetLastModified(uint32_t *_retval)
+{
+  CacheFileAutoLock lock(this);
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  return mMetadata->GetLastModified(_retval);
+}
+
+nsresult
+CacheFile::GetLastFetched(uint32_t *_retval)
+{
+  CacheFileAutoLock lock(this);
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  return mMetadata->GetLastFetched(_retval);
+}
+
+nsresult
+CacheFile::GetFetchCount(uint32_t *_retval)
+{
+  CacheFileAutoLock lock(this);
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  return mMetadata->GetFetchCount(_retval);
+}
+
+nsresult
+CacheFile::GetDiskStorageSizeInKB(uint32_t *aDiskStorageSize)
+{
+  if (!mHandle) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  *aDiskStorageSize = mHandle->FileSizeInK();
+  return NS_OK;
+}
+
+nsresult
+CacheFile::OnFetched()
+{
+  CacheFileAutoLock lock(this);
+
+  LOG(("CacheFile::OnFetched() this=%p", this));
+
+  MOZ_ASSERT(mMetadata);
+  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);
+
+  PostWriteTimer();
+
+  return mMetadata->OnFetched();
+}
+
+void
+CacheFile::Lock()
+{
+  mLock.Lock();
+}
+
+void
+CacheFile::Unlock()
+{
+  // move the elements out of mObjsToRelease
+  // so that they can be released after we unlock
+  nsTArray<RefPtr<nsISupports>> objs;
+  objs.SwapElements(mObjsToRelease);
+
+  mLock.Unlock();
+
+}
+
+void
+CacheFile::AssertOwnsLock() const
+{
+  mLock.AssertCurrentThreadOwns();
+}
+
+void
+CacheFile::ReleaseOutsideLock(RefPtr<nsISupports> aObject)
+{
+  AssertOwnsLock();
+
+  mObjsToRelease.AppendElement(Move(aObject));
+}
+
+nsresult
+CacheFile::GetChunkLocked(uint32_t aIndex, ECallerType aCaller,
+                          CacheFileChunkListener *aCallback,
+                          CacheFileChunk **_retval)
+{
+  AssertOwnsLock();
+
+  LOG(("CacheFile::GetChunkLocked() [this=%p, idx=%u, caller=%d, listener=%p]",
+       this, aIndex, aCaller, aCallback));
+
+  MOZ_ASSERT(mReady);
+  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);
+  MOZ_ASSERT((aCaller == READER && aCallback) ||
+             (aCaller == WRITER && !aCallback) ||
+             (aCaller == PRELOADER && !aCallback));
+
+  // Preload chunks from disk when this is disk backed entry and the listener
+  // is reader.
+  bool preload = !mMemoryOnly && (aCaller == READER);
+
+  nsresult rv;
+
+  RefPtr<CacheFileChunk> chunk;
+  if (mChunks.Get(aIndex, getter_AddRefs(chunk))) {
+    LOG(("CacheFile::GetChunkLocked() - Found chunk %p in mChunks [this=%p]",
+         chunk.get(), this));
+
+    // Preloader calls this method to preload only non-loaded chunks.
+    MOZ_ASSERT(aCaller != PRELOADER, "Unexpected!");
+
+    // We might get failed chunk between releasing the lock in
+    // CacheFileChunk::OnDataWritten/Read and CacheFile::OnChunkWritten/Read
+    rv = chunk->GetStatus();
+    if (NS_FAILED(rv)) {
+      SetError(rv);
+      LOG(("CacheFile::GetChunkLocked() - Found failed chunk in mChunks "
+           "[this=%p]", this));
+      return rv;
+    }
+
+    if (chunk->IsReady() || aCaller == WRITER) {
+      chunk.swap(*_retval);
+    } else {
+      rv = QueueChunkListener(aIndex, aCallback);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    if (preload) {
+      PreloadChunks(aIndex + 1);
+    }
+
+    return NS_OK;
+  }
+
+  if (mCachedChunks.Get(aIndex, getter_AddRefs(chunk))) {
+    LOG(("CacheFile::GetChunkLocked() - Reusing cached chunk %p [this=%p]",
+         chunk.get(), this));
+
+    // Preloader calls this method to preload only non-loaded chunks.
+    MOZ_ASSERT(aCaller != PRELOADER, "Unexpected!");
+
+    mChunks.Put(aIndex, chunk);
+    mCachedChunks.Remove(aIndex);
+    chunk->mFile = this;
+    chunk->mActiveChunk = true;
+
+    MOZ_ASSERT(chunk->IsReady());
+
+    chunk.swap(*_retval);
+
+    if (preload) {
+      PreloadChunks(aIndex + 1);
+    }
+
+    return NS_OK;
+  }
+
+  int64_t off = aIndex * static_cast<int64_t>(kChunkSize);
+
+  if (off < mDataSize) {
+    // We cannot be here if this is memory only entry since the chunk must exist
+    MOZ_ASSERT(!mMemoryOnly);
+    if (mMemoryOnly) {
+      // If this ever really happen it is better to fail rather than crashing on
+      // a null handle.
+      LOG(("CacheFile::GetChunkLocked() - Unexpected state! Offset < mDataSize "
+           "for memory-only entry. [this=%p, off=%lld, mDataSize=%lld]",
+           this, off, mDataSize));
+
+      return NS_ERROR_UNEXPECTED;
+    }
+
+    chunk = new CacheFileChunk(this, aIndex, aCaller == WRITER);
+    mChunks.Put(aIndex, chunk);
+    chunk->mActiveChunk = true;
+
+    LOG(("CacheFile::GetChunkLocked() - Reading newly created chunk %p from "
+         "the disk [this=%p]", chunk.get(), this));
+
+    // Read the chunk from the disk
+    rv = chunk->Read(mHandle, std::min(static_cast<uint32_t>(mDataSize - off),
+                     static_cast<uint32_t>(kChunkSize)),
+                     mMetadata->GetHash(aIndex), this);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      RemoveChunkInternal(chunk, false);
+      return rv;
+    }
+
+    if (aCaller == WRITER) {
+      chunk.swap(*_retval);
+    } else if (aCaller != PRELOADER) {
+      rv = QueueChunkListener(aIndex, aCallback);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    if (preload) {
+      PreloadChunks(aIndex + 1);
+    }
+
+    return NS_OK;
+  } else if (off == mDataSize) {
+    if (aCaller == WRITER) {
+      // this listener is going to write to the chunk
+      chunk = new CacheFileChunk(this, aIndex, true);
+      mChunks.Put(aIndex, chunk);
+      chunk->mActiveChunk = true;
+
+      LOG(("CacheFile::GetChunkLocked() - Created new empty chunk %p [this=%p]",
+           chunk.get(), this));
+
+      chunk->InitNew();
+      mMetadata->SetHash(aIndex, chunk->Hash());
+
+      if (HaveChunkListeners(aIndex)) {
+        rv = NotifyChunkListeners(aIndex, NS_OK, chunk);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+
+      chunk.swap(*_retval);
+      return NS_OK;
+    }
+  } else {
+    if (aCaller == WRITER) {
+      // this chunk was requested by writer, but we need to fill the gap first
+
+      // Fill with zero the last chunk if it is incomplete
+      if (mDataSize % kChunkSize) {
+        rv = PadChunkWithZeroes(mDataSize / kChunkSize);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        MOZ_ASSERT(!(mDataSize % kChunkSize));
+      }
+
+      uint32_t startChunk = mDataSize / kChunkSize;
+
+      if (mMemoryOnly) {
+        // We need to create all missing CacheFileChunks if this is memory-only
+        // entry
+        for (uint32_t i = startChunk ; i < aIndex ; i++) {
+          rv = PadChunkWithZeroes(i);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+      } else {
+        // We don't need to create CacheFileChunk for other empty chunks unless
+        // there is some input stream waiting for this chunk.
+
+        if (startChunk != aIndex) {
+          // Make sure the file contains zeroes at the end of the file
+          rv = CacheFileIOManager::TruncateSeekSetEOF(mHandle,
+                                                      startChunk * kChunkSize,
+                                                      aIndex * kChunkSize,
+                                                      nullptr);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+
+        for (uint32_t i = startChunk ; i < aIndex ; i++) {
+          if (HaveChunkListeners(i)) {
+            rv = PadChunkWithZeroes(i);
+            NS_ENSURE_SUCCESS(rv, rv);
+          } else {
+            mMetadata->SetHash(i, kEmptyChunkHash);
+            mDataSize = (i + 1) * kChunkSize;
+          }
+        }
+      }
+
+      MOZ_ASSERT(mDataSize == off);
+      rv = GetChunkLocked(aIndex, WRITER, nullptr, getter_AddRefs(chunk));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      chunk.swap(*_retval);
+      return NS_OK;
+    }
+  }
+
+  // We can be here only if the caller is reader since writer always create a
+  // new chunk above and preloader calls this method to preload only chunks that
+  // are not loaded but that do exist.
+  MOZ_ASSERT(aCaller == READER, "Unexpected!");
+
+  if (mOutput) {
+    // the chunk doesn't exist but mOutput may create it
+    rv = QueueChunkListener(aIndex, aCallback);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  return NS_OK;
+}
+
+void
+CacheFile::PreloadChunks(uint32_t aIndex)
+{
+  AssertOwnsLock();
+
+  uint32_t limit = aIndex + mPreloadChunkCount;
+
+  for (uint32_t i = aIndex; i < limit; ++i) {
+    int64_t off = i * static_cast<int64_t>(kChunkSize);
+
+    if (off >= mDataSize) {
+      // This chunk is beyond EOF.
+      return;
+    }
+
+    if (mChunks.GetWeak(i) || mCachedChunks.GetWeak(i)) {
+      // This chunk is already in memory or is being read right now.
+      continue;
+    }
+
+    LOG(("CacheFile::PreloadChunks() - Preloading chunk [this=%p, idx=%u]",
+         this, i));
+
+    RefPtr<CacheFileChunk> chunk;
+    GetChunkLocked(i, PRELOADER, nullptr, getter_AddRefs(chunk));
+    // We've checked that we don't have this chunk, so no chunk must be
+    // returned.
+    MOZ_ASSERT(!chunk);
+  }
+}
+
+bool
+CacheFile::ShouldCacheChunk(uint32_t aIndex)
+{
+  AssertOwnsLock();
+
+#ifdef CACHE_CHUNKS
+  // We cache all chunks.
+  return true;
+#else
+
+  if (mPreloadChunkCount != 0 && mInputs.Length() == 0 &&
+      mPreloadWithoutInputStreams && aIndex < mPreloadChunkCount) {
+    // We don't have any input stream yet, but it is likely that some will be
+    // opened soon. Keep first mPreloadChunkCount chunks in memory. The
+    // condition is here instead of in MustKeepCachedChunk() since these
+    // chunks should be preloaded and can be kept in memory as an optimization,
+    // but they can be released at any time until they are considered as
+    // preloaded chunks for any input stream.
+    return true;
+  }
+
+  // Cache only chunks that we really need to keep.
+  return MustKeepCachedChunk(aIndex);
+#endif
+}
+
+bool
+CacheFile::MustKeepCachedChunk(uint32_t aIndex)
+{
+  AssertOwnsLock();
+
+  // We must keep the chunk when this is memory only entry or we don't have
+  // a handle yet.
+  if (mMemoryOnly || mOpeningFile) {
+    return true;
+  }
+
+  if (mPreloadChunkCount == 0) {
+    // Preloading of chunks is disabled
+    return false;
+  }
+
+  // Check whether this chunk should be considered as preloaded chunk for any
+  // existing input stream.
+
+  // maxPos is the position of the last byte in the given chunk
+  int64_t maxPos = static_cast<int64_t>(aIndex + 1) * kChunkSize - 1;
+
+  // minPos is the position of the first byte in a chunk that precedes the given
+  // chunk by mPreloadChunkCount chunks
+  int64_t minPos;
+  if (mPreloadChunkCount >= aIndex) {
+    minPos = 0;
+  } else {
+    minPos = static_cast<int64_t>(aIndex - mPreloadChunkCount) * kChunkSize;
+  }
+
+  for (uint32_t i = 0; i < mInputs.Length(); ++i) {
+    int64_t inputPos = mInputs[i]->GetPosition();
+    if (inputPos >= minPos && inputPos <= maxPos) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+nsresult
+CacheFile::DeactivateChunk(CacheFileChunk *aChunk)
+{
+  nsresult rv;
+
+  // Avoid lock reentrancy by increasing the RefCnt
+  RefPtr<CacheFileChunk> chunk = aChunk;
+
+  {
+    CacheFileAutoLock lock(this);
+
+    LOG(("CacheFile::DeactivateChunk() [this=%p, chunk=%p, idx=%u]",
+         this, aChunk, aChunk->Index()));
+
+    MOZ_ASSERT(mReady);
+    MOZ_ASSERT((mHandle && !mMemoryOnly && !mOpeningFile) ||
+               (!mHandle && mMemoryOnly && !mOpeningFile) ||
+               (!mHandle && !mMemoryOnly && mOpeningFile));
+
+    if (aChunk->mRefCnt != 2) {
+      LOG(("CacheFile::DeactivateChunk() - Chunk is still used [this=%p, "
+           "chunk=%p, refcnt=%d]", this, aChunk, aChunk->mRefCnt.get()));
+
+      // somebody got the reference before the lock was acquired
+      return NS_OK;
+    }
+
+    if (aChunk->mDiscardedChunk) {
+      aChunk->mActiveChunk = false;
+      ReleaseOutsideLock(RefPtr<CacheFileChunkListener>(aChunk->mFile.forget()).forget());
+
+      DebugOnly<bool> removed = mDiscardedChunks.RemoveElement(aChunk);
+      MOZ_ASSERT(removed);
+      return NS_OK;
+    }
+
+#ifdef DEBUG
+    {
+      // We can be here iff the chunk is in the hash table
+      RefPtr<CacheFileChunk> chunkCheck;
+      mChunks.Get(chunk->Index(), getter_AddRefs(chunkCheck));
+      MOZ_ASSERT(chunkCheck == chunk);
+
+      // We also shouldn't have any queued listener for this chunk
+      ChunkListeners *listeners;
+      mChunkListeners.Get(chunk->Index(), &listeners);
+      MOZ_ASSERT(!listeners);
+    }
+#endif
+
+    if (NS_FAILED(chunk->GetStatus())) {
+      SetError(chunk->GetStatus());
+    }
+
+    if (NS_FAILED(mStatus)) {
+      // Don't write any chunk to disk since this entry will be doomed
+      LOG(("CacheFile::DeactivateChunk() - Releasing chunk because of status "
+           "[this=%p, chunk=%p, mStatus=0x%08x]", this, chunk.get(), mStatus));
+
+      RemoveChunkInternal(chunk, false);
+      return mStatus;
+    }
+
+    if (chunk->IsDirty() && !mMemoryOnly && !mOpeningFile) {
+      LOG(("CacheFile::DeactivateChunk() - Writing dirty chunk to the disk "
+           "[this=%p]", this));
+
+      mDataIsDirty = true;
+
+      rv = chunk->Write(mHandle, this);
+      if (NS_FAILED(rv)) {
+        LOG(("CacheFile::DeactivateChunk() - CacheFileChunk::Write() failed "
+             "synchronously. Removing it. [this=%p, chunk=%p, rv=0x%08x]",
+             this, chunk.get(), rv));
+
+        RemoveChunkInternal(chunk, false);
+
+        SetError(rv);
+        return rv;
+      }
+
+      // Chunk will be removed in OnChunkWritten if it is still unused
+
+      // chunk needs to be released under the lock to be able to rely on
+      // CacheFileChunk::mRefCnt in CacheFile::OnChunkWritten()
+      chunk = nullptr;
+      return NS_OK;
+    }
+
+    bool keepChunk = ShouldCacheChunk(aChunk->Index());
+    LOG(("CacheFile::DeactivateChunk() - %s unused chunk [this=%p, chunk=%p]",
+         keepChunk ? "Caching" : "Releasing", this, chunk.get()));
+
+    RemoveChunkInternal(chunk, keepChunk);
+
+    if (!mMemoryOnly)
+      WriteMetadataIfNeededLocked();
+  }
+
+  return NS_OK;
+}
+
+void
+CacheFile::RemoveChunkInternal(CacheFileChunk *aChunk, bool aCacheChunk)
+{
+  AssertOwnsLock();
+
+  aChunk->mActiveChunk = false;
+  ReleaseOutsideLock(RefPtr<CacheFileChunkListener>(aChunk->mFile.forget()).forget());
+
+  if (aCacheChunk) {
+    mCachedChunks.Put(aChunk->Index(), aChunk);
+  }
+
+  mChunks.Remove(aChunk->Index());
+}
+
+bool
+CacheFile::OutputStreamExists(bool aAlternativeData)
+{
+  AssertOwnsLock();
+
+  if (!mOutput) {
+    return false;
+  }
+
+  return mOutput->IsAlternativeData() == aAlternativeData;
+}
+
+int64_t
+CacheFile::BytesFromChunk(uint32_t aIndex, bool aAlternativeData)
+{
+  AssertOwnsLock();
+
+  int64_t dataSize;
+
+  if (mAltDataOffset != -1) {
+    if (aAlternativeData) {
+      dataSize = mDataSize;
+    } else {
+      dataSize = mAltDataOffset;
+    }
+  } else {
+    MOZ_ASSERT(!aAlternativeData);
+    dataSize = mDataSize;
+  }
+
+  if (!dataSize) {
+    return 0;
+  }
+
+  // Index of the last existing chunk.
+  uint32_t lastChunk = (dataSize - 1) / kChunkSize;
+  if (aIndex > lastChunk) {
+    return 0;
+  }
+
+  // We can use only preloaded chunks for the given stream to calculate
+  // available bytes if this is an entry stored on disk, since only those
+  // chunks are guaranteed not to be released.
+  uint32_t maxPreloadedChunk;
+  if (mMemoryOnly) {
+    maxPreloadedChunk = lastChunk;
+  } else {
+    maxPreloadedChunk = std::min(aIndex + mPreloadChunkCount, lastChunk);
+  }
+
+  uint32_t i;
+  for (i = aIndex; i <= maxPreloadedChunk; ++i) {
+    CacheFileChunk * chunk;
+
+    chunk = mChunks.GetWeak(i);
+    if (chunk) {
+      MOZ_ASSERT(i == lastChunk || chunk->DataSize() == kChunkSize);
+      if (chunk->IsReady()) {
+        continue;
+      }
+
+      // don't search this chunk in cached
+      break;
+    }
+
+    chunk = mCachedChunks.GetWeak(i);
+    if (chunk) {
+      MOZ_ASSERT(i == lastChunk || chunk->DataSize() == kChunkSize);
+      continue;
+    }
+
+    break;
+  }
+
+  // theoretic bytes in advance
+  int64_t advance = int64_t(i - aIndex) * kChunkSize;
+  // real bytes till the end of the file
+  int64_t tail = dataSize - (aIndex * kChunkSize);
+
+  return std::min(advance, tail);
+}
+
+nsresult
+CacheFile::Truncate(int64_t aOffset)
+{
+  AssertOwnsLock();
+
+  nsresult rv;
+
+  MOZ_ASSERT(aOffset <= mDataSize);
+  MOZ_ASSERT(mReady);
+
+  uint32_t lastChunk = 0;
+
+  if (aOffset > 0) {
+    lastChunk = (mDataSize - 1) / kChunkSize;
+  }
+
+  uint32_t bytesInLastChunk = aOffset - lastChunk * kChunkSize;
+
+  for (auto iter = mCachedChunks.Iter(); !iter.Done(); iter.Next()) {
+    uint32_t idx = iter.Key();
+
+    if (idx > lastChunk) {
+      // This is unused chunk, simply remove it.
+      iter.Remove();
+      continue;
+    }
+
+    if (idx == lastChunk) {
+      RefPtr<CacheFileChunk>& chunk = iter.Data();
+
+      rv = chunk->Truncate(bytesInLastChunk);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+    }
+  }
+
+  for (auto iter = mChunks.Iter(); !iter.Done(); iter.Next()) {
+    uint32_t idx = iter.Key();
+    RefPtr<CacheFileChunk>& chunk = iter.Data();
+
+    if (idx > lastChunk) {
+      chunk->mDiscardedChunk = true;
+      mDiscardedChunks.AppendElement(chunk);
+      iter.Remove();
+      continue;
+    }
+
+    if (idx == lastChunk) {
+      RefPtr<CacheFileChunk>& chunk = iter.Data();
+
+      rv = chunk->Truncate(bytesInLastChunk);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+    }
+  }
+
+  if (mHandle) {
+    rv = CacheFileIOManager::TruncateSeekSetEOF(mHandle, aOffset, aOffset, nullptr);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  mDataSize = aOffset;
+
+  return NS_OK;
+}
+
+static uint32_t
+StatusToTelemetryEnum(nsresult aStatus)
+{
+  if (NS_SUCCEEDED(aStatus)) {
+    return 0;
+  }
+
+  switch (aStatus) {
+    case NS_BASE_STREAM_CLOSED:
+      return 0; // Log this as a success
+    case NS_ERROR_OUT_OF_MEMORY:
+      return 2;
+    case NS_ERROR_FILE_DISK_FULL:
+      return 3;
+    case NS_ERROR_FILE_CORRUPTED:
+      return 4;
+    case NS_ERROR_FILE_NOT_FOUND:
+      return 5;
+    case NS_BINDING_ABORTED:
+      return 6;
+    default:
+      return 1; // other error
+  }
+
+  NS_NOTREACHED("We should never get here");
+}
+
+nsresult
+CacheFile::RemoveInput(CacheFileInputStream *aInput, nsresult aStatus)
+{
+  CacheFileAutoLock lock(this);
+
+  LOG(("CacheFile::RemoveInput() [this=%p, input=%p, status=0x%08x]", this,
+       aInput, aStatus));
+
+  DebugOnly<bool> found;
+  found = mInputs.RemoveElement(aInput);
+  MOZ_ASSERT(found);
+
+  ReleaseOutsideLock(already_AddRefed<nsIInputStream>(static_cast<nsIInputStream*>(aInput)));
+
+  if (!mMemoryOnly)
+    WriteMetadataIfNeededLocked();
+
+  // If the input didn't read all data, there might be left some preloaded
+  // chunks that won't be used anymore.
+  CleanUpCachedChunks();
+
+  Telemetry::Accumulate(Telemetry::NETWORK_CACHE_V2_INPUT_STREAM_STATUS,
+                        StatusToTelemetryEnum(aStatus));
+
+  return NS_OK;
+}
+
+nsresult
+CacheFile::RemoveOutput(CacheFileOutputStream *aOutput, nsresult aStatus)
+{
+  AssertOwnsLock();
+
+  LOG(("CacheFile::RemoveOutput() [this=%p, output=%p, status=0x%08x]", this,
+       aOutput, aStatus));
+
+  if (mOutput != aOutput) {
+    LOG(("CacheFile::RemoveOutput() - This output was already removed, ignoring"
+         " call [this=%p]", this));
+    return NS_OK;
+  }
+
+  mOutput = nullptr;
+
+  // Cancel all queued chunk and update listeners that cannot be satisfied
+  NotifyListenersAboutOutputRemoval();
+
+  if (!mMemoryOnly)
+    WriteMetadataIfNeededLocked();
+
+  // Make sure the CacheFile status is set to a failure when the output stream
+  // is closed with a fatal error.  This way we propagate correctly and w/o any
+  // windows the failure state of this entry to end consumers.
+  if (NS_SUCCEEDED(mStatus) && NS_FAILED(aStatus) && aStatus != NS_BASE_STREAM_CLOSED) {
+    mStatus = aStatus;
+  }
+
+  // Notify close listener as the last action
+  aOutput->NotifyCloseListener();
+
+  Telemetry::Accumulate(Telemetry::NETWORK_CACHE_V2_OUTPUT_STREAM_STATUS,
+                        StatusToTelemetryEnum(aStatus));
+
+  return NS_OK;
+}
+
+nsresult
+CacheFile::NotifyChunkListener(CacheFileChunkListener *aCallback,
+                               nsIEventTarget *aTarget,
+                               nsresult aResult,
+                               uint32_t aChunkIdx,
+                               CacheFileChunk *aChunk)
+{
+  LOG(("CacheFile::NotifyChunkListener() [this=%p, listener=%p, target=%p, "
+       "rv=0x%08x, idx=%u, chunk=%p]", this, aCallback, aTarget, aResult,
+       aChunkIdx, aChunk));
+
+  nsresult rv;
+  RefPtr<NotifyChunkListenerEvent> ev;
+  ev = new NotifyChunkListenerEvent(aCallback, aResult, aChunkIdx, aChunk);
+  if (aTarget)
+    rv = aTarget->Dispatch(ev, NS_DISPATCH_NORMAL);
+  else
+    rv = NS_DispatchToCurrentThread(ev);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFile::QueueChunkListener(uint32_t aIndex,
+                              CacheFileChunkListener *aCallback)
+{
+  LOG(("CacheFile::QueueChunkListener() [this=%p, idx=%u, listener=%p]",
+       this, aIndex, aCallback));
+
+  AssertOwnsLock();
+
+  MOZ_ASSERT(aCallback);
+
+  ChunkListenerItem *item = new ChunkListenerItem();
+  item->mTarget = CacheFileIOManager::IOTarget();
+  if (!item->mTarget) {
+    LOG(("CacheFile::QueueChunkListener() - Cannot get Cache I/O thread! Using "
+         "main thread for callback."));
+    item->mTarget = do_GetMainThread();
+  }
+  item->mCallback = aCallback;
+
+  ChunkListeners *listeners;
+  if (!mChunkListeners.Get(aIndex, &listeners)) {
+    listeners = new ChunkListeners();
+    mChunkListeners.Put(aIndex, listeners);
+  }
+
+  listeners->mItems.AppendElement(item);
+  return NS_OK;
+}
+
+nsresult
+CacheFile::NotifyChunkListeners(uint32_t aIndex, nsresult aResult,
+                                CacheFileChunk *aChunk)
+{
+  LOG(("CacheFile::NotifyChunkListeners() [this=%p, idx=%u, rv=0x%08x, "
+       "chunk=%p]", this, aIndex, aResult, aChunk));
+
+  AssertOwnsLock();
+
+  nsresult rv, rv2;
+
+  ChunkListeners *listeners;
+  mChunkListeners.Get(aIndex, &listeners);
+  MOZ_ASSERT(listeners);
+
+  rv = NS_OK;
+  for (uint32_t i = 0 ; i < listeners->mItems.Length() ; i++) {
+    ChunkListenerItem *item = listeners->mItems[i];
+    rv2 = NotifyChunkListener(item->mCallback, item->mTarget, aResult, aIndex,
+                              aChunk);
+    if (NS_FAILED(rv2) && NS_SUCCEEDED(rv))
+      rv = rv2;
+    delete item;
+  }
+
+  mChunkListeners.Remove(aIndex);
+
+  return rv;
+}
+
+bool
+CacheFile::HaveChunkListeners(uint32_t aIndex)
+{
+  ChunkListeners *listeners;
+  mChunkListeners.Get(aIndex, &listeners);
+  return !!listeners;
+}
+
+void
+CacheFile::NotifyListenersAboutOutputRemoval()
+{
+  LOG(("CacheFile::NotifyListenersAboutOutputRemoval() [this=%p]", this));
+
+  AssertOwnsLock();
+
+  // First fail all chunk listeners that wait for non-existent chunk
+  for (auto iter = mChunkListeners.Iter(); !iter.Done(); iter.Next()) {
+    uint32_t idx = iter.Key();
+    nsAutoPtr<ChunkListeners>& listeners = iter.Data();
+
+    LOG(("CacheFile::NotifyListenersAboutOutputRemoval() - fail "
+         "[this=%p, idx=%u]", this, idx));
+
+    RefPtr<CacheFileChunk> chunk;
+    mChunks.Get(idx, getter_AddRefs(chunk));
+    if (chunk) {
+      MOZ_ASSERT(!chunk->IsReady());
+      continue;
+    }
+
+    for (uint32_t i = 0 ; i < listeners->mItems.Length() ; i++) {
+      ChunkListenerItem *item = listeners->mItems[i];
+      NotifyChunkListener(item->mCallback, item->mTarget,
+                          NS_ERROR_NOT_AVAILABLE, idx, nullptr);
+      delete item;
+    }
+
+    iter.Remove();
+  }
+
+  // Fail all update listeners
+  for (auto iter = mChunks.Iter(); !iter.Done(); iter.Next()) {
+    const RefPtr<CacheFileChunk>& chunk = iter.Data();
+    LOG(("CacheFile::NotifyListenersAboutOutputRemoval() - fail2 "
+         "[this=%p, idx=%u]", this, iter.Key()));
+
+    if (chunk->IsReady()) {
+      chunk->NotifyUpdateListeners();
+    }
+  }
+}
+
+bool
+CacheFile::DataSize(int64_t* aSize)
+{
+  CacheFileAutoLock lock(this);
+
+  if (OutputStreamExists(false)) {
+    return false;
+  }
+
+  if (mAltDataOffset == -1) {
+    *aSize = mDataSize;
+  } else {
+    *aSize = mAltDataOffset;
+  }
+
+  return true;
+}
+
+nsresult
+CacheFile::GetAltDataSize(int64_t *aSize)
+{
+  CacheFileAutoLock lock(this);
+  if (mOutput) {
+    return NS_ERROR_IN_PROGRESS;
+  }
+
+  if (mAltDataOffset == -1) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  *aSize = mDataSize - mAltDataOffset;
+  return NS_OK;
+}
+
+bool
+CacheFile::IsDoomed()
+{
+  CacheFileAutoLock lock(this);
+
+  if (!mHandle)
+    return false;
+
+  return mHandle->IsDoomed();
+}
+
+bool
+CacheFile::IsWriteInProgress()
+{
+  // Returns true when there is a potentially unfinished write operation.
+  // Not using lock for performance reasons.  mMetadata is never released
+  // during life time of CacheFile.
+
+  bool result = false;
+
+  if (!mMemoryOnly) {
+    result = mDataIsDirty ||
+             (mMetadata && mMetadata->IsDirty()) ||
+             mWritingMetadata;
+  }
+
+  result = result ||
+           mOpeningFile ||
+           mOutput ||
+           mChunks.Count();
+
+  return result;
+}
+
+bool
+CacheFile::IsDirty()
+{
+  return mDataIsDirty || mMetadata->IsDirty();
+}
+
+void
+CacheFile::WriteMetadataIfNeeded()
+{
+  LOG(("CacheFile::WriteMetadataIfNeeded() [this=%p]", this));
+
+  CacheFileAutoLock lock(this);
+
+  if (!mMemoryOnly)
+    WriteMetadataIfNeededLocked();
+}
+
+void
+CacheFile::WriteMetadataIfNeededLocked(bool aFireAndForget)
+{
+  // When aFireAndForget is set to true, we are called from dtor.
+  // |this| must not be referenced after this method returns!
+
+  LOG(("CacheFile::WriteMetadataIfNeededLocked() [this=%p]", this));
+
+  nsresult rv;
+
+  AssertOwnsLock();
+  MOZ_ASSERT(!mMemoryOnly);
+
+  if (!mMetadata) {
+    MOZ_CRASH("Must have metadata here");
+    return;
+  }
+
+  if (NS_FAILED(mStatus))
+    return;
+
+  if (!IsDirty() || mOutput || mInputs.Length() || mChunks.Count() ||
+      mWritingMetadata || mOpeningFile || mKill)
+    return;
+
+  if (!aFireAndForget) {
+    // if aFireAndForget is set, we are called from dtor. Write
+    // scheduler hard-refers CacheFile otherwise, so we cannot be here.
+    CacheFileIOManager::UnscheduleMetadataWrite(this);
+  }
+
+  LOG(("CacheFile::WriteMetadataIfNeededLocked() - Writing metadata [this=%p]",
+       this));
+
+  rv = mMetadata->WriteMetadata(mDataSize, aFireAndForget ? nullptr : this);
+  if (NS_SUCCEEDED(rv)) {
+    mWritingMetadata = true;
+    mDataIsDirty = false;
+  } else {
+    LOG(("CacheFile::WriteMetadataIfNeededLocked() - Writing synchronously "
+         "failed [this=%p]", this));
+    // TODO: close streams with error
+    SetError(rv);
+  }
+}
+
+void
+CacheFile::PostWriteTimer()
+{
+  if (mMemoryOnly)
+    return;
+
+  LOG(("CacheFile::PostWriteTimer() [this=%p]", this));
+
+  CacheFileIOManager::ScheduleMetadataWrite(this);
+}
+
+void
+CacheFile::CleanUpCachedChunks()
+{
+  for (auto iter = mCachedChunks.Iter(); !iter.Done(); iter.Next()) {
+    uint32_t idx = iter.Key();
+    const RefPtr<CacheFileChunk>& chunk = iter.Data();
+
+    LOG(("CacheFile::CleanUpCachedChunks() [this=%p, idx=%u, chunk=%p]", this,
+         idx, chunk.get()));
+
+    if (MustKeepCachedChunk(idx)) {
+      LOG(("CacheFile::CleanUpCachedChunks() - Keeping chunk"));
+      continue;
+    }
+
+    LOG(("CacheFile::CleanUpCachedChunks() - Removing chunk"));
+    iter.Remove();
+  }
+}
+
+nsresult
+CacheFile::PadChunkWithZeroes(uint32_t aChunkIdx)
+{
+  AssertOwnsLock();
+
+  // This method is used to pad last incomplete chunk with zeroes or create
+  // a new chunk full of zeroes
+  MOZ_ASSERT(mDataSize / kChunkSize == aChunkIdx);
+
+  nsresult rv;
+  RefPtr<CacheFileChunk> chunk;
+  rv = GetChunkLocked(aChunkIdx, WRITER, nullptr, getter_AddRefs(chunk));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  LOG(("CacheFile::PadChunkWithZeroes() - Zeroing hole in chunk %d, range %d-%d"
+       " [this=%p]", aChunkIdx, chunk->DataSize(), kChunkSize - 1, this));
+
+  CacheFileChunkWriteHandle hnd = chunk->GetWriteHandle(kChunkSize);
+  if (!hnd.Buf()) {
+    ReleaseOutsideLock(chunk.forget());
+    SetError(NS_ERROR_OUT_OF_MEMORY);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  uint32_t offset = hnd.DataSize();
+  memset(hnd.Buf() + offset, 0, kChunkSize - offset);
+  hnd.UpdateDataSize(offset, kChunkSize - offset);
+
+  ReleaseOutsideLock(chunk.forget());
+
+  return NS_OK;
+}
+
+void
+CacheFile::SetError(nsresult aStatus)
+{
+  AssertOwnsLock();
+
+  if (NS_SUCCEEDED(mStatus)) {
+    mStatus = aStatus;
+    if (mHandle) {
+      CacheFileIOManager::DoomFile(mHandle, nullptr);
+    }
+  }
+}
+
+nsresult
+CacheFile::InitIndexEntry()
+{
+  MOZ_ASSERT(mHandle);
+
+  if (mHandle->IsDoomed())
+    return NS_OK;
+
+  nsresult rv;
+
+  rv = CacheFileIOManager::InitIndexEntry(
+         mHandle, GetOriginAttrsHash(mMetadata->OriginAttributes()),
+         mMetadata->IsAnonymous(), mPinned);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint32_t expTime;
+  mMetadata->GetExpirationTime(&expTime);
+
+  uint32_t frecency;
+  mMetadata->GetFrecency(&frecency);
+
+  rv = CacheFileIOManager::UpdateIndexEntry(mHandle, &frecency, &expTime);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+size_t
+CacheFile::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  CacheFileAutoLock lock(const_cast<CacheFile*>(this));
+
+  size_t n = 0;
+  n += mKey.SizeOfExcludingThisIfUnshared(mallocSizeOf);
+  n += mChunks.ShallowSizeOfExcludingThis(mallocSizeOf);
+  for (auto iter = mChunks.ConstIter(); !iter.Done(); iter.Next()) {
+      n += iter.Data()->SizeOfIncludingThis(mallocSizeOf);
+  }
+  n += mCachedChunks.ShallowSizeOfExcludingThis(mallocSizeOf);
+  for (auto iter = mCachedChunks.ConstIter(); !iter.Done(); iter.Next()) {
+      n += iter.Data()->SizeOfIncludingThis(mallocSizeOf);
+  }
+  if (mMetadata) {
+    n += mMetadata->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  // Input streams are not elsewhere reported.
+  n += mInputs.ShallowSizeOfExcludingThis(mallocSizeOf);
+  for (uint32_t i = 0; i < mInputs.Length(); ++i) {
+    n += mInputs[i]->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  // Output streams are not elsewhere reported.
+  if (mOutput) {
+    n += mOutput->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  // The listeners are usually classes reported just above.
+  n += mChunkListeners.ShallowSizeOfExcludingThis(mallocSizeOf);
+  n += mObjsToRelease.ShallowSizeOfExcludingThis(mallocSizeOf);
+
+  // mHandle reported directly from CacheFileIOManager.
+
+  return n;
+}
+
+size_t
+CacheFile::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheFile.h b/netwerk/cache2/CacheFile.h
new file mode 100644
index 0000000000..3c8f7e97d6
--- /dev/null
+++ b/netwerk/cache2/CacheFile.h
@@ -0,0 +1,272 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheFile__h__
+#define CacheFile__h__
+
+#include "CacheFileChunk.h"
+#include "CacheFileIOManager.h"
+#include "CacheFileMetadata.h"
+#include "nsRefPtrHashtable.h"
+#include "nsClassHashtable.h"
+#include "mozilla/Mutex.h"
+
+class nsIInputStream;
+class nsIOutputStream;
+class nsICacheEntryMetaDataVisitor;
+
+namespace mozilla {
+namespace net {
+
+class CacheFileInputStream;
+class CacheFileOutputStream;
+class CacheOutputCloseListener;
+class MetadataWriteTimer;
+
+#define CACHEFILELISTENER_IID \
+{ /* 95e7f284-84ba-48f9-b1fc-3a7336b4c33c */       \
+  0x95e7f284,                                      \
+  0x84ba,                                          \
+  0x48f9,                                          \
+  {0xb1, 0xfc, 0x3a, 0x73, 0x36, 0xb4, 0xc3, 0x3c} \
+}
+
+class CacheFileListener : public nsISupports
+{
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(CACHEFILELISTENER_IID)
+
+  NS_IMETHOD OnFileReady(nsresult aResult, bool aIsNew) = 0;
+  NS_IMETHOD OnFileDoomed(nsresult aResult) = 0;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(CacheFileListener, CACHEFILELISTENER_IID)
+
+
+class CacheFile final : public CacheFileChunkListener
+                      , public CacheFileIOListener
+                      , public CacheFileMetadataListener
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  CacheFile();
+
+  nsresult Init(const nsACString &aKey,
+                bool aCreateNew,
+                bool aMemoryOnly,
+                bool aSkipSizeCheck,
+                bool aPriority,
+                bool aPinned,
+                CacheFileListener *aCallback);
+
+  NS_IMETHOD OnChunkRead(nsresult aResult, CacheFileChunk *aChunk) override;
+  NS_IMETHOD OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk) override;
+  NS_IMETHOD OnChunkAvailable(nsresult aResult, uint32_t aChunkIdx,
+                              CacheFileChunk *aChunk) override;
+  NS_IMETHOD OnChunkUpdated(CacheFileChunk *aChunk) override;
+
+  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                           nsresult aResult) override;
+  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult) override;
+  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) override;
+  virtual bool IsKilled() override;
+
+  NS_IMETHOD OnMetadataRead(nsresult aResult) override;
+  NS_IMETHOD OnMetadataWritten(nsresult aResult) override;
+
+  NS_IMETHOD OpenInputStream(nsICacheEntry *aCacheEntryHandle, nsIInputStream **_retval);
+  NS_IMETHOD OpenAlternativeInputStream(nsICacheEntry *aCacheEntryHandle,
+                                        const char *aAltDataType, nsIInputStream **_retval);
+  NS_IMETHOD OpenOutputStream(CacheOutputCloseListener *aCloseListener, nsIOutputStream **_retval);
+  NS_IMETHOD OpenAlternativeOutputStream(CacheOutputCloseListener *aCloseListener,
+                                         const char *aAltDataType, nsIOutputStream **_retval);
+  NS_IMETHOD SetMemoryOnly();
+  NS_IMETHOD Doom(CacheFileListener *aCallback);
+
+  void Kill() { mKill = true; }
+  nsresult   ThrowMemoryCachedData();
+
+  nsresult GetAltDataSize(int64_t *aSize);
+
+  // metadata forwarders
+  nsresult GetElement(const char *aKey, char **_retval);
+  nsresult SetElement(const char *aKey, const char *aValue);
+  nsresult VisitMetaData(nsICacheEntryMetaDataVisitor *aVisitor);
+  nsresult ElementsSize(uint32_t *_retval);
+  nsresult SetExpirationTime(uint32_t aExpirationTime);
+  nsresult GetExpirationTime(uint32_t *_retval);
+  nsresult SetFrecency(uint32_t aFrecency);
+  nsresult GetFrecency(uint32_t *_retval);
+  nsresult GetLastModified(uint32_t *_retval);
+  nsresult GetLastFetched(uint32_t *_retval);
+  nsresult GetFetchCount(uint32_t *_retval);
+  nsresult GetDiskStorageSizeInKB(uint32_t *aDiskStorageSize);
+  // Called by upper layers to indicated the entry has been fetched,
+  // i.e. delivered to the consumer.
+  nsresult OnFetched();
+
+  bool DataSize(int64_t* aSize);
+  void Key(nsACString& aKey) { aKey = mKey; }
+  bool IsDoomed();
+  bool IsPinned() const { return mPinned; }
+  bool IsWriteInProgress();
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+private:
+  friend class CacheFileIOManager;
+  friend class CacheFileChunk;
+  friend class CacheFileInputStream;
+  friend class CacheFileOutputStream;
+  friend class CacheFileAutoLock;
+  friend class MetadataWriteTimer;
+
+  virtual ~CacheFile();
+
+  void     Lock();
+  void     Unlock();
+  void     AssertOwnsLock() const;
+  void     ReleaseOutsideLock(RefPtr<nsISupports> aObject);
+
+  enum ECallerType {
+    READER    = 0,
+    WRITER    = 1,
+    PRELOADER = 2
+  };
+
+  nsresult DoomLocked(CacheFileListener *aCallback);
+
+  nsresult GetChunkLocked(uint32_t aIndex, ECallerType aCaller,
+                          CacheFileChunkListener *aCallback,
+                          CacheFileChunk **_retval);
+
+  void     PreloadChunks(uint32_t aIndex);
+  bool     ShouldCacheChunk(uint32_t aIndex);
+  bool     MustKeepCachedChunk(uint32_t aIndex);
+
+  nsresult DeactivateChunk(CacheFileChunk *aChunk);
+  void     RemoveChunkInternal(CacheFileChunk *aChunk, bool aCacheChunk);
+
+  bool     OutputStreamExists(bool aAlternativeData);
+  // Returns number of bytes that are available and can be read by input stream
+  // without waiting for the data. The amount is counted from the start of
+  // aIndex chunk and it is guaranteed that this data won't be released by
+  // CleanUpCachedChunks().
+  int64_t  BytesFromChunk(uint32_t aIndex, bool aAlternativeData);
+  nsresult Truncate(int64_t aOffset);
+
+  nsresult RemoveInput(CacheFileInputStream *aInput, nsresult aStatus);
+  nsresult RemoveOutput(CacheFileOutputStream *aOutput, nsresult aStatus);
+  nsresult NotifyChunkListener(CacheFileChunkListener *aCallback,
+                               nsIEventTarget *aTarget,
+                               nsresult aResult,
+                               uint32_t aChunkIdx,
+                               CacheFileChunk *aChunk);
+  nsresult QueueChunkListener(uint32_t aIndex,
+                              CacheFileChunkListener *aCallback);
+  nsresult NotifyChunkListeners(uint32_t aIndex, nsresult aResult,
+                                CacheFileChunk *aChunk);
+  bool     HaveChunkListeners(uint32_t aIndex);
+  void     NotifyListenersAboutOutputRemoval();
+
+  bool IsDirty();
+  void WriteMetadataIfNeeded();
+  void WriteMetadataIfNeededLocked(bool aFireAndForget = false);
+  void PostWriteTimer();
+
+  void CleanUpCachedChunks();
+
+  nsresult PadChunkWithZeroes(uint32_t aChunkIdx);
+
+  void SetError(nsresult aStatus);
+
+  nsresult InitIndexEntry();
+
+  mozilla::Mutex mLock;
+  bool           mOpeningFile;
+  bool           mReady;
+  bool           mMemoryOnly;
+  bool           mSkipSizeCheck;
+  bool           mOpenAsMemoryOnly;
+  bool           mPinned;
+  bool           mPriority;
+  bool           mDataAccessed;
+  bool           mDataIsDirty;
+  bool           mWritingMetadata;
+  bool           mPreloadWithoutInputStreams;
+  uint32_t       mPreloadChunkCount;
+  nsresult       mStatus;
+  int64_t        mDataSize; // Size of the whole data including eventual
+                            // alternative data represenation.
+  int64_t        mAltDataOffset; // If there is alternative data present, it
+                                 // contains size of the original data, i.e.
+                                 // offset where alternative data starts.
+                                 // Otherwise it is -1.
+  nsCString      mKey;
+
+  RefPtr<CacheFileHandle>      mHandle;
+  RefPtr<CacheFileMetadata>    mMetadata;
+  nsCOMPtr<CacheFileListener>  mListener;
+  nsCOMPtr<CacheFileIOListener>   mDoomAfterOpenListener;
+  Atomic<bool, Relaxed>        mKill;
+
+  nsRefPtrHashtable<nsUint32HashKey, CacheFileChunk> mChunks;
+  nsClassHashtable<nsUint32HashKey, ChunkListeners> mChunkListeners;
+  nsRefPtrHashtable<nsUint32HashKey, CacheFileChunk> mCachedChunks;
+  // We can truncate data only if there is no input/output stream beyond the
+  // truncate position, so only unused chunks can be thrown away. But it can
+  // happen that we need to throw away a chunk that is still in mChunks (i.e.
+  // an active chunk) because deactivation happens with a small delay. We cannot
+  // delete such chunk immediately but we need to ensure that such chunk won't
+  // be returned by GetChunkLocked, so we move this chunk into mDiscardedChunks
+  // and mark it as discarded.
+  nsTArray<RefPtr<CacheFileChunk> > mDiscardedChunks;
+
+  nsTArray<CacheFileInputStream*> mInputs;
+  CacheFileOutputStream          *mOutput;
+
+  nsTArray<RefPtr<nsISupports>> mObjsToRelease;
+};
+
+class CacheFileAutoLock {
+public:
+  explicit CacheFileAutoLock(CacheFile *aFile)
+    : mFile(aFile)
+    , mLocked(true)
+  {
+    mFile->Lock();
+  }
+  ~CacheFileAutoLock()
+  {
+    if (mLocked)
+      mFile->Unlock();
+  }
+  void Lock()
+  {
+    MOZ_ASSERT(!mLocked);
+    mFile->Lock();
+    mLocked = true;
+  }
+  void Unlock()
+  {
+    MOZ_ASSERT(mLocked);
+    mFile->Unlock();
+    mLocked = false;
+  }
+
+private:
+  RefPtr<CacheFile> mFile;
+  bool mLocked;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheFileChunk.cpp b/netwerk/cache2/CacheFileChunk.cpp
new file mode 100644
index 0000000000..83d79f79fc
--- /dev/null
+++ b/netwerk/cache2/CacheFileChunk.cpp
@@ -0,0 +1,932 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheFileChunk.h"
+
+#include "CacheFile.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+namespace net {
+
+#define kMinBufSize        512
+
+CacheFileChunkBuffer::CacheFileChunkBuffer(CacheFileChunk *aChunk)
+  : mChunk(aChunk)
+  , mBuf(nullptr)
+  , mBufSize(0)
+  , mDataSize(0)
+  , mReadHandlesCount(0)
+  , mWriteHandleExists(false)
+{
+}
+
+CacheFileChunkBuffer::~CacheFileChunkBuffer()
+{
+  if (mBuf) {
+    CacheFileUtils::FreeBuffer(mBuf);
+    mBuf = nullptr;
+    mChunk->BuffersAllocationChanged(mBufSize, 0);
+    mBufSize = 0;
+  }
+}
+
+void
+CacheFileChunkBuffer::CopyFrom(CacheFileChunkBuffer *aOther)
+{
+  MOZ_RELEASE_ASSERT(mBufSize >= aOther->mDataSize);
+  mDataSize = aOther->mDataSize;
+  memcpy(mBuf, aOther->mBuf, mDataSize);
+}
+
+nsresult
+CacheFileChunkBuffer::FillInvalidRanges(CacheFileChunkBuffer *aOther,
+                                        CacheFileUtils::ValidityMap *aMap)
+{
+  nsresult rv;
+
+  rv = EnsureBufSize(aOther->mDataSize);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  uint32_t invalidOffset = 0;
+  uint32_t invalidLength;
+
+  for (uint32_t i = 0; i < aMap->Length(); ++i) {
+    uint32_t validOffset = (*aMap)[i].Offset();
+    uint32_t validLength = (*aMap)[i].Len();
+
+    MOZ_RELEASE_ASSERT(invalidOffset <= validOffset);
+    invalidLength = validOffset - invalidOffset;
+    if (invalidLength > 0) {
+      MOZ_RELEASE_ASSERT(invalidOffset + invalidLength <= aOther->mBufSize);
+      memcpy(mBuf + invalidOffset, aOther->mBuf + invalidOffset, invalidLength);
+    }
+    invalidOffset = validOffset + validLength;
+  }
+
+  if (invalidOffset < aOther->mBufSize) {
+    invalidLength = aOther->mBufSize - invalidOffset;
+    memcpy(mBuf + invalidOffset, aOther->mBuf + invalidOffset, invalidLength);
+  }
+
+  return NS_OK;
+}
+
+MOZ_MUST_USE nsresult
+CacheFileChunkBuffer::EnsureBufSize(uint32_t aBufSize)
+{
+  AssertOwnsLock();
+
+  if (mBufSize >= aBufSize) {
+    return NS_OK;
+  }
+
+  // find smallest power of 2 greater than or equal to aBufSize
+  aBufSize--;
+  aBufSize |= aBufSize >> 1;
+  aBufSize |= aBufSize >> 2;
+  aBufSize |= aBufSize >> 4;
+  aBufSize |= aBufSize >> 8;
+  aBufSize |= aBufSize >> 16;
+  aBufSize++;
+
+  const uint32_t minBufSize = kMinBufSize;
+  const uint32_t maxBufSize = kChunkSize;
+  aBufSize = clamped(aBufSize, minBufSize, maxBufSize);
+
+  if (!mChunk->CanAllocate(aBufSize - mBufSize)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  char *newBuf = static_cast<char *>(realloc(mBuf, aBufSize));
+  if (!newBuf) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  mChunk->BuffersAllocationChanged(mBufSize, aBufSize);
+  mBuf = newBuf;
+  mBufSize = aBufSize;
+
+  return NS_OK;
+}
+
+void
+CacheFileChunkBuffer::SetDataSize(uint32_t aDataSize)
+{
+  MOZ_RELEASE_ASSERT(
+    // EnsureBufSize must be called before SetDataSize, so the new data size
+    // is guaranteed to be smaller than or equal to mBufSize.
+    aDataSize <= mBufSize ||
+    // The only exception is an optimization when we read the data from the
+    // disk. The data is read to a separate buffer and CacheFileChunk::mBuf is
+    // empty (see CacheFileChunk::Read). We need to set mBuf::mDataSize
+    // accordingly so that DataSize() methods return correct value, but we don't
+    // want to allocate the buffer since it wouldn't be used in most cases.
+    (mDataSize == 0 && mBufSize == 0 && mChunk->mState == CacheFileChunk::READING));
+
+  mDataSize = aDataSize;
+}
+
+void
+CacheFileChunkBuffer::AssertOwnsLock() const
+{
+  mChunk->AssertOwnsLock();
+}
+
+void
+CacheFileChunkBuffer::RemoveReadHandle()
+{
+  AssertOwnsLock();
+  MOZ_RELEASE_ASSERT(mReadHandlesCount);
+  MOZ_RELEASE_ASSERT(!mWriteHandleExists);
+  mReadHandlesCount--;
+
+  if (mReadHandlesCount == 0 && mChunk->mBuf != this) {
+    DebugOnly<bool> removed = mChunk->mOldBufs.RemoveElement(this);
+    MOZ_ASSERT(removed);
+  }
+}
+
+void
+CacheFileChunkBuffer::RemoveWriteHandle()
+{
+  AssertOwnsLock();
+  MOZ_RELEASE_ASSERT(mReadHandlesCount == 0);
+  MOZ_RELEASE_ASSERT(mWriteHandleExists);
+  mWriteHandleExists = false;
+}
+
+size_t
+CacheFileChunkBuffer::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  size_t n = mallocSizeOf(this);
+
+  if (mBuf) {
+    n += mallocSizeOf(mBuf);
+  }
+
+  return n;
+}
+
+uint32_t
+CacheFileChunkHandle::DataSize()
+{
+  MOZ_ASSERT(mBuf, "Unexpected call on dummy handle");
+  mBuf->AssertOwnsLock();
+  return mBuf->mDataSize;
+}
+
+uint32_t
+CacheFileChunkHandle::Offset()
+{
+  MOZ_ASSERT(mBuf, "Unexpected call on dummy handle");
+  mBuf->AssertOwnsLock();
+  return mBuf->mChunk->Index() * kChunkSize;
+}
+
+CacheFileChunkReadHandle::CacheFileChunkReadHandle(CacheFileChunkBuffer *aBuf)
+{
+  mBuf = aBuf;
+  mBuf->mReadHandlesCount++;
+}
+
+CacheFileChunkReadHandle::~CacheFileChunkReadHandle()
+{
+  mBuf->RemoveReadHandle();
+}
+
+const char *
+CacheFileChunkReadHandle::Buf()
+{
+  return mBuf->mBuf;
+}
+
+CacheFileChunkWriteHandle::CacheFileChunkWriteHandle(CacheFileChunkBuffer *aBuf)
+{
+  mBuf = aBuf;
+  if (mBuf) {
+    MOZ_ASSERT(!mBuf->mWriteHandleExists);
+    mBuf->mWriteHandleExists = true;
+  }
+}
+
+CacheFileChunkWriteHandle::~CacheFileChunkWriteHandle()
+{
+  if (mBuf) {
+    mBuf->RemoveWriteHandle();
+  }
+}
+
+char *
+CacheFileChunkWriteHandle::Buf()
+{
+  return mBuf ? mBuf->mBuf : nullptr;
+}
+
+void
+CacheFileChunkWriteHandle::UpdateDataSize(uint32_t aOffset, uint32_t aLen)
+{
+  MOZ_ASSERT(mBuf, "Write performed on dummy handle?");
+  MOZ_ASSERT(aOffset <= mBuf->mDataSize);
+  MOZ_ASSERT(aOffset + aLen <= mBuf->mBufSize);
+
+  if (aOffset + aLen > mBuf->mDataSize) {
+    mBuf->mDataSize = aOffset + aLen;
+  }
+
+  mBuf->mChunk->UpdateDataSize(aOffset, aLen);
+}
+
+
+class NotifyUpdateListenerEvent : public Runnable {
+public:
+  NotifyUpdateListenerEvent(CacheFileChunkListener *aCallback,
+                            CacheFileChunk *aChunk)
+    : mCallback(aCallback)
+    , mChunk(aChunk)
+  {
+    LOG(("NotifyUpdateListenerEvent::NotifyUpdateListenerEvent() [this=%p]",
+         this));
+    MOZ_COUNT_CTOR(NotifyUpdateListenerEvent);
+  }
+
+protected:
+  ~NotifyUpdateListenerEvent()
+  {
+    LOG(("NotifyUpdateListenerEvent::~NotifyUpdateListenerEvent() [this=%p]",
+         this));
+    MOZ_COUNT_DTOR(NotifyUpdateListenerEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    LOG(("NotifyUpdateListenerEvent::Run() [this=%p]", this));
+
+    mCallback->OnChunkUpdated(mChunk);
+    return NS_OK;
+  }
+
+protected:
+  nsCOMPtr<CacheFileChunkListener> mCallback;
+  RefPtr<CacheFileChunk>           mChunk;
+};
+
+bool
+CacheFileChunk::DispatchRelease()
+{
+  if (NS_IsMainThread()) {
+    return false;
+  }
+
+  NS_DispatchToMainThread(NewNonOwningRunnableMethod(this, &CacheFileChunk::Release));
+
+  return true;
+}
+
+NS_IMPL_ADDREF(CacheFileChunk)
+NS_IMETHODIMP_(MozExternalRefCountType)
+CacheFileChunk::Release()
+{
+  nsrefcnt count = mRefCnt - 1;
+  if (DispatchRelease()) {
+    // Redispatched to the main thread.
+    return count;
+  }
+
+  NS_PRECONDITION(0 != mRefCnt, "dup release");
+  count = --mRefCnt;
+  NS_LOG_RELEASE(this, count, "CacheFileChunk");
+
+  if (0 == count) {
+    mRefCnt = 1;
+    delete (this);
+    return 0;
+  }
+
+  // We can safely access this chunk after decreasing mRefCnt since we re-post
+  // all calls to Release() happening off the main thread to the main thread.
+  // I.e. no other Release() that would delete the object could be run before
+  // we call CacheFile::DeactivateChunk().
+  //
+  // NOTE: we don't grab the CacheFile's lock, so the chunk might be addrefed
+  // on another thread before CacheFile::DeactivateChunk() grabs the lock on
+  // this thread. To make sure we won't deactivate chunk that was just returned
+  // to a new consumer we check mRefCnt once again in
+  // CacheFile::DeactivateChunk() after we grab the lock.
+  if (mActiveChunk && count == 1) {
+    mFile->DeactivateChunk(this);
+  }
+
+  return count;
+}
+
+NS_INTERFACE_MAP_BEGIN(CacheFileChunk)
+  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileIOListener)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END_THREADSAFE
+
+CacheFileChunk::CacheFileChunk(CacheFile *aFile, uint32_t aIndex,
+                               bool aInitByWriter)
+  : CacheMemoryConsumer(aFile->mOpenAsMemoryOnly ? MEMORY_ONLY : DONT_REPORT)
+  , mIndex(aIndex)
+  , mState(INITIAL)
+  , mStatus(NS_OK)
+  , mActiveChunk(false)
+  , mIsDirty(false)
+  , mDiscardedChunk(false)
+  , mBuffersSize(0)
+  , mLimitAllocation(!aFile->mOpenAsMemoryOnly && aInitByWriter)
+  , mIsPriority(aFile->mPriority)
+  , mExpectedHash(0)
+  , mFile(aFile)
+{
+  LOG(("CacheFileChunk::CacheFileChunk() [this=%p, index=%u, initByWriter=%d]",
+       this, aIndex, aInitByWriter));
+  MOZ_COUNT_CTOR(CacheFileChunk);
+
+  mBuf = new CacheFileChunkBuffer(this);
+}
+
+CacheFileChunk::~CacheFileChunk()
+{
+  LOG(("CacheFileChunk::~CacheFileChunk() [this=%p]", this));
+  MOZ_COUNT_DTOR(CacheFileChunk);
+}
+
+void
+CacheFileChunk::AssertOwnsLock() const
+{
+  mFile->AssertOwnsLock();
+}
+
+void
+CacheFileChunk::InitNew()
+{
+  AssertOwnsLock();
+
+  LOG(("CacheFileChunk::InitNew() [this=%p]", this));
+
+  MOZ_ASSERT(mState == INITIAL);
+  MOZ_ASSERT(NS_SUCCEEDED(mStatus));
+  MOZ_ASSERT(!mBuf->Buf());
+  MOZ_ASSERT(!mWritingStateHandle);
+  MOZ_ASSERT(!mReadingStateBuf);
+  MOZ_ASSERT(!mIsDirty);
+
+  mBuf = new CacheFileChunkBuffer(this);
+  mState = READY;
+}
+
+nsresult
+CacheFileChunk::Read(CacheFileHandle *aHandle, uint32_t aLen,
+                     CacheHash::Hash16_t aHash,
+                     CacheFileChunkListener *aCallback)
+{
+  AssertOwnsLock();
+
+  LOG(("CacheFileChunk::Read() [this=%p, handle=%p, len=%d, listener=%p]",
+       this, aHandle, aLen, aCallback));
+
+  MOZ_ASSERT(mState == INITIAL);
+  MOZ_ASSERT(NS_SUCCEEDED(mStatus));
+  MOZ_ASSERT(!mBuf->Buf());
+  MOZ_ASSERT(!mWritingStateHandle);
+  MOZ_ASSERT(!mReadingStateBuf);
+  MOZ_ASSERT(aLen);
+
+  nsresult rv;
+
+  mState = READING;
+
+  RefPtr<CacheFileChunkBuffer> tmpBuf = new CacheFileChunkBuffer(this);
+  rv = tmpBuf->EnsureBufSize(aLen);
+  if (NS_FAILED(rv)) {
+    SetError(rv);
+    return mStatus;
+  }
+  tmpBuf->SetDataSize(aLen);
+
+  rv = CacheFileIOManager::Read(aHandle, mIndex * kChunkSize,
+                                tmpBuf->Buf(), aLen,
+                                this);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    rv = mIndex ? NS_ERROR_FILE_CORRUPTED : NS_ERROR_FILE_NOT_FOUND;
+    SetError(rv);
+  } else {
+    mReadingStateBuf.swap(tmpBuf);
+    mListener = aCallback;
+    // mBuf contains no data but we set datasize to size of the data that will
+    // be read from the disk. No handle is allowed to access the non-existent
+    // data until reading finishes, but data can be appended or overwritten.
+    // These pieces are tracked in mValidityMap and will be merged with the data
+    // read from disk in OnDataRead().
+    mBuf->SetDataSize(aLen);
+    mExpectedHash = aHash;
+  }
+
+  return rv;
+}
+
+nsresult
+CacheFileChunk::Write(CacheFileHandle *aHandle,
+                      CacheFileChunkListener *aCallback)
+{
+  AssertOwnsLock();
+
+  LOG(("CacheFileChunk::Write() [this=%p, handle=%p, listener=%p]",
+       this, aHandle, aCallback));
+
+  MOZ_ASSERT(mState == READY);
+  MOZ_ASSERT(NS_SUCCEEDED(mStatus));
+  MOZ_ASSERT(!mWritingStateHandle);
+  MOZ_ASSERT(mBuf->DataSize()); // Don't write chunk when it is empty
+  MOZ_ASSERT(mBuf->ReadHandlesCount() == 0);
+  MOZ_ASSERT(!mBuf->WriteHandleExists());
+
+  nsresult rv;
+
+  mState = WRITING;
+  mWritingStateHandle = new CacheFileChunkReadHandle(mBuf);
+
+  rv = CacheFileIOManager::Write(aHandle, mIndex * kChunkSize,
+                                 mWritingStateHandle->Buf(),
+                                 mWritingStateHandle->DataSize(),
+                                 false, false, this);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    mWritingStateHandle = nullptr;
+    SetError(rv);
+  } else {
+    mListener = aCallback;
+    mIsDirty = false;
+  }
+
+  return rv;
+}
+
+void
+CacheFileChunk::WaitForUpdate(CacheFileChunkListener *aCallback)
+{
+  AssertOwnsLock();
+
+  LOG(("CacheFileChunk::WaitForUpdate() [this=%p, listener=%p]",
+       this, aCallback));
+
+  MOZ_ASSERT(mFile->mOutput);
+  MOZ_ASSERT(IsReady());
+
+#ifdef DEBUG
+  for (uint32_t i = 0 ; i < mUpdateListeners.Length() ; i++) {
+    MOZ_ASSERT(mUpdateListeners[i]->mCallback != aCallback);
+  }
+#endif
+
+  ChunkListenerItem *item = new ChunkListenerItem();
+  item->mTarget = CacheFileIOManager::IOTarget();
+  if (!item->mTarget) {
+    LOG(("CacheFileChunk::WaitForUpdate() - Cannot get Cache I/O thread! Using "
+         "main thread for callback."));
+    item->mTarget = do_GetMainThread();
+  }
+  item->mCallback = aCallback;
+  MOZ_ASSERT(item->mTarget);
+  item->mCallback = aCallback;
+
+  mUpdateListeners.AppendElement(item);
+}
+
+nsresult
+CacheFileChunk::CancelWait(CacheFileChunkListener *aCallback)
+{
+  AssertOwnsLock();
+
+  LOG(("CacheFileChunk::CancelWait() [this=%p, listener=%p]", this, aCallback));
+
+  MOZ_ASSERT(IsReady());
+
+  uint32_t i;
+  for (i = 0 ; i < mUpdateListeners.Length() ; i++) {
+    ChunkListenerItem *item = mUpdateListeners[i];
+
+    if (item->mCallback == aCallback) {
+      mUpdateListeners.RemoveElementAt(i);
+      delete item;
+      break;
+    }
+  }
+
+#ifdef DEBUG
+  for ( ; i < mUpdateListeners.Length() ; i++) {
+    MOZ_ASSERT(mUpdateListeners[i]->mCallback != aCallback);
+  }
+#endif
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileChunk::NotifyUpdateListeners()
+{
+  AssertOwnsLock();
+
+  LOG(("CacheFileChunk::NotifyUpdateListeners() [this=%p]", this));
+
+  MOZ_ASSERT(IsReady());
+
+  nsresult rv, rv2;
+
+  rv = NS_OK;
+  for (uint32_t i = 0 ; i < mUpdateListeners.Length() ; i++) {
+    ChunkListenerItem *item = mUpdateListeners[i];
+
+    LOG(("CacheFileChunk::NotifyUpdateListeners() - Notifying listener %p "
+         "[this=%p]", item->mCallback.get(), this));
+
+    RefPtr<NotifyUpdateListenerEvent> ev;
+    ev = new NotifyUpdateListenerEvent(item->mCallback, this);
+    rv2 = item->mTarget->Dispatch(ev, NS_DISPATCH_NORMAL);
+    if (NS_FAILED(rv2) && NS_SUCCEEDED(rv))
+      rv = rv2;
+    delete item;
+  }
+
+  mUpdateListeners.Clear();
+
+  return rv;
+}
+
+uint32_t
+CacheFileChunk::Index() const
+{
+  return mIndex;
+}
+
+CacheHash::Hash16_t
+CacheFileChunk::Hash() const
+{
+  AssertOwnsLock();
+
+  MOZ_ASSERT(!mListener);
+  MOZ_ASSERT(IsReady());
+
+  return CacheHash::Hash16(mBuf->Buf(), mBuf->DataSize());
+}
+
+uint32_t
+CacheFileChunk::DataSize() const
+{
+  return mBuf->DataSize();
+}
+
+void
+CacheFileChunk::UpdateDataSize(uint32_t aOffset, uint32_t aLen)
+{
+  AssertOwnsLock();
+
+  // UpdateDataSize() is called only when we've written some data to the chunk
+  // and we never write data anymore once some error occurs.
+  MOZ_ASSERT(NS_SUCCEEDED(mStatus));
+
+  LOG(("CacheFileChunk::UpdateDataSize() [this=%p, offset=%d, len=%d]",
+       this, aOffset, aLen));
+
+  mIsDirty = true;
+
+  int64_t fileSize = static_cast<int64_t>(kChunkSize) * mIndex + aOffset + aLen;
+  bool notify = false;
+
+  if (fileSize > mFile->mDataSize) {
+    mFile->mDataSize = fileSize;
+    notify = true;
+  }
+
+  if (mState == READY || mState == WRITING) {
+    MOZ_ASSERT(mValidityMap.Length() == 0);
+
+    if (notify) {
+      NotifyUpdateListeners();
+    }
+
+    return;
+  }
+
+  // We're still waiting for data from the disk. This chunk cannot be used by
+  // input stream, so there must be no update listener. We also need to keep
+  // track of where the data is written so that we can correctly merge the new
+  // data with the old one.
+
+  MOZ_ASSERT(mUpdateListeners.Length() == 0);
+  MOZ_ASSERT(mState == READING);
+
+  mValidityMap.AddPair(aOffset, aLen);
+  mValidityMap.Log();
+}
+
+nsresult
+CacheFileChunk::Truncate(uint32_t aOffset)
+{
+  mBuf->SetDataSize(aOffset);
+  return NS_OK;
+}
+
+nsresult
+CacheFileChunk::OnFileOpened(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFileChunk::OnFileOpened should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileChunk::OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                              nsresult aResult)
+{
+  LOG(("CacheFileChunk::OnDataWritten() [this=%p, handle=%p, result=0x%08x]",
+       this, aHandle, aResult));
+
+  nsCOMPtr<CacheFileChunkListener> listener;
+
+  {
+    CacheFileAutoLock lock(mFile);
+
+    MOZ_ASSERT(mState == WRITING);
+    MOZ_ASSERT(mListener);
+
+    mWritingStateHandle = nullptr;
+
+    if (NS_WARN_IF(NS_FAILED(aResult))) {
+      SetError(aResult);
+    }
+
+    mState = READY;
+    mListener.swap(listener);
+  }
+
+  listener->OnChunkWritten(aResult, this);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileChunk::OnDataRead(CacheFileHandle *aHandle, char *aBuf,
+                           nsresult aResult)
+{
+  LOG(("CacheFileChunk::OnDataRead() [this=%p, handle=%p, result=0x%08x]",
+       this, aHandle, aResult));
+
+  nsCOMPtr<CacheFileChunkListener> listener;
+
+  {
+    CacheFileAutoLock lock(mFile);
+
+    MOZ_ASSERT(mState == READING);
+    MOZ_ASSERT(mListener);
+    MOZ_ASSERT(mReadingStateBuf);
+    MOZ_RELEASE_ASSERT(mBuf->ReadHandlesCount() == 0);
+    MOZ_RELEASE_ASSERT(!mBuf->WriteHandleExists());
+
+    RefPtr<CacheFileChunkBuffer> tmpBuf;
+    tmpBuf.swap(mReadingStateBuf);
+
+    if (NS_SUCCEEDED(aResult)) {
+      CacheHash::Hash16_t hash = CacheHash::Hash16(tmpBuf->Buf(),
+                                                   tmpBuf->DataSize());
+      if (hash != mExpectedHash) {
+        LOG(("CacheFileChunk::OnDataRead() - Hash mismatch! Hash of the data is"
+             " %hx, hash in metadata is %hx. [this=%p, idx=%d]",
+             hash, mExpectedHash, this, mIndex));
+        aResult = NS_ERROR_FILE_CORRUPTED;
+      } else {
+        if (!mBuf->Buf()) {
+          // Just swap the buffers if mBuf is still empty
+          mBuf.swap(tmpBuf);
+        } else {
+          LOG(("CacheFileChunk::OnDataRead() - Merging buffers. [this=%p]",
+               this));
+
+          mValidityMap.Log();
+          aResult = mBuf->FillInvalidRanges(tmpBuf, &mValidityMap);
+          mValidityMap.Clear();
+        }
+      }
+    }
+
+    if (NS_FAILED(aResult)) {
+      aResult = mIndex ? NS_ERROR_FILE_CORRUPTED : NS_ERROR_FILE_NOT_FOUND;
+      SetError(aResult);
+      mBuf->SetDataSize(0);
+    }
+
+    mState = READY;
+    mListener.swap(listener);
+  }
+
+  listener->OnChunkRead(aResult, this);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileChunk::OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFileChunk::OnFileDoomed should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileChunk::OnEOFSet(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFileChunk::OnEOFSet should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileChunk::OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFileChunk::OnFileRenamed should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+bool
+CacheFileChunk::IsKilled()
+{
+  return mFile->IsKilled();
+}
+
+bool
+CacheFileChunk::IsReady() const
+{
+  AssertOwnsLock();
+
+  return (NS_SUCCEEDED(mStatus) && (mState == READY || mState == WRITING));
+}
+
+bool
+CacheFileChunk::IsDirty() const
+{
+  AssertOwnsLock();
+
+  return mIsDirty;
+}
+
+nsresult
+CacheFileChunk::GetStatus()
+{
+  AssertOwnsLock();
+
+  return mStatus;
+}
+
+void
+CacheFileChunk::SetError(nsresult aStatus)
+{
+  LOG(("CacheFileChunk::SetError() [this=%p, status=0x%08x]", this, aStatus));
+
+  MOZ_ASSERT(NS_FAILED(aStatus));
+
+  if (NS_FAILED(mStatus)) {
+    // Remember only the first error code.
+    return;
+  }
+
+  mStatus = aStatus;
+}
+
+CacheFileChunkReadHandle
+CacheFileChunk::GetReadHandle()
+{
+  LOG(("CacheFileChunk::GetReadHandle() [this=%p]", this));
+
+  AssertOwnsLock();
+
+  MOZ_RELEASE_ASSERT(mState == READY || mState == WRITING);
+  // We don't release the lock when writing the data and CacheFileOutputStream
+  // doesn't get the read handle, so there cannot be a write handle when read
+  // handle is obtained.
+  MOZ_RELEASE_ASSERT(!mBuf->WriteHandleExists());
+
+  return CacheFileChunkReadHandle(mBuf);
+}
+
+CacheFileChunkWriteHandle
+CacheFileChunk::GetWriteHandle(uint32_t aEnsuredBufSize)
+{
+  LOG(("CacheFileChunk::GetWriteHandle() [this=%p, ensuredBufSize=%u]",
+       this, aEnsuredBufSize));
+
+  AssertOwnsLock();
+
+  if (NS_FAILED(mStatus)) {
+    return CacheFileChunkWriteHandle(nullptr); // dummy handle
+  }
+
+  nsresult rv;
+
+  // We don't support multiple write handles
+  MOZ_RELEASE_ASSERT(!mBuf->WriteHandleExists());
+
+  if (mBuf->ReadHandlesCount()) {
+    LOG(("CacheFileChunk::GetWriteHandle() - cloning buffer because of existing"
+         " read handle"));
+
+    MOZ_RELEASE_ASSERT(mState != READING);
+    RefPtr<CacheFileChunkBuffer> newBuf = new CacheFileChunkBuffer(this);
+    rv = newBuf->EnsureBufSize(std::max(aEnsuredBufSize, mBuf->DataSize()));
+    if (NS_SUCCEEDED(rv)) {
+      newBuf->CopyFrom(mBuf);
+      mOldBufs.AppendElement(mBuf);
+      mBuf = newBuf;
+    }
+  } else {
+    rv = mBuf->EnsureBufSize(aEnsuredBufSize);
+  }
+
+  if (NS_FAILED(rv)) {
+    SetError(NS_ERROR_OUT_OF_MEMORY);
+    return CacheFileChunkWriteHandle(nullptr); // dummy handle
+  }
+
+  return CacheFileChunkWriteHandle(mBuf);
+}
+
+// Memory reporting
+
+size_t
+CacheFileChunk::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  size_t n = mBuf->SizeOfIncludingThis(mallocSizeOf);
+
+  if (mReadingStateBuf) {
+    n += mReadingStateBuf->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  for (uint32_t i = 0; i < mOldBufs.Length(); ++i) {
+    n += mOldBufs[i]->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  n += mValidityMap.SizeOfExcludingThis(mallocSizeOf);
+
+  return n;
+}
+
+size_t
+CacheFileChunk::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+bool
+CacheFileChunk::CanAllocate(uint32_t aSize) const
+{
+  if (!mLimitAllocation) {
+    return true;
+  }
+
+  LOG(("CacheFileChunk::CanAllocate() [this=%p, size=%u]", this, aSize));
+
+  uint32_t limit = CacheObserver::MaxDiskChunksMemoryUsage(mIsPriority);
+  if (limit == 0) {
+    return true;
+  }
+
+  uint32_t usage = ChunksMemoryUsage();
+  if (usage + aSize > limit) {
+    LOG(("CacheFileChunk::CanAllocate() - Returning false. [this=%p]", this));
+    return false;
+  }
+
+  return true;
+}
+
+void
+CacheFileChunk::BuffersAllocationChanged(uint32_t aFreed, uint32_t aAllocated)
+{
+  uint32_t oldBuffersSize = mBuffersSize;
+  mBuffersSize += aAllocated;
+  mBuffersSize -= aFreed;
+
+  DoMemoryReport(sizeof(CacheFileChunk) + mBuffersSize);
+
+  if (!mLimitAllocation) {
+    return;
+  }
+
+  ChunksMemoryUsage() -= oldBuffersSize;
+  ChunksMemoryUsage() += mBuffersSize;
+  LOG(("CacheFileChunk::BuffersAllocationChanged() - %s chunks usage %u "
+       "[this=%p]", mIsPriority ? "Priority" : "Normal",
+       static_cast<uint32_t>(ChunksMemoryUsage()), this));
+}
+
+mozilla::Atomic<uint32_t, ReleaseAcquire>& CacheFileChunk::ChunksMemoryUsage() const
+{
+  static mozilla::Atomic<uint32_t, ReleaseAcquire> chunksMemoryUsage(0);
+  static mozilla::Atomic<uint32_t, ReleaseAcquire> prioChunksMemoryUsage(0);
+  return mIsPriority ? prioChunksMemoryUsage : chunksMemoryUsage;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheFileChunk.h b/netwerk/cache2/CacheFileChunk.h
new file mode 100644
index 0000000000..09acb62c5a
--- /dev/null
+++ b/netwerk/cache2/CacheFileChunk.h
@@ -0,0 +1,252 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheFileChunk__h__
+#define CacheFileChunk__h__
+
+#include "CacheFileIOManager.h"
+#include "CacheStorageService.h"
+#include "CacheHashUtils.h"
+#include "CacheFileUtils.h"
+#include "nsAutoPtr.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla {
+namespace net {
+
+#define kChunkSize        (256 * 1024)
+#define kEmptyChunkHash   0x1826
+
+class CacheFileChunk;
+class CacheFile;
+
+class CacheFileChunkBuffer
+{
+public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CacheFileChunkBuffer)
+
+  explicit CacheFileChunkBuffer(CacheFileChunk *aChunk);
+
+  nsresult EnsureBufSize(uint32_t aSize);
+  void     CopyFrom(CacheFileChunkBuffer *aOther);
+  nsresult FillInvalidRanges(CacheFileChunkBuffer *aOther,
+                             CacheFileUtils::ValidityMap *aMap);
+  size_t   SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  char *   Buf() const { return mBuf; }
+  void     SetDataSize(uint32_t aDataSize);
+  uint32_t DataSize() const { return mDataSize; }
+  uint32_t ReadHandlesCount() const { return mReadHandlesCount; }
+  bool     WriteHandleExists() const { return mWriteHandleExists; }
+
+private:
+  friend class CacheFileChunkHandle;
+  friend class CacheFileChunkReadHandle;
+  friend class CacheFileChunkWriteHandle;
+
+  ~CacheFileChunkBuffer();
+
+  void AssertOwnsLock() const;
+
+  void RemoveReadHandle();
+  void RemoveWriteHandle();
+
+  // We keep a weak reference to the chunk to not create a reference cycle. The
+  // buffer is referenced only by chunk and handles. Handles are always
+  // destroyed before the chunk so it is guaranteed that mChunk is a valid
+  // pointer for the whole buffer's lifetime.
+  CacheFileChunk *mChunk;
+  char           *mBuf;
+  uint32_t        mBufSize;
+  uint32_t        mDataSize;
+  uint32_t        mReadHandlesCount;
+  bool            mWriteHandleExists;
+};
+
+class CacheFileChunkHandle
+{
+public:
+  uint32_t DataSize();
+  uint32_t Offset();
+
+protected:
+  RefPtr<CacheFileChunkBuffer> mBuf;
+};
+
+class CacheFileChunkReadHandle : public CacheFileChunkHandle
+{
+public:
+  explicit CacheFileChunkReadHandle(CacheFileChunkBuffer *aBuf);
+  ~CacheFileChunkReadHandle();
+
+  const char *Buf();
+};
+
+class CacheFileChunkWriteHandle : public CacheFileChunkHandle
+{
+public:
+  explicit CacheFileChunkWriteHandle(CacheFileChunkBuffer *aBuf);
+  ~CacheFileChunkWriteHandle();
+
+  char *Buf();
+  void UpdateDataSize(uint32_t aOffset, uint32_t aLen);
+};
+
+#define CACHEFILECHUNKLISTENER_IID \
+{ /* baf16149-2ab5-499c-a9c2-5904eb95c288 */       \
+  0xbaf16149,                                      \
+  0x2ab5,                                          \
+  0x499c,                                          \
+  {0xa9, 0xc2, 0x59, 0x04, 0xeb, 0x95, 0xc2, 0x88} \
+}
+
+class CacheFileChunkListener : public nsISupports
+{
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(CACHEFILECHUNKLISTENER_IID)
+
+  NS_IMETHOD OnChunkRead(nsresult aResult, CacheFileChunk *aChunk) = 0;
+  NS_IMETHOD OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk) = 0;
+  NS_IMETHOD OnChunkAvailable(nsresult aResult, uint32_t aChunkIdx,
+                              CacheFileChunk *aChunk) = 0;
+  NS_IMETHOD OnChunkUpdated(CacheFileChunk *aChunk) = 0;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(CacheFileChunkListener,
+                              CACHEFILECHUNKLISTENER_IID)
+
+
+class ChunkListenerItem {
+public:
+  ChunkListenerItem()  { MOZ_COUNT_CTOR(ChunkListenerItem); }
+  ~ChunkListenerItem() { MOZ_COUNT_DTOR(ChunkListenerItem); }
+
+  nsCOMPtr<nsIEventTarget>         mTarget;
+  nsCOMPtr<CacheFileChunkListener> mCallback;
+};
+
+class ChunkListeners {
+public:
+  ChunkListeners()  { MOZ_COUNT_CTOR(ChunkListeners); }
+  ~ChunkListeners() { MOZ_COUNT_DTOR(ChunkListeners); }
+
+  nsTArray<ChunkListenerItem *> mItems;
+};
+
+class CacheFileChunk : public CacheFileIOListener
+                     , public CacheMemoryConsumer
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  bool DispatchRelease();
+
+  CacheFileChunk(CacheFile *aFile, uint32_t aIndex, bool aInitByWriter);
+
+  void     InitNew();
+  nsresult Read(CacheFileHandle *aHandle, uint32_t aLen,
+                CacheHash::Hash16_t aHash,
+                CacheFileChunkListener *aCallback);
+  nsresult Write(CacheFileHandle *aHandle, CacheFileChunkListener *aCallback);
+  void     WaitForUpdate(CacheFileChunkListener *aCallback);
+  nsresult CancelWait(CacheFileChunkListener *aCallback);
+  nsresult NotifyUpdateListeners();
+
+  uint32_t            Index() const;
+  CacheHash::Hash16_t Hash() const;
+  uint32_t            DataSize() const;
+
+  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                           nsresult aResult) override;
+  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult) override;
+  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) override;
+  virtual bool IsKilled() override;
+
+  bool   IsReady() const;
+  bool   IsDirty() const;
+
+  nsresult GetStatus();
+  void     SetError(nsresult aStatus);
+
+  CacheFileChunkReadHandle  GetReadHandle();
+  CacheFileChunkWriteHandle GetWriteHandle(uint32_t aEnsuredBufSize);
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+private:
+  friend class CacheFileChunkBuffer;
+  friend class CacheFileChunkWriteHandle;
+  friend class CacheFileInputStream;
+  friend class CacheFileOutputStream;
+  friend class CacheFile;
+
+  virtual ~CacheFileChunk();
+
+  void AssertOwnsLock() const;
+
+  void UpdateDataSize(uint32_t aOffset, uint32_t aLen);
+  nsresult Truncate(uint32_t aOffset);
+
+  bool CanAllocate(uint32_t aSize) const;
+  void BuffersAllocationChanged(uint32_t aFreed, uint32_t aAllocated);
+
+  mozilla::Atomic<uint32_t, ReleaseAcquire>& ChunksMemoryUsage() const;
+
+  enum EState {
+    INITIAL = 0,
+    READING = 1,
+    WRITING = 2,
+    READY   = 3
+  };
+
+  uint32_t mIndex;
+  EState   mState;
+  nsresult mStatus;
+
+  Atomic<bool> mActiveChunk; // Is true iff the chunk is in CacheFile::mChunks.
+                             // Adding/removing chunk to/from mChunks as well as
+                             // changing this member happens under the
+                             // CacheFile's lock.
+  bool mIsDirty : 1;
+  bool mDiscardedChunk : 1;
+
+  uint32_t   mBuffersSize;
+  bool const mLimitAllocation : 1; // Whether this chunk respects limit for disk
+                                   // chunks memory usage.
+  bool const mIsPriority : 1;
+
+  // Buffer containing the chunk data. Multiple read handles can access the same
+  // buffer. When write handle is created and some read handle exists a new copy
+  // of the buffer is created. This prevents invalidating the buffer when
+  // CacheFileInputStream::ReadSegments calls the handler outside the lock.
+  RefPtr<CacheFileChunkBuffer> mBuf;
+
+  // We need to keep pointers of the old buffers for memory reporting.
+  nsTArray<RefPtr<CacheFileChunkBuffer>> mOldBufs;
+
+  // Read handle that is used during writing the chunk to the disk.
+  nsAutoPtr<CacheFileChunkReadHandle> mWritingStateHandle;
+
+  // Buffer that is used to read the chunk from the disk. It is allowed to write
+  // a new data to chunk while we wait for the data from the disk. In this case
+  // this buffer is merged with mBuf in OnDataRead().
+  RefPtr<CacheFileChunkBuffer> mReadingStateBuf;
+  CacheHash::Hash16_t          mExpectedHash;
+
+  RefPtr<CacheFile>                mFile; // is null if chunk is cached to
+                                          // prevent reference cycles
+  nsCOMPtr<CacheFileChunkListener> mListener;
+  nsTArray<ChunkListenerItem *>    mUpdateListeners;
+  CacheFileUtils::ValidityMap      mValidityMap;
+};
+
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheFileContextEvictor.cpp b/netwerk/cache2/CacheFileContextEvictor.cpp
new file mode 100644
index 0000000000..acf089b797
--- /dev/null
+++ b/netwerk/cache2/CacheFileContextEvictor.cpp
@@ -0,0 +1,663 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheFileContextEvictor.h"
+#include "CacheFileIOManager.h"
+#include "CacheIndex.h"
+#include "CacheIndexIterator.h"
+#include "CacheFileUtils.h"
+#include "nsIFile.h"
+#include "LoadContextInfo.h"
+#include "nsThreadUtils.h"
+#include "nsString.h"
+#include "nsISimpleEnumerator.h"
+#include "nsIDirectoryEnumerator.h"
+#include "mozilla/Base64.h"
+
+
+namespace mozilla {
+namespace net {
+
+#define CONTEXT_EVICTION_PREFIX "ce_"
+const uint32_t kContextEvictionPrefixLength =
+  sizeof(CONTEXT_EVICTION_PREFIX) - 1;
+
+bool CacheFileContextEvictor::sDiskAlreadySearched = false;
+
+CacheFileContextEvictor::CacheFileContextEvictor()
+  : mEvicting(false)
+  , mIndexIsUpToDate(false)
+{
+  LOG(("CacheFileContextEvictor::CacheFileContextEvictor() [this=%p]", this));
+}
+
+CacheFileContextEvictor::~CacheFileContextEvictor()
+{
+  LOG(("CacheFileContextEvictor::~CacheFileContextEvictor() [this=%p]", this));
+}
+
+nsresult
+CacheFileContextEvictor::Init(nsIFile *aCacheDirectory)
+{
+  LOG(("CacheFileContextEvictor::Init()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  CacheIndex::IsUpToDate(&mIndexIsUpToDate);
+
+  mCacheDirectory = aCacheDirectory;
+
+  rv = aCacheDirectory->Clone(getter_AddRefs(mEntriesDir));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  rv = mEntriesDir->AppendNative(NS_LITERAL_CSTRING(ENTRIES_DIR));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (!sDiskAlreadySearched) {
+    LoadEvictInfoFromDisk();
+    if ((mEntries.Length() != 0) && mIndexIsUpToDate) {
+      CreateIterators();
+      StartEvicting();
+    }
+  }
+
+  return NS_OK;
+}
+
+uint32_t
+CacheFileContextEvictor::ContextsCount()
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  return mEntries.Length();
+}
+
+nsresult
+CacheFileContextEvictor::AddContext(nsILoadContextInfo *aLoadContextInfo,
+                                    bool aPinned)
+{
+  LOG(("CacheFileContextEvictor::AddContext() [this=%p, loadContextInfo=%p, pinned=%d]",
+       this, aLoadContextInfo, aPinned));
+
+  nsresult rv;
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  CacheFileContextEvictorEntry *entry = nullptr;
+  if (aLoadContextInfo) {
+    for (uint32_t i = 0; i < mEntries.Length(); ++i) {
+      if (mEntries[i]->mInfo &&
+          mEntries[i]->mInfo->Equals(aLoadContextInfo) &&
+          mEntries[i]->mPinned == aPinned) {
+        entry = mEntries[i];
+        break;
+      }
+    }
+  } else {
+    // Not providing load context info means we want to delete everything,
+    // so let's not bother with any currently running context cleanups
+    // for the same pinning state.
+    for (uint32_t i = mEntries.Length(); i > 0;) {
+      --i;
+      if (mEntries[i]->mInfo && mEntries[i]->mPinned == aPinned) {
+        RemoveEvictInfoFromDisk(mEntries[i]->mInfo, mEntries[i]->mPinned);
+        mEntries.RemoveElementAt(i);
+      }
+    }
+  }
+
+  if (!entry) {
+    entry = new CacheFileContextEvictorEntry();
+    entry->mInfo = aLoadContextInfo;
+    entry->mPinned = aPinned;
+    mEntries.AppendElement(entry);
+  }
+
+  entry->mTimeStamp = PR_Now() / PR_USEC_PER_MSEC;
+
+  PersistEvictionInfoToDisk(aLoadContextInfo, aPinned);
+
+  if (mIndexIsUpToDate) {
+    // Already existing context could be added again, in this case the iterator
+    // would be recreated. Close the old iterator explicitely.
+    if (entry->mIterator) {
+      entry->mIterator->Close();
+      entry->mIterator = nullptr;
+    }
+
+    rv = CacheIndex::GetIterator(aLoadContextInfo, false,
+                                 getter_AddRefs(entry->mIterator));
+    if (NS_FAILED(rv)) {
+      // This could probably happen during shutdown. Remove the entry from
+      // the array, but leave the info on the disk. No entry can be opened
+      // during shutdown and we'll load the eviction info on next start.
+      LOG(("CacheFileContextEvictor::AddContext() - Cannot get an iterator. "
+           "[rv=0x%08x]", rv));
+      mEntries.RemoveElement(entry);
+      return rv;
+    }
+
+    StartEvicting();
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileContextEvictor::CacheIndexStateChanged()
+{
+  LOG(("CacheFileContextEvictor::CacheIndexStateChanged() [this=%p]", this));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  bool isUpToDate = false;
+  CacheIndex::IsUpToDate(&isUpToDate);
+  if (mEntries.Length() == 0) {
+    // Just save the state and exit, since there is nothing to do
+    mIndexIsUpToDate = isUpToDate;
+    return NS_OK;
+  }
+
+  if (!isUpToDate && !mIndexIsUpToDate) {
+    // Index is outdated and status has not changed, nothing to do.
+    return NS_OK;
+  }
+
+  if (isUpToDate && mIndexIsUpToDate) {
+    // Status has not changed, but make sure the eviction is running.
+    if (mEvicting) {
+      return NS_OK;
+    }
+
+    // We're not evicting, but we should be evicting?!
+    LOG(("CacheFileContextEvictor::CacheIndexStateChanged() - Index is up to "
+         "date, we have some context to evict but eviction is not running! "
+         "Starting now."));
+  }
+
+  mIndexIsUpToDate = isUpToDate;
+
+  if (mIndexIsUpToDate) {
+    CreateIterators();
+    StartEvicting();
+  } else {
+    CloseIterators();
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileContextEvictor::WasEvicted(const nsACString &aKey, nsIFile *aFile,
+                                    bool *aEvictedAsPinned, bool *aEvictedAsNonPinned)
+{
+  LOG(("CacheFileContextEvictor::WasEvicted() [key=%s]",
+       PromiseFlatCString(aKey).get()));
+
+  nsresult rv;
+
+  *aEvictedAsPinned = false;
+  *aEvictedAsNonPinned = false;
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsCOMPtr<nsILoadContextInfo> info = CacheFileUtils::ParseKey(aKey);
+  MOZ_ASSERT(info);
+  if (!info) {
+    LOG(("CacheFileContextEvictor::WasEvicted() - Cannot parse key!"));
+    return NS_OK;
+  }
+
+  for (uint32_t i = 0; i < mEntries.Length(); ++i) {
+    CacheFileContextEvictorEntry *entry = mEntries[i];
+
+    if (entry->mInfo && !info->Equals(entry->mInfo)) {
+      continue;
+    }
+
+    PRTime lastModifiedTime;
+    rv = aFile->GetLastModifiedTime(&lastModifiedTime);
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileContextEvictor::WasEvicted() - Cannot get last modified time"
+            ", returning false."));
+      return NS_OK;
+    }
+
+    if (lastModifiedTime > entry->mTimeStamp) {
+      // File has been modified since context eviction.
+      continue;
+    }
+
+    LOG(("CacheFileContextEvictor::WasEvicted() - evicted [pinning=%d, "
+         "mTimeStamp=%lld, lastModifiedTime=%lld]",
+         entry->mPinned, entry->mTimeStamp, lastModifiedTime));
+
+    if (entry->mPinned) {
+      *aEvictedAsPinned = true;
+    } else {
+      *aEvictedAsNonPinned = true;
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileContextEvictor::PersistEvictionInfoToDisk(
+  nsILoadContextInfo *aLoadContextInfo, bool aPinned)
+{
+  LOG(("CacheFileContextEvictor::PersistEvictionInfoToDisk() [this=%p, "
+       "loadContextInfo=%p]", this, aLoadContextInfo));
+
+  nsresult rv;
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsCOMPtr<nsIFile> file;
+  rv = GetContextFile(aLoadContextInfo, aPinned, getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsAutoCString path;
+  file->GetNativePath(path);
+
+  PRFileDesc *fd;
+  rv = file->OpenNSPRFileDesc(PR_RDWR | PR_CREATE_FILE | PR_TRUNCATE, 0600,
+                              &fd);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    LOG(("CacheFileContextEvictor::PersistEvictionInfoToDisk() - Creating file "
+         "failed! [path=%s, rv=0x%08x]", path.get(), rv));
+    return rv;
+  }
+
+  PR_Close(fd);
+
+  LOG(("CacheFileContextEvictor::PersistEvictionInfoToDisk() - Successfully "
+       "created file. [path=%s]", path.get()));
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileContextEvictor::RemoveEvictInfoFromDisk(
+  nsILoadContextInfo *aLoadContextInfo, bool aPinned)
+{
+  LOG(("CacheFileContextEvictor::RemoveEvictInfoFromDisk() [this=%p, "
+       "loadContextInfo=%p]", this, aLoadContextInfo));
+
+  nsresult rv;
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsCOMPtr<nsIFile> file;
+  rv = GetContextFile(aLoadContextInfo, aPinned, getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsAutoCString path;
+  file->GetNativePath(path);
+
+  rv = file->Remove(false);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    LOG(("CacheFileContextEvictor::RemoveEvictionInfoFromDisk() - Removing file"
+         " failed! [path=%s, rv=0x%08x]", path.get(), rv));
+    return rv;
+  }
+
+  LOG(("CacheFileContextEvictor::RemoveEvictionInfoFromDisk() - Successfully "
+       "removed file. [path=%s]", path.get()));
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileContextEvictor::LoadEvictInfoFromDisk()
+{
+  LOG(("CacheFileContextEvictor::LoadEvictInfoFromDisk() [this=%p]", this));
+
+  nsresult rv;
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  sDiskAlreadySearched = true;
+
+  nsCOMPtr<nsISimpleEnumerator> enumerator;
+  rv = mCacheDirectory->GetDirectoryEntries(getter_AddRefs(enumerator));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIDirectoryEnumerator> dirEnum = do_QueryInterface(enumerator, &rv);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  while (true) {
+    nsCOMPtr<nsIFile> file;
+    rv = dirEnum->GetNextFile(getter_AddRefs(file));
+    if (!file) {
+      break;
+    }
+
+    bool isDir = false;
+    file->IsDirectory(&isDir);
+    if (isDir) {
+      continue;
+    }
+
+    nsAutoCString leaf;
+    rv = file->GetNativeLeafName(leaf);
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileContextEvictor::LoadEvictInfoFromDisk() - "
+           "GetNativeLeafName() failed! Skipping file."));
+      continue;
+    }
+
+    if (leaf.Length() < kContextEvictionPrefixLength) {
+      continue;
+    }
+
+    if (!StringBeginsWith(leaf, NS_LITERAL_CSTRING(CONTEXT_EVICTION_PREFIX))) {
+      continue;
+    }
+
+    nsAutoCString encoded;
+    encoded = Substring(leaf, kContextEvictionPrefixLength);
+    encoded.ReplaceChar('-', '/');
+
+    nsAutoCString decoded;
+    rv = Base64Decode(encoded, decoded);
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileContextEvictor::LoadEvictInfoFromDisk() - Base64 decoding "
+           "failed. Removing the file. [file=%s]", leaf.get()));
+      file->Remove(false);
+      continue;
+    }
+
+    bool pinned = decoded[0] == '\t';
+    if (pinned) {
+      decoded = Substring(decoded, 1);
+    }
+
+    nsCOMPtr<nsILoadContextInfo> info;
+    if (!NS_LITERAL_CSTRING("*").Equals(decoded)) {
+      // "*" is indication of 'delete all', info left null will pass
+      // to CacheFileContextEvictor::AddContext and clear all the cache data.
+      info = CacheFileUtils::ParseKey(decoded);
+      if (!info) {
+        LOG(("CacheFileContextEvictor::LoadEvictInfoFromDisk() - Cannot parse "
+             "context key, removing file. [contextKey=%s, file=%s]",
+             decoded.get(), leaf.get()));
+        file->Remove(false);
+        continue;
+      }
+    }
+
+
+    PRTime lastModifiedTime;
+    rv = file->GetLastModifiedTime(&lastModifiedTime);
+    if (NS_FAILED(rv)) {
+      continue;
+    }
+
+    CacheFileContextEvictorEntry *entry = new CacheFileContextEvictorEntry();
+    entry->mInfo = info;
+    entry->mPinned = pinned;
+    entry->mTimeStamp = lastModifiedTime;
+    mEntries.AppendElement(entry);
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileContextEvictor::GetContextFile(nsILoadContextInfo *aLoadContextInfo,
+                                        bool aPinned,
+                                        nsIFile **_retval)
+{
+  nsresult rv;
+
+  nsAutoCString leafName;
+  leafName.AssignLiteral(CONTEXT_EVICTION_PREFIX);
+
+  nsAutoCString keyPrefix;
+  if (aPinned) {
+    // Mark pinned context files with a tab char at the start.
+    // Tab is chosen because it can never be used as a context key tag.
+    keyPrefix.Append('\t');
+  }
+  if (aLoadContextInfo) {
+    CacheFileUtils::AppendKeyPrefix(aLoadContextInfo, keyPrefix);
+  } else {
+    keyPrefix.Append('*');
+  }
+
+  nsAutoCString data64;
+  rv = Base64Encode(keyPrefix, data64);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  // Replace '/' with '-' since '/' cannot be part of the filename.
+  data64.ReplaceChar('/', '-');
+
+  leafName.Append(data64);
+
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  rv = file->AppendNative(leafName);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  file.swap(*_retval);
+  return NS_OK;
+}
+
+void
+CacheFileContextEvictor::CreateIterators()
+{
+  LOG(("CacheFileContextEvictor::CreateIterators() [this=%p]", this));
+
+  CloseIterators();
+
+  nsresult rv;
+
+  for (uint32_t i = 0; i < mEntries.Length(); ) {
+    rv = CacheIndex::GetIterator(mEntries[i]->mInfo, false,
+                                 getter_AddRefs(mEntries[i]->mIterator));
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileContextEvictor::CreateIterators() - Cannot get an iterator"
+           ". [rv=0x%08x]", rv));
+      mEntries.RemoveElementAt(i);
+      continue;
+    }
+
+    ++i;
+  }
+}
+
+void
+CacheFileContextEvictor::CloseIterators()
+{
+  LOG(("CacheFileContextEvictor::CloseIterators() [this=%p]", this));
+
+  for (uint32_t i = 0; i < mEntries.Length(); ++i) {
+    if (mEntries[i]->mIterator) {
+      mEntries[i]->mIterator->Close();
+      mEntries[i]->mIterator = nullptr;
+    }
+  }
+}
+
+void
+CacheFileContextEvictor::StartEvicting()
+{
+  LOG(("CacheFileContextEvictor::StartEvicting() [this=%p]", this));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  if (mEvicting) {
+    LOG(("CacheFileContextEvictor::StartEvicting() - already evicintg."));
+    return;
+  }
+
+  if (mEntries.Length() == 0) {
+    LOG(("CacheFileContextEvictor::StartEvicting() - no context to evict."));
+    return;
+  }
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(this, &CacheFileContextEvictor::EvictEntries);
+
+  RefPtr<CacheIOThread> ioThread = CacheFileIOManager::IOThread();
+
+  nsresult rv = ioThread->Dispatch(ev, CacheIOThread::EVICT);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheFileContextEvictor::StartEvicting() - Cannot dispatch event to "
+         "IO thread. [rv=0x%08x]", rv));
+  }
+
+  mEvicting = true;
+}
+
+nsresult
+CacheFileContextEvictor::EvictEntries()
+{
+  LOG(("CacheFileContextEvictor::EvictEntries()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  mEvicting = false;
+
+  if (!mIndexIsUpToDate) {
+    LOG(("CacheFileContextEvictor::EvictEntries() - Stopping evicting due to "
+         "outdated index."));
+    return NS_OK;
+  }
+
+  while (true) {
+    if (CacheObserver::ShuttingDown()) {
+      LOG(("CacheFileContextEvictor::EvictEntries() - Stopping evicting due to "
+           "shutdown."));
+      mEvicting = true; // We don't want to start eviction again during shutdown
+                        // process. Setting this flag to true ensures it.
+      return NS_OK;
+    }
+
+    if (CacheIOThread::YieldAndRerun()) {
+      LOG(("CacheFileContextEvictor::EvictEntries() - Breaking loop for higher "
+           "level events."));
+      mEvicting = true;
+      return NS_OK;
+    }
+
+    if (mEntries.Length() == 0) {
+      LOG(("CacheFileContextEvictor::EvictEntries() - Stopping evicting, there "
+           "is no context to evict."));
+
+      // Allow index to notify AsyncGetDiskConsumption callbacks.  The size is
+      // actual again.
+      CacheIndex::OnAsyncEviction(false);
+      return NS_OK;
+    }
+
+    SHA1Sum::Hash hash;
+    rv = mEntries[0]->mIterator->GetNextHash(&hash);
+    if (rv == NS_ERROR_NOT_AVAILABLE) {
+      LOG(("CacheFileContextEvictor::EvictEntries() - No more entries left in "
+           "iterator. [iterator=%p, info=%p]", mEntries[0]->mIterator.get(),
+           mEntries[0]->mInfo.get()));
+      RemoveEvictInfoFromDisk(mEntries[0]->mInfo, mEntries[0]->mPinned);
+      mEntries.RemoveElementAt(0);
+      continue;
+    } else if (NS_FAILED(rv)) {
+      LOG(("CacheFileContextEvictor::EvictEntries() - Iterator failed to "
+           "provide next hash (shutdown?), keeping eviction info on disk."
+           " [iterator=%p, info=%p]", mEntries[0]->mIterator.get(),
+           mEntries[0]->mInfo.get()));
+      mEntries.RemoveElementAt(0);
+      continue;
+    }
+
+    LOG(("CacheFileContextEvictor::EvictEntries() - Processing hash. "
+         "[hash=%08x%08x%08x%08x%08x, iterator=%p, info=%p]", LOGSHA1(&hash),
+         mEntries[0]->mIterator.get(), mEntries[0]->mInfo.get()));
+
+    RefPtr<CacheFileHandle> handle;
+    CacheFileIOManager::gInstance->mHandles.GetHandle(&hash,
+                                                      getter_AddRefs(handle));
+    if (handle) {
+      // We doom any active handle in CacheFileIOManager::EvictByContext(), so
+      // this must be a new one. Skip it.
+      LOG(("CacheFileContextEvictor::EvictEntries() - Skipping entry since we "
+           "found an active handle. [handle=%p]", handle.get()));
+      continue;
+    }
+
+    CacheIndex::EntryStatus status;
+    bool pinned;
+    rv = CacheIndex::HasEntry(hash, &status, &pinned);
+    // This must never fail, since eviction (this code) happens only when the index
+    // is up-to-date and thus the informatin is known.
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+    if (pinned != mEntries[0]->mPinned) {
+      LOG(("CacheFileContextEvictor::EvictEntries() - Skipping entry since pinning "
+           "doesn't match [evicting pinned=%d, entry pinned=%d]",
+           mEntries[0]->mPinned, pinned));
+      continue;
+    }
+
+    nsAutoCString leafName;
+    CacheFileIOManager::HashToStr(&hash, leafName);
+
+    PRTime lastModifiedTime;
+    nsCOMPtr<nsIFile> file;
+    rv = mEntriesDir->Clone(getter_AddRefs(file));
+    if (NS_SUCCEEDED(rv)) {
+      rv = file->AppendNative(leafName);
+    }
+    if (NS_SUCCEEDED(rv)) {
+      rv = file->GetLastModifiedTime(&lastModifiedTime);
+    }
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileContextEvictor::EvictEntries() - Cannot get last modified "
+           "time, skipping entry."));
+      continue;
+    }
+
+    if (lastModifiedTime > mEntries[0]->mTimeStamp) {
+      LOG(("CacheFileContextEvictor::EvictEntries() - Skipping newer entry. "
+           "[mTimeStamp=%lld, lastModifiedTime=%lld]", mEntries[0]->mTimeStamp,
+           lastModifiedTime));
+      continue;
+    }
+
+    LOG(("CacheFileContextEvictor::EvictEntries - Removing entry."));
+    file->Remove(false);
+    CacheIndex::RemoveEntry(&hash);
+  }
+
+  NS_NOTREACHED("We should never get here");
+  return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheFileContextEvictor.h b/netwerk/cache2/CacheFileContextEvictor.h
new file mode 100644
index 0000000000..f5fd49ecae
--- /dev/null
+++ b/netwerk/cache2/CacheFileContextEvictor.h
@@ -0,0 +1,96 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheFileContextEvictor__h__
+#define CacheFileContextEvictor__h__
+
+#include "nsTArray.h"
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+
+class nsIFile;
+class nsILoadContextInfo;
+
+namespace mozilla {
+namespace net {
+
+class CacheIndexIterator;
+
+struct CacheFileContextEvictorEntry
+{
+  nsCOMPtr<nsILoadContextInfo> mInfo;
+  bool                         mPinned;
+  PRTime                       mTimeStamp; // in milliseconds
+  RefPtr<CacheIndexIterator> mIterator;
+};
+
+class CacheFileContextEvictor
+{
+public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CacheFileContextEvictor)
+
+  CacheFileContextEvictor();
+
+private:
+  virtual ~CacheFileContextEvictor();
+
+public:
+  nsresult Init(nsIFile *aCacheDirectory);
+
+  // Returns number of contexts that are being evicted.
+  uint32_t ContextsCount();
+  // Start evicting given context.
+  nsresult AddContext(nsILoadContextInfo *aLoadContextInfo, bool aPinned);
+  // CacheFileIOManager calls this method when CacheIndex's state changes. We
+  // check whether the index is up to date and start or stop evicting according
+  // to index's state.
+  nsresult CacheIndexStateChanged();
+  // CacheFileIOManager calls this method to check whether an entry file should
+  // be considered as evicted. It returns true when there is a matching context
+  // info to the given key and the last modified time of the entry file is
+  // earlier than the time stamp of the time when the context was added to the
+  // evictor.
+  nsresult WasEvicted(const nsACString &aKey, nsIFile *aFile,
+                      bool *aEvictedAsPinned, bool *aEvictedAsNonPinned);
+
+private:
+  // Writes information about eviction of the given context to the disk. This is
+  // done for every context added to the evictor to be able to recover eviction
+  // after a shutdown or crash. When the context file is found after startup, we
+  // restore mTimeStamp from the last modified time of the file.
+  nsresult PersistEvictionInfoToDisk(nsILoadContextInfo *aLoadContextInfo, bool aPinned);
+  // Once we are done with eviction for the given context, the eviction info is
+  // removed from the disk.
+  nsresult RemoveEvictInfoFromDisk(nsILoadContextInfo *aLoadContextInfo, bool aPinned);
+  // Tries to load all contexts from the disk. This method is called just once
+  // after startup.
+  nsresult LoadEvictInfoFromDisk();
+  nsresult GetContextFile(nsILoadContextInfo *aLoadContextInfo, bool aPinned,
+                          nsIFile **_retval);
+
+  void     CreateIterators();
+  void     CloseIterators();
+  void     StartEvicting();
+  nsresult EvictEntries();
+
+  // Whether eviction is in progress
+  bool mEvicting;
+  // Whether index is up to date. We wait with eviction until the index finishes
+  // update process when it is outdated. NOTE: We also stop eviction in progress
+  // when the index is found outdated, the eviction is restarted again once the
+  // update process finishes.
+  bool mIndexIsUpToDate;
+  // Whether we already tried to restore unfinished jobs from previous run after
+  // startup.
+  static bool sDiskAlreadySearched;
+  // Array of contexts being evicted.
+  nsTArray<nsAutoPtr<CacheFileContextEvictorEntry> > mEntries;
+  nsCOMPtr<nsIFile> mCacheDirectory;
+  nsCOMPtr<nsIFile> mEntriesDir;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheFileIOManager.cpp b/netwerk/cache2/CacheFileIOManager.cpp
new file mode 100644
index 0000000000..1d0d576355
--- /dev/null
+++ b/netwerk/cache2/CacheFileIOManager.cpp
@@ -0,0 +1,4274 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheFileIOManager.h"
+
+#include "../cache/nsCacheUtils.h"
+#include "CacheHashUtils.h"
+#include "CacheStorageService.h"
+#include "CacheIndex.h"
+#include "CacheFileUtils.h"
+#include "nsThreadUtils.h"
+#include "CacheFile.h"
+#include "CacheObserver.h"
+#include "nsIFile.h"
+#include "CacheFileContextEvictor.h"
+#include "nsITimer.h"
+#include "nsISimpleEnumerator.h"
+#include "nsIDirectoryEnumerator.h"
+#include "nsIObserverService.h"
+#include "nsICacheStorageVisitor.h"
+#include "nsISizeOf.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Services.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include "private/pprio.h"
+#include "mozilla/Preferences.h"
+#include "nsNetUtil.h"
+
+// include files for ftruncate (or equivalent)
+#if defined(XP_UNIX)
+#include <unistd.h>
+#elif defined(XP_WIN)
+#include <windows.h>
+#undef CreateFile
+#undef CREATE_NEW
+#else
+// XXX add necessary include file for ftruncate (or equivalent)
+#endif
+
+
+namespace mozilla {
+namespace net {
+
+#define kOpenHandlesLimit        128
+#define kMetadataWriteDelay      5000
+#define kRemoveTrashStartDelay   60000 // in milliseconds
+#define kSmartSizeUpdateInterval 60000 // in milliseconds
+
+#ifdef ANDROID
+const uint32_t kMaxCacheSizeKB = 200*1024; // 200 MB
+#else
+const uint32_t kMaxCacheSizeKB = 350*1024; // 350 MB
+#endif
+
+bool
+CacheFileHandle::DispatchRelease()
+{
+  if (CacheFileIOManager::IsOnIOThreadOrCeased()) {
+    return false;
+  }
+
+  nsCOMPtr<nsIEventTarget> ioTarget = CacheFileIOManager::IOTarget();
+  if (!ioTarget) {
+    return false;
+  }
+
+  nsresult rv =
+    ioTarget->Dispatch(NewNonOwningRunnableMethod(this,
+						  &CacheFileHandle::Release),
+		       nsIEventTarget::DISPATCH_NORMAL);
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  return true;
+}
+
+NS_IMPL_ADDREF(CacheFileHandle)
+NS_IMETHODIMP_(MozExternalRefCountType)
+CacheFileHandle::Release()
+{
+  nsrefcnt count = mRefCnt - 1;
+  if (DispatchRelease()) {
+    // Redispatched to the IO thread.
+    return count;
+  }
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  LOG(("CacheFileHandle::Release() [this=%p, refcnt=%d]", this, mRefCnt.get()));
+  NS_PRECONDITION(0 != mRefCnt, "dup release");
+  count = --mRefCnt;
+  NS_LOG_RELEASE(this, count, "CacheFileHandle");
+
+  if (0 == count) {
+    mRefCnt = 1;
+    delete (this);
+    return 0;
+  }
+
+  return count;
+}
+
+NS_INTERFACE_MAP_BEGIN(CacheFileHandle)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END_THREADSAFE
+
+CacheFileHandle::CacheFileHandle(const SHA1Sum::Hash *aHash, bool aPriority, PinningStatus aPinning)
+  : mHash(aHash)
+  , mIsDoomed(false)
+  , mClosed(false)
+  , mPriority(aPriority)
+  , mSpecialFile(false)
+  , mInvalid(false)
+  , mFileExists(false)
+  , mDoomWhenFoundPinned(false)
+  , mDoomWhenFoundNonPinned(false)
+  , mKilled(false)
+  , mPinning(aPinning)
+  , mFileSize(-1)
+  , mFD(nullptr)
+{
+  // If we initialize mDoomed in the initialization list, that initialization is
+  // not guaranteeded to be atomic.  Whereas this assignment here is guaranteed
+  // to be atomic.  TSan will see this (atomic) assignment and be satisfied
+  // that cross-thread accesses to mIsDoomed are properly synchronized.
+  mIsDoomed = false;
+  LOG(("CacheFileHandle::CacheFileHandle() [this=%p, hash=%08x%08x%08x%08x%08x]"
+       , this, LOGSHA1(aHash)));
+}
+
+CacheFileHandle::CacheFileHandle(const nsACString &aKey, bool aPriority, PinningStatus aPinning)
+  : mHash(nullptr)
+  , mIsDoomed(false)
+  , mClosed(false)
+  , mPriority(aPriority)
+  , mSpecialFile(true)
+  , mInvalid(false)
+  , mFileExists(false)
+  , mDoomWhenFoundPinned(false)
+  , mDoomWhenFoundNonPinned(false)
+  , mKilled(false)
+  , mPinning(aPinning)
+  , mFileSize(-1)
+  , mFD(nullptr)
+  , mKey(aKey)
+{
+  // See comment above about the initialization of mIsDoomed.
+  mIsDoomed = false;
+  LOG(("CacheFileHandle::CacheFileHandle() [this=%p, key=%s]", this,
+       PromiseFlatCString(aKey).get()));
+}
+
+CacheFileHandle::~CacheFileHandle()
+{
+  LOG(("CacheFileHandle::~CacheFileHandle() [this=%p]", this));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  RefPtr<CacheFileIOManager> ioMan = CacheFileIOManager::gInstance;
+  if (!IsClosed() && ioMan) {
+    ioMan->CloseHandleInternal(this);
+  }
+}
+
+void
+CacheFileHandle::Log()
+{
+  nsAutoCString leafName;
+  if (mFile) {
+    mFile->GetNativeLeafName(leafName);
+  }
+
+  if (mSpecialFile) {
+    LOG(("CacheFileHandle::Log() - special file [this=%p, "
+         "isDoomed=%d, priority=%d, closed=%d, invalid=%d, "
+         "pinning=%d, fileExists=%d, fileSize=%lld, leafName=%s, key=%s]",
+         this,
+         bool(mIsDoomed), bool(mPriority), bool(mClosed), bool(mInvalid),
+         mPinning, bool(mFileExists), mFileSize, leafName.get(), mKey.get()));
+  } else {
+    LOG(("CacheFileHandle::Log() - entry file [this=%p, hash=%08x%08x%08x%08x%08x, "
+         "isDoomed=%d, priority=%d, closed=%d, invalid=%d, "
+         "pinning=%d, fileExists=%d, fileSize=%lld, leafName=%s, key=%s]",
+         this, LOGSHA1(mHash),
+         bool(mIsDoomed), bool(mPriority), bool(mClosed), bool(mInvalid),
+         mPinning, bool(mFileExists), mFileSize, leafName.get(), mKey.get()));
+  }
+}
+
+uint32_t
+CacheFileHandle::FileSizeInK() const
+{
+  MOZ_ASSERT(mFileSize != -1);
+  uint64_t size64 = mFileSize;
+
+  size64 += 0x3FF;
+  size64 >>= 10;
+
+  uint32_t size;
+  if (size64 >> 32) {
+    NS_WARNING("CacheFileHandle::FileSizeInK() - FileSize is too large, "
+               "truncating to PR_UINT32_MAX");
+    size = PR_UINT32_MAX;
+  } else {
+    size = static_cast<uint32_t>(size64);
+  }
+
+  return size;
+}
+
+bool
+CacheFileHandle::SetPinned(bool aPinned)
+{
+  LOG(("CacheFileHandle::SetPinned [this=%p, pinned=%d]", this, aPinned));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  mPinning = aPinned
+    ? PinningStatus::PINNED
+    : PinningStatus::NON_PINNED;
+
+  if ((MOZ_UNLIKELY(mDoomWhenFoundPinned) && aPinned) ||
+      (MOZ_UNLIKELY(mDoomWhenFoundNonPinned) && !aPinned)) {
+
+    LOG(("  dooming, when: pinned=%d, non-pinned=%d, found: pinned=%d",
+      bool(mDoomWhenFoundPinned), bool(mDoomWhenFoundNonPinned), aPinned));
+
+    mDoomWhenFoundPinned = false;
+    mDoomWhenFoundNonPinned = false;
+
+    return false;
+  }
+
+  return true;
+}
+
+// Memory reporting
+
+size_t
+CacheFileHandle::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  size_t n = 0;
+  nsCOMPtr<nsISizeOf> sizeOf;
+
+  sizeOf = do_QueryInterface(mFile);
+  if (sizeOf) {
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  n += mallocSizeOf(mFD);
+  n += mKey.SizeOfExcludingThisIfUnshared(mallocSizeOf);
+  return n;
+}
+
+size_t
+CacheFileHandle::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+/******************************************************************************
+ *  CacheFileHandles::HandleHashKey
+ *****************************************************************************/
+
+void
+CacheFileHandles::HandleHashKey::AddHandle(CacheFileHandle* aHandle)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  mHandles.InsertElementAt(0, aHandle);
+}
+
+void
+CacheFileHandles::HandleHashKey::RemoveHandle(CacheFileHandle* aHandle)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  DebugOnly<bool> found;
+  found = mHandles.RemoveElement(aHandle);
+  MOZ_ASSERT(found);
+}
+
+already_AddRefed<CacheFileHandle>
+CacheFileHandles::HandleHashKey::GetNewestHandle()
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  RefPtr<CacheFileHandle> handle;
+  if (mHandles.Length()) {
+    handle = mHandles[0];
+  }
+
+  return handle.forget();
+}
+
+void
+CacheFileHandles::HandleHashKey::GetHandles(nsTArray<RefPtr<CacheFileHandle> > &aResult)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  for (uint32_t i = 0; i < mHandles.Length(); ++i) {
+    CacheFileHandle* handle = mHandles[i];
+    aResult.AppendElement(handle);
+  }
+}
+
+#ifdef DEBUG
+
+void
+CacheFileHandles::HandleHashKey::AssertHandlesState()
+{
+  for (uint32_t i = 0; i < mHandles.Length(); ++i) {
+    CacheFileHandle* handle = mHandles[i];
+    MOZ_ASSERT(handle->IsDoomed());
+  }
+}
+
+#endif
+
+size_t
+CacheFileHandles::HandleHashKey::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  size_t n = 0;
+  n += mallocSizeOf(mHash.get());
+  for (uint32_t i = 0; i < mHandles.Length(); ++i) {
+    n += mHandles[i]->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  return n;
+}
+
+/******************************************************************************
+ *  CacheFileHandles
+ *****************************************************************************/
+
+CacheFileHandles::CacheFileHandles()
+{
+  LOG(("CacheFileHandles::CacheFileHandles() [this=%p]", this));
+  MOZ_COUNT_CTOR(CacheFileHandles);
+}
+
+CacheFileHandles::~CacheFileHandles()
+{
+  LOG(("CacheFileHandles::~CacheFileHandles() [this=%p]", this));
+  MOZ_COUNT_DTOR(CacheFileHandles);
+}
+
+nsresult
+CacheFileHandles::GetHandle(const SHA1Sum::Hash *aHash,
+                            CacheFileHandle **_retval)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(aHash);
+
+#ifdef DEBUG_HANDLES
+  LOG(("CacheFileHandles::GetHandle() [hash=%08x%08x%08x%08x%08x]",
+       LOGSHA1(aHash)));
+#endif
+
+  // find hash entry for key
+  HandleHashKey *entry = mTable.GetEntry(*aHash);
+  if (!entry) {
+    LOG(("CacheFileHandles::GetHandle() hash=%08x%08x%08x%08x%08x "
+         "no handle entries found", LOGSHA1(aHash)));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+#ifdef DEBUG_HANDLES
+  Log(entry);
+#endif
+
+  // Check if the entry is doomed
+  RefPtr<CacheFileHandle> handle = entry->GetNewestHandle();
+  if (!handle) {
+    LOG(("CacheFileHandles::GetHandle() hash=%08x%08x%08x%08x%08x "
+         "no handle found %p, entry %p", LOGSHA1(aHash), handle.get(), entry));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (handle->IsDoomed()) {
+    LOG(("CacheFileHandles::GetHandle() hash=%08x%08x%08x%08x%08x "
+         "found doomed handle %p, entry %p", LOGSHA1(aHash), handle.get(), entry));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  LOG(("CacheFileHandles::GetHandle() hash=%08x%08x%08x%08x%08x "
+       "found handle %p, entry %p", LOGSHA1(aHash), handle.get(), entry));
+
+  handle.forget(_retval);
+  return NS_OK;
+}
+
+
+nsresult
+CacheFileHandles::NewHandle(const SHA1Sum::Hash *aHash,
+                            bool aPriority, CacheFileHandle::PinningStatus aPinning,
+                            CacheFileHandle **_retval)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(aHash);
+
+#ifdef DEBUG_HANDLES
+  LOG(("CacheFileHandles::NewHandle() [hash=%08x%08x%08x%08x%08x]", LOGSHA1(aHash)));
+#endif
+
+  // find hash entry for key
+  HandleHashKey *entry = mTable.PutEntry(*aHash);
+
+#ifdef DEBUG_HANDLES
+  Log(entry);
+#endif
+
+#ifdef DEBUG
+  entry->AssertHandlesState();
+#endif
+
+  RefPtr<CacheFileHandle> handle = new CacheFileHandle(entry->Hash(), aPriority, aPinning);
+  entry->AddHandle(handle);
+
+  LOG(("CacheFileHandles::NewHandle() hash=%08x%08x%08x%08x%08x "
+       "created new handle %p, entry=%p", LOGSHA1(aHash), handle.get(), entry));
+
+  handle.forget(_retval);
+  return NS_OK;
+}
+
+void
+CacheFileHandles::RemoveHandle(CacheFileHandle *aHandle)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(aHandle);
+
+  if (!aHandle) {
+    return;
+  }
+
+#ifdef DEBUG_HANDLES
+  LOG(("CacheFileHandles::RemoveHandle() [handle=%p, hash=%08x%08x%08x%08x%08x]"
+       , aHandle, LOGSHA1(aHandle->Hash())));
+#endif
+
+  // find hash entry for key
+  HandleHashKey *entry = mTable.GetEntry(*aHandle->Hash());
+  if (!entry) {
+    MOZ_ASSERT(CacheFileIOManager::IsShutdown(),
+      "Should find entry when removing a handle before shutdown");
+
+    LOG(("CacheFileHandles::RemoveHandle() hash=%08x%08x%08x%08x%08x "
+         "no entries found", LOGSHA1(aHandle->Hash())));
+    return;
+  }
+
+#ifdef DEBUG_HANDLES
+  Log(entry);
+#endif
+
+  LOG(("CacheFileHandles::RemoveHandle() hash=%08x%08x%08x%08x%08x "
+       "removing handle %p", LOGSHA1(entry->Hash()), aHandle));
+  entry->RemoveHandle(aHandle);
+
+  if (entry->IsEmpty()) {
+    LOG(("CacheFileHandles::RemoveHandle() hash=%08x%08x%08x%08x%08x "
+         "list is empty, removing entry %p", LOGSHA1(entry->Hash()), entry));
+    mTable.RemoveEntry(*entry->Hash());
+  }
+}
+
+void
+CacheFileHandles::GetAllHandles(nsTArray<RefPtr<CacheFileHandle> > *_retval)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  for (auto iter = mTable.Iter(); !iter.Done(); iter.Next()) {
+    iter.Get()->GetHandles(*_retval);
+  }
+}
+
+void
+CacheFileHandles::GetActiveHandles(
+  nsTArray<RefPtr<CacheFileHandle> > *_retval)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  for (auto iter = mTable.Iter(); !iter.Done(); iter.Next()) {
+    RefPtr<CacheFileHandle> handle = iter.Get()->GetNewestHandle();
+    MOZ_ASSERT(handle);
+
+    if (!handle->IsDoomed()) {
+      _retval->AppendElement(handle);
+    }
+  }
+}
+
+void
+CacheFileHandles::ClearAll()
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  mTable.Clear();
+}
+
+uint32_t
+CacheFileHandles::HandleCount()
+{
+  return mTable.Count();
+}
+
+#ifdef DEBUG_HANDLES
+void
+CacheFileHandles::Log(CacheFileHandlesEntry *entry)
+{
+  LOG(("CacheFileHandles::Log() BEGIN [entry=%p]", entry));
+
+  nsTArray<RefPtr<CacheFileHandle> > array;
+  aEntry->GetHandles(array);
+
+  for (uint32_t i = 0; i < array.Length(); ++i) {
+    CacheFileHandle *handle = array[i];
+    handle->Log();
+  }
+
+  LOG(("CacheFileHandles::Log() END [entry=%p]", entry));
+}
+#endif
+
+// Memory reporting
+
+size_t
+CacheFileHandles::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  return mTable.SizeOfExcludingThis(mallocSizeOf);
+}
+
+// Events
+
+class ShutdownEvent : public Runnable {
+public:
+  ShutdownEvent()
+    : mMonitor("ShutdownEvent.mMonitor")
+    , mNotified(false)
+  {
+    MOZ_COUNT_CTOR(ShutdownEvent);
+  }
+
+protected:
+  ~ShutdownEvent()
+  {
+    MOZ_COUNT_DTOR(ShutdownEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    MonitorAutoLock mon(mMonitor);
+
+    CacheFileIOManager::gInstance->ShutdownInternal();
+
+    mNotified = true;
+    mon.Notify();
+
+    return NS_OK;
+  }
+
+  void PostAndWait()
+  {
+    MonitorAutoLock mon(mMonitor);
+
+    DebugOnly<nsresult> rv;
+    rv = CacheFileIOManager::gInstance->mIOThread->Dispatch(
+      this, CacheIOThread::WRITE); // When writes and closing of handles is done
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+    PRIntervalTime const waitTime = PR_MillisecondsToInterval(1000);
+    while (!mNotified) {
+      mon.Wait(waitTime);
+      if (!mNotified) {
+        // If there is any IO blocking on the IO thread, this will
+        // try to cancel it.  Returns no later than after two seconds.
+        MonitorAutoUnlock unmon(mMonitor); // Prevent delays
+        CacheFileIOManager::gInstance->mIOThread->CancelBlockingIO();
+      }
+    }
+  }
+
+protected:
+  mozilla::Monitor mMonitor;
+  bool             mNotified;
+};
+
+class OpenFileEvent : public Runnable {
+public:
+  OpenFileEvent(const nsACString &aKey, uint32_t aFlags,
+                CacheFileIOListener *aCallback)
+    : mFlags(aFlags)
+    , mCallback(aCallback)
+    , mKey(aKey)
+  {
+    MOZ_COUNT_CTOR(OpenFileEvent);
+    mIOMan = CacheFileIOManager::gInstance;
+  }
+
+protected:
+  ~OpenFileEvent()
+  {
+    MOZ_COUNT_DTOR(OpenFileEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv = NS_OK;
+
+    if (!(mFlags & CacheFileIOManager::SPECIAL_FILE)) {
+      SHA1Sum sum;
+      sum.update(mKey.BeginReading(), mKey.Length());
+      sum.finish(mHash);
+    }
+
+    if (!mIOMan) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      if (mFlags & CacheFileIOManager::SPECIAL_FILE) {
+        rv = mIOMan->OpenSpecialFileInternal(mKey, mFlags,
+                                             getter_AddRefs(mHandle));
+      } else {
+        rv = mIOMan->OpenFileInternal(&mHash, mKey, mFlags,
+                                      getter_AddRefs(mHandle));
+      }
+      mIOMan = nullptr;
+      if (mHandle) {
+        if (mHandle->Key().IsEmpty()) {
+          mHandle->Key() = mKey;
+        }
+      }
+    }
+
+    mCallback->OnFileOpened(mHandle, rv);
+    return NS_OK;
+  }
+
+protected:
+  SHA1Sum::Hash                 mHash;
+  uint32_t                      mFlags;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+  RefPtr<CacheFileIOManager>    mIOMan;
+  RefPtr<CacheFileHandle>       mHandle;
+  nsCString                     mKey;
+};
+
+class ReadEvent : public Runnable {
+public:
+  ReadEvent(CacheFileHandle *aHandle, int64_t aOffset, char *aBuf,
+            int32_t aCount, CacheFileIOListener *aCallback)
+    : mHandle(aHandle)
+    , mOffset(aOffset)
+    , mBuf(aBuf)
+    , mCount(aCount)
+    , mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(ReadEvent);
+  }
+
+protected:
+  ~ReadEvent()
+  {
+    MOZ_COUNT_DTOR(ReadEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed() || (mCallback && mCallback->IsKilled())) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->ReadInternal(
+        mHandle, mOffset, mBuf, mCount);
+    }
+
+    mCallback->OnDataRead(mHandle, mBuf, rv);
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+  int64_t                       mOffset;
+  char                         *mBuf;
+  int32_t                       mCount;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+};
+
+class WriteEvent : public Runnable {
+public:
+  WriteEvent(CacheFileHandle *aHandle, int64_t aOffset, const char *aBuf,
+             int32_t aCount, bool aValidate, bool aTruncate,
+             CacheFileIOListener *aCallback)
+    : mHandle(aHandle)
+    , mOffset(aOffset)
+    , mBuf(aBuf)
+    , mCount(aCount)
+    , mValidate(aValidate)
+    , mTruncate(aTruncate)
+    , mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(WriteEvent);
+  }
+
+protected:
+  ~WriteEvent()
+  {
+    MOZ_COUNT_DTOR(WriteEvent);
+
+    if (!mCallback && mBuf) {
+      free(const_cast<char *>(mBuf));
+    }
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed() || (mCallback && mCallback->IsKilled())) {
+      // We usually get here only after the internal shutdown
+      // (i.e. mShuttingDown == true).  Pretend write has succeeded
+      // to avoid any past-shutdown file dooming.
+      rv = (CacheObserver::IsPastShutdownIOLag() ||
+            CacheFileIOManager::gInstance->mShuttingDown)
+        ? NS_OK
+        : NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->WriteInternal(
+          mHandle, mOffset, mBuf, mCount, mValidate, mTruncate);
+      if (NS_FAILED(rv) && !mCallback) {
+        // No listener is going to handle the error, doom the file
+        CacheFileIOManager::gInstance->DoomFileInternal(mHandle);
+      }
+    }
+    if (mCallback) {
+      mCallback->OnDataWritten(mHandle, mBuf, rv);
+    } else {
+      free(const_cast<char *>(mBuf));
+      mBuf = nullptr;
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+  int64_t                       mOffset;
+  const char                   *mBuf;
+  int32_t                       mCount;
+  bool                          mValidate : 1;
+  bool                          mTruncate : 1;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+};
+
+class DoomFileEvent : public Runnable {
+public:
+  DoomFileEvent(CacheFileHandle *aHandle,
+                CacheFileIOListener *aCallback)
+    : mCallback(aCallback)
+    , mHandle(aHandle)
+  {
+    MOZ_COUNT_CTOR(DoomFileEvent);
+  }
+
+protected:
+  ~DoomFileEvent()
+  {
+    MOZ_COUNT_DTOR(DoomFileEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed()) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->DoomFileInternal(mHandle);
+    }
+
+    if (mCallback) {
+      mCallback->OnFileDoomed(mHandle, rv);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  nsCOMPtr<CacheFileIOListener>              mCallback;
+  nsCOMPtr<nsIEventTarget>                   mTarget;
+  RefPtr<CacheFileHandle>                    mHandle;
+};
+
+class DoomFileByKeyEvent : public Runnable {
+public:
+  DoomFileByKeyEvent(const nsACString &aKey,
+                     CacheFileIOListener *aCallback)
+    : mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(DoomFileByKeyEvent);
+
+    SHA1Sum sum;
+    sum.update(aKey.BeginReading(), aKey.Length());
+    sum.finish(mHash);
+
+    mIOMan = CacheFileIOManager::gInstance;
+  }
+
+protected:
+  ~DoomFileByKeyEvent()
+  {
+    MOZ_COUNT_DTOR(DoomFileByKeyEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (!mIOMan) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = mIOMan->DoomFileByKeyInternal(&mHash);
+      mIOMan = nullptr;
+    }
+
+    if (mCallback) {
+      mCallback->OnFileDoomed(nullptr, rv);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  SHA1Sum::Hash                 mHash;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+  RefPtr<CacheFileIOManager>    mIOMan;
+};
+
+class ReleaseNSPRHandleEvent : public Runnable {
+public:
+  explicit ReleaseNSPRHandleEvent(CacheFileHandle *aHandle)
+    : mHandle(aHandle)
+  {
+    MOZ_COUNT_CTOR(ReleaseNSPRHandleEvent);
+  }
+
+protected:
+  ~ReleaseNSPRHandleEvent()
+  {
+    MOZ_COUNT_DTOR(ReleaseNSPRHandleEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    if (!mHandle->IsClosed()) {
+      CacheFileIOManager::gInstance->MaybeReleaseNSPRHandleInternal(mHandle);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+};
+
+class TruncateSeekSetEOFEvent : public Runnable {
+public:
+  TruncateSeekSetEOFEvent(CacheFileHandle *aHandle, int64_t aTruncatePos,
+                          int64_t aEOFPos, CacheFileIOListener *aCallback)
+    : mHandle(aHandle)
+    , mTruncatePos(aTruncatePos)
+    , mEOFPos(aEOFPos)
+    , mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(TruncateSeekSetEOFEvent);
+  }
+
+protected:
+  ~TruncateSeekSetEOFEvent()
+  {
+    MOZ_COUNT_DTOR(TruncateSeekSetEOFEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed() || (mCallback && mCallback->IsKilled())) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->TruncateSeekSetEOFInternal(
+        mHandle, mTruncatePos, mEOFPos);
+    }
+
+    if (mCallback) {
+      mCallback->OnEOFSet(mHandle, rv);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+  int64_t                       mTruncatePos;
+  int64_t                       mEOFPos;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+};
+
+class RenameFileEvent : public Runnable {
+public:
+  RenameFileEvent(CacheFileHandle *aHandle, const nsACString &aNewName,
+                  CacheFileIOListener *aCallback)
+    : mHandle(aHandle)
+    , mNewName(aNewName)
+    , mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(RenameFileEvent);
+  }
+
+protected:
+  ~RenameFileEvent()
+  {
+    MOZ_COUNT_DTOR(RenameFileEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed()) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->RenameFileInternal(mHandle,
+                                                             mNewName);
+    }
+
+    if (mCallback) {
+      mCallback->OnFileRenamed(mHandle, rv);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+  nsCString                     mNewName;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+};
+
+class InitIndexEntryEvent : public Runnable {
+public:
+  InitIndexEntryEvent(CacheFileHandle *aHandle,
+                      OriginAttrsHash aOriginAttrsHash, bool aAnonymous,
+                      bool aPinning)
+    : mHandle(aHandle)
+    , mOriginAttrsHash(aOriginAttrsHash)
+    , mAnonymous(aAnonymous)
+    , mPinning(aPinning)
+  {
+    MOZ_COUNT_CTOR(InitIndexEntryEvent);
+  }
+
+protected:
+  ~InitIndexEntryEvent()
+  {
+    MOZ_COUNT_DTOR(InitIndexEntryEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    if (mHandle->IsClosed() || mHandle->IsDoomed()) {
+      return NS_OK;
+    }
+
+    CacheIndex::InitEntry(mHandle->Hash(), mOriginAttrsHash, mAnonymous,
+                          mPinning);
+
+    // We cannot set the filesize before we init the entry. If we're opening
+    // an existing entry file, frecency and expiration time will be set after
+    // parsing the entry file, but we must set the filesize here since nobody is
+    // going to set it if there is no write to the file.
+    uint32_t sizeInK = mHandle->FileSizeInK();
+    CacheIndex::UpdateEntry(mHandle->Hash(), nullptr, nullptr, &sizeInK);
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle> mHandle;
+  OriginAttrsHash         mOriginAttrsHash;
+  bool                    mAnonymous;
+  bool                    mPinning;
+};
+
+class UpdateIndexEntryEvent : public Runnable {
+public:
+  UpdateIndexEntryEvent(CacheFileHandle *aHandle, const uint32_t *aFrecency,
+                        const uint32_t *aExpirationTime)
+    : mHandle(aHandle)
+    , mHasFrecency(false)
+    , mHasExpirationTime(false)
+  {
+    MOZ_COUNT_CTOR(UpdateIndexEntryEvent);
+    if (aFrecency) {
+      mHasFrecency = true;
+      mFrecency = *aFrecency;
+    }
+    if (aExpirationTime) {
+      mHasExpirationTime = true;
+      mExpirationTime = *aExpirationTime;
+    }
+  }
+
+protected:
+  ~UpdateIndexEntryEvent()
+  {
+    MOZ_COUNT_DTOR(UpdateIndexEntryEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    if (mHandle->IsClosed() || mHandle->IsDoomed()) {
+      return NS_OK;
+    }
+
+    CacheIndex::UpdateEntry(mHandle->Hash(),
+                            mHasFrecency ? &mFrecency : nullptr,
+                            mHasExpirationTime ? &mExpirationTime : nullptr,
+                            nullptr);
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle> mHandle;
+  bool                      mHasFrecency;
+  bool                      mHasExpirationTime;
+  uint32_t                  mFrecency;
+  uint32_t                  mExpirationTime;
+};
+
+class MetadataWriteScheduleEvent : public Runnable
+{
+public:
+  enum EMode {
+    SCHEDULE,
+    UNSCHEDULE,
+    SHUTDOWN
+  } mMode;
+
+  RefPtr<CacheFile> mFile;
+  RefPtr<CacheFileIOManager> mIOMan;
+
+  MetadataWriteScheduleEvent(CacheFileIOManager * aManager,
+                             CacheFile * aFile,
+                             EMode aMode)
+    : mMode(aMode)
+    , mFile(aFile)
+    , mIOMan(aManager)
+  { }
+
+  virtual ~MetadataWriteScheduleEvent() { }
+
+  NS_IMETHOD Run() override
+  {
+    RefPtr<CacheFileIOManager> ioMan = CacheFileIOManager::gInstance;
+    if (!ioMan) {
+      NS_WARNING("CacheFileIOManager already gone in MetadataWriteScheduleEvent::Run()");
+      return NS_OK;
+    }
+
+    switch (mMode)
+    {
+    case SCHEDULE:
+      ioMan->ScheduleMetadataWriteInternal(mFile);
+      break;
+    case UNSCHEDULE:
+      ioMan->UnscheduleMetadataWriteInternal(mFile);
+      break;
+    case SHUTDOWN:
+      ioMan->ShutdownMetadataWriteSchedulingInternal();
+      break;
+    }
+    return NS_OK;
+  }
+};
+
+StaticRefPtr<CacheFileIOManager> CacheFileIOManager::gInstance;
+
+NS_IMPL_ISUPPORTS(CacheFileIOManager, nsITimerCallback)
+
+CacheFileIOManager::CacheFileIOManager()
+  : mShuttingDown(false)
+  , mTreeCreated(false)
+  , mTreeCreationFailed(false)
+  , mOverLimitEvicting(false)
+  , mRemovingTrashDirs(false)
+{
+  LOG(("CacheFileIOManager::CacheFileIOManager [this=%p]", this));
+  MOZ_COUNT_CTOR(CacheFileIOManager);
+  MOZ_ASSERT(!gInstance, "multiple CacheFileIOManager instances!");
+}
+
+CacheFileIOManager::~CacheFileIOManager()
+{
+  LOG(("CacheFileIOManager::~CacheFileIOManager [this=%p]", this));
+  MOZ_COUNT_DTOR(CacheFileIOManager);
+}
+
+// static
+nsresult
+CacheFileIOManager::Init()
+{
+  LOG(("CacheFileIOManager::Init()"));
+
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (gInstance) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+  RefPtr<CacheFileIOManager> ioMan = new CacheFileIOManager();
+
+  nsresult rv = ioMan->InitInternal();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  gInstance = ioMan.forget();
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::InitInternal()
+{
+  nsresult rv;
+
+  mIOThread = new CacheIOThread();
+
+  rv = mIOThread->Init();
+  MOZ_ASSERT(NS_SUCCEEDED(rv), "Can't create background thread");
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mStartTime = TimeStamp::NowLoRes();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::Shutdown()
+{
+  LOG(("CacheFileIOManager::Shutdown() [gInstance=%p]", gInstance.get()));
+
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!gInstance) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  Telemetry::AutoTimer<Telemetry::NETWORK_DISK_CACHE_SHUTDOWN_V2> shutdownTimer;
+
+  CacheIndex::PreShutdown();
+
+  ShutdownMetadataWriteScheduling();
+
+  RefPtr<ShutdownEvent> ev = new ShutdownEvent();
+  ev->PostAndWait();
+
+  MOZ_ASSERT(gInstance->mHandles.HandleCount() == 0);
+  MOZ_ASSERT(gInstance->mHandlesByLastUsed.Length() == 0);
+
+  if (gInstance->mIOThread) {
+    gInstance->mIOThread->Shutdown();
+  }
+
+  CacheIndex::Shutdown();
+
+  if (CacheObserver::ClearCacheOnShutdown()) {
+    Telemetry::AutoTimer<Telemetry::NETWORK_DISK_CACHE2_SHUTDOWN_CLEAR_PRIVATE> totalTimer;
+    gInstance->SyncRemoveAllCacheFiles();
+  }
+
+  gInstance = nullptr;
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::ShutdownInternal()
+{
+  LOG(("CacheFileIOManager::ShutdownInternal() [this=%p]", this));
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  // No new handles can be created after this flag is set
+  mShuttingDown = true;
+
+  // close all handles and delete all associated files
+  nsTArray<RefPtr<CacheFileHandle> > handles;
+  mHandles.GetAllHandles(&handles);
+  handles.AppendElements(mSpecialHandles);
+
+  for (uint32_t i=0 ; i<handles.Length() ; i++) {
+    CacheFileHandle *h = handles[i];
+    h->mClosed = true;
+
+    h->Log();
+
+    // Close completely written files.
+    MaybeReleaseNSPRHandleInternal(h);
+    // Don't bother removing invalid and/or doomed files to improve
+    // shutdown perfomrance.
+    // Doomed files are already in the doomed directory from which
+    // we never reuse files and delete the dir on next session startup.
+    // Invalid files don't have metadata and thus won't load anyway
+    // (hashes won't match).
+
+    if (!h->IsSpecialFile() && !h->mIsDoomed && !h->mFileExists) {
+      CacheIndex::RemoveEntry(h->Hash());
+    }
+
+    // Remove the handle from mHandles/mSpecialHandles
+    if (h->IsSpecialFile()) {
+      mSpecialHandles.RemoveElement(h);
+    } else {
+      mHandles.RemoveHandle(h);
+    }
+
+    // Pointer to the hash is no longer valid once the last handle with the
+    // given hash is released. Null out the pointer so that we crash if there
+    // is a bug in this code and we dereference the pointer after this point.
+    if (!h->IsSpecialFile()) {
+      h->mHash = nullptr;
+    }
+  }
+
+  // Assert the table is empty. When we are here, no new handles can be added
+  // and handles will no longer remove them self from this table and we don't
+  // want to keep invalid handles here. Also, there is no lookup after this
+  // point to happen.
+  MOZ_ASSERT(mHandles.HandleCount() == 0);
+
+  // Release trash directory enumerator
+  if (mTrashDirEnumerator) {
+    mTrashDirEnumerator->Close();
+    mTrashDirEnumerator = nullptr;
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::OnProfile()
+{
+  LOG(("CacheFileIOManager::OnProfile() [gInstance=%p]", gInstance.get()));
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (!ioMan) {
+    // CacheFileIOManager::Init() failed, probably could not create the IO
+    // thread, just go with it...
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> directory;
+
+  CacheObserver::ParentDirOverride(getter_AddRefs(directory));
+
+#if defined(MOZ_WIDGET_ANDROID)
+  nsCOMPtr<nsIFile> profilelessDirectory;
+  char* cachePath = getenv("CACHE_DIRECTORY");
+  if (!directory && cachePath && *cachePath) {
+    rv = NS_NewNativeLocalFile(nsDependentCString(cachePath),
+                               true, getter_AddRefs(directory));
+    if (NS_SUCCEEDED(rv)) {
+      // Save this directory as the profileless path.
+      rv = directory->Clone(getter_AddRefs(profilelessDirectory));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Add profile leaf name to the directory name to distinguish
+      // multiple profiles Fennec supports.
+      nsCOMPtr<nsIFile> profD;
+      rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
+                                  getter_AddRefs(profD));
+
+      nsAutoCString leafName;
+      if (NS_SUCCEEDED(rv)) {
+        rv = profD->GetNativeLeafName(leafName);
+      }
+      if (NS_SUCCEEDED(rv)) {
+        rv = directory->AppendNative(leafName);
+      }
+      if (NS_FAILED(rv)) {
+        directory = nullptr;
+      }
+    }
+  }
+#endif
+
+  if (!directory) {
+    rv = NS_GetSpecialDirectory(NS_APP_CACHE_PARENT_DIR,
+                                getter_AddRefs(directory));
+  }
+
+  if (!directory) {
+    rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_LOCAL_50_DIR,
+                                getter_AddRefs(directory));
+  }
+
+  if (directory) {
+    rv = directory->Append(NS_LITERAL_STRING("cache2"));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // All functions return a clone.
+  ioMan->mCacheDirectory.swap(directory);
+
+#if defined(MOZ_WIDGET_ANDROID)
+  if (profilelessDirectory) {
+    rv = profilelessDirectory->Append(NS_LITERAL_STRING("cache2"));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  ioMan->mCacheProfilelessDirectory.swap(profilelessDirectory);
+#endif
+
+  if (ioMan->mCacheDirectory) {
+    CacheIndex::Init(ioMan->mCacheDirectory);
+  }
+
+  return NS_OK;
+}
+
+// static
+already_AddRefed<nsIEventTarget>
+CacheFileIOManager::IOTarget()
+{
+  nsCOMPtr<nsIEventTarget> target;
+  if (gInstance && gInstance->mIOThread) {
+    target = gInstance->mIOThread->Target();
+  }
+
+  return target.forget();
+}
+
+// static
+already_AddRefed<CacheIOThread>
+CacheFileIOManager::IOThread()
+{
+  RefPtr<CacheIOThread> thread;
+  if (gInstance) {
+    thread = gInstance->mIOThread;
+  }
+
+  return thread.forget();
+}
+
+// static
+bool
+CacheFileIOManager::IsOnIOThread()
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (ioMan && ioMan->mIOThread) {
+    return ioMan->mIOThread->IsCurrentThread();
+  }
+
+  return false;
+}
+
+// static
+bool
+CacheFileIOManager::IsOnIOThreadOrCeased()
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (ioMan && ioMan->mIOThread) {
+    return ioMan->mIOThread->IsCurrentThread();
+  }
+
+  // Ceased...
+  return true;
+}
+
+// static
+bool
+CacheFileIOManager::IsShutdown()
+{
+  if (!gInstance) {
+    return true;
+  }
+  return gInstance->mShuttingDown;
+}
+
+// static
+nsresult
+CacheFileIOManager::ScheduleMetadataWrite(CacheFile * aFile)
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  NS_ENSURE_TRUE(ioMan, NS_ERROR_NOT_INITIALIZED);
+
+  NS_ENSURE_TRUE(!ioMan->mShuttingDown, NS_ERROR_NOT_INITIALIZED);
+
+  RefPtr<MetadataWriteScheduleEvent> event = new MetadataWriteScheduleEvent(
+    ioMan, aFile, MetadataWriteScheduleEvent::SCHEDULE);
+  nsCOMPtr<nsIEventTarget> target = ioMan->IOTarget();
+  NS_ENSURE_TRUE(target, NS_ERROR_UNEXPECTED);
+  return target->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+}
+
+nsresult
+CacheFileIOManager::ScheduleMetadataWriteInternal(CacheFile * aFile)
+{
+  MOZ_ASSERT(IsOnIOThreadOrCeased());
+
+  nsresult rv;
+
+  if (!mMetadataWritesTimer) {
+    mMetadataWritesTimer = do_CreateInstance("@mozilla.org/timer;1", &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = mMetadataWritesTimer->InitWithCallback(
+      this, kMetadataWriteDelay, nsITimer::TYPE_ONE_SHOT);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (mScheduledMetadataWrites.IndexOf(aFile) !=
+      mScheduledMetadataWrites.NoIndex) {
+    return NS_OK;
+  }
+
+  mScheduledMetadataWrites.AppendElement(aFile);
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::UnscheduleMetadataWrite(CacheFile * aFile)
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  NS_ENSURE_TRUE(ioMan, NS_ERROR_NOT_INITIALIZED);
+
+  NS_ENSURE_TRUE(!ioMan->mShuttingDown, NS_ERROR_NOT_INITIALIZED);
+
+  RefPtr<MetadataWriteScheduleEvent> event = new MetadataWriteScheduleEvent(
+    ioMan, aFile, MetadataWriteScheduleEvent::UNSCHEDULE);
+  nsCOMPtr<nsIEventTarget> target = ioMan->IOTarget();
+  NS_ENSURE_TRUE(target, NS_ERROR_UNEXPECTED);
+  return target->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+}
+
+nsresult
+CacheFileIOManager::UnscheduleMetadataWriteInternal(CacheFile * aFile)
+{
+  MOZ_ASSERT(IsOnIOThreadOrCeased());
+
+  mScheduledMetadataWrites.RemoveElement(aFile);
+
+  if (mScheduledMetadataWrites.Length() == 0 &&
+      mMetadataWritesTimer) {
+    mMetadataWritesTimer->Cancel();
+    mMetadataWritesTimer = nullptr;
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::ShutdownMetadataWriteScheduling()
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  NS_ENSURE_TRUE(ioMan, NS_ERROR_NOT_INITIALIZED);
+
+  RefPtr<MetadataWriteScheduleEvent> event = new MetadataWriteScheduleEvent(
+    ioMan, nullptr, MetadataWriteScheduleEvent::SHUTDOWN);
+  nsCOMPtr<nsIEventTarget> target = ioMan->IOTarget();
+  NS_ENSURE_TRUE(target, NS_ERROR_UNEXPECTED);
+  return target->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+}
+
+nsresult
+CacheFileIOManager::ShutdownMetadataWriteSchedulingInternal()
+{
+  MOZ_ASSERT(IsOnIOThreadOrCeased());
+
+  nsTArray<RefPtr<CacheFile> > files;
+  files.SwapElements(mScheduledMetadataWrites);
+  for (uint32_t i = 0; i < files.Length(); ++i) {
+    CacheFile * file = files[i];
+    file->WriteMetadataIfNeeded();
+  }
+
+  if (mMetadataWritesTimer) {
+    mMetadataWritesTimer->Cancel();
+    mMetadataWritesTimer = nullptr;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheFileIOManager::Notify(nsITimer * aTimer)
+{
+  MOZ_ASSERT(IsOnIOThreadOrCeased());
+  MOZ_ASSERT(mMetadataWritesTimer == aTimer);
+
+  mMetadataWritesTimer = nullptr;
+
+  nsTArray<RefPtr<CacheFile> > files;
+  files.SwapElements(mScheduledMetadataWrites);
+  for (uint32_t i = 0; i < files.Length(); ++i) {
+    CacheFile * file = files[i];
+    file->WriteMetadataIfNeeded();
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::OpenFile(const nsACString &aKey,
+                             uint32_t aFlags, CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::OpenFile() [key=%s, flags=%d, listener=%p]",
+       PromiseFlatCString(aKey).get(), aFlags, aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  bool priority = aFlags & CacheFileIOManager::PRIORITY;
+  RefPtr<OpenFileEvent> ev = new OpenFileEvent(aKey, aFlags, aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, priority
+    ? CacheIOThread::OPEN_PRIORITY
+    : CacheIOThread::OPEN);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::OpenFileInternal(const SHA1Sum::Hash *aHash,
+                                     const nsACString &aKey,
+                                     uint32_t aFlags,
+                                     CacheFileHandle **_retval)
+{
+  LOG(("CacheFileIOManager::OpenFileInternal() [hash=%08x%08x%08x%08x%08x, "
+       "key=%s, flags=%d]", LOGSHA1(aHash), PromiseFlatCString(aKey).get(),
+       aFlags));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsresult rv;
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  CacheIOThread::Cancelable cancelable(true /* never called for special handles */);
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  CacheFileHandle::PinningStatus pinning = aFlags & PINNED
+    ? CacheFileHandle::PinningStatus::PINNED
+    : CacheFileHandle::PinningStatus::NON_PINNED;
+
+  nsCOMPtr<nsIFile> file;
+  rv = GetFile(aHash, getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<CacheFileHandle> handle;
+  mHandles.GetHandle(aHash, getter_AddRefs(handle));
+
+  if ((aFlags & (OPEN | CREATE | CREATE_NEW)) == CREATE_NEW) {
+    if (handle) {
+      rv = DoomFileInternal(handle);
+      NS_ENSURE_SUCCESS(rv, rv);
+      handle = nullptr;
+    }
+
+    rv = mHandles.NewHandle(aHash, aFlags & PRIORITY, pinning, getter_AddRefs(handle));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    bool exists;
+    rv = file->Exists(&exists);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (exists) {
+      CacheIndex::RemoveEntry(aHash);
+
+      LOG(("CacheFileIOManager::OpenFileInternal() - Removing old file from "
+           "disk"));
+      rv = file->Remove(false);
+      if (NS_FAILED(rv)) {
+        NS_WARNING("Cannot remove old entry from the disk");
+        LOG(("CacheFileIOManager::OpenFileInternal() - Removing old file failed"
+             ". [rv=0x%08x]", rv));
+      }
+    }
+
+    CacheIndex::AddEntry(aHash);
+    handle->mFile.swap(file);
+    handle->mFileSize = 0;
+  }
+
+  if (handle) {
+    handle.swap(*_retval);
+    return NS_OK;
+  }
+
+  bool exists, evictedAsPinned = false, evictedAsNonPinned = false;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (exists && mContextEvictor) {
+    if (mContextEvictor->ContextsCount() == 0) {
+      mContextEvictor = nullptr;
+    } else {
+      mContextEvictor->WasEvicted(aKey, file, &evictedAsPinned, &evictedAsNonPinned);
+    }
+  }
+
+  if (!exists && (aFlags & (OPEN | CREATE | CREATE_NEW)) == OPEN) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (exists) {
+    // For existing files we determine the pinning status later, after the metadata gets parsed.
+    pinning = CacheFileHandle::PinningStatus::UNKNOWN;
+  }
+
+  rv = mHandles.NewHandle(aHash, aFlags & PRIORITY, pinning, getter_AddRefs(handle));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (exists) {
+    // If this file has been found evicted through the context file evictor above for
+    // any of pinned or non-pinned state, these calls ensure we doom the handle ASAP
+    // we know the real pinning state after metadta has been parsed.  DoomFileInternal
+    // on the |handle| doesn't doom right now, since the pinning state is unknown
+    // and we pass down a pinning restriction.
+    if (evictedAsPinned) {
+      rv = DoomFileInternal(handle, DOOM_WHEN_PINNED);
+      MOZ_ASSERT(!handle->IsDoomed() && NS_SUCCEEDED(rv));
+    }
+    if (evictedAsNonPinned) {
+      rv = DoomFileInternal(handle, DOOM_WHEN_NON_PINNED);
+      MOZ_ASSERT(!handle->IsDoomed() && NS_SUCCEEDED(rv));
+    }
+
+    rv = file->GetFileSize(&handle->mFileSize);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    handle->mFileExists = true;
+
+    CacheIndex::EnsureEntryExists(aHash);
+  } else {
+    handle->mFileSize = 0;
+
+    CacheIndex::AddEntry(aHash);
+  }
+
+  handle->mFile.swap(file);
+  handle.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::OpenSpecialFileInternal(const nsACString &aKey,
+                                            uint32_t aFlags,
+                                            CacheFileHandle **_retval)
+{
+  LOG(("CacheFileIOManager::OpenSpecialFileInternal() [key=%s, flags=%d]",
+       PromiseFlatCString(aKey).get(), aFlags));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsresult rv;
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  nsCOMPtr<nsIFile> file;
+  rv = GetSpecialFile(aKey, getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<CacheFileHandle> handle;
+  for (uint32_t i = 0 ; i < mSpecialHandles.Length() ; i++) {
+    if (!mSpecialHandles[i]->IsDoomed() && mSpecialHandles[i]->Key() == aKey) {
+      handle = mSpecialHandles[i];
+      break;
+    }
+  }
+
+  if ((aFlags & (OPEN | CREATE | CREATE_NEW)) == CREATE_NEW) {
+    if (handle) {
+      rv = DoomFileInternal(handle);
+      NS_ENSURE_SUCCESS(rv, rv);
+      handle = nullptr;
+    }
+
+    handle = new CacheFileHandle(aKey, aFlags & PRIORITY, CacheFileHandle::PinningStatus::NON_PINNED);
+    mSpecialHandles.AppendElement(handle);
+
+    bool exists;
+    rv = file->Exists(&exists);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (exists) {
+      LOG(("CacheFileIOManager::OpenSpecialFileInternal() - Removing file from "
+           "disk"));
+      rv = file->Remove(false);
+      if (NS_FAILED(rv)) {
+        NS_WARNING("Cannot remove old entry from the disk");
+        LOG(("CacheFileIOManager::OpenSpecialFileInternal() - Removing file "
+             "failed. [rv=0x%08x]", rv));
+      }
+    }
+
+    handle->mFile.swap(file);
+    handle->mFileSize = 0;
+  }
+
+  if (handle) {
+    handle.swap(*_retval);
+    return NS_OK;
+  }
+
+  bool exists;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!exists && (aFlags & (OPEN | CREATE | CREATE_NEW)) == OPEN) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  handle = new CacheFileHandle(aKey, aFlags & PRIORITY, CacheFileHandle::PinningStatus::NON_PINNED);
+  mSpecialHandles.AppendElement(handle);
+
+  if (exists) {
+    rv = file->GetFileSize(&handle->mFileSize);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    handle->mFileExists = true;
+  } else {
+    handle->mFileSize = 0;
+  }
+
+  handle->mFile.swap(file);
+  handle.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CloseHandleInternal(CacheFileHandle *aHandle)
+{
+  nsresult rv;
+
+  LOG(("CacheFileIOManager::CloseHandleInternal() [handle=%p]", aHandle));
+
+  MOZ_ASSERT(!aHandle->IsClosed());
+
+  aHandle->Log();
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  // Maybe close file handle (can be legally bypassed after shutdown)
+  rv = MaybeReleaseNSPRHandleInternal(aHandle);
+
+  // Delete the file if the entry was doomed or invalid and
+  // filedesc properly closed
+  if ((aHandle->mIsDoomed || aHandle->mInvalid) && NS_SUCCEEDED(rv)) {
+    LOG(("CacheFileIOManager::CloseHandleInternal() - Removing file from "
+         "disk"));
+
+    aHandle->mFile->Remove(false);
+  }
+
+  if (!aHandle->IsSpecialFile() && !aHandle->mIsDoomed &&
+      (aHandle->mInvalid || !aHandle->mFileExists)) {
+    CacheIndex::RemoveEntry(aHandle->Hash());
+  }
+
+  // Don't remove handles after shutdown
+  if (!mShuttingDown) {
+    if (aHandle->IsSpecialFile()) {
+      mSpecialHandles.RemoveElement(aHandle);
+    } else {
+      mHandles.RemoveHandle(aHandle);
+    }
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::Read(CacheFileHandle *aHandle, int64_t aOffset,
+                         char *aBuf, int32_t aCount,
+                         CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::Read() [handle=%p, offset=%lld, count=%d, "
+       "listener=%p]", aHandle, aOffset, aCount, aCallback));
+
+  if (CacheObserver::ShuttingDown()) {
+    LOG(("  no reads after shutdown"));
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<ReadEvent> ev = new ReadEvent(aHandle, aOffset, aBuf, aCount,
+                                         aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->IsPriority()
+    ? CacheIOThread::READ_PRIORITY
+    : CacheIOThread::READ);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::ReadInternal(CacheFileHandle *aHandle, int64_t aOffset,
+                                 char *aBuf, int32_t aCount)
+{
+  LOG(("CacheFileIOManager::ReadInternal() [handle=%p, offset=%lld, count=%d]",
+       aHandle, aOffset, aCount));
+
+  nsresult rv;
+
+  if (CacheObserver::ShuttingDown()) {
+    LOG(("  no reads after shutdown"));
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!aHandle->mFileExists) {
+    NS_WARNING("Trying to read from non-existent file");
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  if (!aHandle->mFD) {
+    rv = OpenNSPRHandle(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    NSPRHandleUsed(aHandle);
+  }
+
+  // Check again, OpenNSPRHandle could figure out the file was gone.
+  if (!aHandle->mFileExists) {
+    NS_WARNING("Trying to read from non-existent file");
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  int64_t offset = PR_Seek64(aHandle->mFD, aOffset, PR_SEEK_SET);
+  if (offset == -1) {
+    return NS_ERROR_FAILURE;
+  }
+
+  int32_t bytesRead = PR_Read(aHandle->mFD, aBuf, aCount);
+  if (bytesRead != aCount) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::Write(CacheFileHandle *aHandle, int64_t aOffset,
+                          const char *aBuf, int32_t aCount, bool aValidate,
+                          bool aTruncate, CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::Write() [handle=%p, offset=%lld, count=%d, "
+       "validate=%d, truncate=%d, listener=%p]", aHandle, aOffset, aCount,
+       aValidate, aTruncate, aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || (aCallback && aCallback->IsKilled()) || !ioMan) {
+    if (!aCallback) {
+      // When no callback is provided, CacheFileIOManager is responsible for
+      // releasing the buffer. We must release it even in case of failure.
+      free(const_cast<char *>(aBuf));
+    }
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<WriteEvent> ev = new WriteEvent(aHandle, aOffset, aBuf, aCount,
+                                           aValidate, aTruncate, aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+static nsresult
+TruncFile(PRFileDesc *aFD, int64_t aEOF)
+{
+#if defined(XP_UNIX)
+  if (ftruncate(PR_FileDesc2NativeHandle(aFD), aEOF) != 0) {
+    NS_ERROR("ftruncate failed");
+    return NS_ERROR_FAILURE;
+  }
+#elif defined(XP_WIN)
+  int64_t cnt = PR_Seek64(aFD, aEOF, PR_SEEK_SET);
+  if (cnt == -1) {
+    return NS_ERROR_FAILURE;
+  }
+  if (!SetEndOfFile((HANDLE) PR_FileDesc2NativeHandle(aFD))) {
+    NS_ERROR("SetEndOfFile failed");
+    return NS_ERROR_FAILURE;
+  }
+#else
+  MOZ_ASSERT(false, "Not implemented!");
+  return NS_ERROR_NOT_IMPLEMENTED;
+#endif
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::WriteInternal(CacheFileHandle *aHandle, int64_t aOffset,
+                                  const char *aBuf, int32_t aCount,
+                                  bool aValidate, bool aTruncate)
+{
+  LOG(("CacheFileIOManager::WriteInternal() [handle=%p, offset=%lld, count=%d, "
+       "validate=%d, truncate=%d]", aHandle, aOffset, aCount, aValidate,
+       aTruncate));
+
+  nsresult rv;
+
+  if (aHandle->mKilled) {
+    LOG(("  handle already killed, nothing written"));
+    return NS_OK;
+  }
+
+  if (CacheObserver::ShuttingDown() && (!aValidate || !aHandle->mFD)) {
+    aHandle->mKilled = true;
+    LOG(("  killing the handle, nothing written"));
+    return NS_OK;
+  }
+
+  if (CacheObserver::IsPastShutdownIOLag()) {
+    LOG(("  past the shutdown I/O lag, nothing written"));
+    // Pretend the write has succeeded, otherwise upper layers will doom
+    // the file and we end up with I/O anyway.
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  if (!aHandle->mFileExists) {
+    rv = CreateFile(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (!aHandle->mFD) {
+    rv = OpenNSPRHandle(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    NSPRHandleUsed(aHandle);
+  }
+
+  // Check again, OpenNSPRHandle could figure out the file was gone.
+  if (!aHandle->mFileExists) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Check whether this write would cause critical low disk space.
+  if (aHandle->mFileSize < aOffset + aCount) {
+    int64_t freeSpace = -1;
+    rv = mCacheDirectory->GetDiskSpaceAvailable(&freeSpace);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::WriteInternal() - GetDiskSpaceAvailable() "
+           "failed! [rv=0x%08x]", rv));
+    } else {
+      uint32_t limit = CacheObserver::DiskFreeSpaceHardLimit();
+      if (freeSpace - aOffset - aCount + aHandle->mFileSize < limit) {
+        LOG(("CacheFileIOManager::WriteInternal() - Low free space, refusing "
+             "to write! [freeSpace=%lld, limit=%u]", freeSpace, limit));
+        return NS_ERROR_FILE_DISK_FULL;
+      }
+    }
+  }
+
+  // Write invalidates the entry by default
+  aHandle->mInvalid = true;
+
+  int64_t offset = PR_Seek64(aHandle->mFD, aOffset, PR_SEEK_SET);
+  if (offset == -1) {
+    return NS_ERROR_FAILURE;
+  }
+
+  int32_t bytesWritten = PR_Write(aHandle->mFD, aBuf, aCount);
+
+  if (bytesWritten != -1) {
+    uint32_t oldSizeInK = aHandle->FileSizeInK();
+    int64_t writeEnd = aOffset + bytesWritten;
+
+    if (aTruncate) {
+      rv = TruncFile(aHandle->mFD, writeEnd);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      aHandle->mFileSize = writeEnd;
+    } else {
+      if (aHandle->mFileSize < writeEnd) {
+        aHandle->mFileSize = writeEnd;
+      }
+    }
+
+    uint32_t newSizeInK = aHandle->FileSizeInK();
+
+    if (oldSizeInK != newSizeInK && !aHandle->IsDoomed() &&
+        !aHandle->IsSpecialFile()) {
+      CacheIndex::UpdateEntry(aHandle->Hash(), nullptr, nullptr, &newSizeInK);
+
+      if (oldSizeInK < newSizeInK) {
+        EvictIfOverLimitInternal();
+      }
+    }
+  }
+
+  if (bytesWritten != aCount) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Write was successful and this write validates the entry (i.e. metadata)
+  if (aValidate) {
+    aHandle->mInvalid = false;
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::DoomFile(CacheFileHandle *aHandle,
+                             CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::DoomFile() [handle=%p, listener=%p]",
+       aHandle, aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<DoomFileEvent> ev = new DoomFileEvent(aHandle, aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->IsPriority()
+    ? CacheIOThread::OPEN_PRIORITY
+    : CacheIOThread::OPEN);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::DoomFileInternal(CacheFileHandle *aHandle,
+                                     PinningDoomRestriction aPinningDoomRestriction)
+{
+  LOG(("CacheFileIOManager::DoomFileInternal() [handle=%p]", aHandle));
+  aHandle->Log();
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  nsresult rv;
+
+  if (aHandle->IsDoomed()) {
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  if (aPinningDoomRestriction > NO_RESTRICTION) {
+    switch (aHandle->mPinning) {
+    case CacheFileHandle::PinningStatus::NON_PINNED:
+      if (MOZ_LIKELY(aPinningDoomRestriction != DOOM_WHEN_NON_PINNED)) {
+        LOG(("  not dooming, it's a non-pinned handle"));
+        return NS_OK;
+      }
+      // Doom now
+      break;
+
+    case CacheFileHandle::PinningStatus::PINNED:
+      if (MOZ_UNLIKELY(aPinningDoomRestriction != DOOM_WHEN_PINNED)) {
+        LOG(("  not dooming, it's a pinned handle"));
+        return NS_OK;
+      }
+      // Doom now
+      break;
+
+    case CacheFileHandle::PinningStatus::UNKNOWN:
+      if (MOZ_LIKELY(aPinningDoomRestriction == DOOM_WHEN_NON_PINNED)) {
+        LOG(("  doom when non-pinned set"));
+        aHandle->mDoomWhenFoundNonPinned = true;
+      } else if (MOZ_UNLIKELY(aPinningDoomRestriction == DOOM_WHEN_PINNED)) {
+        LOG(("  doom when pinned set"));
+        aHandle->mDoomWhenFoundPinned = true;
+      }
+
+      LOG(("  pinning status not known, deferring doom decision"));
+      return NS_OK;
+    }
+  }
+
+  if (aHandle->mFileExists) {
+    // we need to move the current file to the doomed directory
+    rv = MaybeReleaseNSPRHandleInternal(aHandle, true);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // find unused filename
+    nsCOMPtr<nsIFile> file;
+    rv = GetDoomedFile(getter_AddRefs(file));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIFile> parentDir;
+    rv = file->GetParent(getter_AddRefs(parentDir));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoCString leafName;
+    rv = file->GetNativeLeafName(leafName);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = aHandle->mFile->MoveToNative(parentDir, leafName);
+    if (NS_ERROR_FILE_NOT_FOUND == rv || NS_ERROR_FILE_TARGET_DOES_NOT_EXIST == rv) {
+      LOG(("  file already removed under our hands"));
+      aHandle->mFileExists = false;
+      rv = NS_OK;
+    } else {
+      NS_ENSURE_SUCCESS(rv, rv);
+      aHandle->mFile.swap(file);
+    }
+  }
+
+  if (!aHandle->IsSpecialFile()) {
+    CacheIndex::RemoveEntry(aHandle->Hash());
+  }
+
+  aHandle->mIsDoomed = true;
+
+  if (!aHandle->IsSpecialFile()) {
+    RefPtr<CacheStorageService> storageService = CacheStorageService::Self();
+    if (storageService) {
+      nsAutoCString idExtension, url;
+      nsCOMPtr<nsILoadContextInfo> info =
+        CacheFileUtils::ParseKey(aHandle->Key(), &idExtension, &url);
+      MOZ_ASSERT(info);
+      if (info) {
+        storageService->CacheFileDoomed(info, idExtension, url);
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::DoomFileByKey(const nsACString &aKey,
+                                  CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::DoomFileByKey() [key=%s, listener=%p]",
+       PromiseFlatCString(aKey).get(), aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<DoomFileByKeyEvent> ev = new DoomFileByKeyEvent(aKey, aCallback);
+  rv = ioMan->mIOThread->DispatchAfterPendingOpens(ev);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::DoomFileByKeyInternal(const SHA1Sum::Hash *aHash)
+{
+  LOG(("CacheFileIOManager::DoomFileByKeyInternal() [hash=%08x%08x%08x%08x%08x]"
+       , LOGSHA1(aHash)));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  nsresult rv;
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mCacheDirectory) {
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  // Find active handle
+  RefPtr<CacheFileHandle> handle;
+  mHandles.GetHandle(aHash, getter_AddRefs(handle));
+
+  if (handle) {
+    handle->Log();
+
+    return DoomFileInternal(handle);
+  }
+
+  CacheIOThread::Cancelable cancelable(true);
+
+  // There is no handle for this file, delete the file if exists
+  nsCOMPtr<nsIFile> file;
+  rv = GetFile(aHash, getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool exists;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!exists) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  LOG(("CacheFileIOManager::DoomFileByKeyInternal() - Removing file from "
+       "disk"));
+  rv = file->Remove(false);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("Cannot remove old entry from the disk");
+    LOG(("CacheFileIOManager::DoomFileByKeyInternal() - Removing file failed. "
+         "[rv=0x%08x]", rv));
+  }
+
+  CacheIndex::RemoveEntry(aHash);
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::ReleaseNSPRHandle(CacheFileHandle *aHandle)
+{
+  LOG(("CacheFileIOManager::ReleaseNSPRHandle() [handle=%p]", aHandle));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<ReleaseNSPRHandleEvent> ev = new ReleaseNSPRHandleEvent(aHandle);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::MaybeReleaseNSPRHandleInternal(CacheFileHandle *aHandle,
+                                                   bool aIgnoreShutdownLag)
+{
+  LOG(("CacheFileIOManager::MaybeReleaseNSPRHandleInternal() [handle=%p, ignore shutdown=%d]",
+       aHandle, aIgnoreShutdownLag));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  if (aHandle->mFD) {
+    DebugOnly<bool> found;
+    found = mHandlesByLastUsed.RemoveElement(aHandle);
+    MOZ_ASSERT(found);
+  }
+
+  PRFileDesc *fd = aHandle->mFD;
+  aHandle->mFD = nullptr;
+
+  // Leak invalid (w/o metadata) and doomed handles immediately after shutdown.
+  // Leak other handles when past the shutdown time maximum lag.
+  if (
+#ifndef DEBUG
+      ((aHandle->mInvalid || aHandle->mIsDoomed) &&
+      MOZ_UNLIKELY(CacheObserver::ShuttingDown())) ||
+#endif
+      MOZ_UNLIKELY(!aIgnoreShutdownLag &&
+                   CacheObserver::IsPastShutdownIOLag())) {
+    // Don't bother closing this file.  Return a failure code from here will
+    // cause any following IO operation on the file (mainly removal) to be
+    // bypassed, which is what we want.
+    // For mInvalid == true the entry will never be used, since it doesn't
+    // have correct metadata, thus we don't need to worry about removing it.
+    // For mIsDoomed == true the file is already in the doomed sub-dir and
+    // will be removed on next session start.
+    LOG(("  past the shutdown I/O lag, leaking file handle"));
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+
+  if (!fd) {
+    // The filedesc has already been closed before, just let go.
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  PRStatus status = PR_Close(fd);
+  if (status != PR_SUCCESS) {
+    LOG(("CacheFileIOManager::MaybeReleaseNSPRHandleInternal() "
+         "failed to close [handle=%p, status=%u]", aHandle, status));
+    return NS_ERROR_FAILURE;
+  }
+
+  LOG(("CacheFileIOManager::MaybeReleaseNSPRHandleInternal() DONE"));
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::TruncateSeekSetEOF(CacheFileHandle *aHandle,
+                                       int64_t aTruncatePos, int64_t aEOFPos,
+                                       CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::TruncateSeekSetEOF() [handle=%p, truncatePos=%lld, "
+       "EOFPos=%lld, listener=%p]", aHandle, aTruncatePos, aEOFPos, aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || (aCallback && aCallback->IsKilled()) || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<TruncateSeekSetEOFEvent> ev = new TruncateSeekSetEOFEvent(
+                                           aHandle, aTruncatePos, aEOFPos,
+                                           aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+// static
+void CacheFileIOManager::GetCacheDirectory(nsIFile** result)
+{
+  *result = nullptr;
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (!ioMan || !ioMan->mCacheDirectory) {
+    return;
+  }
+
+  ioMan->mCacheDirectory->Clone(result);
+}
+
+#if defined(MOZ_WIDGET_ANDROID)
+
+// static
+void CacheFileIOManager::GetProfilelessCacheDirectory(nsIFile** result)
+{
+  *result = nullptr;
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (!ioMan || !ioMan->mCacheProfilelessDirectory) {
+    return;
+  }
+
+  ioMan->mCacheProfilelessDirectory->Clone(result);
+}
+
+#endif
+
+// static
+nsresult
+CacheFileIOManager::GetEntryInfo(const SHA1Sum::Hash *aHash,
+                                 CacheStorageService::EntryInfoCallback *aCallback)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsresult rv;
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsAutoCString enhanceId;
+  nsAutoCString uriSpec;
+
+  RefPtr<CacheFileHandle> handle;
+  ioMan->mHandles.GetHandle(aHash, getter_AddRefs(handle));
+  if (handle) {
+    RefPtr<nsILoadContextInfo> info =
+      CacheFileUtils::ParseKey(handle->Key(), &enhanceId, &uriSpec);
+
+    MOZ_ASSERT(info);
+    if (!info) {
+      return NS_OK; // ignore
+    }
+
+    RefPtr<CacheStorageService> service = CacheStorageService::Self();
+    if (!service) {
+      return NS_ERROR_NOT_INITIALIZED;
+    }
+
+    // Invokes OnCacheEntryInfo when an existing entry is found
+    if (service->GetCacheEntryInfo(info, enhanceId, uriSpec, aCallback)) {
+      return NS_OK;
+    }
+
+    // When we are here, there is no existing entry and we need
+    // to synchrnously load metadata from a disk file.
+  }
+
+  // Locate the actual file
+  nsCOMPtr<nsIFile> file;
+  ioMan->GetFile(aHash, getter_AddRefs(file));
+
+  // Read metadata from the file synchronously
+  RefPtr<CacheFileMetadata> metadata = new CacheFileMetadata();
+  rv = metadata->SyncReadMetadata(file);
+  if (NS_FAILED(rv)) {
+    return NS_OK;
+  }
+
+  // Now get the context + enhance id + URL from the key.
+  nsAutoCString key;
+  metadata->GetKey(key);
+
+  RefPtr<nsILoadContextInfo> info =
+    CacheFileUtils::ParseKey(key, &enhanceId, &uriSpec);
+  MOZ_ASSERT(info);
+  if (!info) {
+    return NS_OK;
+  }
+
+  // Pick all data to pass to the callback.
+  int64_t dataSize = metadata->Offset();
+  uint32_t fetchCount;
+  if (NS_FAILED(metadata->GetFetchCount(&fetchCount))) {
+    fetchCount = 0;
+  }
+  uint32_t expirationTime;
+  if (NS_FAILED(metadata->GetExpirationTime(&expirationTime))) {
+    expirationTime = 0;
+  }
+  uint32_t lastModified;
+  if (NS_FAILED(metadata->GetLastModified(&lastModified))) {
+    lastModified = 0;
+  }
+
+  // Call directly on the callback.
+  aCallback->OnEntryInfo(uriSpec, enhanceId, dataSize, fetchCount,
+                         lastModified, expirationTime, metadata->Pinned());
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::TruncateSeekSetEOFInternal(CacheFileHandle *aHandle,
+                                               int64_t aTruncatePos,
+                                               int64_t aEOFPos)
+{
+  LOG(("CacheFileIOManager::TruncateSeekSetEOFInternal() [handle=%p, "
+       "truncatePos=%lld, EOFPos=%lld]", aHandle, aTruncatePos, aEOFPos));
+
+  nsresult rv;
+
+  if (aHandle->mKilled) {
+    LOG(("  handle already killed, file not truncated"));
+    return NS_OK;
+  }
+
+  if (CacheObserver::ShuttingDown() && !aHandle->mFD) {
+    aHandle->mKilled = true;
+    LOG(("  killing the handle, file not truncated"));
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  if (!aHandle->mFileExists) {
+    rv = CreateFile(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (!aHandle->mFD) {
+    rv = OpenNSPRHandle(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    NSPRHandleUsed(aHandle);
+  }
+
+  // Check again, OpenNSPRHandle could figure out the file was gone.
+  if (!aHandle->mFileExists) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Check whether this operation would cause critical low disk space.
+  if (aHandle->mFileSize < aEOFPos) {
+    int64_t freeSpace = -1;
+    rv = mCacheDirectory->GetDiskSpaceAvailable(&freeSpace);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::TruncateSeekSetEOFInternal() - "
+           "GetDiskSpaceAvailable() failed! [rv=0x%08x]", rv));
+    } else {
+      uint32_t limit = CacheObserver::DiskFreeSpaceHardLimit();
+      if (freeSpace - aEOFPos + aHandle->mFileSize < limit) {
+        LOG(("CacheFileIOManager::TruncateSeekSetEOFInternal() - Low free space"
+             ", refusing to write! [freeSpace=%lld, limit=%u]", freeSpace,
+             limit));
+        return NS_ERROR_FILE_DISK_FULL;
+      }
+    }
+  }
+
+  // This operation always invalidates the entry
+  aHandle->mInvalid = true;
+
+  rv = TruncFile(aHandle->mFD, aTruncatePos);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (aTruncatePos != aEOFPos) {
+    rv = TruncFile(aHandle->mFD, aEOFPos);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  uint32_t oldSizeInK = aHandle->FileSizeInK();
+  aHandle->mFileSize = aEOFPos;
+  uint32_t newSizeInK = aHandle->FileSizeInK();
+
+  if (oldSizeInK != newSizeInK && !aHandle->IsDoomed() &&
+      !aHandle->IsSpecialFile()) {
+    CacheIndex::UpdateEntry(aHandle->Hash(), nullptr, nullptr, &newSizeInK);
+
+    if (oldSizeInK < newSizeInK) {
+      EvictIfOverLimitInternal();
+    }
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::RenameFile(CacheFileHandle *aHandle,
+                               const nsACString &aNewName,
+                               CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::RenameFile() [handle=%p, newName=%s, listener=%p]",
+       aHandle, PromiseFlatCString(aNewName).get(), aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!aHandle->IsSpecialFile()) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  RefPtr<RenameFileEvent> ev = new RenameFileEvent(aHandle, aNewName,
+                                                     aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::RenameFileInternal(CacheFileHandle *aHandle,
+                                       const nsACString &aNewName)
+{
+  LOG(("CacheFileIOManager::RenameFileInternal() [handle=%p, newName=%s]",
+       aHandle, PromiseFlatCString(aNewName).get()));
+
+  nsresult rv;
+
+  MOZ_ASSERT(aHandle->IsSpecialFile());
+
+  if (aHandle->IsDoomed()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Doom old handle if it exists and is not doomed
+  for (uint32_t i = 0 ; i < mSpecialHandles.Length() ; i++) {
+    if (!mSpecialHandles[i]->IsDoomed() &&
+        mSpecialHandles[i]->Key() == aNewName) {
+      MOZ_ASSERT(aHandle != mSpecialHandles[i]);
+      rv = DoomFileInternal(mSpecialHandles[i]);
+      NS_ENSURE_SUCCESS(rv, rv);
+      break;
+    }
+  }
+
+  nsCOMPtr<nsIFile> file;
+  rv = GetSpecialFile(aNewName, getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool exists;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (exists) {
+    LOG(("CacheFileIOManager::RenameFileInternal() - Removing old file from "
+         "disk"));
+    rv = file->Remove(false);
+    if (NS_FAILED(rv)) {
+      NS_WARNING("Cannot remove file from the disk");
+      LOG(("CacheFileIOManager::RenameFileInternal() - Removing old file failed"
+           ". [rv=0x%08x]", rv));
+    }
+  }
+
+  if (!aHandle->FileExists()) {
+    aHandle->mKey = aNewName;
+    return NS_OK;
+  }
+
+  rv = MaybeReleaseNSPRHandleInternal(aHandle, true);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = aHandle->mFile->MoveToNative(nullptr, aNewName);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aHandle->mKey = aNewName;
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::EvictIfOverLimit()
+{
+  LOG(("CacheFileIOManager::EvictIfOverLimit()"));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(ioMan,
+			 &CacheFileIOManager::EvictIfOverLimitInternal);
+
+  rv = ioMan->mIOThread->Dispatch(ev, CacheIOThread::EVICT);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::EvictIfOverLimitInternal()
+{
+  LOG(("CacheFileIOManager::EvictIfOverLimitInternal()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (mOverLimitEvicting) {
+    LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - Eviction already "
+         "running."));
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(true);
+
+  int64_t freeSpace;
+  rv = mCacheDirectory->GetDiskSpaceAvailable(&freeSpace);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    freeSpace = -1;
+
+    // Do not change smart size.
+    LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - "
+         "GetDiskSpaceAvailable() failed! [rv=0x%08x]", rv));
+  } else {
+    UpdateSmartCacheSize(freeSpace);
+  }
+
+  uint32_t cacheUsage;
+  rv = CacheIndex::GetCacheSize(&cacheUsage);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint32_t cacheLimit = CacheObserver::DiskCacheCapacity() >> 10;
+  uint32_t freeSpaceLimit = CacheObserver::DiskFreeSpaceSoftLimit();
+
+  if (cacheUsage <= cacheLimit &&
+      (freeSpace == -1 || freeSpace >= freeSpaceLimit)) {
+    LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - Cache size and free "
+         "space in limits. [cacheSize=%ukB, cacheSizeLimit=%ukB, "
+         "freeSpace=%lld, freeSpaceLimit=%u]", cacheUsage, cacheLimit,
+         freeSpace, freeSpaceLimit));
+    return NS_OK;
+  }
+
+  LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - Cache size exceeded "
+       "limit. Starting overlimit eviction. [cacheSize=%u, limit=%u]",
+       cacheUsage, cacheLimit));
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(this,
+			 &CacheFileIOManager::OverLimitEvictionInternal);
+
+  rv = mIOThread->Dispatch(ev, CacheIOThread::EVICT);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mOverLimitEvicting = true;
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::OverLimitEvictionInternal()
+{
+  LOG(("CacheFileIOManager::OverLimitEvictionInternal()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  // mOverLimitEvicting is accessed only on IO thread, so we can set it to false
+  // here and set it to true again once we dispatch another event that will
+  // continue with the eviction. The reason why we do so is that we can fail
+  // early anywhere in this method and the variable will contain a correct
+  // value. Otherwise we would need to set it to false on every failing place.
+  mOverLimitEvicting = false;
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  while (true) {
+    int64_t freeSpace = -1;
+    rv = mCacheDirectory->GetDiskSpaceAvailable(&freeSpace);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      // Do not change smart size.
+      LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - "
+           "GetDiskSpaceAvailable() failed! [rv=0x%08x]", rv));
+    } else {
+      UpdateSmartCacheSize(freeSpace);
+    }
+
+    uint32_t cacheUsage;
+    rv = CacheIndex::GetCacheSize(&cacheUsage);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    uint32_t cacheLimit = CacheObserver::DiskCacheCapacity() >> 10;
+    uint32_t freeSpaceLimit = CacheObserver::DiskFreeSpaceSoftLimit();
+
+    if (cacheUsage > cacheLimit) {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - Cache size over "
+           "limit. [cacheSize=%u, limit=%u]", cacheUsage, cacheLimit));
+    } else if (freeSpace != 1 && freeSpace < freeSpaceLimit) {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - Free space under "
+           "limit. [freeSpace=%lld, freeSpaceLimit=%u]", freeSpace,
+           freeSpaceLimit));
+    } else {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - Cache size and "
+           "free space in limits. [cacheSize=%ukB, cacheSizeLimit=%ukB, "
+           "freeSpace=%lld, freeSpaceLimit=%u]", cacheUsage, cacheLimit,
+           freeSpace, freeSpaceLimit));
+      return NS_OK;
+    }
+
+    if (CacheIOThread::YieldAndRerun()) {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - Breaking loop "
+           "for higher level events."));
+      mOverLimitEvicting = true;
+      return NS_OK;
+    }
+
+    SHA1Sum::Hash hash;
+    uint32_t cnt;
+    static uint32_t consecutiveFailures = 0;
+    rv = CacheIndex::GetEntryForEviction(false, &hash, &cnt);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = DoomFileByKeyInternal(&hash);
+    if (NS_SUCCEEDED(rv)) {
+      consecutiveFailures = 0;
+    } else if (rv == NS_ERROR_NOT_AVAILABLE) {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - "
+           "DoomFileByKeyInternal() failed. [rv=0x%08x]", rv));
+      // TODO index is outdated, start update
+
+      // Make sure index won't return the same entry again
+      CacheIndex::RemoveEntry(&hash);
+      consecutiveFailures = 0;
+    } else {
+      // This shouldn't normally happen, but the eviction must not fail
+      // completely if we ever encounter this problem.
+      NS_WARNING("CacheFileIOManager::OverLimitEvictionInternal() - Unexpected "
+                 "failure of DoomFileByKeyInternal()");
+
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - "
+           "DoomFileByKeyInternal() failed. [rv=0x%08x]", rv));
+
+      // Normally, CacheIndex::UpdateEntry() is called only to update newly
+      // created/opened entries which are always fresh and UpdateEntry() expects
+      // and checks this flag. The way we use UpdateEntry() here is a kind of
+      // hack and we must make sure the flag is set by calling
+      // EnsureEntryExists().
+      rv = CacheIndex::EnsureEntryExists(&hash);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Move the entry at the end of both lists to make sure we won't end up
+      // failing on one entry forever.
+      uint32_t frecency = 0;
+      uint32_t expTime = nsICacheEntry::NO_EXPIRATION_TIME;
+      rv = CacheIndex::UpdateEntry(&hash, &frecency, &expTime, nullptr);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      consecutiveFailures++;
+      if (consecutiveFailures >= cnt) {
+        // This doesn't necessarily mean that we've tried to doom every entry
+        // but we've reached a sane number of tries. It is likely that another
+        // eviction will start soon. And as said earlier, this normally doesn't
+        // happen at all.
+        return NS_OK;
+      }
+    }
+  }
+
+  NS_NOTREACHED("We should never get here");
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::EvictAll()
+{
+  LOG(("CacheFileIOManager::EvictAll()"));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(ioMan, &CacheFileIOManager::EvictAllInternal);
+
+  rv = ioMan->mIOThread->DispatchAfterPendingOpens(ev);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+namespace {
+
+class EvictionNotifierRunnable : public Runnable
+{
+public:
+  NS_DECL_NSIRUNNABLE
+};
+
+NS_IMETHODIMP
+EvictionNotifierRunnable::Run()
+{
+  nsCOMPtr<nsIObserverService> obsSvc = mozilla::services::GetObserverService();
+  if (obsSvc) {
+    obsSvc->NotifyObservers(nullptr, "cacheservice:empty-cache", nullptr);
+  }
+  return NS_OK;
+}
+
+} // namespace
+
+nsresult
+CacheFileIOManager::EvictAllInternal()
+{
+  LOG(("CacheFileIOManager::EvictAllInternal()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  RefPtr<EvictionNotifierRunnable> r = new EvictionNotifierRunnable();
+
+  if (!mCacheDirectory) {
+    // This is a kind of hack. Somebody called EvictAll() without a profile.
+    // This happens in xpcshell tests that use cache without profile. We need
+    // to notify observers in this case since the tests are waiting for it.
+    NS_DispatchToMainThread(r);
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  // Doom all active handles
+  nsTArray<RefPtr<CacheFileHandle> > handles;
+  mHandles.GetActiveHandles(&handles);
+
+  for (uint32_t i = 0; i < handles.Length(); ++i) {
+    rv = DoomFileInternal(handles[i]);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::EvictAllInternal() - Cannot doom handle "
+           "[handle=%p]", handles[i].get()));
+    }
+  }
+
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  rv = file->AppendNative(NS_LITERAL_CSTRING(ENTRIES_DIR));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  // Trash current entries directory
+  rv = TrashDirectory(file);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  // Files are now inaccessible in entries directory, notify observers.
+  NS_DispatchToMainThread(r);
+
+  // Create a new empty entries directory
+  rv = CheckAndCreateDir(mCacheDirectory, ENTRIES_DIR, false);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  CacheIndex::RemoveAll();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::EvictByContext(nsILoadContextInfo *aLoadContextInfo, bool aPinned)
+{
+  LOG(("CacheFileIOManager::EvictByContext() [loadContextInfo=%p]",
+       aLoadContextInfo));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod<nsCOMPtr<nsILoadContextInfo>, bool>
+         (ioMan, &CacheFileIOManager::EvictByContextInternal, aLoadContextInfo, aPinned);
+
+  rv = ioMan->mIOThread->DispatchAfterPendingOpens(ev);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::EvictByContextInternal(nsILoadContextInfo *aLoadContextInfo, bool aPinned)
+{
+  LOG(("CacheFileIOManager::EvictByContextInternal() [loadContextInfo=%p, pinned=%d]",
+      aLoadContextInfo, aPinned));
+
+  nsresult rv;
+
+  if (aLoadContextInfo) {
+    nsAutoCString suffix;
+    aLoadContextInfo->OriginAttributesPtr()->CreateSuffix(suffix);
+    LOG(("  anonymous=%u, suffix=%s]", aLoadContextInfo->IsAnonymous(), suffix.get()));
+
+    MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+    MOZ_ASSERT(!aLoadContextInfo->IsPrivate());
+    if (aLoadContextInfo->IsPrivate()) {
+      return NS_ERROR_INVALID_ARG;
+    }
+  }
+
+  if (!mCacheDirectory) {
+    // This is a kind of hack. Somebody called EvictAll() without a profile.
+    // This happens in xpcshell tests that use cache without profile. We need
+    // to notify observers in this case since the tests are waiting for it.
+    // Also notify for aPinned == true, those are interested as well.
+    if (!aLoadContextInfo) {
+      RefPtr<EvictionNotifierRunnable> r = new EvictionNotifierRunnable();
+      NS_DispatchToMainThread(r);
+    }
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  // Doom all active handles that matches the load context
+  nsTArray<RefPtr<CacheFileHandle> > handles;
+  mHandles.GetActiveHandles(&handles);
+
+  for (uint32_t i = 0; i < handles.Length(); ++i) {
+    CacheFileHandle* handle = handles[i];
+
+    if (aLoadContextInfo) {
+      bool equals;
+      rv = CacheFileUtils::KeyMatchesLoadContextInfo(handle->Key(),
+                                                     aLoadContextInfo,
+                                                     &equals);
+      if (NS_FAILED(rv)) {
+        LOG(("CacheFileIOManager::EvictByContextInternal() - Cannot parse key in "
+             "handle! [handle=%p, key=%s]", handle, handle->Key().get()));
+        MOZ_CRASH("Unexpected error!");
+      }
+
+      if (!equals) {
+        continue;
+      }
+    }
+
+    // handle will be doomed only when pinning status is known and equal or
+    // doom decision will be deferred until pinning status is determined.
+    rv = DoomFileInternal(handle, aPinned
+                                  ? CacheFileIOManager::DOOM_WHEN_PINNED
+                                  : CacheFileIOManager::DOOM_WHEN_NON_PINNED);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::EvictByContextInternal() - Cannot doom handle"
+            " [handle=%p]", handle));
+    }
+  }
+
+  if (!aLoadContextInfo) {
+    RefPtr<EvictionNotifierRunnable> r = new EvictionNotifierRunnable();
+    NS_DispatchToMainThread(r);
+  }
+
+  if (!mContextEvictor) {
+    mContextEvictor = new CacheFileContextEvictor();
+    mContextEvictor->Init(mCacheDirectory);
+  }
+
+  mContextEvictor->AddContext(aLoadContextInfo, aPinned);
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::CacheIndexStateChanged()
+{
+  LOG(("CacheFileIOManager::CacheIndexStateChanged()"));
+
+  nsresult rv;
+
+  // CacheFileIOManager lives longer than CacheIndex so gInstance must be
+  // non-null here.
+  MOZ_ASSERT(gInstance);
+
+  // We have to re-distatch even if we are on IO thread to prevent reentering
+  // the lock in CacheIndex
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(
+    gInstance.get(), &CacheFileIOManager::CacheIndexStateChangedInternal);
+
+  nsCOMPtr<nsIEventTarget> ioTarget = IOTarget();
+  MOZ_ASSERT(ioTarget);
+
+  rv = ioTarget->Dispatch(ev, nsIEventTarget::DISPATCH_NORMAL);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CacheIndexStateChangedInternal()
+{
+  if (mShuttingDown) {
+    // ignore notification during shutdown
+    return NS_OK;
+  }
+
+  if (!mContextEvictor) {
+    return NS_OK;
+  }
+
+  mContextEvictor->CacheIndexStateChanged();
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::TrashDirectory(nsIFile *aFile)
+{
+  nsAutoCString path;
+  aFile->GetNativePath(path);
+  LOG(("CacheFileIOManager::TrashDirectory() [file=%s]", path.get()));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+  MOZ_ASSERT(mCacheDirectory);
+
+  // When the directory is empty, it is cheaper to remove it directly instead of
+  // using the trash mechanism.
+  bool isEmpty;
+  rv = IsEmptyDirectory(aFile, &isEmpty);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (isEmpty) {
+    rv = aFile->Remove(false);
+    LOG(("CacheFileIOManager::TrashDirectory() - Directory removed [rv=0x%08x]",
+         rv));
+    return rv;
+  }
+
+#ifdef DEBUG
+  nsCOMPtr<nsIFile> dirCheck;
+  rv = aFile->GetParent(getter_AddRefs(dirCheck));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool equals = false;
+  rv = dirCheck->Equals(mCacheDirectory, &equals);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  MOZ_ASSERT(equals);
+#endif
+
+  nsCOMPtr<nsIFile> dir, trash;
+  nsAutoCString leaf;
+
+  rv = aFile->Clone(getter_AddRefs(dir));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = aFile->Clone(getter_AddRefs(trash));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  const int32_t kMaxTries = 16;
+  srand(static_cast<unsigned>(PR_Now()));
+  for (int32_t triesCount = 0; ; ++triesCount) {
+    leaf = TRASH_DIR;
+    leaf.AppendInt(rand());
+    rv = trash->SetNativeLeafName(leaf);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    bool exists;
+    if (NS_SUCCEEDED(trash->Exists(&exists)) && !exists) {
+      break;
+    }
+
+    LOG(("CacheFileIOManager::TrashDirectory() - Trash directory already "
+         "exists [leaf=%s]", leaf.get()));
+
+    if (triesCount == kMaxTries) {
+      LOG(("CacheFileIOManager::TrashDirectory() - Could not find unused trash "
+           "directory in %d tries.", kMaxTries));
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  LOG(("CacheFileIOManager::TrashDirectory() - Renaming directory [leaf=%s]",
+       leaf.get()));
+
+  rv = dir->MoveToNative(nullptr, leaf);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  StartRemovingTrash();
+  return NS_OK;
+}
+
+// static
+void
+CacheFileIOManager::OnTrashTimer(nsITimer *aTimer, void *aClosure)
+{
+  LOG(("CacheFileIOManager::OnTrashTimer() [timer=%p, closure=%p]", aTimer,
+       aClosure));
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return;
+  }
+
+  ioMan->mTrashTimer = nullptr;
+  ioMan->StartRemovingTrash();
+}
+
+nsresult
+CacheFileIOManager::StartRemovingTrash()
+{
+  LOG(("CacheFileIOManager::StartRemovingTrash()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mCacheDirectory) {
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  if (mTrashTimer) {
+    LOG(("CacheFileIOManager::StartRemovingTrash() - Trash timer exists."));
+    return NS_OK;
+  }
+
+  if (mRemovingTrashDirs) {
+    LOG(("CacheFileIOManager::StartRemovingTrash() - Trash removing in "
+         "progress."));
+    return NS_OK;
+  }
+
+  uint32_t elapsed = (TimeStamp::NowLoRes() - mStartTime).ToMilliseconds();
+  if (elapsed < kRemoveTrashStartDelay) {
+    nsCOMPtr<nsITimer> timer = do_CreateInstance("@mozilla.org/timer;1", &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIEventTarget> ioTarget = IOTarget();
+    MOZ_ASSERT(ioTarget);
+
+    rv = timer->SetTarget(ioTarget);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = timer->InitWithFuncCallback(CacheFileIOManager::OnTrashTimer, nullptr,
+                                     kRemoveTrashStartDelay - elapsed,
+                                     nsITimer::TYPE_ONE_SHOT);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mTrashTimer.swap(timer);
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(this,
+			 &CacheFileIOManager::RemoveTrashInternal);
+
+  rv = mIOThread->Dispatch(ev, CacheIOThread::EVICT);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mRemovingTrashDirs = true;
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::RemoveTrashInternal()
+{
+  LOG(("CacheFileIOManager::RemoveTrashInternal()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  CacheIOThread::Cancelable cancelable(true);
+
+  MOZ_ASSERT(!mTrashTimer);
+  MOZ_ASSERT(mRemovingTrashDirs);
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  // mRemovingTrashDirs is accessed only on IO thread, so we can drop the flag
+  // here and set it again once we dispatch a continuation event. By doing so,
+  // we don't have to drop the flag on any possible early return.
+  mRemovingTrashDirs = false;
+
+  while (true) {
+    if (CacheIOThread::YieldAndRerun()) {
+      LOG(("CacheFileIOManager::RemoveTrashInternal() - Breaking loop for "
+           "higher level events."));
+      mRemovingTrashDirs = true;
+      return NS_OK;
+    }
+
+    // Find some trash directory
+    if (!mTrashDir) {
+      MOZ_ASSERT(!mTrashDirEnumerator);
+
+      rv = FindTrashDirToRemove();
+      if (rv == NS_ERROR_NOT_AVAILABLE) {
+        LOG(("CacheFileIOManager::RemoveTrashInternal() - No trash directory "
+             "found."));
+        return NS_OK;
+      }
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      nsCOMPtr<nsISimpleEnumerator> enumerator;
+      rv = mTrashDir->GetDirectoryEntries(getter_AddRefs(enumerator));
+      if (NS_SUCCEEDED(rv)) {
+        mTrashDirEnumerator = do_QueryInterface(enumerator, &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+
+      continue; // check elapsed time
+    }
+
+    // We null out mTrashDirEnumerator once we remove all files in the
+    // directory, so remove the trash directory if we don't have enumerator.
+    if (!mTrashDirEnumerator) {
+      rv = mTrashDir->Remove(false);
+      if (NS_FAILED(rv)) {
+        // There is no reason why removing an empty directory should fail, but
+        // if it does, we should continue and try to remove all other trash
+        // directories.
+        nsAutoCString leafName;
+        mTrashDir->GetNativeLeafName(leafName);
+        mFailedTrashDirs.AppendElement(leafName);
+        LOG(("CacheFileIOManager::RemoveTrashInternal() - Cannot remove "
+             "trashdir. [name=%s]", leafName.get()));
+      }
+
+      mTrashDir = nullptr;
+      continue; // check elapsed time
+    }
+
+    nsCOMPtr<nsIFile> file;
+    rv = mTrashDirEnumerator->GetNextFile(getter_AddRefs(file));
+    if (!file) {
+      mTrashDirEnumerator->Close();
+      mTrashDirEnumerator = nullptr;
+      continue; // check elapsed time
+    } else {
+      bool isDir = false;
+      file->IsDirectory(&isDir);
+      if (isDir) {
+        NS_WARNING("Found a directory in a trash directory! It will be removed "
+                   "recursively, but this can block IO thread for a while!");
+        if (LOG_ENABLED()) {
+          nsAutoCString path;
+          file->GetNativePath(path);
+          LOG(("CacheFileIOManager::RemoveTrashInternal() - Found a directory in a trash "
+              "directory! It will be removed recursively, but this can block IO "
+              "thread for a while! [file=%s]", path.get()));
+        }
+      }
+      file->Remove(isDir);
+    }
+  }
+
+  NS_NOTREACHED("We should never get here");
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::FindTrashDirToRemove()
+{
+  LOG(("CacheFileIOManager::FindTrashDirToRemove()"));
+
+  nsresult rv;
+
+  // We call this method on the main thread during shutdown when user wants to
+  // remove all cache files.
+  MOZ_ASSERT(mIOThread->IsCurrentThread() || mShuttingDown);
+
+  nsCOMPtr<nsISimpleEnumerator> iter;
+  rv = mCacheDirectory->GetDirectoryEntries(getter_AddRefs(iter));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool more;
+  nsCOMPtr<nsISupports> elem;
+
+  while (NS_SUCCEEDED(iter->HasMoreElements(&more)) && more) {
+    rv = iter->GetNext(getter_AddRefs(elem));
+    if (NS_FAILED(rv)) {
+      continue;
+    }
+
+    nsCOMPtr<nsIFile> file = do_QueryInterface(elem);
+    if (!file) {
+      continue;
+    }
+
+    bool isDir = false;
+    file->IsDirectory(&isDir);
+    if (!isDir) {
+      continue;
+    }
+
+    nsAutoCString leafName;
+    rv = file->GetNativeLeafName(leafName);
+    if (NS_FAILED(rv)) {
+      continue;
+    }
+
+    if (leafName.Length() < strlen(TRASH_DIR)) {
+      continue;
+    }
+
+    if (!StringBeginsWith(leafName, NS_LITERAL_CSTRING(TRASH_DIR))) {
+      continue;
+    }
+
+    if (mFailedTrashDirs.Contains(leafName)) {
+      continue;
+    }
+
+    LOG(("CacheFileIOManager::FindTrashDirToRemove() - Returning directory %s",
+         leafName.get()));
+
+    mTrashDir = file;
+    return NS_OK;
+  }
+
+  // When we're here we've tried to delete all trash directories. Clear
+  // mFailedTrashDirs so we will try to delete them again when we start removing
+  // trash directories next time.
+  mFailedTrashDirs.Clear();
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+// static
+nsresult
+CacheFileIOManager::InitIndexEntry(CacheFileHandle *aHandle,
+                                   OriginAttrsHash  aOriginAttrsHash,
+                                   bool             aAnonymous,
+                                   bool             aPinning)
+{
+  LOG(("CacheFileIOManager::InitIndexEntry() [handle=%p, originAttrsHash=%llx, "
+       "anonymous=%d, pinning=%d]", aHandle, aOriginAttrsHash, aAnonymous,
+       aPinning));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (aHandle->IsSpecialFile()) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  RefPtr<InitIndexEntryEvent> ev =
+    new InitIndexEntryEvent(aHandle, aOriginAttrsHash, aAnonymous, aPinning);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::UpdateIndexEntry(CacheFileHandle *aHandle,
+                                     const uint32_t  *aFrecency,
+                                     const uint32_t  *aExpirationTime)
+{
+  LOG(("CacheFileIOManager::UpdateIndexEntry() [handle=%p, frecency=%s, "
+       "expirationTime=%s]", aHandle,
+       aFrecency ? nsPrintfCString("%u", *aFrecency).get() : "",
+       aExpirationTime ? nsPrintfCString("%u", *aExpirationTime).get() : ""));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (aHandle->IsSpecialFile()) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  RefPtr<UpdateIndexEntryEvent> ev =
+    new UpdateIndexEntryEvent(aHandle, aFrecency, aExpirationTime);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CreateFile(CacheFileHandle *aHandle)
+{
+  MOZ_ASSERT(!aHandle->mFD);
+  MOZ_ASSERT(aHandle->mFile);
+
+  nsresult rv;
+
+  if (aHandle->IsDoomed()) {
+    nsCOMPtr<nsIFile> file;
+
+    rv = GetDoomedFile(getter_AddRefs(file));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aHandle->mFile.swap(file);
+  } else {
+    bool exists;
+    if (NS_SUCCEEDED(aHandle->mFile->Exists(&exists)) && exists) {
+      NS_WARNING("Found a file that should not exist!");
+    }
+  }
+
+  rv = OpenNSPRHandle(aHandle, true);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aHandle->mFileSize = 0;
+  return NS_OK;
+}
+
+// static
+void
+CacheFileIOManager::HashToStr(const SHA1Sum::Hash *aHash, nsACString &_retval)
+{
+  _retval.Truncate();
+  const char hexChars[] = {'0', '1', '2', '3', '4', '5', '6', '7',
+                           '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+  for (uint32_t i=0 ; i<sizeof(SHA1Sum::Hash) ; i++) {
+    _retval.Append(hexChars[(*aHash)[i] >> 4]);
+    _retval.Append(hexChars[(*aHash)[i] & 0xF]);
+  }
+}
+
+// static
+nsresult
+CacheFileIOManager::StrToHash(const nsACString &aHash, SHA1Sum::Hash *_retval)
+{
+  if (aHash.Length() != 2*sizeof(SHA1Sum::Hash)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  for (uint32_t i=0 ; i<aHash.Length() ; i++) {
+    uint8_t value;
+
+    if (aHash[i] >= '0' && aHash[i] <= '9') {
+      value = aHash[i] - '0';
+    } else if (aHash[i] >= 'A' && aHash[i] <= 'F') {
+      value = aHash[i] - 'A' + 10;
+    } else if (aHash[i] >= 'a' && aHash[i] <= 'f') {
+      value = aHash[i] - 'a' + 10;
+    } else {
+      return NS_ERROR_INVALID_ARG;
+    }
+
+    if (i%2 == 0) {
+      (reinterpret_cast<uint8_t *>(_retval))[i/2] = value << 4;
+    } else {
+      (reinterpret_cast<uint8_t *>(_retval))[i/2] += value;
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::GetFile(const SHA1Sum::Hash *aHash, nsIFile **_retval)
+{
+  nsresult rv;
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(NS_LITERAL_CSTRING(ENTRIES_DIR));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString leafName;
+  HashToStr(aHash, leafName);
+
+  rv = file->AppendNative(leafName);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  file.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::GetSpecialFile(const nsACString &aKey, nsIFile **_retval)
+{
+  nsresult rv;
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(aKey);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  file.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::GetDoomedFile(nsIFile **_retval)
+{
+  nsresult rv;
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(NS_LITERAL_CSTRING(DOOMED_DIR));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(NS_LITERAL_CSTRING("dummyleaf"));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  const int32_t kMaxTries = 64;
+  srand(static_cast<unsigned>(PR_Now()));
+  nsAutoCString leafName;
+  for (int32_t triesCount = 0; ; ++triesCount) {
+    leafName.AppendInt(rand());
+    rv = file->SetNativeLeafName(leafName);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    bool exists;
+    if (NS_SUCCEEDED(file->Exists(&exists)) && !exists) {
+      break;
+    }
+
+    if (triesCount == kMaxTries) {
+      LOG(("CacheFileIOManager::GetDoomedFile() - Could not find unused file "
+           "name in %d tries.", kMaxTries));
+      return NS_ERROR_FAILURE;
+    }
+
+    leafName.Truncate();
+  }
+
+  file.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::IsEmptyDirectory(nsIFile *aFile, bool *_retval)
+{
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  nsresult rv;
+
+  nsCOMPtr<nsISimpleEnumerator> enumerator;
+  rv = aFile->GetDirectoryEntries(getter_AddRefs(enumerator));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool hasMoreElements = false;
+  rv = enumerator->HasMoreElements(&hasMoreElements);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *_retval = !hasMoreElements;
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CheckAndCreateDir(nsIFile *aFile, const char *aDir,
+                                      bool aEnsureEmptyDir)
+{
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> file;
+  if (!aDir) {
+    file = aFile;
+  } else {
+    nsAutoCString dir(aDir);
+    rv = aFile->Clone(getter_AddRefs(file));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = file->AppendNative(dir);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  bool exists = false;
+  rv = file->Exists(&exists);
+  if (NS_SUCCEEDED(rv) && exists) {
+    bool isDirectory = false;
+    rv = file->IsDirectory(&isDirectory);
+    if (NS_FAILED(rv) || !isDirectory) {
+      // Try to remove the file
+      rv = file->Remove(false);
+      if (NS_SUCCEEDED(rv)) {
+        exists = false;
+      }
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (aEnsureEmptyDir && NS_SUCCEEDED(rv) && exists) {
+    bool isEmpty;
+    rv = IsEmptyDirectory(file, &isEmpty);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!isEmpty) {
+      // Don't check the result, if this fails, it's OK.  We do this
+      // only for the doomed directory that doesn't need to be deleted
+      // for the cost of completely disabling the whole browser.
+      TrashDirectory(file);
+    }
+  }
+
+  if (NS_SUCCEEDED(rv) && !exists) {
+    rv = file->Create(nsIFile::DIRECTORY_TYPE, 0700);
+  }
+  if (NS_FAILED(rv)) {
+    NS_WARNING("Cannot create directory");
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CreateCacheTree()
+{
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+  MOZ_ASSERT(!mTreeCreated);
+
+  if (!mCacheDirectory || mTreeCreationFailed) {
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  nsresult rv;
+
+  // Set the flag here and clear it again below when the tree is created
+  // successfully.
+  mTreeCreationFailed = true;
+
+  // ensure parent directory exists
+  nsCOMPtr<nsIFile> parentDir;
+  rv = mCacheDirectory->GetParent(getter_AddRefs(parentDir));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = CheckAndCreateDir(parentDir, nullptr, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // ensure cache directory exists
+  rv = CheckAndCreateDir(mCacheDirectory, nullptr, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // ensure entries directory exists
+  rv = CheckAndCreateDir(mCacheDirectory, ENTRIES_DIR, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // ensure doomed directory exists
+  rv = CheckAndCreateDir(mCacheDirectory, DOOMED_DIR, true);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mTreeCreated = true;
+  mTreeCreationFailed = false;
+
+  if (!mContextEvictor) {
+    RefPtr<CacheFileContextEvictor> contextEvictor;
+    contextEvictor = new CacheFileContextEvictor();
+
+    // Init() method will try to load unfinished contexts from the disk. Store
+    // the evictor as a member only when there is some unfinished job.
+    contextEvictor->Init(mCacheDirectory);
+    if (contextEvictor->ContextsCount()) {
+      contextEvictor.swap(mContextEvictor);
+    }
+  }
+
+  StartRemovingTrash();
+
+  if (!CacheObserver::CacheFSReported()) {
+    uint32_t fsType = 4; // Other OS
+
+#ifdef XP_WIN
+    nsAutoString target;
+    nsresult rv = mCacheDirectory->GetTarget(target);
+    if (NS_FAILED(rv)) {
+      return NS_OK;
+    }
+
+    wchar_t volume_path[MAX_PATH + 1] = { 0 };
+    if (!::GetVolumePathNameW(target.get(),
+                              volume_path,
+                              mozilla::ArrayLength(volume_path))) {
+      return NS_OK;
+    }
+
+    wchar_t fsName[6] = { 0 };
+    if (!::GetVolumeInformationW(volume_path, nullptr, 0, nullptr, nullptr,
+                                 nullptr, fsName,
+                                 mozilla::ArrayLength(fsName))) {
+      return NS_OK;
+    }
+
+    if (wcscmp(fsName, L"NTFS") == 0) {
+      fsType = 0;
+    } else if (wcscmp(fsName, L"FAT32") == 0) {
+      fsType = 1;
+    } else if (wcscmp(fsName, L"FAT") == 0) {
+      fsType = 2;
+    } else {
+      fsType = 3;
+    }
+#endif
+
+    Telemetry::Accumulate(Telemetry::NETWORK_CACHE_FS_TYPE, fsType);
+    CacheObserver::SetCacheFSReported();
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::OpenNSPRHandle(CacheFileHandle *aHandle, bool aCreate)
+{
+  LOG(("CacheFileIOManager::OpenNSPRHandle BEGIN, handle=%p", aHandle));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(!aHandle->mFD);
+  MOZ_ASSERT(mHandlesByLastUsed.IndexOf(aHandle) == mHandlesByLastUsed.NoIndex);
+  MOZ_ASSERT(mHandlesByLastUsed.Length() <= kOpenHandlesLimit);
+  MOZ_ASSERT((aCreate && !aHandle->mFileExists) ||
+             (!aCreate && aHandle->mFileExists));
+
+  nsresult rv;
+
+  if (mHandlesByLastUsed.Length() == kOpenHandlesLimit) {
+    // close handle that hasn't been used for the longest time
+    rv = MaybeReleaseNSPRHandleInternal(mHandlesByLastUsed[0], true);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (aCreate) {
+    rv = aHandle->mFile->OpenNSPRFileDesc(
+           PR_RDWR | PR_CREATE_FILE | PR_TRUNCATE, 0600, &aHandle->mFD);
+    if (rv == NS_ERROR_FILE_ALREADY_EXISTS ||  // error from nsLocalFileWin
+        rv == NS_ERROR_FILE_NO_DEVICE_SPACE) { // error from nsLocalFileUnix
+      LOG(("CacheFileIOManager::OpenNSPRHandle() - Cannot create a new file, we"
+           " might reached a limit on FAT32. Will evict a single entry and try "
+           "again. [hash=%08x%08x%08x%08x%08x]", LOGSHA1(aHandle->Hash())));
+
+      SHA1Sum::Hash hash;
+      uint32_t cnt;
+
+      rv = CacheIndex::GetEntryForEviction(true, &hash, &cnt);
+      if (NS_SUCCEEDED(rv)) {
+        rv = DoomFileByKeyInternal(&hash);
+      }
+      if (NS_SUCCEEDED(rv)) {
+        rv = aHandle->mFile->OpenNSPRFileDesc(
+               PR_RDWR | PR_CREATE_FILE | PR_TRUNCATE, 0600, &aHandle->mFD);
+        LOG(("CacheFileIOManager::OpenNSPRHandle() - Successfully evicted entry"
+             " with hash %08x%08x%08x%08x%08x. %s to create the new file.",
+             LOGSHA1(&hash), NS_SUCCEEDED(rv) ? "Succeeded" : "Failed"));
+
+        // Report the full size only once per session
+        static bool sSizeReported = false;
+        if (!sSizeReported) {
+          uint32_t cacheUsage;
+          if (NS_SUCCEEDED(CacheIndex::GetCacheSize(&cacheUsage))) {
+            cacheUsage >>= 10;
+            Telemetry::Accumulate(Telemetry::NETWORK_CACHE_SIZE_FULL_FAT,
+                                  cacheUsage);
+            sSizeReported = true;
+          }
+        }
+      } else {
+        LOG(("CacheFileIOManager::OpenNSPRHandle() - Couldn't evict an existing"
+             " entry."));
+        rv = NS_ERROR_FILE_NO_DEVICE_SPACE;
+      }
+    }
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileIOManager::OpenNSPRHandle() Create failed with 0x%08x", rv));
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aHandle->mFileExists = true;
+  } else {
+    rv = aHandle->mFile->OpenNSPRFileDesc(PR_RDWR, 0600, &aHandle->mFD);
+    if (NS_ERROR_FILE_NOT_FOUND == rv) {
+      LOG(("  file doesn't exists"));
+      aHandle->mFileExists = false;
+      return DoomFileInternal(aHandle);
+    }
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileIOManager::OpenNSPRHandle() Open failed with 0x%08x", rv));
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  mHandlesByLastUsed.AppendElement(aHandle);
+
+  LOG(("CacheFileIOManager::OpenNSPRHandle END, handle=%p", aHandle));
+
+  return NS_OK;
+}
+
+void
+CacheFileIOManager::NSPRHandleUsed(CacheFileHandle *aHandle)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(aHandle->mFD);
+
+  DebugOnly<bool> found;
+  found = mHandlesByLastUsed.RemoveElement(aHandle);
+  MOZ_ASSERT(found);
+
+  mHandlesByLastUsed.AppendElement(aHandle);
+}
+
+nsresult
+CacheFileIOManager::SyncRemoveDir(nsIFile *aFile, const char *aDir)
+{
+  nsresult rv;
+  nsCOMPtr<nsIFile> file;
+
+  if (!aDir) {
+    file = aFile;
+  } else {
+    rv = aFile->Clone(getter_AddRefs(file));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+
+    rv = file->AppendNative(nsDependentCString(aDir));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  if (LOG_ENABLED()) {
+    nsAutoCString path;
+    file->GetNativePath(path);
+    LOG(("CacheFileIOManager::SyncRemoveDir() - Removing directory %s",
+         path.get()));
+  }
+
+  rv = file->Remove(true);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    LOG(("CacheFileIOManager::SyncRemoveDir() - Removing failed! [rv=0x%08x]",
+         rv));
+  }
+
+  return rv;
+}
+
+void
+CacheFileIOManager::SyncRemoveAllCacheFiles()
+{
+  LOG(("CacheFileIOManager::SyncRemoveAllCacheFiles()"));
+
+  nsresult rv;
+
+  SyncRemoveDir(mCacheDirectory, ENTRIES_DIR);
+  SyncRemoveDir(mCacheDirectory, DOOMED_DIR);
+
+  // Clear any intermediate state of trash dir enumeration.
+  mFailedTrashDirs.Clear();
+  mTrashDir = nullptr;
+
+  while (true) {
+    // FindTrashDirToRemove() fills mTrashDir if there is any trash directory.
+    rv = FindTrashDirToRemove();
+    if (rv == NS_ERROR_NOT_AVAILABLE) {
+      LOG(("CacheFileIOManager::SyncRemoveAllCacheFiles() - No trash directory "
+           "found."));
+      break;
+    }
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::SyncRemoveAllCacheFiles() - "
+           "FindTrashDirToRemove() returned an unexpected error. [rv=0x%08x]",
+           rv));
+      break;
+    }
+
+    rv = SyncRemoveDir(mTrashDir, nullptr);
+    if (NS_FAILED(rv)) {
+      nsAutoCString leafName;
+      mTrashDir->GetNativeLeafName(leafName);
+      mFailedTrashDirs.AppendElement(leafName);
+    }
+  }
+}
+
+// Returns default ("smart") size (in KB) of cache, given available disk space
+// (also in KB)
+static uint32_t
+SmartCacheSize(const uint32_t availKB)
+{
+  uint32_t maxSize = kMaxCacheSizeKB;
+
+  if (availKB > 100 * 1024 * 1024) {
+    return maxSize;  // skip computing if we're over 100 GB
+  }
+
+  // Grow/shrink in 10 MB units, deliberately, so that in the common case we
+  // don't shrink cache and evict items every time we startup (it's important
+  // that we don't slow down startup benchmarks).
+  uint32_t sz10MBs = 0;
+  uint32_t avail10MBs = availKB / (1024*10);
+
+  // .5% of space above 25 GB
+  if (avail10MBs > 2500) {
+    sz10MBs += static_cast<uint32_t>((avail10MBs - 2500)*.005);
+    avail10MBs = 2500;
+  }
+  // 1% of space between 7GB -> 25 GB
+  if (avail10MBs > 700) {
+    sz10MBs += static_cast<uint32_t>((avail10MBs - 700)*.01);
+    avail10MBs = 700;
+  }
+  // 5% of space between 500 MB -> 7 GB
+  if (avail10MBs > 50) {
+    sz10MBs += static_cast<uint32_t>((avail10MBs - 50)*.05);
+    avail10MBs = 50;
+  }
+
+#ifdef ANDROID
+  // On Android, smaller/older devices may have very little storage and
+  // device owners may be sensitive to storage footprint: Use a smaller
+  // percentage of available space and a smaller minimum.
+
+  // 20% of space up to 500 MB (10 MB min)
+  sz10MBs += std::max<uint32_t>(1, static_cast<uint32_t>(avail10MBs * .2));
+#else
+  // 40% of space up to 500 MB (50 MB min)
+  sz10MBs += std::max<uint32_t>(5, static_cast<uint32_t>(avail10MBs * .4));
+#endif
+
+  return std::min<uint32_t>(maxSize, sz10MBs * 10 * 1024);
+}
+
+nsresult
+CacheFileIOManager::UpdateSmartCacheSize(int64_t aFreeSpace)
+{
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  nsresult rv;
+
+  if (!CacheObserver::UseNewCache()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (!CacheObserver::SmartCacheSizeEnabled()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Wait at least kSmartSizeUpdateInterval before recomputing smart size.
+  static const TimeDuration kUpdateLimit =
+    TimeDuration::FromMilliseconds(kSmartSizeUpdateInterval);
+  if (!mLastSmartSizeTime.IsNull() &&
+      (TimeStamp::NowLoRes() - mLastSmartSizeTime) < kUpdateLimit) {
+    return NS_OK;
+  }
+
+  // Do not compute smart size when cache size is not reliable.
+  bool isUpToDate = false;
+  CacheIndex::IsUpToDate(&isUpToDate);
+  if (!isUpToDate) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  uint32_t cacheUsage;
+  rv = CacheIndex::GetCacheSize(&cacheUsage);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    LOG(("CacheFileIOManager::UpdateSmartCacheSize() - Cannot get cacheUsage! "
+         "[rv=0x%08x]", rv));
+    return rv;
+  }
+
+  mLastSmartSizeTime = TimeStamp::NowLoRes();
+
+  uint32_t smartSize = SmartCacheSize(static_cast<uint32_t>(aFreeSpace / 1024) +
+                                      cacheUsage);
+
+  if (smartSize == (CacheObserver::DiskCacheCapacity() >> 10)) {
+    // Smart size has not changed.
+    return NS_OK;
+  }
+
+  CacheObserver::SetDiskCacheCapacity(smartSize << 10);
+
+  return NS_OK;
+}
+
+// Memory reporting
+
+namespace {
+
+// A helper class that dispatches and waits for an event that gets result of
+// CacheFileIOManager->mHandles.SizeOfExcludingThis() on the I/O thread
+// to safely get handles memory report.
+// We must do this, since the handle list is only accessed and managed w/o
+// locking on the I/O thread.  That is by design.
+class SizeOfHandlesRunnable : public Runnable
+{
+public:
+  SizeOfHandlesRunnable(mozilla::MallocSizeOf mallocSizeOf,
+                        CacheFileHandles const &handles,
+                        nsTArray<CacheFileHandle *> const &specialHandles)
+    : mMonitor("SizeOfHandlesRunnable.mMonitor")
+    , mMallocSizeOf(mallocSizeOf)
+    , mHandles(handles)
+    , mSpecialHandles(specialHandles)
+  {
+  }
+
+  size_t Get(CacheIOThread* thread)
+  {
+    nsCOMPtr<nsIEventTarget> target = thread->Target();
+    if (!target) {
+      NS_ERROR("If we have the I/O thread we also must have the I/O target");
+      return 0;
+    }
+
+    mozilla::MonitorAutoLock mon(mMonitor);
+    mMonitorNotified = false;
+    nsresult rv = target->Dispatch(this, nsIEventTarget::DISPATCH_NORMAL);
+    if (NS_FAILED(rv)) {
+      NS_ERROR("Dispatch failed, cannot do memory report of CacheFileHandles");
+      return 0;
+    }
+
+    while (!mMonitorNotified) {
+      mon.Wait();
+    }
+    return mSize;
+  }
+
+  NS_IMETHOD Run() override
+  {
+    mozilla::MonitorAutoLock mon(mMonitor);
+    // Excluding this since the object itself is a member of CacheFileIOManager
+    // reported in CacheFileIOManager::SizeOfIncludingThis as part of |this|.
+    mSize = mHandles.SizeOfExcludingThis(mMallocSizeOf);
+    for (uint32_t i = 0; i < mSpecialHandles.Length(); ++i) {
+      mSize += mSpecialHandles[i]->SizeOfIncludingThis(mMallocSizeOf);
+    }
+
+    mMonitorNotified = true;
+    mon.Notify();
+    return NS_OK;
+  }
+
+private:
+  mozilla::Monitor mMonitor;
+  bool mMonitorNotified;
+  mozilla::MallocSizeOf mMallocSizeOf;
+  CacheFileHandles const &mHandles;
+  nsTArray<CacheFileHandle *> const &mSpecialHandles;
+  size_t mSize;
+};
+
+} // namespace
+
+size_t
+CacheFileIOManager::SizeOfExcludingThisInternal(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  size_t n = 0;
+  nsCOMPtr<nsISizeOf> sizeOf;
+
+  if (mIOThread) {
+    n += mIOThread->SizeOfIncludingThis(mallocSizeOf);
+
+    // mHandles and mSpecialHandles must be accessed only on the I/O thread,
+    // must sync dispatch.
+    RefPtr<SizeOfHandlesRunnable> sizeOfHandlesRunnable =
+      new SizeOfHandlesRunnable(mallocSizeOf, mHandles, mSpecialHandles);
+    n += sizeOfHandlesRunnable->Get(mIOThread);
+  }
+
+  // mHandlesByLastUsed just refers handles reported by mHandles.
+
+  sizeOf = do_QueryInterface(mCacheDirectory);
+  if (sizeOf)
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+
+  sizeOf = do_QueryInterface(mMetadataWritesTimer);
+  if (sizeOf)
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+
+  sizeOf = do_QueryInterface(mTrashTimer);
+  if (sizeOf)
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+
+  sizeOf = do_QueryInterface(mTrashDir);
+  if (sizeOf)
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+
+  for (uint32_t i = 0; i < mFailedTrashDirs.Length(); ++i) {
+    n += mFailedTrashDirs[i].SizeOfExcludingThisIfUnshared(mallocSizeOf);
+  }
+
+  return n;
+}
+
+// static
+size_t
+CacheFileIOManager::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+  if (!gInstance)
+    return 0;
+
+  return gInstance->SizeOfExcludingThisInternal(mallocSizeOf);
+}
+
+// static
+size_t
+CacheFileIOManager::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+  return mallocSizeOf(gInstance) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheFileIOManager.h b/netwerk/cache2/CacheFileIOManager.h
new file mode 100644
index 0000000000..5ac812da5d
--- /dev/null
+++ b/netwerk/cache2/CacheFileIOManager.h
@@ -0,0 +1,489 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheFileIOManager__h__
+#define CacheFileIOManager__h__
+
+#include "CacheIOThread.h"
+#include "CacheStorageService.h"
+#include "CacheHashUtils.h"
+#include "nsIEventTarget.h"
+#include "nsITimer.h"
+#include "nsCOMPtr.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/SHA1.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/TimeStamp.h"
+#include "nsTArray.h"
+#include "nsString.h"
+#include "nsTHashtable.h"
+#include "prio.h"
+
+//#define DEBUG_HANDLES 1
+
+class nsIFile;
+class nsITimer;
+class nsIDirectoryEnumerator;
+class nsILoadContextInfo;
+
+namespace mozilla {
+namespace net {
+
+class CacheFile;
+class CacheFileIOListener;
+
+#ifdef DEBUG_HANDLES
+class CacheFileHandlesEntry;
+#endif
+
+#define ENTRIES_DIR "entries"
+#define DOOMED_DIR  "doomed"
+#define TRASH_DIR   "trash"
+
+
+class CacheFileHandle : public nsISupports
+{
+public:
+  enum class PinningStatus : uint32_t {
+    UNKNOWN,
+    NON_PINNED,
+    PINNED
+  };
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  bool DispatchRelease();
+
+  CacheFileHandle(const SHA1Sum::Hash *aHash, bool aPriority, PinningStatus aPinning);
+  CacheFileHandle(const nsACString &aKey, bool aPriority, PinningStatus aPinning);
+  void Log();
+  bool IsDoomed() const { return mIsDoomed; }
+  const SHA1Sum::Hash *Hash() const { return mHash; }
+  int64_t FileSize() const { return mFileSize; }
+  uint32_t FileSizeInK() const;
+  bool IsPriority() const { return mPriority; }
+  bool FileExists() const { return mFileExists; }
+  bool IsClosed() const { return mClosed; }
+  bool IsSpecialFile() const { return mSpecialFile; }
+  nsCString & Key() { return mKey; }
+
+  // Returns false when this handle has been doomed based on the pinning state update.
+  bool SetPinned(bool aPinned);
+  void SetInvalid() { mInvalid = true; }
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+private:
+  friend class CacheFileIOManager;
+  friend class CacheFileHandles;
+  friend class ReleaseNSPRHandleEvent;
+
+  virtual ~CacheFileHandle();
+
+  const SHA1Sum::Hash *mHash;
+  mozilla::Atomic<bool, ReleaseAcquire> mIsDoomed;
+  mozilla::Atomic<bool, ReleaseAcquire> mClosed;
+
+  // mPriority and mSpecialFile are plain "bool", not "bool:1", so as to
+  // avoid bitfield races with the byte containing mInvalid et al.  See
+  // bug 1278502.
+  bool const           mPriority;
+  bool const           mSpecialFile;
+
+  mozilla::Atomic<bool, Relaxed> mInvalid;
+
+  // These bit flags are all accessed only on the IO thread
+  bool                 mFileExists : 1; // This means that the file should exists,
+                                        // but it can be still deleted by OS/user
+                                        // and then a subsequent OpenNSPRFileDesc()
+                                        // will fail.
+
+  // Both initially false.  Can be raised to true only when this handle is to be doomed
+  // during the period when the pinning status is unknown.  After the pinning status
+  // determination we check these flags and possibly doom.
+  // These flags are only accessed on the IO thread.
+  bool                 mDoomWhenFoundPinned : 1;
+  bool                 mDoomWhenFoundNonPinned : 1;
+  // Set when after shutdown AND:
+  // - when writing: writing data (not metadata) OR the physical file handle is not currently open
+  // - when truncating: the physical file handle is not currently open
+  // When set it prevents any further writes or truncates on such handles to happen immediately
+  // after shutdown and gives a chance to write metadata of already open files quickly as possible
+  // (only that renders them actually usable by the cache.)
+  bool                 mKilled : 1;
+  // For existing files this is always pre-set to UNKNOWN.  The status is udpated accordingly
+  // after the matadata has been parsed.
+  // For new files the flag is set according to which storage kind is opening
+  // the cache entry and remains so for the handle's lifetime.
+  // The status can only change from UNKNOWN (if set so initially) to one of PINNED or NON_PINNED
+  // and it stays unchanged afterwards.
+  // This status is only accessed on the IO thread.
+  PinningStatus        mPinning;
+
+  nsCOMPtr<nsIFile>    mFile;
+  int64_t              mFileSize;
+  PRFileDesc          *mFD;  // if null then the file doesn't exists on the disk
+  nsCString            mKey;
+};
+
+class CacheFileHandles {
+public:
+  CacheFileHandles();
+  ~CacheFileHandles();
+
+  nsresult GetHandle(const SHA1Sum::Hash *aHash, CacheFileHandle **_retval);
+  nsresult NewHandle(const SHA1Sum::Hash *aHash, bool aPriority,
+                     CacheFileHandle::PinningStatus aPinning, CacheFileHandle **_retval);
+  void     RemoveHandle(CacheFileHandle *aHandlle);
+  void     GetAllHandles(nsTArray<RefPtr<CacheFileHandle> > *_retval);
+  void     GetActiveHandles(nsTArray<RefPtr<CacheFileHandle> > *_retval);
+  void     ClearAll();
+  uint32_t HandleCount();
+
+#ifdef DEBUG_HANDLES
+  void     Log(CacheFileHandlesEntry *entry);
+#endif
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  class HandleHashKey : public PLDHashEntryHdr
+  {
+  public:
+    typedef const SHA1Sum::Hash& KeyType;
+    typedef const SHA1Sum::Hash* KeyTypePointer;
+
+    explicit HandleHashKey(KeyTypePointer aKey)
+    {
+      MOZ_COUNT_CTOR(HandleHashKey);
+      mHash = MakeUnique<uint8_t[]>(SHA1Sum::kHashSize);
+      memcpy(mHash.get(), aKey, sizeof(SHA1Sum::Hash));
+    }
+    HandleHashKey(const HandleHashKey& aOther)
+    {
+      NS_NOTREACHED("HandleHashKey copy constructor is forbidden!");
+    }
+    ~HandleHashKey()
+    {
+      MOZ_COUNT_DTOR(HandleHashKey);
+    }
+
+    bool KeyEquals(KeyTypePointer aKey) const
+    {
+      return memcmp(mHash.get(), aKey, sizeof(SHA1Sum::Hash)) == 0;
+    }
+    static KeyTypePointer KeyToPointer(KeyType aKey)
+    {
+      return &aKey;
+    }
+    static PLDHashNumber HashKey(KeyTypePointer aKey)
+    {
+      return (reinterpret_cast<const uint32_t *>(aKey))[0];
+    }
+
+    void AddHandle(CacheFileHandle* aHandle);
+    void RemoveHandle(CacheFileHandle* aHandle);
+    already_AddRefed<CacheFileHandle> GetNewestHandle();
+    void GetHandles(nsTArray<RefPtr<CacheFileHandle> > &aResult);
+
+    SHA1Sum::Hash *Hash() const
+    {
+      return reinterpret_cast<SHA1Sum::Hash*>(mHash.get());
+    }
+    bool IsEmpty() const { return mHandles.Length() == 0; }
+
+    enum { ALLOW_MEMMOVE = true };
+
+#ifdef DEBUG
+    void AssertHandlesState();
+#endif
+
+    // Memory reporting
+    size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+    size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  private:
+    // We can't make this UniquePtr<SHA1Sum::Hash>, because you can't have
+    // UniquePtrs with known bounds.  So we settle for this representation
+    // and using appropriate casts when we need to access it as a
+    // SHA1Sum::Hash.
+    UniquePtr<uint8_t[]> mHash;
+    // Use weak pointers since the hash table access is on a single thread
+    // only and CacheFileHandle removes itself from this table in its dtor
+    // that may only be called on the same thread as we work with the hashtable
+    // since we dispatch its Release() to this thread.
+    nsTArray<CacheFileHandle*> mHandles;
+  };
+
+private:
+  nsTHashtable<HandleHashKey> mTable;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class OpenFileEvent;
+class ReadEvent;
+class WriteEvent;
+class MetadataWriteScheduleEvent;
+class CacheFileContextEvictor;
+
+#define CACHEFILEIOLISTENER_IID \
+{ /* dcaf2ddc-17cf-4242-bca1-8c86936375a5 */       \
+  0xdcaf2ddc,                                      \
+  0x17cf,                                          \
+  0x4242,                                          \
+  {0xbc, 0xa1, 0x8c, 0x86, 0x93, 0x63, 0x75, 0xa5} \
+}
+
+class CacheFileIOListener : public nsISupports
+{
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(CACHEFILEIOLISTENER_IID)
+
+  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) = 0;
+  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                           nsresult aResult) = 0;
+  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf,
+                        nsresult aResult) = 0;
+  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) = 0;
+  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) = 0;
+  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) = 0;
+
+  virtual bool IsKilled() { return false; }
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(CacheFileIOListener, CACHEFILEIOLISTENER_IID)
+
+
+class CacheFileIOManager : public nsITimerCallback
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITIMERCALLBACK
+
+  enum {
+    OPEN         =  0U,
+    CREATE       =  1U,
+    CREATE_NEW   =  2U,
+    PRIORITY     =  4U,
+    SPECIAL_FILE =  8U,
+    PINNED       = 16U
+  };
+
+  CacheFileIOManager();
+
+  static nsresult Init();
+  static nsresult Shutdown();
+  static nsresult OnProfile();
+  static already_AddRefed<nsIEventTarget> IOTarget();
+  static already_AddRefed<CacheIOThread> IOThread();
+  static bool IsOnIOThread();
+  static bool IsOnIOThreadOrCeased();
+  static bool IsShutdown();
+
+  // Make aFile's WriteMetadataIfNeeded be called automatically after
+  // a short interval.
+  static nsresult ScheduleMetadataWrite(CacheFile * aFile);
+  // Remove aFile from the scheduling registry array.
+  // WriteMetadataIfNeeded will not be automatically called.
+  static nsresult UnscheduleMetadataWrite(CacheFile * aFile);
+  // Shuts the scheduling off and flushes all pending metadata writes.
+  static nsresult ShutdownMetadataWriteScheduling();
+
+  static nsresult OpenFile(const nsACString &aKey,
+                           uint32_t aFlags, CacheFileIOListener *aCallback);
+  static nsresult Read(CacheFileHandle *aHandle, int64_t aOffset,
+                       char *aBuf, int32_t aCount,
+                       CacheFileIOListener *aCallback);
+  static nsresult Write(CacheFileHandle *aHandle, int64_t aOffset,
+                        const char *aBuf, int32_t aCount, bool aValidate,
+                        bool aTruncate, CacheFileIOListener *aCallback);
+  // PinningDoomRestriction:
+  // NO_RESTRICTION
+  //    no restriction is checked, the file is simply always doomed
+  // DOOM_WHEN_(NON)_PINNED, we branch based on the pinning status of the handle:
+  //   UNKNOWN: the handle is marked to be doomed when later found (non)pinned
+  //   PINNED/NON_PINNED: doom only when the restriction matches the pin status
+  //      and the handle has not yet been required to doom during the UNKNOWN
+  //      period
+  enum PinningDoomRestriction {
+    NO_RESTRICTION,
+    DOOM_WHEN_NON_PINNED,
+    DOOM_WHEN_PINNED
+  };
+  static nsresult DoomFile(CacheFileHandle *aHandle,
+                           CacheFileIOListener *aCallback);
+  static nsresult DoomFileByKey(const nsACString &aKey,
+                                CacheFileIOListener *aCallback);
+  static nsresult ReleaseNSPRHandle(CacheFileHandle *aHandle);
+  static nsresult TruncateSeekSetEOF(CacheFileHandle *aHandle,
+                                     int64_t aTruncatePos, int64_t aEOFPos,
+                                     CacheFileIOListener *aCallback);
+  static nsresult RenameFile(CacheFileHandle *aHandle,
+                             const nsACString &aNewName,
+                             CacheFileIOListener *aCallback);
+  static nsresult EvictIfOverLimit();
+  static nsresult EvictAll();
+  static nsresult EvictByContext(nsILoadContextInfo *aLoadContextInfo,
+                                 bool aPinning);
+
+  static nsresult InitIndexEntry(CacheFileHandle *aHandle,
+                                 OriginAttrsHash  aOriginAttrsHash,
+                                 bool             aAnonymous,
+                                 bool             aPinning);
+  static nsresult UpdateIndexEntry(CacheFileHandle *aHandle,
+                                   const uint32_t  *aFrecency,
+                                   const uint32_t  *aExpirationTime);
+
+  static nsresult UpdateIndexEntry();
+
+  enum EEnumerateMode {
+    ENTRIES,
+    DOOMED
+  };
+
+  static void GetCacheDirectory(nsIFile** result);
+#if defined(MOZ_WIDGET_ANDROID)
+  static void GetProfilelessCacheDirectory(nsIFile** result);
+#endif
+
+  // Calls synchronously OnEntryInfo for an entry with the given hash.
+  // Tries to find an existing entry in the service hashtables first, if not
+  // found, loads synchronously from disk file.
+  // Callable on the IO thread only.
+  static nsresult GetEntryInfo(const SHA1Sum::Hash *aHash,
+                               CacheStorageService::EntryInfoCallback *aCallback);
+
+  // Memory reporting
+  static size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf);
+  static size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf);
+
+private:
+  friend class CacheFileHandle;
+  friend class CacheFileChunk;
+  friend class CacheFile;
+  friend class ShutdownEvent;
+  friend class OpenFileEvent;
+  friend class CloseHandleEvent;
+  friend class ReadEvent;
+  friend class WriteEvent;
+  friend class DoomFileEvent;
+  friend class DoomFileByKeyEvent;
+  friend class ReleaseNSPRHandleEvent;
+  friend class TruncateSeekSetEOFEvent;
+  friend class RenameFileEvent;
+  friend class CacheIndex;
+  friend class MetadataWriteScheduleEvent;
+  friend class CacheFileContextEvictor;
+
+  virtual ~CacheFileIOManager();
+
+  nsresult InitInternal();
+  nsresult ShutdownInternal();
+
+  nsresult OpenFileInternal(const SHA1Sum::Hash *aHash,
+                            const nsACString &aKey,
+                            uint32_t aFlags,
+                            CacheFileHandle **_retval);
+  nsresult OpenSpecialFileInternal(const nsACString &aKey,
+                                   uint32_t aFlags,
+                                   CacheFileHandle **_retval);
+  nsresult CloseHandleInternal(CacheFileHandle *aHandle);
+  nsresult ReadInternal(CacheFileHandle *aHandle, int64_t aOffset,
+                        char *aBuf, int32_t aCount);
+  nsresult WriteInternal(CacheFileHandle *aHandle, int64_t aOffset,
+                         const char *aBuf, int32_t aCount, bool aValidate,
+                         bool aTruncate);
+  nsresult DoomFileInternal(CacheFileHandle *aHandle,
+                            PinningDoomRestriction aPinningStatusRestriction = NO_RESTRICTION);
+  nsresult DoomFileByKeyInternal(const SHA1Sum::Hash *aHash);
+  nsresult MaybeReleaseNSPRHandleInternal(CacheFileHandle *aHandle,
+                                     bool aIgnoreShutdownLag = false);
+  nsresult TruncateSeekSetEOFInternal(CacheFileHandle *aHandle,
+                                      int64_t aTruncatePos, int64_t aEOFPos);
+  nsresult RenameFileInternal(CacheFileHandle *aHandle,
+                              const nsACString &aNewName);
+  nsresult EvictIfOverLimitInternal();
+  nsresult OverLimitEvictionInternal();
+  nsresult EvictAllInternal();
+  nsresult EvictByContextInternal(nsILoadContextInfo *aLoadContextInfo,
+                                  bool aPinning);
+
+  nsresult TrashDirectory(nsIFile *aFile);
+  static void OnTrashTimer(nsITimer *aTimer, void *aClosure);
+  nsresult StartRemovingTrash();
+  nsresult RemoveTrashInternal();
+  nsresult FindTrashDirToRemove();
+
+  nsresult CreateFile(CacheFileHandle *aHandle);
+  static void HashToStr(const SHA1Sum::Hash *aHash, nsACString &_retval);
+  static nsresult StrToHash(const nsACString &aHash, SHA1Sum::Hash *_retval);
+  nsresult GetFile(const SHA1Sum::Hash *aHash, nsIFile **_retval);
+  nsresult GetSpecialFile(const nsACString &aKey, nsIFile **_retval);
+  nsresult GetDoomedFile(nsIFile **_retval);
+  nsresult IsEmptyDirectory(nsIFile *aFile, bool *_retval);
+  nsresult CheckAndCreateDir(nsIFile *aFile, const char *aDir,
+                             bool aEnsureEmptyDir);
+  nsresult CreateCacheTree();
+  nsresult OpenNSPRHandle(CacheFileHandle *aHandle, bool aCreate = false);
+  void     NSPRHandleUsed(CacheFileHandle *aHandle);
+
+  // Removing all cache files during shutdown
+  nsresult SyncRemoveDir(nsIFile *aFile, const char *aDir);
+  void     SyncRemoveAllCacheFiles();
+
+  nsresult ScheduleMetadataWriteInternal(CacheFile * aFile);
+  nsresult UnscheduleMetadataWriteInternal(CacheFile * aFile);
+  nsresult ShutdownMetadataWriteSchedulingInternal();
+
+  static nsresult CacheIndexStateChanged();
+  nsresult CacheIndexStateChangedInternal();
+
+  // Smart size calculation. UpdateSmartCacheSize() must be called on IO thread.
+  // It is called in EvictIfOverLimitInternal() just before we decide whether to
+  // start overlimit eviction or not and also in OverLimitEvictionInternal()
+  // before we start an eviction loop.
+  nsresult UpdateSmartCacheSize(int64_t aFreeSpace);
+
+  // Memory reporting (private part)
+  size_t SizeOfExcludingThisInternal(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  static StaticRefPtr<CacheFileIOManager> gInstance;
+
+  TimeStamp                            mStartTime;
+  // Set true on the IO thread, CLOSE level as part of the internal shutdown
+  // procedure.
+  bool                                 mShuttingDown;
+  RefPtr<CacheIOThread>                mIOThread;
+  nsCOMPtr<nsIFile>                    mCacheDirectory;
+#if defined(MOZ_WIDGET_ANDROID)
+  // On Android we add the active profile directory name between the path
+  // and the 'cache2' leaf name.  However, to delete any leftover data from
+  // times before we were doing it, we still need to access the directory
+  // w/o the profile name in the path.  Here it is stored.
+  nsCOMPtr<nsIFile>                    mCacheProfilelessDirectory;
+#endif
+  bool                                 mTreeCreated;
+  bool                                 mTreeCreationFailed;
+  CacheFileHandles                     mHandles;
+  nsTArray<CacheFileHandle *>          mHandlesByLastUsed;
+  nsTArray<CacheFileHandle *>          mSpecialHandles;
+  nsTArray<RefPtr<CacheFile> >         mScheduledMetadataWrites;
+  nsCOMPtr<nsITimer>                   mMetadataWritesTimer;
+  bool                                 mOverLimitEvicting;
+  bool                                 mRemovingTrashDirs;
+  nsCOMPtr<nsITimer>                   mTrashTimer;
+  nsCOMPtr<nsIFile>                    mTrashDir;
+  nsCOMPtr<nsIDirectoryEnumerator>     mTrashDirEnumerator;
+  nsTArray<nsCString>                  mFailedTrashDirs;
+  RefPtr<CacheFileContextEvictor>      mContextEvictor;
+  TimeStamp                            mLastSmartSizeTime;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheFileInputStream.cpp b/netwerk/cache2/CacheFileInputStream.cpp
new file mode 100644
index 0000000000..26ca575370
--- /dev/null
+++ b/netwerk/cache2/CacheFileInputStream.cpp
@@ -0,0 +1,723 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheFileInputStream.h"
+
+#include "CacheFile.h"
+#include "nsStreamUtils.h"
+#include "nsThreadUtils.h"
+#include <algorithm>
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ADDREF(CacheFileInputStream)
+NS_IMETHODIMP_(MozExternalRefCountType)
+CacheFileInputStream::Release()
+{
+  NS_PRECONDITION(0 != mRefCnt, "dup release");
+  nsrefcnt count = --mRefCnt;
+  NS_LOG_RELEASE(this, count, "CacheFileInputStream");
+
+  if (0 == count) {
+    mRefCnt = 1;
+    delete (this);
+    return 0;
+  }
+
+  if (count == 1) {
+    mFile->RemoveInput(this, mStatus);
+  }
+
+  return count;
+}
+
+NS_INTERFACE_MAP_BEGIN(CacheFileInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIAsyncInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsISeekableStream)
+  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileChunkListener)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIInputStream)
+NS_INTERFACE_MAP_END_THREADSAFE
+
+CacheFileInputStream::CacheFileInputStream(CacheFile *aFile,
+                                           nsISupports *aEntry,
+                                           bool aAlternativeData)
+  : mFile(aFile)
+  , mPos(0)
+  , mStatus(NS_OK)
+  , mClosed(false)
+  , mInReadSegments(false)
+  , mWaitingForUpdate(false)
+  , mAlternativeData(aAlternativeData)
+  , mListeningForChunk(-1)
+  , mCallbackFlags(0)
+  , mCacheEntryHandle(aEntry)
+{
+  LOG(("CacheFileInputStream::CacheFileInputStream() [this=%p]", this));
+  MOZ_COUNT_CTOR(CacheFileInputStream);
+
+  if (mAlternativeData) {
+    mPos = mFile->mAltDataOffset;
+  }
+}
+
+CacheFileInputStream::~CacheFileInputStream()
+{
+  LOG(("CacheFileInputStream::~CacheFileInputStream() [this=%p]", this));
+  MOZ_COUNT_DTOR(CacheFileInputStream);
+  MOZ_ASSERT(!mInReadSegments);
+}
+
+// nsIInputStream
+NS_IMETHODIMP
+CacheFileInputStream::Close()
+{
+  LOG(("CacheFileInputStream::Close() [this=%p]", this));
+  return CloseWithStatus(NS_OK);
+}
+
+NS_IMETHODIMP
+CacheFileInputStream::Available(uint64_t *_retval)
+{
+  CacheFileAutoLock lock(mFile);
+
+  if (mClosed) {
+    LOG(("CacheFileInputStream::Available() - Stream is closed. [this=%p, "
+         "status=0x%08x]", this, mStatus));
+    return NS_FAILED(mStatus) ? mStatus : NS_BASE_STREAM_CLOSED;
+  }
+
+  EnsureCorrectChunk(false);
+  if (NS_FAILED(mStatus)) {
+    LOG(("CacheFileInputStream::Available() - EnsureCorrectChunk failed. "
+         "[this=%p, status=0x%08x]", this, mStatus));
+    return mStatus;
+  }
+
+  nsresult rv = NS_OK;
+  *_retval = 0;
+
+  if (mChunk) {
+    int64_t canRead = mFile->BytesFromChunk(mChunk->Index(), mAlternativeData);
+    canRead -= (mPos % kChunkSize);
+
+    if (canRead > 0) {
+      *_retval = canRead;
+    } else if (canRead == 0 && !mFile->OutputStreamExists(mAlternativeData)) {
+      rv = NS_BASE_STREAM_CLOSED;
+    }
+  }
+
+  LOG(("CacheFileInputStream::Available() [this=%p, retval=%lld, rv=0x%08x]",
+       this, *_retval, rv));
+
+  return rv;
+}
+
+NS_IMETHODIMP
+CacheFileInputStream::Read(char *aBuf, uint32_t aCount, uint32_t *_retval)
+{
+  LOG(("CacheFileInputStream::Read() [this=%p, count=%d]", this, aCount));
+  return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, _retval);
+}
+
+NS_IMETHODIMP
+CacheFileInputStream::ReadSegments(nsWriteSegmentFun aWriter, void *aClosure,
+                                   uint32_t aCount, uint32_t *_retval)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileInputStream::ReadSegments() [this=%p, count=%d]",
+       this, aCount));
+
+  nsresult rv;
+
+  *_retval = 0;
+
+  if (mInReadSegments) {
+    LOG(("CacheFileInputStream::ReadSegments() - Cannot be called while the "
+         "stream is in ReadSegments!"));
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (mClosed) {
+    LOG(("CacheFileInputStream::ReadSegments() - Stream is closed. [this=%p, "
+         "status=0x%08x]", this, mStatus));
+
+    if NS_FAILED(mStatus)
+      return mStatus;
+
+    return NS_OK;
+  }
+
+  EnsureCorrectChunk(false);
+
+  while (true) {
+    if (NS_FAILED(mStatus))
+      return mStatus;
+
+    if (!mChunk) {
+      if (mListeningForChunk == -1) {
+        return NS_OK;
+      } else {
+        return NS_BASE_STREAM_WOULD_BLOCK;
+      }
+    }
+
+    CacheFileChunkReadHandle hnd = mChunk->GetReadHandle();
+    int64_t canRead = CanRead(&hnd);
+    if (NS_FAILED(mStatus)) {
+      return mStatus;
+    }
+
+    if (canRead < 0) {
+      // file was truncated ???
+      MOZ_ASSERT(false, "SetEOF is currenty not implemented?!");
+      rv = NS_OK;
+    } else if (canRead > 0) {
+      uint32_t toRead = std::min(static_cast<uint32_t>(canRead), aCount);
+      uint32_t read;
+      const char *buf = hnd.Buf() + (mPos - hnd.Offset());
+
+      mInReadSegments = true;
+      lock.Unlock();
+
+      rv = aWriter(this, aClosure, buf, *_retval, toRead, &read);
+
+      lock.Lock();
+      mInReadSegments = false;
+
+      if (NS_SUCCEEDED(rv)) {
+        MOZ_ASSERT(read <= toRead,
+                   "writer should not write more than we asked it to write");
+
+        *_retval += read;
+        mPos += read;
+        aCount -= read;
+
+        if (!mClosed) {
+          if (hnd.DataSize() != mChunk->DataSize()) {
+            // New data was written to this chunk while the lock was released.
+            continue;
+          }
+
+          // The last chunk is released after the caller closes this stream.
+          EnsureCorrectChunk(false);
+
+          if (mChunk && aCount) {
+            // We have the next chunk! Go on.
+            continue;
+          }
+        }
+      }
+
+      if (mClosed) {
+        // The stream was closed from aWriter, do the cleanup.
+        CleanUp();
+      }
+
+      rv = NS_OK;
+    } else {
+      if (mFile->OutputStreamExists(mAlternativeData)) {
+        rv = NS_BASE_STREAM_WOULD_BLOCK;
+      } else {
+        rv = NS_OK;
+      }
+    }
+
+    break;
+  }
+
+  LOG(("CacheFileInputStream::ReadSegments() [this=%p, rv=0x%08x, retval=%d]",
+       this, rv, *_retval));
+
+  return rv;
+}
+
+NS_IMETHODIMP
+CacheFileInputStream::IsNonBlocking(bool *_retval)
+{
+  *_retval = true;
+  return NS_OK;
+}
+
+// nsIAsyncInputStream
+NS_IMETHODIMP
+CacheFileInputStream::CloseWithStatus(nsresult aStatus)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileInputStream::CloseWithStatus() [this=%p, aStatus=0x%08x]",
+       this, aStatus));
+
+  return CloseWithStatusLocked(aStatus);
+}
+
+nsresult
+CacheFileInputStream::CloseWithStatusLocked(nsresult aStatus)
+{
+  LOG(("CacheFileInputStream::CloseWithStatusLocked() [this=%p, "
+       "aStatus=0x%08x]", this, aStatus));
+
+  if (mClosed) {
+    // We notify listener and null out mCallback immediately after closing
+    // the stream. If we're in ReadSegments we postpone notification until we
+    // step out from ReadSegments. So if the stream is already closed the
+    // following assertion must be true.
+    MOZ_ASSERT(!mCallback || mInReadSegments);
+
+    return NS_OK;
+  }
+
+  mClosed = true;
+  mStatus = NS_FAILED(aStatus) ? aStatus : NS_BASE_STREAM_CLOSED;
+
+  if (!mInReadSegments) {
+    CleanUp();
+  }
+
+  return NS_OK;
+}
+
+void
+CacheFileInputStream::CleanUp()
+{
+  MOZ_ASSERT(!mInReadSegments);
+  MOZ_ASSERT(mClosed);
+
+  if (mChunk) {
+    ReleaseChunk();
+  }
+
+  // TODO propagate error from input stream to other streams ???
+
+  MaybeNotifyListener();
+
+  mFile->ReleaseOutsideLock(mCacheEntryHandle.forget());
+}
+
+NS_IMETHODIMP
+CacheFileInputStream::AsyncWait(nsIInputStreamCallback *aCallback,
+                                uint32_t aFlags,
+                                uint32_t aRequestedCount,
+                                nsIEventTarget *aEventTarget)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileInputStream::AsyncWait() [this=%p, callback=%p, flags=%d, "
+       "requestedCount=%d, eventTarget=%p]", this, aCallback, aFlags,
+       aRequestedCount, aEventTarget));
+
+  if (mInReadSegments) {
+    LOG(("CacheFileInputStream::AsyncWait() - Cannot be called while the stream"
+         " is in ReadSegments!"));
+    MOZ_ASSERT(false, "Unexpected call. If it's a valid usage implement it. "
+               "Otherwise fix the caller.");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  mCallback = aCallback;
+  mCallbackFlags = aFlags;
+  mCallbackTarget = aEventTarget;
+
+  if (!mCallback) {
+    if (mWaitingForUpdate) {
+      mChunk->CancelWait(this);
+      mWaitingForUpdate = false;
+    }
+    return NS_OK;
+  }
+
+  if (mClosed) {
+    NotifyListener();
+    return NS_OK;
+  }
+
+  EnsureCorrectChunk(false);
+
+  MaybeNotifyListener();
+
+  return NS_OK;
+}
+
+// nsISeekableStream
+NS_IMETHODIMP
+CacheFileInputStream::Seek(int32_t whence, int64_t offset)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileInputStream::Seek() [this=%p, whence=%d, offset=%lld]",
+       this, whence, offset));
+
+  if (mInReadSegments) {
+    LOG(("CacheFileInputStream::Seek() - Cannot be called while the stream is "
+         "in ReadSegments!"));
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (mClosed) {
+    LOG(("CacheFileInputStream::Seek() - Stream is closed. [this=%p]", this));
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  int64_t newPos = offset;
+  switch (whence) {
+    case NS_SEEK_SET:
+      if (mAlternativeData) {
+        newPos += mFile->mAltDataOffset;
+      }
+      break;
+    case NS_SEEK_CUR:
+      newPos += mPos;
+      break;
+    case NS_SEEK_END:
+      if (mAlternativeData) {
+        newPos += mFile->mDataSize;
+      } else {
+        newPos += mFile->mAltDataOffset;
+      }
+      break;
+    default:
+      NS_ERROR("invalid whence");
+      return NS_ERROR_INVALID_ARG;
+  }
+  mPos = newPos;
+  EnsureCorrectChunk(false);
+
+  LOG(("CacheFileInputStream::Seek() [this=%p, pos=%lld]", this, mPos));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheFileInputStream::Tell(int64_t *_retval)
+{
+  CacheFileAutoLock lock(mFile);
+
+  if (mClosed) {
+    LOG(("CacheFileInputStream::Tell() - Stream is closed. [this=%p]", this));
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  *_retval = mPos;
+
+  if (mAlternativeData) {
+    *_retval -= mFile->mAltDataOffset;
+  }
+
+  LOG(("CacheFileInputStream::Tell() [this=%p, retval=%lld]", this, *_retval));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheFileInputStream::SetEOF()
+{
+  MOZ_ASSERT(false, "Don't call SetEOF on cache input stream");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+// CacheFileChunkListener
+nsresult
+CacheFileInputStream::OnChunkRead(nsresult aResult, CacheFileChunk *aChunk)
+{
+  MOZ_CRASH("CacheFileInputStream::OnChunkRead should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileInputStream::OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk)
+{
+  MOZ_CRASH("CacheFileInputStream::OnChunkWritten should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileInputStream::OnChunkAvailable(nsresult aResult, uint32_t aChunkIdx,
+                                       CacheFileChunk *aChunk)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileInputStream::OnChunkAvailable() [this=%p, result=0x%08x, "
+       "idx=%d, chunk=%p]", this, aResult, aChunkIdx, aChunk));
+
+  MOZ_ASSERT(mListeningForChunk != -1);
+
+  if (mListeningForChunk != static_cast<int64_t>(aChunkIdx)) {
+    // This is not a chunk that we're waiting for
+    LOG(("CacheFileInputStream::OnChunkAvailable() - Notification is for a "
+         "different chunk. [this=%p, listeningForChunk=%lld]",
+         this, mListeningForChunk));
+
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(!mChunk);
+  MOZ_ASSERT(!mWaitingForUpdate);
+  MOZ_ASSERT(!mInReadSegments);
+  mListeningForChunk = -1;
+
+  if (mClosed) {
+    MOZ_ASSERT(!mCallback);
+
+    LOG(("CacheFileInputStream::OnChunkAvailable() - Stream is closed, "
+         "ignoring notification. [this=%p]", this));
+
+    return NS_OK;
+  }
+
+  if (NS_SUCCEEDED(aResult)) {
+    mChunk = aChunk;
+  } else if (aResult != NS_ERROR_NOT_AVAILABLE) {
+    // Close the stream with error. The consumer will receive this error later
+    // in Read(), Available() etc. We need to handle NS_ERROR_NOT_AVAILABLE
+    // differently since it is returned when the requested chunk is not
+    // available and there is no writer that could create it, i.e. it means that
+    // we've reached the end of the file.
+    CloseWithStatusLocked(aResult);
+
+    return NS_OK;
+  }
+
+  MaybeNotifyListener();
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileInputStream::OnChunkUpdated(CacheFileChunk *aChunk)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileInputStream::OnChunkUpdated() [this=%p, idx=%d]",
+       this, aChunk->Index()));
+
+  if (!mWaitingForUpdate) {
+    LOG(("CacheFileInputStream::OnChunkUpdated() - Ignoring notification since "
+         "mWaitingforUpdate == false. [this=%p]", this));
+
+    return NS_OK;
+  }
+  else {
+    mWaitingForUpdate = false;
+  }
+
+  MOZ_ASSERT(mChunk == aChunk);
+
+  MaybeNotifyListener();
+
+  return NS_OK;
+}
+
+void
+CacheFileInputStream::ReleaseChunk()
+{
+  mFile->AssertOwnsLock();
+
+  LOG(("CacheFileInputStream::ReleaseChunk() [this=%p, idx=%d]",
+       this, mChunk->Index()));
+
+  MOZ_ASSERT(!mInReadSegments);
+
+  if (mWaitingForUpdate) {
+    LOG(("CacheFileInputStream::ReleaseChunk() - Canceling waiting for update. "
+         "[this=%p]", this));
+
+    mChunk->CancelWait(this);
+    mWaitingForUpdate = false;
+  }
+
+  mFile->ReleaseOutsideLock(mChunk.forget());
+}
+
+void
+CacheFileInputStream::EnsureCorrectChunk(bool aReleaseOnly)
+{
+  mFile->AssertOwnsLock();
+
+  LOG(("CacheFileInputStream::EnsureCorrectChunk() [this=%p, releaseOnly=%d]",
+       this, aReleaseOnly));
+
+  nsresult rv;
+
+  uint32_t chunkIdx = mPos / kChunkSize;
+
+  if (mInReadSegments) {
+    // We must have correct chunk
+    MOZ_ASSERT(mChunk);
+    MOZ_ASSERT(mChunk->Index() == chunkIdx);
+    return;
+  }
+
+  if (mChunk) {
+    if (mChunk->Index() == chunkIdx) {
+      // we have a correct chunk
+      LOG(("CacheFileInputStream::EnsureCorrectChunk() - Have correct chunk "
+           "[this=%p, idx=%d]", this, chunkIdx));
+
+      return;
+    } else {
+      ReleaseChunk();
+    }
+  }
+
+  MOZ_ASSERT(!mWaitingForUpdate);
+
+  if (aReleaseOnly)
+    return;
+
+  if (mListeningForChunk == static_cast<int64_t>(chunkIdx)) {
+    // We're already waiting for this chunk
+    LOG(("CacheFileInputStream::EnsureCorrectChunk() - Already listening for "
+         "chunk %lld [this=%p]", mListeningForChunk, this));
+
+    return;
+  }
+
+  rv = mFile->GetChunkLocked(chunkIdx, CacheFile::READER, this,
+                             getter_AddRefs(mChunk));
+  if (NS_FAILED(rv)) {
+    LOG(("CacheFileInputStream::EnsureCorrectChunk() - GetChunkLocked failed. "
+         "[this=%p, idx=%d, rv=0x%08x]", this, chunkIdx, rv));
+    if (rv != NS_ERROR_NOT_AVAILABLE) {
+      // Close the stream with error. The consumer will receive this error later
+      // in Read(), Available() etc. We need to handle NS_ERROR_NOT_AVAILABLE
+      // differently since it is returned when the requested chunk is not
+      // available and there is no writer that could create it, i.e. it means
+      // that we've reached the end of the file.
+      CloseWithStatusLocked(rv);
+
+      return;
+    }
+  } else if (!mChunk) {
+    mListeningForChunk = static_cast<int64_t>(chunkIdx);
+  }
+
+  MaybeNotifyListener();
+}
+
+int64_t
+CacheFileInputStream::CanRead(CacheFileChunkReadHandle *aHandle)
+{
+  mFile->AssertOwnsLock();
+
+  MOZ_ASSERT(mChunk);
+  MOZ_ASSERT(mPos / kChunkSize == mChunk->Index());
+
+  int64_t retval = aHandle->Offset() + aHandle->DataSize() - mPos;
+  if (retval <= 0 && NS_FAILED(mChunk->GetStatus())) {
+    CloseWithStatusLocked(mChunk->GetStatus());
+  }
+
+  LOG(("CacheFileInputStream::CanRead() [this=%p, canRead=%lld]",
+       this, retval));
+
+  return retval;
+}
+
+void
+CacheFileInputStream::NotifyListener()
+{
+  mFile->AssertOwnsLock();
+
+  LOG(("CacheFileInputStream::NotifyListener() [this=%p]", this));
+
+  MOZ_ASSERT(mCallback);
+  MOZ_ASSERT(!mInReadSegments);
+
+  if (!mCallbackTarget) {
+    mCallbackTarget = CacheFileIOManager::IOTarget();
+    if (!mCallbackTarget) {
+      LOG(("CacheFileInputStream::NotifyListener() - Cannot get Cache I/O "
+           "thread! Using main thread for callback."));
+      mCallbackTarget = do_GetMainThread();
+    }
+  }
+
+  nsCOMPtr<nsIInputStreamCallback> asyncCallback =
+    NS_NewInputStreamReadyEvent(mCallback, mCallbackTarget);
+
+  mCallback = nullptr;
+  mCallbackTarget = nullptr;
+
+  asyncCallback->OnInputStreamReady(this);
+}
+
+void
+CacheFileInputStream::MaybeNotifyListener()
+{
+  mFile->AssertOwnsLock();
+
+  LOG(("CacheFileInputStream::MaybeNotifyListener() [this=%p, mCallback=%p, "
+       "mClosed=%d, mStatus=0x%08x, mChunk=%p, mListeningForChunk=%lld, "
+       "mWaitingForUpdate=%d]", this, mCallback.get(), mClosed, mStatus,
+       mChunk.get(), mListeningForChunk, mWaitingForUpdate));
+
+  MOZ_ASSERT(!mInReadSegments);
+
+  if (!mCallback)
+    return;
+
+  if (mClosed || NS_FAILED(mStatus)) {
+    NotifyListener();
+    return;
+  }
+
+  if (!mChunk) {
+    if (mListeningForChunk == -1) {
+      // EOF, should we notify even if mCallbackFlags == WAIT_CLOSURE_ONLY ??
+      NotifyListener();
+    }
+    return;
+  }
+
+  MOZ_ASSERT(mPos / kChunkSize == mChunk->Index());
+
+  if (mWaitingForUpdate)
+    return;
+
+  CacheFileChunkReadHandle hnd = mChunk->GetReadHandle();
+  int64_t canRead = CanRead(&hnd);
+  if (NS_FAILED(mStatus)) {
+    // CanRead() called CloseWithStatusLocked() which called
+    // MaybeNotifyListener() so the listener was already notified. Stop here.
+    MOZ_ASSERT(!mCallback);
+    return;
+  }
+
+  if (canRead > 0) {
+    if (!(mCallbackFlags & WAIT_CLOSURE_ONLY))
+      NotifyListener();
+  }
+  else if (canRead == 0) {
+    if (!mFile->OutputStreamExists(mAlternativeData)) {
+      // EOF
+      NotifyListener();
+    }
+    else {
+      mChunk->WaitForUpdate(this);
+      mWaitingForUpdate = true;
+    }
+  }
+  else {
+    // Output have set EOF before mPos?
+    MOZ_ASSERT(false, "SetEOF is currenty not implemented?!");
+    NotifyListener();
+  }
+}
+
+// Memory reporting
+
+size_t
+CacheFileInputStream::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  // Everything the stream keeps a reference to is already reported somewhere else.
+  // mFile reports itself.
+  // mChunk reported as part of CacheFile.
+  // mCallback is usually CacheFile or a class that is reported elsewhere.
+  return mallocSizeOf(this);
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheFileInputStream.h b/netwerk/cache2/CacheFileInputStream.h
new file mode 100644
index 0000000000..ab632f3687
--- /dev/null
+++ b/netwerk/cache2/CacheFileInputStream.h
@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheFileInputStream__h__
+#define CacheFileInputStream__h__
+
+#include "nsIAsyncInputStream.h"
+#include "nsISeekableStream.h"
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+#include "CacheFileChunk.h"
+
+namespace mozilla {
+namespace net {
+
+class CacheFile;
+
+class CacheFileInputStream : public nsIAsyncInputStream
+                           , public nsISeekableStream
+                           , public CacheFileChunkListener
+{
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+  NS_DECL_NSISEEKABLESTREAM
+
+public:
+  explicit CacheFileInputStream(CacheFile *aFile, nsISupports *aEntry,
+                                bool aAlternativeData);
+
+  NS_IMETHOD OnChunkRead(nsresult aResult, CacheFileChunk *aChunk) override;
+  NS_IMETHOD OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk) override;
+  NS_IMETHOD OnChunkAvailable(nsresult aResult, uint32_t aChunkIdx,
+                              CacheFileChunk *aChunk) override;
+  NS_IMETHOD OnChunkUpdated(CacheFileChunk *aChunk) override;
+
+  // Memory reporting
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  uint32_t GetPosition() const { return mPos; };
+  bool IsAlternativeData() const { return mAlternativeData; };
+
+private:
+  virtual ~CacheFileInputStream();
+
+  nsresult CloseWithStatusLocked(nsresult aStatus);
+  void CleanUp();
+  void ReleaseChunk();
+  void EnsureCorrectChunk(bool aReleaseOnly);
+
+  // CanRead returns negative value when output stream truncates the data before
+  // the input stream's mPos.
+  int64_t CanRead(CacheFileChunkReadHandle *aHandle);
+  void NotifyListener();
+  void MaybeNotifyListener();
+
+  RefPtr<CacheFile>      mFile;
+  RefPtr<CacheFileChunk> mChunk;
+  int64_t                mPos;
+  nsresult               mStatus;
+  bool                   mClosed : 1;
+  bool                   mInReadSegments : 1;
+  bool                   mWaitingForUpdate : 1;
+  bool const             mAlternativeData : 1;
+  int64_t                mListeningForChunk;
+
+  nsCOMPtr<nsIInputStreamCallback> mCallback;
+  uint32_t                         mCallbackFlags;
+  nsCOMPtr<nsIEventTarget>         mCallbackTarget;
+  // Held purely for referencing purposes
+  RefPtr<nsISupports>              mCacheEntryHandle;
+};
+
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheFileMetadata.cpp b/netwerk/cache2/CacheFileMetadata.cpp
new file mode 100644
index 0000000000..3814b4c878
--- /dev/null
+++ b/netwerk/cache2/CacheFileMetadata.cpp
@@ -0,0 +1,1095 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheFileMetadata.h"
+
+#include "CacheFileIOManager.h"
+#include "nsICacheEntry.h"
+#include "CacheHashUtils.h"
+#include "CacheFileChunk.h"
+#include "CacheFileUtils.h"
+#include "nsILoadContextInfo.h"
+#include "nsICacheEntry.h" // for nsICacheEntryMetaDataVisitor
+#include "../cache/nsCacheUtils.h"
+#include "nsIFile.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/DebugOnly.h"
+#include "prnetdb.h"
+
+
+namespace mozilla {
+namespace net {
+
+#define kMinMetadataRead 1024  // TODO find optimal value from telemetry
+#define kAlignSize       4096
+
+// Most of the cache entries fit into one chunk due to current chunk size. Make
+// sure to tweak this value if kChunkSize is going to change.
+#define kInitialHashArraySize 1
+
+// Initial elements buffer size.
+#define kInitialBufSize 64
+
+// Max size of elements in bytes.
+#define kMaxElementsSize 64*1024
+
+#define NOW_SECONDS() (uint32_t(PR_Now() / PR_USEC_PER_SEC))
+
+NS_IMPL_ISUPPORTS(CacheFileMetadata, CacheFileIOListener)
+
+CacheFileMetadata::CacheFileMetadata(CacheFileHandle *aHandle, const nsACString &aKey)
+  : CacheMemoryConsumer(NORMAL)
+  , mHandle(aHandle)
+  , mHashArray(nullptr)
+  , mHashArraySize(0)
+  , mHashCount(0)
+  , mOffset(-1)
+  , mBuf(nullptr)
+  , mBufSize(0)
+  , mWriteBuf(nullptr)
+  , mElementsSize(0)
+  , mIsDirty(false)
+  , mAnonymous(false)
+  , mAllocExactSize(false)
+  , mFirstRead(true)
+{
+  LOG(("CacheFileMetadata::CacheFileMetadata() [this=%p, handle=%p, key=%s]",
+       this, aHandle, PromiseFlatCString(aKey).get()));
+
+  MOZ_COUNT_CTOR(CacheFileMetadata);
+  memset(&mMetaHdr, 0, sizeof(CacheFileMetadataHeader));
+  mMetaHdr.mVersion = kCacheEntryVersion;
+  mMetaHdr.mExpirationTime = nsICacheEntry::NO_EXPIRATION_TIME;
+  mKey = aKey;
+
+  DebugOnly<nsresult> rv;
+  rv = ParseKey(aKey);
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+}
+
+CacheFileMetadata::CacheFileMetadata(bool aMemoryOnly, bool aPinned, const nsACString &aKey)
+  : CacheMemoryConsumer(aMemoryOnly ? MEMORY_ONLY : NORMAL)
+  , mHandle(nullptr)
+  , mHashArray(nullptr)
+  , mHashArraySize(0)
+  , mHashCount(0)
+  , mOffset(0)
+  , mBuf(nullptr)
+  , mBufSize(0)
+  , mWriteBuf(nullptr)
+  , mElementsSize(0)
+  , mIsDirty(true)
+  , mAnonymous(false)
+  , mAllocExactSize(false)
+  , mFirstRead(true)
+{
+  LOG(("CacheFileMetadata::CacheFileMetadata() [this=%p, key=%s]",
+       this, PromiseFlatCString(aKey).get()));
+
+  MOZ_COUNT_CTOR(CacheFileMetadata);
+  memset(&mMetaHdr, 0, sizeof(CacheFileMetadataHeader));
+  mMetaHdr.mVersion = kCacheEntryVersion;
+  if (aPinned) {
+    AddFlags(kCacheEntryIsPinned);
+  }
+  mMetaHdr.mExpirationTime = nsICacheEntry::NO_EXPIRATION_TIME;
+  mKey = aKey;
+  mMetaHdr.mKeySize = mKey.Length();
+
+  DebugOnly<nsresult> rv;
+  rv = ParseKey(aKey);
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+}
+
+CacheFileMetadata::CacheFileMetadata()
+  : CacheMemoryConsumer(DONT_REPORT /* This is a helper class */)
+  , mHandle(nullptr)
+  , mHashArray(nullptr)
+  , mHashArraySize(0)
+  , mHashCount(0)
+  , mOffset(0)
+  , mBuf(nullptr)
+  , mBufSize(0)
+  , mWriteBuf(nullptr)
+  , mElementsSize(0)
+  , mIsDirty(false)
+  , mAnonymous(false)
+  , mAllocExactSize(false)
+  , mFirstRead(true)
+{
+  LOG(("CacheFileMetadata::CacheFileMetadata() [this=%p]", this));
+
+  MOZ_COUNT_CTOR(CacheFileMetadata);
+  memset(&mMetaHdr, 0, sizeof(CacheFileMetadataHeader));
+}
+
+CacheFileMetadata::~CacheFileMetadata()
+{
+  LOG(("CacheFileMetadata::~CacheFileMetadata() [this=%p]", this));
+
+  MOZ_COUNT_DTOR(CacheFileMetadata);
+  MOZ_ASSERT(!mListener);
+
+  if (mHashArray) {
+    CacheFileUtils::FreeBuffer(mHashArray);
+    mHashArray = nullptr;
+    mHashArraySize = 0;
+  }
+
+  if (mBuf) {
+    CacheFileUtils::FreeBuffer(mBuf);
+    mBuf = nullptr;
+    mBufSize = 0;
+  }
+}
+
+void
+CacheFileMetadata::SetHandle(CacheFileHandle *aHandle)
+{
+  LOG(("CacheFileMetadata::SetHandle() [this=%p, handle=%p]", this, aHandle));
+
+  MOZ_ASSERT(!mHandle);
+
+  mHandle = aHandle;
+}
+
+nsresult
+CacheFileMetadata::GetKey(nsACString &_retval)
+{
+  _retval = mKey;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::ReadMetadata(CacheFileMetadataListener *aListener)
+{
+  LOG(("CacheFileMetadata::ReadMetadata() [this=%p, listener=%p]", this, aListener));
+
+  MOZ_ASSERT(!mListener);
+  MOZ_ASSERT(!mHashArray);
+  MOZ_ASSERT(!mBuf);
+  MOZ_ASSERT(!mWriteBuf);
+
+  nsresult rv;
+
+  int64_t size = mHandle->FileSize();
+  MOZ_ASSERT(size != -1);
+
+  if (size == 0) {
+    // this is a new entry
+    LOG(("CacheFileMetadata::ReadMetadata() - Filesize == 0, creating empty "
+         "metadata. [this=%p]", this));
+
+    InitEmptyMetadata();
+    aListener->OnMetadataRead(NS_OK);
+    return NS_OK;
+  }
+
+  if (size < int64_t(sizeof(CacheFileMetadataHeader) + 2*sizeof(uint32_t))) {
+    // there must be at least checksum, header and offset
+    LOG(("CacheFileMetadata::ReadMetadata() - File is corrupted, creating "
+         "empty metadata. [this=%p, filesize=%lld]", this, size));
+
+    InitEmptyMetadata();
+    aListener->OnMetadataRead(NS_OK);
+    return NS_OK;
+  }
+
+  // Set offset so that we read at least kMinMetadataRead if the file is big
+  // enough.
+  int64_t offset;
+  if (size < kMinMetadataRead) {
+    offset = 0;
+  } else {
+    offset = size - kMinMetadataRead;
+  }
+
+  // round offset to kAlignSize blocks
+  offset = (offset / kAlignSize) * kAlignSize;
+
+  mBufSize = size - offset;
+  mBuf = static_cast<char *>(moz_xmalloc(mBufSize));
+
+  DoMemoryReport(MemoryUsage());
+
+  LOG(("CacheFileMetadata::ReadMetadata() - Reading metadata from disk, trying "
+       "offset=%lld, filesize=%lld [this=%p]", offset, size, this));
+
+  mReadStart = mozilla::TimeStamp::Now();
+  mListener = aListener;
+  rv = CacheFileIOManager::Read(mHandle, offset, mBuf, mBufSize, this);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheFileMetadata::ReadMetadata() - CacheFileIOManager::Read() failed"
+         " synchronously, creating empty metadata. [this=%p, rv=0x%08x]",
+         this, rv));
+
+    mListener = nullptr;
+    InitEmptyMetadata();
+    aListener->OnMetadataRead(NS_OK);
+    return NS_OK;
+  }
+
+  return NS_OK;
+}
+
+uint32_t
+CacheFileMetadata::CalcMetadataSize(uint32_t aElementsSize, uint32_t aHashCount)
+{
+  return sizeof(uint32_t) +                         // hash of the metadata
+         aHashCount * sizeof(CacheHash::Hash16_t) + // array of chunk hashes
+         sizeof(CacheFileMetadataHeader) +          // metadata header
+         mKey.Length() + 1 +                        // key with trailing null
+         aElementsSize +                            // elements
+         sizeof(uint32_t);                          // offset
+}
+
+nsresult
+CacheFileMetadata::WriteMetadata(uint32_t aOffset,
+                                 CacheFileMetadataListener *aListener)
+{
+  LOG(("CacheFileMetadata::WriteMetadata() [this=%p, offset=%d, listener=%p]",
+       this, aOffset, aListener));
+
+  MOZ_ASSERT(!mListener);
+  MOZ_ASSERT(!mWriteBuf);
+
+  nsresult rv;
+
+  mIsDirty = false;
+
+  mWriteBuf = static_cast<char *>(malloc(CalcMetadataSize(mElementsSize,
+                                                          mHashCount)));
+  if (!mWriteBuf) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  char *p = mWriteBuf + sizeof(uint32_t);
+  memcpy(p, mHashArray, mHashCount * sizeof(CacheHash::Hash16_t));
+  p += mHashCount * sizeof(CacheHash::Hash16_t);
+  mMetaHdr.WriteToBuf(p);
+  p += sizeof(CacheFileMetadataHeader);
+  memcpy(p, mKey.get(), mKey.Length());
+  p += mKey.Length();
+  *p = 0;
+  p++;
+  memcpy(p, mBuf, mElementsSize);
+  p += mElementsSize;
+
+  CacheHash::Hash32_t hash;
+  hash = CacheHash::Hash(mWriteBuf + sizeof(uint32_t),
+                         p - mWriteBuf - sizeof(uint32_t));
+  NetworkEndian::writeUint32(mWriteBuf, hash);
+
+  NetworkEndian::writeUint32(p, aOffset);
+  p += sizeof(uint32_t);
+
+  char * writeBuffer = mWriteBuf;
+  if (aListener) {
+    mListener = aListener;
+  } else {
+    // We are not going to pass |this| as a callback so the buffer will be
+    // released by CacheFileIOManager. Just null out mWriteBuf here.
+    mWriteBuf = nullptr;
+  }
+
+  rv = CacheFileIOManager::Write(mHandle, aOffset, writeBuffer, p - writeBuffer,
+                                 true, true, aListener ? this : nullptr);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheFileMetadata::WriteMetadata() - CacheFileIOManager::Write() "
+         "failed synchronously. [this=%p, rv=0x%08x]", this, rv));
+
+    mListener = nullptr;
+    if (mWriteBuf) {
+      CacheFileUtils::FreeBuffer(mWriteBuf);
+      mWriteBuf = nullptr;
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  DoMemoryReport(MemoryUsage());
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::SyncReadMetadata(nsIFile *aFile)
+{
+  LOG(("CacheFileMetadata::SyncReadMetadata() [this=%p]", this));
+
+  MOZ_ASSERT(!mListener);
+  MOZ_ASSERT(!mHandle);
+  MOZ_ASSERT(!mHashArray);
+  MOZ_ASSERT(!mBuf);
+  MOZ_ASSERT(!mWriteBuf);
+  MOZ_ASSERT(mKey.IsEmpty());
+
+  nsresult rv;
+
+  int64_t fileSize;
+  rv = aFile->GetFileSize(&fileSize);
+  if (NS_FAILED(rv)) {
+    // Don't bloat the console
+    return rv;
+  }
+
+  PRFileDesc *fd;
+  rv = aFile->OpenNSPRFileDesc(PR_RDONLY, 0600, &fd);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  int64_t offset = PR_Seek64(fd, fileSize - sizeof(uint32_t), PR_SEEK_SET);
+  if (offset == -1) {
+    PR_Close(fd);
+    return NS_ERROR_FAILURE;
+  }
+
+  uint32_t metaOffset;
+  int32_t bytesRead = PR_Read(fd, &metaOffset, sizeof(uint32_t));
+  if (bytesRead != sizeof(uint32_t)) {
+    PR_Close(fd);
+    return NS_ERROR_FAILURE;
+  }
+
+  metaOffset = NetworkEndian::readUint32(&metaOffset);
+  if (metaOffset > fileSize) {
+    PR_Close(fd);
+    return NS_ERROR_FAILURE;
+  }
+
+  mBuf = static_cast<char *>(malloc(fileSize - metaOffset));
+  if (!mBuf) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  mBufSize = fileSize - metaOffset;
+
+  DoMemoryReport(MemoryUsage());
+
+  offset = PR_Seek64(fd, metaOffset, PR_SEEK_SET);
+  if (offset == -1) {
+    PR_Close(fd);
+    return NS_ERROR_FAILURE;
+  }
+
+  bytesRead = PR_Read(fd, mBuf, mBufSize);
+  PR_Close(fd);
+  if (bytesRead != static_cast<int32_t>(mBufSize)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = ParseMetadata(metaOffset, 0, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+const char *
+CacheFileMetadata::GetElement(const char *aKey)
+{
+  const char *data = mBuf;
+  const char *limit = mBuf + mElementsSize;
+
+  while (data < limit) {
+    // Point to the value part
+    const char *value = data + strlen(data) + 1;
+    MOZ_ASSERT(value < limit, "Metadata elements corrupted");
+    if (strcmp(data, aKey) == 0) {
+      LOG(("CacheFileMetadata::GetElement() - Key found [this=%p, key=%s]",
+           this, aKey));
+      return value;
+    }
+
+    // Skip value part
+    data = value + strlen(value) + 1;
+  }
+  MOZ_ASSERT(data == limit, "Metadata elements corrupted");
+  LOG(("CacheFileMetadata::GetElement() - Key not found [this=%p, key=%s]",
+       this, aKey));
+  return nullptr;
+}
+
+nsresult
+CacheFileMetadata::SetElement(const char *aKey, const char *aValue)
+{
+  LOG(("CacheFileMetadata::SetElement() [this=%p, key=%s, value=%p]",
+       this, aKey, aValue));
+
+  MarkDirty();
+
+  nsresult rv;
+
+  const uint32_t keySize = strlen(aKey) + 1;
+  char *pos = const_cast<char *>(GetElement(aKey));
+
+  if (!aValue) {
+    // No value means remove the key/value pair completely, if existing
+    if (pos) {
+      uint32_t oldValueSize = strlen(pos) + 1;
+      uint32_t offset = pos - mBuf;
+      uint32_t remainder = mElementsSize - (offset + oldValueSize);
+
+      memmove(pos - keySize, pos + oldValueSize, remainder);
+      mElementsSize -= keySize + oldValueSize;
+    }
+    return NS_OK;
+  }
+
+  const uint32_t valueSize = strlen(aValue) + 1;
+  uint32_t newSize = mElementsSize + valueSize;
+  if (pos) {
+    const uint32_t oldValueSize = strlen(pos) + 1;
+    const uint32_t offset = pos - mBuf;
+    const uint32_t remainder = mElementsSize - (offset + oldValueSize);
+
+    // Update the value in place
+    newSize -= oldValueSize;
+    rv = EnsureBuffer(newSize);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    // Move the remainder to the right place
+    pos = mBuf + offset;
+    memmove(pos + valueSize, pos + oldValueSize, remainder);
+  } else {
+    // allocate new meta data element
+    newSize += keySize;
+    rv = EnsureBuffer(newSize);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    // Add after last element
+    pos = mBuf + mElementsSize;
+    memcpy(pos, aKey, keySize);
+    pos += keySize;
+  }
+
+  // Update value
+  memcpy(pos, aValue, valueSize);
+  mElementsSize = newSize;
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::Visit(nsICacheEntryMetaDataVisitor *aVisitor)
+{
+  const char *data = mBuf;
+  const char *limit = mBuf + mElementsSize;
+
+  while (data < limit) {
+    // Point to the value part
+    const char *value = data + strlen(data) + 1;
+    MOZ_ASSERT(value < limit, "Metadata elements corrupted");
+
+    aVisitor->OnMetaDataElement(data, value);
+
+    // Skip value part
+    data = value + strlen(value) + 1;
+  }
+
+  MOZ_ASSERT(data == limit, "Metadata elements corrupted");
+
+  return NS_OK;
+}
+
+CacheHash::Hash16_t
+CacheFileMetadata::GetHash(uint32_t aIndex)
+{
+  MOZ_ASSERT(aIndex < mHashCount);
+  return NetworkEndian::readUint16(&mHashArray[aIndex]);
+}
+
+nsresult
+CacheFileMetadata::SetHash(uint32_t aIndex, CacheHash::Hash16_t aHash)
+{
+  LOG(("CacheFileMetadata::SetHash() [this=%p, idx=%d, hash=%x]",
+       this, aIndex, aHash));
+
+  MarkDirty();
+
+  MOZ_ASSERT(aIndex <= mHashCount);
+
+  if (aIndex > mHashCount) {
+    return NS_ERROR_INVALID_ARG;
+  } else if (aIndex == mHashCount) {
+    if ((aIndex + 1) * sizeof(CacheHash::Hash16_t) > mHashArraySize) {
+      // reallocate hash array buffer
+      if (mHashArraySize == 0) {
+        mHashArraySize = kInitialHashArraySize * sizeof(CacheHash::Hash16_t);
+      } else {
+        mHashArraySize *= 2;
+      }
+      mHashArray = static_cast<CacheHash::Hash16_t *>(
+                     moz_xrealloc(mHashArray, mHashArraySize));
+    }
+
+    mHashCount++;
+  }
+
+  NetworkEndian::writeUint16(&mHashArray[aIndex], aHash);
+
+  DoMemoryReport(MemoryUsage());
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::AddFlags(uint32_t aFlags)
+{
+  MarkDirty(false);
+  mMetaHdr.mFlags |= aFlags;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::RemoveFlags(uint32_t aFlags)
+{
+  MarkDirty(false);
+  mMetaHdr.mFlags &= ~aFlags;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::GetFlags(uint32_t *_retval)
+{
+  *_retval = mMetaHdr.mFlags;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::SetExpirationTime(uint32_t aExpirationTime)
+{
+  LOG(("CacheFileMetadata::SetExpirationTime() [this=%p, expirationTime=%d]",
+       this, aExpirationTime));
+
+  MarkDirty(false);
+  mMetaHdr.mExpirationTime = aExpirationTime;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::GetExpirationTime(uint32_t *_retval)
+{
+  *_retval = mMetaHdr.mExpirationTime;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::SetFrecency(uint32_t aFrecency)
+{
+  LOG(("CacheFileMetadata::SetFrecency() [this=%p, frecency=%f]",
+       this, (double)aFrecency));
+
+  MarkDirty(false);
+  mMetaHdr.mFrecency = aFrecency;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::GetFrecency(uint32_t *_retval)
+{
+  *_retval = mMetaHdr.mFrecency;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::GetLastModified(uint32_t *_retval)
+{
+  *_retval = mMetaHdr.mLastModified;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::GetLastFetched(uint32_t *_retval)
+{
+  *_retval = mMetaHdr.mLastFetched;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::GetFetchCount(uint32_t *_retval)
+{
+  *_retval = mMetaHdr.mFetchCount;
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::OnFetched()
+{
+  MarkDirty(false);
+
+  mMetaHdr.mLastFetched = NOW_SECONDS();
+  ++mMetaHdr.mFetchCount;
+  return NS_OK;
+}
+
+void
+CacheFileMetadata::MarkDirty(bool aUpdateLastModified)
+{
+  mIsDirty = true;
+  if (aUpdateLastModified) {
+    mMetaHdr.mLastModified = NOW_SECONDS();
+  }
+}
+
+nsresult
+CacheFileMetadata::OnFileOpened(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFileMetadata::OnFileOpened should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileMetadata::OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                                 nsresult aResult)
+{
+  LOG(("CacheFileMetadata::OnDataWritten() [this=%p, handle=%p, result=0x%08x]",
+       this, aHandle, aResult));
+
+  MOZ_ASSERT(mListener);
+  MOZ_ASSERT(mWriteBuf);
+
+  CacheFileUtils::FreeBuffer(mWriteBuf);
+  mWriteBuf = nullptr;
+
+  nsCOMPtr<CacheFileMetadataListener> listener;
+
+  mListener.swap(listener);
+  listener->OnMetadataWritten(aResult);
+
+  DoMemoryReport(MemoryUsage());
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::OnDataRead(CacheFileHandle *aHandle, char *aBuf,
+                              nsresult aResult)
+{
+  LOG(("CacheFileMetadata::OnDataRead() [this=%p, handle=%p, result=0x%08x]",
+       this, aHandle, aResult));
+
+  MOZ_ASSERT(mListener);
+
+  nsresult rv;
+  nsCOMPtr<CacheFileMetadataListener> listener;
+
+  if (NS_FAILED(aResult)) {
+    LOG(("CacheFileMetadata::OnDataRead() - CacheFileIOManager::Read() failed"
+         ", creating empty metadata. [this=%p, rv=0x%08x]", this, aResult));
+
+    InitEmptyMetadata();
+
+    mListener.swap(listener);
+    listener->OnMetadataRead(NS_OK);
+    return NS_OK;
+  }
+
+  if (mFirstRead) {
+    Telemetry::AccumulateTimeDelta(
+      Telemetry::NETWORK_CACHE_METADATA_FIRST_READ_TIME_MS, mReadStart);
+    Telemetry::Accumulate(
+      Telemetry::NETWORK_CACHE_METADATA_FIRST_READ_SIZE, mBufSize);
+  } else {
+    Telemetry::AccumulateTimeDelta(
+      Telemetry::NETWORK_CACHE_METADATA_SECOND_READ_TIME_MS, mReadStart);
+  }
+
+  // check whether we have read all necessary data
+  uint32_t realOffset = NetworkEndian::readUint32(mBuf + mBufSize -
+                                                  sizeof(uint32_t));
+
+  int64_t size = mHandle->FileSize();
+  MOZ_ASSERT(size != -1);
+
+  if (realOffset >= size) {
+    LOG(("CacheFileMetadata::OnDataRead() - Invalid realOffset, creating "
+         "empty metadata. [this=%p, realOffset=%u, size=%lld]", this,
+         realOffset, size));
+
+    InitEmptyMetadata();
+
+    mListener.swap(listener);
+    listener->OnMetadataRead(NS_OK);
+    return NS_OK;
+  }
+
+  uint32_t maxHashCount = size / kChunkSize;
+  uint32_t maxMetadataSize = CalcMetadataSize(kMaxElementsSize, maxHashCount);
+  if (size - realOffset > maxMetadataSize) {
+    LOG(("CacheFileMetadata::OnDataRead() - Invalid realOffset, metadata would "
+         "be too big, creating empty metadata. [this=%p, realOffset=%u, "
+         "maxMetadataSize=%u, size=%lld]", this, realOffset, maxMetadataSize,
+         size));
+
+    InitEmptyMetadata();
+
+    mListener.swap(listener);
+    listener->OnMetadataRead(NS_OK);
+    return NS_OK;
+  }
+
+  uint32_t usedOffset = size - mBufSize;
+
+  if (realOffset < usedOffset) {
+    uint32_t missing = usedOffset - realOffset;
+    // we need to read more data
+    char *newBuf = static_cast<char *>(realloc(mBuf, mBufSize + missing));
+    if (!newBuf) {
+      LOG(("CacheFileMetadata::OnDataRead() - Error allocating %d more bytes "
+           "for the missing part of the metadata, creating empty metadata. "
+           "[this=%p]", missing, this));
+
+      InitEmptyMetadata();
+
+      mListener.swap(listener);
+      listener->OnMetadataRead(NS_OK);
+      return NS_OK;
+    }
+
+    mBuf = newBuf;
+    memmove(mBuf + missing, mBuf, mBufSize);
+    mBufSize += missing;
+
+    DoMemoryReport(MemoryUsage());
+
+    LOG(("CacheFileMetadata::OnDataRead() - We need to read %d more bytes to "
+         "have full metadata. [this=%p]", missing, this));
+
+    mFirstRead = false;
+    mReadStart = mozilla::TimeStamp::Now();
+    rv = CacheFileIOManager::Read(mHandle, realOffset, mBuf, missing, this);
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileMetadata::OnDataRead() - CacheFileIOManager::Read() "
+           "failed synchronously, creating empty metadata. [this=%p, "
+           "rv=0x%08x]", this, rv));
+
+      InitEmptyMetadata();
+
+      mListener.swap(listener);
+      listener->OnMetadataRead(NS_OK);
+      return NS_OK;
+    }
+
+    return NS_OK;
+  }
+
+  Telemetry::Accumulate(Telemetry::NETWORK_CACHE_METADATA_SIZE,
+                        size - realOffset);
+
+  // We have all data according to offset information at the end of the entry.
+  // Try to parse it.
+  rv = ParseMetadata(realOffset, realOffset - usedOffset, true);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheFileMetadata::OnDataRead() - Error parsing metadata, creating "
+         "empty metadata. [this=%p]", this));
+    InitEmptyMetadata();
+  } else {
+    // Shrink elements buffer.
+    mBuf = static_cast<char *>(moz_xrealloc(mBuf, mElementsSize));
+    mBufSize = mElementsSize;
+
+    // There is usually no or just one call to SetMetadataElement() when the
+    // metadata is parsed from disk. Avoid allocating power of two sized buffer
+    // which we do in case of newly created metadata.
+    mAllocExactSize = true;
+  }
+
+  mListener.swap(listener);
+  listener->OnMetadataRead(NS_OK);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFileMetadata::OnFileDoomed should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileMetadata::OnEOFSet(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFileMetadata::OnEOFSet should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileMetadata::OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheFileMetadata::OnFileRenamed should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+void
+CacheFileMetadata::InitEmptyMetadata()
+{
+  if (mBuf) {
+    CacheFileUtils::FreeBuffer(mBuf);
+    mBuf = nullptr;
+    mBufSize = 0;
+  }
+  mAllocExactSize = false;
+  mOffset = 0;
+  mMetaHdr.mVersion = kCacheEntryVersion;
+  mMetaHdr.mFetchCount = 0;
+  mMetaHdr.mExpirationTime = nsICacheEntry::NO_EXPIRATION_TIME;
+  mMetaHdr.mKeySize = mKey.Length();
+
+  // Deliberately not touching the "kCacheEntryIsPinned" flag.
+
+  DoMemoryReport(MemoryUsage());
+
+  // We're creating a new entry. If there is any old data truncate it.
+  if (mHandle) {
+    mHandle->SetPinned(Pinned());
+    // We can pronounce the handle as invalid now, because it simply
+    // doesn't have the correct metadata.  This will cause IO operations
+    // be bypassed during shutdown (mainly dooming it, when a channel
+    // is canceled by closing the window.)
+    mHandle->SetInvalid();
+    if (mHandle->FileExists() && mHandle->FileSize()) {
+      CacheFileIOManager::TruncateSeekSetEOF(mHandle, 0, 0, nullptr);
+    }
+  }
+}
+
+nsresult
+CacheFileMetadata::ParseMetadata(uint32_t aMetaOffset, uint32_t aBufOffset,
+                                 bool aHaveKey)
+{
+  LOG(("CacheFileMetadata::ParseMetadata() [this=%p, metaOffset=%d, "
+       "bufOffset=%d, haveKey=%u]", this, aMetaOffset, aBufOffset, aHaveKey));
+
+  nsresult rv;
+
+  uint32_t metaposOffset = mBufSize - sizeof(uint32_t);
+  uint32_t hashesOffset = aBufOffset + sizeof(uint32_t);
+  uint32_t hashCount = aMetaOffset / kChunkSize;
+  if (aMetaOffset % kChunkSize)
+    hashCount++;
+  uint32_t hashesLen = hashCount * sizeof(CacheHash::Hash16_t);
+  uint32_t hdrOffset = hashesOffset + hashesLen;
+  uint32_t keyOffset = hdrOffset + sizeof(CacheFileMetadataHeader);
+
+  LOG(("CacheFileMetadata::ParseMetadata() [this=%p]\n  metaposOffset=%d\n  "
+       "hashesOffset=%d\n  hashCount=%d\n  hashesLen=%d\n  hdfOffset=%d\n  "
+       "keyOffset=%d\n", this, metaposOffset, hashesOffset, hashCount,
+       hashesLen,hdrOffset, keyOffset));
+
+  if (keyOffset > metaposOffset) {
+    LOG(("CacheFileMetadata::ParseMetadata() - Wrong keyOffset! [this=%p]",
+         this));
+    return NS_ERROR_FILE_CORRUPTED;
+  }
+
+  mMetaHdr.ReadFromBuf(mBuf + hdrOffset);
+
+  if (mMetaHdr.mVersion == 1) {
+    // Backward compatibility before we've added flags to the header
+    keyOffset -= sizeof(uint32_t);
+  } else if (mMetaHdr.mVersion == 2) {
+    // Version 2 just lacks the ability to store alternative data. Nothing to do
+    // here.
+  } else if (mMetaHdr.mVersion != kCacheEntryVersion) {
+    LOG(("CacheFileMetadata::ParseMetadata() - Not a version we understand to. "
+         "[version=0x%x, this=%p]", mMetaHdr.mVersion, this));
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // Update the version stored in the header to make writes
+  // store the header in the current version form.
+  mMetaHdr.mVersion = kCacheEntryVersion;
+
+  uint32_t elementsOffset = mMetaHdr.mKeySize + keyOffset + 1;
+
+  if (elementsOffset > metaposOffset) {
+    LOG(("CacheFileMetadata::ParseMetadata() - Wrong elementsOffset %d "
+         "[this=%p]", elementsOffset, this));
+    return NS_ERROR_FILE_CORRUPTED;
+  }
+
+  // check that key ends with \0
+  if (mBuf[elementsOffset - 1] != 0) {
+    LOG(("CacheFileMetadata::ParseMetadata() - Elements not null terminated. "
+         "[this=%p]", this));
+    return NS_ERROR_FILE_CORRUPTED;
+  }
+
+
+  if (!aHaveKey) {
+    // get the key form metadata
+    mKey.Assign(mBuf + keyOffset, mMetaHdr.mKeySize);
+
+    rv = ParseKey(mKey);
+    if (NS_FAILED(rv))
+      return rv;
+  }
+  else {
+    if (mMetaHdr.mKeySize != mKey.Length()) {
+      LOG(("CacheFileMetadata::ParseMetadata() - Key collision (1), key=%s "
+           "[this=%p]", nsCString(mBuf + keyOffset, mMetaHdr.mKeySize).get(),
+           this));
+      return NS_ERROR_FILE_CORRUPTED;
+    }
+
+    if (memcmp(mKey.get(), mBuf + keyOffset, mKey.Length()) != 0) {
+      LOG(("CacheFileMetadata::ParseMetadata() - Key collision (2), key=%s "
+           "[this=%p]", nsCString(mBuf + keyOffset, mMetaHdr.mKeySize).get(),
+           this));
+      return NS_ERROR_FILE_CORRUPTED;
+    }
+  }
+
+  // check metadata hash (data from hashesOffset to metaposOffset)
+  CacheHash::Hash32_t hashComputed, hashExpected;
+  hashComputed = CacheHash::Hash(mBuf + hashesOffset,
+                                 metaposOffset - hashesOffset);
+  hashExpected = NetworkEndian::readUint32(mBuf + aBufOffset);
+
+  if (hashComputed != hashExpected) {
+    LOG(("CacheFileMetadata::ParseMetadata() - Metadata hash mismatch! Hash of "
+         "the metadata is %x, hash in file is %x [this=%p]", hashComputed,
+         hashExpected, this));
+    return NS_ERROR_FILE_CORRUPTED;
+  }
+
+  // check elements
+  rv = CheckElements(mBuf + elementsOffset, metaposOffset - elementsOffset);
+  if (NS_FAILED(rv))
+    return rv;
+
+  if (mHandle) {
+    if (!mHandle->SetPinned(Pinned())) {
+      LOG(("CacheFileMetadata::ParseMetadata() - handle was doomed for this "
+           "pinning state, truncate the file [this=%p, pinned=%d]", this, Pinned()));
+      return NS_ERROR_FILE_CORRUPTED;
+    }
+  }
+
+  mHashArraySize = hashesLen;
+  mHashCount = hashCount;
+  if (mHashArraySize) {
+    mHashArray = static_cast<CacheHash::Hash16_t *>(
+                   moz_xmalloc(mHashArraySize));
+    memcpy(mHashArray, mBuf + hashesOffset, mHashArraySize);
+  }
+
+  MarkDirty();
+
+  mElementsSize = metaposOffset - elementsOffset;
+  memmove(mBuf, mBuf + elementsOffset, mElementsSize);
+  mOffset = aMetaOffset;
+
+  DoMemoryReport(MemoryUsage());
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::CheckElements(const char *aBuf, uint32_t aSize)
+{
+  if (aSize) {
+    // Check if the metadata ends with a zero byte.
+    if (aBuf[aSize - 1] != 0) {
+      NS_ERROR("Metadata elements are not null terminated");
+      LOG(("CacheFileMetadata::CheckElements() - Elements are not null "
+           "terminated. [this=%p]", this));
+      return NS_ERROR_FILE_CORRUPTED;
+    }
+    // Check that there are an even number of zero bytes
+    // to match the pattern { key \0 value \0 }
+    bool odd = false;
+    for (uint32_t i = 0; i < aSize; i++) {
+      if (aBuf[i] == 0)
+        odd = !odd;
+    }
+    if (odd) {
+      NS_ERROR("Metadata elements are malformed");
+      LOG(("CacheFileMetadata::CheckElements() - Elements are malformed. "
+           "[this=%p]", this));
+      return NS_ERROR_FILE_CORRUPTED;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::EnsureBuffer(uint32_t aSize)
+{
+  if (aSize > kMaxElementsSize) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (mBufSize < aSize) {
+    if (mAllocExactSize) {
+      // If this is not the only allocation, use power of two for following
+      // allocations.
+      mAllocExactSize = false;
+    } else {
+      // find smallest power of 2 greater than or equal to aSize
+      --aSize;
+      aSize |= aSize >> 1;
+      aSize |= aSize >> 2;
+      aSize |= aSize >> 4;
+      aSize |= aSize >> 8;
+      aSize |= aSize >> 16;
+      ++aSize;
+    }
+
+    if (aSize < kInitialBufSize) {
+      aSize = kInitialBufSize;
+    }
+
+    char *newBuf = static_cast<char *>(realloc(mBuf, aSize));
+    if (!newBuf) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+    mBufSize = aSize;
+    mBuf = newBuf;
+
+    DoMemoryReport(MemoryUsage());
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileMetadata::ParseKey(const nsACString &aKey)
+{
+  nsCOMPtr<nsILoadContextInfo> info = CacheFileUtils::ParseKey(aKey);
+  NS_ENSURE_TRUE(info, NS_ERROR_FAILURE);
+
+  mAnonymous =  info->IsAnonymous();
+  mOriginAttributes = *info->OriginAttributesPtr();
+
+  return NS_OK;
+}
+
+// Memory reporting
+
+size_t
+CacheFileMetadata::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  size_t n = 0;
+  // mHandle reported via CacheFileIOManager.
+  n += mKey.SizeOfExcludingThisIfUnshared(mallocSizeOf);
+  n += mallocSizeOf(mHashArray);
+  n += mallocSizeOf(mBuf);
+  n += mallocSizeOf(mWriteBuf);
+  // mListener is usually the owning CacheFile.
+
+  return n;
+}
+
+size_t
+CacheFileMetadata::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheFileMetadata.h b/netwerk/cache2/CacheFileMetadata.h
new file mode 100644
index 0000000000..97a0fff575
--- /dev/null
+++ b/netwerk/cache2/CacheFileMetadata.h
@@ -0,0 +1,227 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheFileMetadata__h__
+#define CacheFileMetadata__h__
+
+#include "CacheFileIOManager.h"
+#include "CacheStorageService.h"
+#include "CacheHashUtils.h"
+#include "CacheObserver.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/BasePrincipal.h"
+#include "nsAutoPtr.h"
+#include "nsString.h"
+
+class nsICacheEntryMetaDataVisitor;
+
+namespace mozilla {
+namespace net {
+
+// Flags stored in CacheFileMetadataHeader.mFlags
+
+// Whether an entry is a pinned entry (created with
+// nsICacheStorageService.pinningCacheStorage.)
+static const uint32_t kCacheEntryIsPinned = 1 << 0;
+
+// By multiplying with the current half-life we convert the frecency
+// to time independent of half-life value.  The range fits 32bits.
+// When decay time changes on next run of the browser, we convert
+// the frecency value to a correct internal representation again.
+// It might not be 100% accurate, but for the purpose it suffice.
+#define FRECENCY2INT(aFrecency) \
+  ((uint32_t)((aFrecency) * CacheObserver::HalfLifeSeconds()))
+#define INT2FRECENCY(aInt) \
+  ((double)(aInt) / (double)CacheObserver::HalfLifeSeconds())
+
+
+#define kCacheEntryVersion 3
+
+
+#pragma pack(push)
+#pragma pack(1)
+
+class CacheFileMetadataHeader {
+public:
+  uint32_t        mVersion;
+  uint32_t        mFetchCount;
+  uint32_t        mLastFetched;
+  uint32_t        mLastModified;
+  uint32_t        mFrecency;
+  uint32_t        mExpirationTime;
+  uint32_t        mKeySize;
+  uint32_t        mFlags;
+
+  void WriteToBuf(void *aBuf)
+  {
+    EnsureCorrectClassSize();
+
+    uint8_t* ptr = static_cast<uint8_t*>(aBuf);
+    MOZ_ASSERT(mVersion == kCacheEntryVersion);
+    NetworkEndian::writeUint32(ptr, mVersion); ptr += sizeof(uint32_t);
+    NetworkEndian::writeUint32(ptr, mFetchCount); ptr += sizeof(uint32_t);
+    NetworkEndian::writeUint32(ptr, mLastFetched); ptr += sizeof(uint32_t);
+    NetworkEndian::writeUint32(ptr, mLastModified); ptr += sizeof(uint32_t);
+    NetworkEndian::writeUint32(ptr, mFrecency); ptr += sizeof(uint32_t);
+    NetworkEndian::writeUint32(ptr, mExpirationTime); ptr += sizeof(uint32_t);
+    NetworkEndian::writeUint32(ptr, mKeySize); ptr += sizeof(uint32_t);
+    NetworkEndian::writeUint32(ptr, mFlags);
+  }
+
+  void ReadFromBuf(const void *aBuf)
+  {
+    EnsureCorrectClassSize();
+
+    const uint8_t* ptr = static_cast<const uint8_t*>(aBuf);
+    mVersion = BigEndian::readUint32(ptr); ptr += sizeof(uint32_t);
+    mFetchCount = BigEndian::readUint32(ptr); ptr += sizeof(uint32_t);
+    mLastFetched = BigEndian::readUint32(ptr); ptr += sizeof(uint32_t);
+    mLastModified = BigEndian::readUint32(ptr); ptr += sizeof(uint32_t);
+    mFrecency = BigEndian::readUint32(ptr); ptr += sizeof(uint32_t);
+    mExpirationTime = BigEndian::readUint32(ptr); ptr += sizeof(uint32_t);
+    mKeySize = BigEndian::readUint32(ptr); ptr += sizeof(uint32_t);
+    if (mVersion >= 2) {
+      mFlags = BigEndian::readUint32(ptr);
+    } else {
+      mFlags = 0;
+    }
+  }
+
+  inline void EnsureCorrectClassSize()
+  {
+    static_assert((sizeof(mVersion) + sizeof(mFetchCount) +
+      sizeof(mLastFetched) + sizeof(mLastModified) + sizeof(mFrecency) +
+      sizeof(mExpirationTime) + sizeof(mKeySize)) + sizeof(mFlags) ==
+      sizeof(CacheFileMetadataHeader),
+      "Unexpected sizeof(CacheFileMetadataHeader)!");
+  }
+};
+
+#pragma pack(pop)
+
+
+#define CACHEFILEMETADATALISTENER_IID \
+{ /* a9e36125-3f01-4020-9540-9dafa8d31ba7 */       \
+  0xa9e36125,                                      \
+  0x3f01,                                          \
+  0x4020,                                          \
+  {0x95, 0x40, 0x9d, 0xaf, 0xa8, 0xd3, 0x1b, 0xa7} \
+}
+
+class CacheFileMetadataListener : public nsISupports
+{
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(CACHEFILEMETADATALISTENER_IID)
+
+  NS_IMETHOD OnMetadataRead(nsresult aResult) = 0;
+  NS_IMETHOD OnMetadataWritten(nsresult aResult) = 0;
+  virtual bool IsKilled() = 0;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(CacheFileMetadataListener,
+                              CACHEFILEMETADATALISTENER_IID)
+
+
+class CacheFileMetadata : public CacheFileIOListener
+                        , public CacheMemoryConsumer
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  CacheFileMetadata(CacheFileHandle *aHandle,
+                    const nsACString &aKey);
+  CacheFileMetadata(bool aMemoryOnly,
+                    bool aPinned,
+                    const nsACString &aKey);
+  CacheFileMetadata();
+
+  void SetHandle(CacheFileHandle *aHandle);
+
+  nsresult GetKey(nsACString &_retval);
+
+  nsresult ReadMetadata(CacheFileMetadataListener *aListener);
+  uint32_t CalcMetadataSize(uint32_t aElementsSize, uint32_t aHashCount);
+  nsresult WriteMetadata(uint32_t aOffset,
+                         CacheFileMetadataListener *aListener);
+  nsresult SyncReadMetadata(nsIFile *aFile);
+
+  bool     IsAnonymous() const { return mAnonymous; }
+  mozilla::NeckoOriginAttributes const & OriginAttributes() const { return mOriginAttributes; }
+  bool     Pinned() const      { return !!(mMetaHdr.mFlags & kCacheEntryIsPinned); }
+
+  const char * GetElement(const char *aKey);
+  nsresult     SetElement(const char *aKey, const char *aValue);
+  nsresult     Visit(nsICacheEntryMetaDataVisitor *aVisitor);
+
+  CacheHash::Hash16_t GetHash(uint32_t aIndex);
+  nsresult            SetHash(uint32_t aIndex, CacheHash::Hash16_t aHash);
+
+  nsresult AddFlags(uint32_t aFlags);
+  nsresult RemoveFlags(uint32_t aFlags);
+  nsresult GetFlags(uint32_t *_retval);
+  nsresult SetExpirationTime(uint32_t aExpirationTime);
+  nsresult GetExpirationTime(uint32_t *_retval);
+  nsresult SetFrecency(uint32_t aFrecency);
+  nsresult GetFrecency(uint32_t *_retval);
+  nsresult GetLastModified(uint32_t *_retval);
+  nsresult GetLastFetched(uint32_t *_retval);
+  nsresult GetFetchCount(uint32_t *_retval);
+  // Called by upper layers to indicate the entry this metadata belongs
+  // with has been fetched, i.e. delivered to the consumer.
+  nsresult OnFetched();
+
+  int64_t  Offset() { return mOffset; }
+  uint32_t ElementsSize() { return mElementsSize; }
+  void     MarkDirty(bool aUpdateLastModified = true);
+  bool     IsDirty() { return mIsDirty; }
+  uint32_t MemoryUsage() { return sizeof(CacheFileMetadata) + mHashArraySize + mBufSize; }
+
+  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                           nsresult aResult) override;
+  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult) override;
+  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) override;
+  virtual bool IsKilled() override { return mListener && mListener->IsKilled(); }
+  void InitEmptyMetadata();
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+private:
+  virtual ~CacheFileMetadata();
+
+  nsresult ParseMetadata(uint32_t aMetaOffset, uint32_t aBufOffset, bool aHaveKey);
+  nsresult CheckElements(const char *aBuf, uint32_t aSize);
+  nsresult EnsureBuffer(uint32_t aSize);
+  nsresult ParseKey(const nsACString &aKey);
+
+  RefPtr<CacheFileHandle>             mHandle;
+  nsCString                           mKey;
+  CacheHash::Hash16_t                *mHashArray;
+  uint32_t                            mHashArraySize;
+  uint32_t                            mHashCount;
+  int64_t                             mOffset;
+  char                               *mBuf; // used for parsing, then points
+                                            // to elements
+  uint32_t                            mBufSize;
+  char                               *mWriteBuf;
+  CacheFileMetadataHeader             mMetaHdr;
+  uint32_t                            mElementsSize;
+  bool                                mIsDirty        : 1;
+  bool                                mAnonymous      : 1;
+  bool                                mAllocExactSize : 1;
+  bool                                mFirstRead      : 1;
+  mozilla::NeckoOriginAttributes      mOriginAttributes;
+  mozilla::TimeStamp                  mReadStart;
+  nsCOMPtr<CacheFileMetadataListener> mListener;
+};
+
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheFileOutputStream.cpp b/netwerk/cache2/CacheFileOutputStream.cpp
new file mode 100644
index 0000000000..a3d414b8fa
--- /dev/null
+++ b/netwerk/cache2/CacheFileOutputStream.cpp
@@ -0,0 +1,483 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheFileOutputStream.h"
+
+#include "CacheFile.h"
+#include "CacheEntry.h"
+#include "nsStreamUtils.h"
+#include "nsThreadUtils.h"
+#include "mozilla/DebugOnly.h"
+#include <algorithm>
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ADDREF(CacheFileOutputStream)
+NS_IMETHODIMP_(MozExternalRefCountType)
+CacheFileOutputStream::Release()
+{
+  NS_PRECONDITION(0 != mRefCnt, "dup release");
+  nsrefcnt count = --mRefCnt;
+  NS_LOG_RELEASE(this, count, "CacheFileOutputStream");
+
+  if (0 == count) {
+    mRefCnt = 1;
+    {
+      CacheFileAutoLock lock(mFile);
+      mFile->RemoveOutput(this, mStatus);
+    }
+    delete (this);
+    return 0;
+  }
+
+  return count;
+}
+
+NS_INTERFACE_MAP_BEGIN(CacheFileOutputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIOutputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIAsyncOutputStream)
+  NS_INTERFACE_MAP_ENTRY(nsISeekableStream)
+  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileChunkListener)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIOutputStream)
+NS_INTERFACE_MAP_END_THREADSAFE
+
+CacheFileOutputStream::CacheFileOutputStream(CacheFile *aFile,
+                                             CacheOutputCloseListener *aCloseListener,
+                                             bool aAlternativeData)
+  : mFile(aFile)
+  , mCloseListener(aCloseListener)
+  , mPos(0)
+  , mClosed(false)
+  , mAlternativeData(aAlternativeData)
+  , mStatus(NS_OK)
+  , mCallbackFlags(0)
+{
+  LOG(("CacheFileOutputStream::CacheFileOutputStream() [this=%p]", this));
+  MOZ_COUNT_CTOR(CacheFileOutputStream);
+
+  if (mAlternativeData) {
+    mPos = mFile->mAltDataOffset;
+  }
+}
+
+CacheFileOutputStream::~CacheFileOutputStream()
+{
+  LOG(("CacheFileOutputStream::~CacheFileOutputStream() [this=%p]", this));
+  MOZ_COUNT_DTOR(CacheFileOutputStream);
+}
+
+// nsIOutputStream
+NS_IMETHODIMP
+CacheFileOutputStream::Close()
+{
+  LOG(("CacheFileOutputStream::Close() [this=%p]", this));
+  return CloseWithStatus(NS_OK);
+}
+
+NS_IMETHODIMP
+CacheFileOutputStream::Flush()
+{
+  // TODO do we need to implement flush ???
+  LOG(("CacheFileOutputStream::Flush() [this=%p]", this));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheFileOutputStream::Write(const char * aBuf, uint32_t aCount,
+                             uint32_t *_retval)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileOutputStream::Write() [this=%p, count=%d]", this, aCount));
+
+  if (mClosed) {
+    LOG(("CacheFileOutputStream::Write() - Stream is closed. [this=%p, "
+         "status=0x%08x]", this, mStatus));
+
+    return NS_FAILED(mStatus) ? mStatus : NS_BASE_STREAM_CLOSED;
+  }
+
+  if (!mFile->mSkipSizeCheck && CacheObserver::EntryIsTooBig(mPos + aCount, !mFile->mMemoryOnly)) {
+    LOG(("CacheFileOutputStream::Write() - Entry is too big, failing and "
+         "dooming the entry. [this=%p]", this));
+
+    mFile->DoomLocked(nullptr);
+    CloseWithStatusLocked(NS_ERROR_FILE_TOO_BIG);
+    return NS_ERROR_FILE_TOO_BIG;
+  }
+
+  // We use 64-bit offset when accessing the file, unfortunatelly we use 32-bit
+  // metadata offset, so we cannot handle data bigger than 4GB.
+  if (mPos + aCount > PR_UINT32_MAX) {
+    LOG(("CacheFileOutputStream::Write() - Entry's size exceeds 4GB while it "
+         "isn't too big according to CacheObserver::EntryIsTooBig(). Failing "
+         "and dooming the entry. [this=%p]", this));
+
+    mFile->DoomLocked(nullptr);
+    CloseWithStatusLocked(NS_ERROR_FILE_TOO_BIG);
+    return NS_ERROR_FILE_TOO_BIG;
+  }
+
+  *_retval = aCount;
+
+  while (aCount) {
+    EnsureCorrectChunk(false);
+    if (NS_FAILED(mStatus)) {
+      return mStatus;
+    }
+
+    FillHole();
+    if (NS_FAILED(mStatus)) {
+      return mStatus;
+    }
+
+    uint32_t chunkOffset = mPos - (mPos / kChunkSize) * kChunkSize;
+    uint32_t canWrite = kChunkSize - chunkOffset;
+    uint32_t thisWrite = std::min(static_cast<uint32_t>(canWrite), aCount);
+
+    CacheFileChunkWriteHandle hnd = mChunk->GetWriteHandle(chunkOffset + thisWrite);
+    if (!hnd.Buf()) {
+      CloseWithStatusLocked(NS_ERROR_OUT_OF_MEMORY);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    memcpy(hnd.Buf() + chunkOffset, aBuf, thisWrite);
+    hnd.UpdateDataSize(chunkOffset, thisWrite);
+
+    mPos += thisWrite;
+    aBuf += thisWrite;
+    aCount -= thisWrite;
+  }
+
+  EnsureCorrectChunk(true);
+
+  LOG(("CacheFileOutputStream::Write() - Wrote %d bytes [this=%p]",
+       *_retval, this));
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheFileOutputStream::WriteFrom(nsIInputStream *aFromStream, uint32_t aCount,
+                                 uint32_t *_retval)
+{
+  LOG(("CacheFileOutputStream::WriteFrom() - NOT_IMPLEMENTED [this=%p, from=%p"
+       ", count=%d]", this, aFromStream, aCount));
+
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+CacheFileOutputStream::WriteSegments(nsReadSegmentFun aReader, void *aClosure,
+                                     uint32_t aCount, uint32_t *_retval)
+{
+  LOG(("CacheFileOutputStream::WriteSegments() - NOT_IMPLEMENTED [this=%p, "
+       "count=%d]", this, aCount));
+
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+CacheFileOutputStream::IsNonBlocking(bool *_retval)
+{
+  *_retval = false;
+  return NS_OK;
+}
+
+// nsIAsyncOutputStream
+NS_IMETHODIMP
+CacheFileOutputStream::CloseWithStatus(nsresult aStatus)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileOutputStream::CloseWithStatus() [this=%p, aStatus=0x%08x]",
+       this, aStatus));
+
+  return CloseWithStatusLocked(aStatus);
+}
+
+nsresult
+CacheFileOutputStream::CloseWithStatusLocked(nsresult aStatus)
+{
+  LOG(("CacheFileOutputStream::CloseWithStatusLocked() [this=%p, "
+       "aStatus=0x%08x]", this, aStatus));
+
+  if (mClosed) {
+    MOZ_ASSERT(!mCallback);
+    return NS_OK;
+  }
+
+  mClosed = true;
+  mStatus = NS_FAILED(aStatus) ? aStatus : NS_BASE_STREAM_CLOSED;
+
+  if (mChunk) {
+    ReleaseChunk();
+  }
+
+  if (mCallback) {
+    NotifyListener();
+  }
+
+  mFile->RemoveOutput(this, mStatus);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheFileOutputStream::AsyncWait(nsIOutputStreamCallback *aCallback,
+                                 uint32_t aFlags,
+                                 uint32_t aRequestedCount,
+                                 nsIEventTarget *aEventTarget)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileOutputStream::AsyncWait() [this=%p, callback=%p, flags=%d, "
+       "requestedCount=%d, eventTarget=%p]", this, aCallback, aFlags,
+       aRequestedCount, aEventTarget));
+
+  mCallback = aCallback;
+  mCallbackFlags = aFlags;
+  mCallbackTarget = aEventTarget;
+
+  if (!mCallback)
+    return NS_OK;
+
+  // The stream is blocking so it is writable at any time
+  if (mClosed || !(aFlags & WAIT_CLOSURE_ONLY))
+    NotifyListener();
+
+  return NS_OK;
+}
+
+// nsISeekableStream
+NS_IMETHODIMP
+CacheFileOutputStream::Seek(int32_t whence, int64_t offset)
+{
+  CacheFileAutoLock lock(mFile);
+
+  LOG(("CacheFileOutputStream::Seek() [this=%p, whence=%d, offset=%lld]",
+       this, whence, offset));
+
+  if (mClosed) {
+    LOG(("CacheFileOutputStream::Seek() - Stream is closed. [this=%p]", this));
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  int64_t newPos = offset;
+  switch (whence) {
+    case NS_SEEK_SET:
+      if (mAlternativeData) {
+        newPos += mFile->mAltDataOffset;
+      }
+      break;
+    case NS_SEEK_CUR:
+      newPos += mPos;
+      break;
+    case NS_SEEK_END:
+      if (mAlternativeData) {
+        newPos += mFile->mDataSize;
+      } else {
+        newPos += mFile->mAltDataOffset;
+      }
+      break;
+    default:
+      NS_ERROR("invalid whence");
+      return NS_ERROR_INVALID_ARG;
+  }
+  mPos = newPos;
+  EnsureCorrectChunk(true);
+
+  LOG(("CacheFileOutputStream::Seek() [this=%p, pos=%lld]", this, mPos));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheFileOutputStream::Tell(int64_t *_retval)
+{
+  CacheFileAutoLock lock(mFile);
+
+  if (mClosed) {
+    LOG(("CacheFileOutputStream::Tell() - Stream is closed. [this=%p]", this));
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  *_retval = mPos;
+
+  if (mAlternativeData) {
+    *_retval -= mFile->mAltDataOffset;
+  }
+
+  LOG(("CacheFileOutputStream::Tell() [this=%p, retval=%lld]", this, *_retval));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheFileOutputStream::SetEOF()
+{
+  MOZ_ASSERT(false, "CacheFileOutputStream::SetEOF() not implemented");
+  // Right now we don't use SetEOF(). If we ever need this method, we need
+  // to think about what to do with input streams that already points beyond
+  // new EOF.
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+// CacheFileChunkListener
+nsresult
+CacheFileOutputStream::OnChunkRead(nsresult aResult, CacheFileChunk *aChunk)
+{
+  MOZ_CRASH("CacheFileOutputStream::OnChunkRead should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileOutputStream::OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk)
+{
+  MOZ_CRASH(
+    "CacheFileOutputStream::OnChunkWritten should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileOutputStream::OnChunkAvailable(nsresult aResult,
+                                        uint32_t aChunkIdx,
+                                        CacheFileChunk *aChunk)
+{
+  MOZ_CRASH(
+    "CacheFileOutputStream::OnChunkAvailable should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheFileOutputStream::OnChunkUpdated(CacheFileChunk *aChunk)
+{
+  MOZ_CRASH(
+    "CacheFileOutputStream::OnChunkUpdated should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+void CacheFileOutputStream::NotifyCloseListener()
+{
+  RefPtr<CacheOutputCloseListener> listener;
+  listener.swap(mCloseListener);
+  if (!listener)
+    return;
+
+  listener->OnOutputClosed();
+}
+
+void
+CacheFileOutputStream::ReleaseChunk()
+{
+  LOG(("CacheFileOutputStream::ReleaseChunk() [this=%p, idx=%d]",
+       this, mChunk->Index()));
+
+  mFile->ReleaseOutsideLock(mChunk.forget());
+}
+
+void
+CacheFileOutputStream::EnsureCorrectChunk(bool aReleaseOnly)
+{
+  mFile->AssertOwnsLock();
+
+  LOG(("CacheFileOutputStream::EnsureCorrectChunk() [this=%p, releaseOnly=%d]",
+       this, aReleaseOnly));
+
+  uint32_t chunkIdx = mPos / kChunkSize;
+
+  if (mChunk) {
+    if (mChunk->Index() == chunkIdx) {
+      // we have a correct chunk
+      LOG(("CacheFileOutputStream::EnsureCorrectChunk() - Have correct chunk "
+           "[this=%p, idx=%d]", this, chunkIdx));
+
+      return;
+    }
+    else {
+      ReleaseChunk();
+    }
+  }
+
+  if (aReleaseOnly)
+    return;
+
+  nsresult rv;
+  rv = mFile->GetChunkLocked(chunkIdx, CacheFile::WRITER, nullptr,
+                             getter_AddRefs(mChunk));
+  if (NS_FAILED(rv)) {
+    LOG(("CacheFileOutputStream::EnsureCorrectChunk() - GetChunkLocked failed. "
+         "[this=%p, idx=%d, rv=0x%08x]", this, chunkIdx, rv));
+    CloseWithStatusLocked(rv);
+  }
+}
+
+void
+CacheFileOutputStream::FillHole()
+{
+  mFile->AssertOwnsLock();
+
+  MOZ_ASSERT(mChunk);
+  MOZ_ASSERT(mPos / kChunkSize == mChunk->Index());
+
+  uint32_t pos = mPos - (mPos / kChunkSize) * kChunkSize;
+  if (mChunk->DataSize() >= pos)
+    return;
+
+  LOG(("CacheFileOutputStream::FillHole() - Zeroing hole in chunk %d, range "
+       "%d-%d [this=%p]", mChunk->Index(), mChunk->DataSize(), pos - 1, this));
+
+  CacheFileChunkWriteHandle hnd = mChunk->GetWriteHandle(pos);
+  if (!hnd.Buf()) {
+    CloseWithStatusLocked(NS_ERROR_OUT_OF_MEMORY);
+    return;
+  }
+
+  uint32_t offset = hnd.DataSize();
+  memset(hnd.Buf() + offset, 0, pos - offset);
+  hnd.UpdateDataSize(offset, pos - offset);
+}
+
+void
+CacheFileOutputStream::NotifyListener()
+{
+  mFile->AssertOwnsLock();
+
+  LOG(("CacheFileOutputStream::NotifyListener() [this=%p]", this));
+
+  MOZ_ASSERT(mCallback);
+
+  if (!mCallbackTarget) {
+    mCallbackTarget = CacheFileIOManager::IOTarget();
+    if (!mCallbackTarget) {
+      LOG(("CacheFileOutputStream::NotifyListener() - Cannot get Cache I/O "
+           "thread! Using main thread for callback."));
+      mCallbackTarget = do_GetMainThread();
+    }
+  }
+
+  nsCOMPtr<nsIOutputStreamCallback> asyncCallback =
+    NS_NewOutputStreamReadyEvent(mCallback, mCallbackTarget);
+
+  mCallback = nullptr;
+  mCallbackTarget = nullptr;
+
+  asyncCallback->OnOutputStreamReady(this);
+}
+
+// Memory reporting
+
+size_t
+CacheFileOutputStream::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  // Everything the stream keeps a reference to is already reported somewhere else.
+  // mFile reports itself.
+  // mChunk reported as part of CacheFile.
+  // mCloseListener is CacheEntry, already reported.
+  // mCallback is usually CacheFile or a class that is reported elsewhere.
+  return mallocSizeOf(this);
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheFileOutputStream.h b/netwerk/cache2/CacheFileOutputStream.h
new file mode 100644
index 0000000000..c283d702b6
--- /dev/null
+++ b/netwerk/cache2/CacheFileOutputStream.h
@@ -0,0 +1,73 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheFileOutputStream__h__
+#define CacheFileOutputStream__h__
+
+#include "nsIAsyncOutputStream.h"
+#include "nsISeekableStream.h"
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+#include "CacheFileChunk.h"
+
+
+namespace mozilla {
+namespace net {
+
+class CacheFile;
+class CacheOutputCloseListener;
+
+class CacheFileOutputStream : public nsIAsyncOutputStream
+                            , public nsISeekableStream
+                            , public CacheFileChunkListener
+{
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIOUTPUTSTREAM
+  NS_DECL_NSIASYNCOUTPUTSTREAM
+  NS_DECL_NSISEEKABLESTREAM
+
+public:
+  CacheFileOutputStream(CacheFile *aFile,
+                        CacheOutputCloseListener *aCloseListener,
+                        bool aAlternativeData);
+
+  NS_IMETHOD OnChunkRead(nsresult aResult, CacheFileChunk *aChunk) override;
+  NS_IMETHOD OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk) override;
+  NS_IMETHOD OnChunkAvailable(nsresult aResult, uint32_t aChunkIdx,
+                              CacheFileChunk *aChunk) override;
+  NS_IMETHOD OnChunkUpdated(CacheFileChunk *aChunk) override;
+
+  void NotifyCloseListener();
+  bool IsAlternativeData() const { return mAlternativeData; };
+
+  // Memory reporting
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+private:
+  virtual ~CacheFileOutputStream();
+
+  nsresult CloseWithStatusLocked(nsresult aStatus);
+  void ReleaseChunk();
+  void EnsureCorrectChunk(bool aReleaseOnly);
+  void FillHole();
+  void NotifyListener();
+
+  RefPtr<CacheFile>        mFile;
+  RefPtr<CacheFileChunk> mChunk;
+  RefPtr<CacheOutputCloseListener> mCloseListener;
+  int64_t                  mPos;
+  bool                     mClosed : 1;
+  bool const               mAlternativeData : 1;
+  nsresult                 mStatus;
+
+  nsCOMPtr<nsIOutputStreamCallback> mCallback;
+  uint32_t                          mCallbackFlags;
+  nsCOMPtr<nsIEventTarget>          mCallbackTarget;
+};
+
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheFileUtils.cpp b/netwerk/cache2/CacheFileUtils.cpp
new file mode 100644
index 0000000000..d43e958bff
--- /dev/null
+++ b/netwerk/cache2/CacheFileUtils.cpp
@@ -0,0 +1,575 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheIndex.h"
+#include "CacheLog.h"
+#include "CacheFileUtils.h"
+#include "LoadContextInfo.h"
+#include "mozilla/Tokenizer.h"
+#include "mozilla/Telemetry.h"
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+#include "nsString.h"
+#include <algorithm>
+#include "mozilla/Unused.h"
+
+
+namespace mozilla {
+namespace net {
+namespace CacheFileUtils {
+
+// This designates the format for the "alt-data" metadata.
+// When the format changes we need to update the version.
+static uint32_t const kAltDataVersion = 1;
+const char *kAltDataKey = "alt-data";
+
+namespace {
+
+/**
+ * A simple recursive descent parser for the mapping key.
+ */
+class KeyParser : protected Tokenizer
+{
+public:
+  explicit KeyParser(nsACString const& aInput)
+    : Tokenizer(aInput)
+    // Initialize attributes to their default values
+    , originAttribs(0, false)
+    , isAnonymous(false)
+    // Initialize the cache key to a zero length by default
+    , lastTag(0)
+  {
+  }
+
+private:
+  // Results
+  NeckoOriginAttributes originAttribs;
+  bool isAnonymous;
+  nsCString idEnhance;
+  nsDependentCSubstring cacheKey;
+
+  // Keeps the last tag name, used for alphabetical sort checking
+  char lastTag;
+
+  // Classifier for the 'tag' character valid range
+  static bool TagChar(const char aChar)
+  {
+    return aChar >= ' ' && aChar <= '~';
+  }
+
+  bool ParseTags()
+  {
+    // Expects to be at the tag name or at the end
+    if (CheckEOF()) {
+      return true;
+    }
+
+    char tag;
+    if (!ReadChar(&TagChar, &tag)) {
+      return false;
+    }
+
+    // Check the alphabetical order, hard-fail on disobedience
+    if (!(lastTag < tag || tag == ':')) {
+      return false;
+    }
+    lastTag = tag;
+
+    switch (tag) {
+    case ':':
+      // last possible tag, when present there is the cacheKey following,
+      // not terminated with ',' and no need to unescape.
+      cacheKey.Rebind(mCursor, mEnd - mCursor);
+      return true;
+    case 'O': {
+      nsAutoCString originSuffix;
+      if (!ParseValue(&originSuffix) || !originAttribs.PopulateFromSuffix(originSuffix)) {
+        return false;
+      }
+      break;
+    }
+    case 'p':
+      originAttribs.SyncAttributesWithPrivateBrowsing(true);
+      break;
+    case 'b':
+      // Leaving to be able to read and understand oldformatted entries
+      originAttribs.mInIsolatedMozBrowser = true;
+      break;
+    case 'a':
+      isAnonymous = true;
+      break;
+    case 'i': {
+      // Leaving to be able to read and understand oldformatted entries
+      if (!ReadInteger(&originAttribs.mAppId)) {
+        return false; // not a valid 32-bit integer
+      }
+      break;
+    }
+    case '~':
+      if (!ParseValue(&idEnhance)) {
+        return false;
+      }
+      break;
+    default:
+      if (!ParseValue()) { // skip any tag values, optional
+        return false;
+      }
+      break;
+    }
+
+    // We expect a comma after every tag
+    if (!CheckChar(',')) {
+      return false;
+    }
+
+    // Recurse to the next tag
+    return ParseTags();
+  }
+
+  bool ParseValue(nsACString *result = nullptr)
+  {
+    // If at the end, fail since we expect a comma ; value may be empty tho
+    if (CheckEOF()) {
+      return false;
+    }
+
+    Token t;
+    while (Next(t)) {
+      if (!Token::Char(',').Equals(t)) {
+        if (result) {
+          result->Append(t.Fragment());
+        }
+        continue;
+      }
+
+      if (CheckChar(',')) {
+        // Two commas in a row, escaping
+        if (result) {
+          result->Append(',');
+        }
+        continue;
+      }
+
+      // We must give the comma back since the upper calls expect it
+      Rollback();
+      return true;
+    }
+
+    return false;
+  }
+
+public:
+  already_AddRefed<LoadContextInfo> Parse()
+  {
+    RefPtr<LoadContextInfo> info;
+    if (ParseTags()) {
+      info = GetLoadContextInfo(isAnonymous, originAttribs);
+    }
+
+    return info.forget();
+  }
+
+  void URISpec(nsACString &result)
+  {
+    result.Assign(cacheKey);
+  }
+
+  void IdEnhance(nsACString &result)
+  {
+    result.Assign(idEnhance);
+  }
+};
+
+} // namespace
+
+already_AddRefed<nsILoadContextInfo>
+ParseKey(const nsCSubstring &aKey,
+         nsCSubstring *aIdEnhance,
+         nsCSubstring *aURISpec)
+{
+  KeyParser parser(aKey);
+  RefPtr<LoadContextInfo> info = parser.Parse();
+
+  if (info) {
+    if (aIdEnhance)
+      parser.IdEnhance(*aIdEnhance);
+    if (aURISpec)
+      parser.URISpec(*aURISpec);
+  }
+
+  return info.forget();
+}
+
+void
+AppendKeyPrefix(nsILoadContextInfo* aInfo, nsACString &_retval)
+{
+  /**
+   * This key is used to salt file hashes.  When form of the key is changed
+   * cache entries will fail to find on disk.
+   *
+   * IMPORTANT NOTE:
+   * Keep the attributes list sorted according their ASCII code.
+   */
+
+  NeckoOriginAttributes const *oa = aInfo->OriginAttributesPtr();
+  nsAutoCString suffix;
+  oa->CreateSuffix(suffix);
+  if (!suffix.IsEmpty()) {
+    AppendTagWithValue(_retval, 'O', suffix);
+  }
+
+  if (aInfo->IsAnonymous()) {
+    _retval.AppendLiteral("a,");
+  }
+
+  if (aInfo->IsPrivate()) {
+    _retval.AppendLiteral("p,");
+  }
+}
+
+void
+AppendTagWithValue(nsACString & aTarget, char const aTag, nsCSubstring const & aValue)
+{
+  aTarget.Append(aTag);
+
+  // First check the value string to save some memory copying
+  // for cases we don't need to escape at all (most likely).
+  if (!aValue.IsEmpty()) {
+    if (!aValue.Contains(',')) {
+      // No need to escape
+      aTarget.Append(aValue);
+    } else {
+      nsAutoCString escapedValue(aValue);
+      escapedValue.ReplaceSubstring(
+        NS_LITERAL_CSTRING(","), NS_LITERAL_CSTRING(",,"));
+      aTarget.Append(escapedValue);
+    }
+  }
+
+  aTarget.Append(',');
+}
+
+nsresult
+KeyMatchesLoadContextInfo(const nsACString &aKey, nsILoadContextInfo *aInfo,
+                          bool *_retval)
+{
+  nsCOMPtr<nsILoadContextInfo> info = ParseKey(aKey);
+
+  if (!info) {
+    return NS_ERROR_FAILURE;
+  }
+
+  *_retval = info->Equals(aInfo);
+  return NS_OK;
+}
+
+ValidityPair::ValidityPair(uint32_t aOffset, uint32_t aLen)
+  : mOffset(aOffset), mLen(aLen)
+{}
+
+ValidityPair&
+ValidityPair::operator=(const ValidityPair& aOther)
+{
+  mOffset = aOther.mOffset;
+  mLen = aOther.mLen;
+  return *this;
+}
+
+bool
+ValidityPair::CanBeMerged(const ValidityPair& aOther) const
+{
+  // The pairs can be merged into a single one if the start of one of the pairs
+  // is placed anywhere in the validity interval of other pair or exactly after
+  // its end.
+  return IsInOrFollows(aOther.mOffset) || aOther.IsInOrFollows(mOffset);
+}
+
+bool
+ValidityPair::IsInOrFollows(uint32_t aOffset) const
+{
+  return mOffset <= aOffset && mOffset + mLen >= aOffset;
+}
+
+bool
+ValidityPair::LessThan(const ValidityPair& aOther) const
+{
+  if (mOffset < aOther.mOffset) {
+    return true;
+  }
+
+  if (mOffset == aOther.mOffset && mLen < aOther.mLen) {
+    return true;
+  }
+
+  return false;
+}
+
+void
+ValidityPair::Merge(const ValidityPair& aOther)
+{
+  MOZ_ASSERT(CanBeMerged(aOther));
+
+  uint32_t offset = std::min(mOffset, aOther.mOffset);
+  uint32_t end = std::max(mOffset + mLen, aOther.mOffset + aOther.mLen);
+
+  mOffset = offset;
+  mLen = end - offset;
+}
+
+void
+ValidityMap::Log() const
+{
+  LOG(("ValidityMap::Log() - number of pairs: %u", mMap.Length()));
+  for (uint32_t i=0; i<mMap.Length(); i++) {
+    LOG(("    (%u, %u)", mMap[i].Offset() + 0, mMap[i].Len() + 0));
+  }
+}
+
+uint32_t
+ValidityMap::Length() const
+{
+  return mMap.Length();
+}
+
+void
+ValidityMap::AddPair(uint32_t aOffset, uint32_t aLen)
+{
+  ValidityPair pair(aOffset, aLen);
+
+  if (mMap.Length() == 0) {
+    mMap.AppendElement(pair);
+    return;
+  }
+
+  // Find out where to place this pair into the map, it can overlap only with
+  // one preceding pair and all subsequent pairs.
+  uint32_t pos = 0;
+  for (pos = mMap.Length(); pos > 0; ) {
+    --pos;
+
+    if (mMap[pos].LessThan(pair)) {
+      // The new pair should be either inserted after pos or merged with it.
+      if (mMap[pos].CanBeMerged(pair)) {
+        // Merge with the preceding pair
+        mMap[pos].Merge(pair);
+      } else {
+        // They don't overlap, element must be placed after pos element
+        ++pos;
+        if (pos == mMap.Length()) {
+          mMap.AppendElement(pair);
+        } else {
+          mMap.InsertElementAt(pos, pair);
+        }
+      }
+
+      break;
+    }
+
+    if (pos == 0) {
+      // The new pair should be placed in front of all existing pairs.
+      mMap.InsertElementAt(0, pair);
+    }
+  }
+
+  // pos now points to merged or inserted pair, check whether it overlaps with
+  // subsequent pairs.
+  while (pos + 1 < mMap.Length()) {
+    if (mMap[pos].CanBeMerged(mMap[pos + 1])) {
+      mMap[pos].Merge(mMap[pos + 1]);
+      mMap.RemoveElementAt(pos + 1);
+    } else {
+      break;
+    }
+  }
+}
+
+void
+ValidityMap::Clear()
+{
+  mMap.Clear();
+}
+
+size_t
+ValidityMap::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  return mMap.ShallowSizeOfExcludingThis(mallocSizeOf);
+}
+
+ValidityPair&
+ValidityMap::operator[](uint32_t aIdx)
+{
+  return mMap.ElementAt(aIdx);
+}
+
+StaticMutex DetailedCacheHitTelemetry::sLock;
+uint32_t DetailedCacheHitTelemetry::sRecordCnt = 0;
+DetailedCacheHitTelemetry::HitRate DetailedCacheHitTelemetry::sHRStats[kNumOfRanges];
+
+DetailedCacheHitTelemetry::HitRate::HitRate()
+{
+  Reset();
+}
+
+void
+DetailedCacheHitTelemetry::HitRate::AddRecord(ERecType aType)
+{
+  if (aType == HIT) {
+    ++mHitCnt;
+  } else {
+    ++mMissCnt;
+  }
+}
+
+uint32_t
+DetailedCacheHitTelemetry::HitRate::GetHitRateBucket(uint32_t aNumOfBuckets) const
+{
+  uint32_t bucketIdx = (aNumOfBuckets * mHitCnt) / (mHitCnt + mMissCnt);
+  if (bucketIdx == aNumOfBuckets) { // make sure 100% falls into the last bucket
+    --bucketIdx;
+  }
+
+  return bucketIdx;
+}
+
+uint32_t
+DetailedCacheHitTelemetry::HitRate::Count()
+{
+  return mHitCnt + mMissCnt;
+}
+
+void
+DetailedCacheHitTelemetry::HitRate::Reset()
+{
+  mHitCnt = 0;
+  mMissCnt = 0;
+}
+
+// static
+void
+DetailedCacheHitTelemetry::AddRecord(ERecType aType, TimeStamp aLoadStart)
+{
+  bool isUpToDate = false;
+  CacheIndex::IsUpToDate(&isUpToDate);
+  if (!isUpToDate) {
+    // Ignore the record when the entry file count might be incorrect
+    return;
+  }
+
+  uint32_t entryCount;
+  nsresult rv = CacheIndex::GetEntryFileCount(&entryCount);
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  uint32_t rangeIdx = entryCount / kRangeSize;
+  if (rangeIdx >= kNumOfRanges) { // The last range has no upper limit.
+    rangeIdx = kNumOfRanges - 1;
+  }
+
+  uint32_t hitMissValue = 2 * rangeIdx; // 2 values per range
+  if (aType == MISS) { // The order is HIT, MISS
+    ++hitMissValue;
+  }
+
+  StaticMutexAutoLock lock(sLock);
+
+  if (aType == MISS) {
+    mozilla::Telemetry::AccumulateTimeDelta(
+      mozilla::Telemetry::NETWORK_CACHE_V2_MISS_TIME_MS,
+      aLoadStart);
+  } else {
+    mozilla::Telemetry::AccumulateTimeDelta(
+      mozilla::Telemetry::NETWORK_CACHE_V2_HIT_TIME_MS,
+      aLoadStart);
+  }
+
+  Telemetry::Accumulate(Telemetry::NETWORK_CACHE_HIT_MISS_STAT_PER_CACHE_SIZE,
+                        hitMissValue);
+
+  sHRStats[rangeIdx].AddRecord(aType);
+  ++sRecordCnt;
+
+  if (sRecordCnt < kTotalSamplesReportLimit) {
+    return;
+  }
+
+  sRecordCnt = 0;
+
+  for (uint32_t i = 0; i < kNumOfRanges; ++i) {
+    if (sHRStats[i].Count() >= kHitRateSamplesReportLimit) {
+      // The telemetry enums are grouped by buckets as follows:
+      // Telemetry value : 0,1,2,3, ... ,19,20,21,22, ... ,398,399
+      // Hit rate bucket : 0,0,0,0, ... , 0, 1, 1, 1, ... , 19, 19
+      // Cache size range: 0,1,2,3, ... ,19, 0, 1, 2, ... , 18, 19
+      uint32_t bucketOffset = sHRStats[i].GetHitRateBucket(kHitRateBuckets) *
+                              kNumOfRanges;
+
+      Telemetry::Accumulate(Telemetry::NETWORK_CACHE_HIT_RATE_PER_CACHE_SIZE,
+                            bucketOffset + i);
+      sHRStats[i].Reset();
+    }
+  }
+}
+
+void
+FreeBuffer(void *aBuf) {
+#ifndef NS_FREE_PERMANENT_DATA
+  if (CacheObserver::ShuttingDown()) {
+    return;
+  }
+#endif
+
+  free(aBuf);
+}
+
+nsresult
+ParseAlternativeDataInfo(const char *aInfo, int64_t *_offset, nsACString *_type)
+{
+  // The format is: "1;12345,javascript/binary"
+  //         <version>;<offset>,<type>
+  mozilla::Tokenizer p(aInfo, nullptr, "/");
+  uint32_t altDataVersion = 0;
+  int64_t altDataOffset = -1;
+
+  // The metadata format has a wrong version number.
+  if (!p.ReadInteger(&altDataVersion) ||
+      altDataVersion != kAltDataVersion) {
+    LOG(("ParseAlternativeDataInfo() - altDataVersion=%u, "
+         "expectedVersion=%u", altDataVersion, kAltDataVersion));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (!p.CheckChar(';') ||
+      !p.ReadInteger(&altDataOffset) ||
+      !p.CheckChar(',')) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // The requested alt-data representation is not available
+  if (altDataOffset < 0) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  *_offset = altDataOffset;
+  if (_type) {
+    mozilla::Unused << p.ReadUntil(Tokenizer::Token::EndOfFile(), *_type);
+  }
+
+  return NS_OK;
+}
+
+void
+BuildAlternativeDataInfo(const char *aInfo, int64_t aOffset, nsACString &_retval)
+{
+  _retval.Truncate();
+  _retval.AppendInt(kAltDataVersion);
+  _retval.Append(';');
+  _retval.AppendInt(aOffset);
+  _retval.Append(',');
+  _retval.Append(aInfo);
+}
+
+} // namespace CacheFileUtils
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheFileUtils.h b/netwerk/cache2/CacheFileUtils.h
new file mode 100644
index 0000000000..3371c3eb56
--- /dev/null
+++ b/netwerk/cache2/CacheFileUtils.h
@@ -0,0 +1,164 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheFileUtils__h__
+#define CacheFileUtils__h__
+
+#include "nsError.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsTArray.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/TimeStamp.h"
+
+class nsILoadContextInfo;
+class nsACString;
+
+namespace mozilla {
+namespace net {
+namespace CacheFileUtils {
+
+extern const char *kAltDataKey;
+
+already_AddRefed<nsILoadContextInfo>
+ParseKey(const nsCSubstring &aKey,
+         nsCSubstring *aIdEnhance = nullptr,
+         nsCSubstring *aURISpec = nullptr);
+
+void
+AppendKeyPrefix(nsILoadContextInfo *aInfo, nsACString &_retval);
+
+void
+AppendTagWithValue(nsACString & aTarget, char const aTag, nsCSubstring const & aValue);
+
+nsresult
+KeyMatchesLoadContextInfo(const nsACString &aKey,
+                          nsILoadContextInfo *aInfo,
+                          bool *_retval);
+
+class ValidityPair {
+public:
+  ValidityPair(uint32_t aOffset, uint32_t aLen);
+
+  ValidityPair& operator=(const ValidityPair& aOther);
+
+  // Returns true when two pairs can be merged, i.e. they do overlap or the one
+  // ends exactly where the other begins.
+  bool CanBeMerged(const ValidityPair& aOther) const;
+
+  // Returns true when aOffset is placed anywhere in the validity interval or
+  // exactly after its end.
+  bool IsInOrFollows(uint32_t aOffset) const;
+
+  // Returns true when this pair has lower offset than the other pair. In case
+  // both pairs have the same offset it returns true when this pair has a
+  // shorter length.
+  bool LessThan(const ValidityPair& aOther) const;
+
+  // Merges two pair into one.
+  void Merge(const ValidityPair& aOther);
+
+  uint32_t Offset() const { return mOffset; }
+  uint32_t Len() const    { return mLen; }
+
+private:
+  uint32_t mOffset;
+  uint32_t mLen;
+};
+
+class ValidityMap {
+public:
+  // Prints pairs in the map into log.
+  void Log() const;
+
+  // Returns number of pairs in the map.
+  uint32_t Length() const;
+
+  // Adds a new pair to the map. It keeps the pairs ordered and merges pairs
+  // when possible.
+  void AddPair(uint32_t aOffset, uint32_t aLen);
+
+  // Removes all pairs from the map.
+  void Clear();
+
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  ValidityPair& operator[](uint32_t aIdx);
+
+private:
+  nsTArray<ValidityPair> mMap;
+};
+
+
+class DetailedCacheHitTelemetry {
+public:
+  enum ERecType {
+    HIT  = 0,
+    MISS = 1
+  };
+
+  static void AddRecord(ERecType aType, TimeStamp aLoadStart);
+
+private:
+  class HitRate {
+  public:
+    HitRate();
+
+    void     AddRecord(ERecType aType);
+    // Returns the bucket index that the current hit rate falls into according
+    // to the given aNumOfBuckets.
+    uint32_t GetHitRateBucket(uint32_t aNumOfBuckets) const;
+    uint32_t Count();
+    void     Reset();
+
+  private:
+    uint32_t mHitCnt;
+    uint32_t mMissCnt;
+  };
+
+  // Group the hits and misses statistics by cache files count ranges (0-5000,
+  // 5001-10000, ... , 95001- )
+  static const uint32_t kRangeSize = 5000;
+  static const uint32_t kNumOfRanges = 20;
+
+  // Use the same ranges to report an average hit rate. Report the hit rates
+  // (and reset the counters) every kTotalSamplesReportLimit samples.
+  static const uint32_t kTotalSamplesReportLimit = 1000;
+
+  // Report hit rate for a given cache size range only if it contains
+  // kHitRateSamplesReportLimit or more samples. This limit should avoid
+  // reporting a biased statistics.
+  static const uint32_t kHitRateSamplesReportLimit = 500;
+
+  // All hit rates are accumulated in a single telemetry probe, so to use
+  // a sane number of enumerated values the hit rate is divided into buckets
+  // instead of using a percent value. This constant defines number of buckets
+  // that we divide the hit rates into. I.e. we'll report ranges 0%-5%, 5%-10%,
+  // 10-%15%, ...
+  static const uint32_t kHitRateBuckets = 20;
+
+  // Protects sRecordCnt, sHitStats and Telemetry::Accumulated() calls.
+  static StaticMutex sLock;
+
+  // Counter of samples that is compared against kTotalSamplesReportLimit.
+  static uint32_t sRecordCnt;
+ 
+  // Hit rate statistics for every cache size range.
+  static HitRate sHRStats[kNumOfRanges];
+};
+
+void
+FreeBuffer(void *aBuf);
+
+nsresult
+ParseAlternativeDataInfo(const char *aInfo, int64_t *_offset, nsACString *_type);
+
+void
+BuildAlternativeDataInfo(const char *aInfo, int64_t aOffset, nsACString &_retval);
+
+} // namespace CacheFileUtils
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheHashUtils.cpp b/netwerk/cache2/CacheHashUtils.cpp
new file mode 100644
index 0000000000..1f816e3471
--- /dev/null
+++ b/netwerk/cache2/CacheHashUtils.cpp
@@ -0,0 +1,206 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheHashUtils.h"
+
+#include "mozilla/BasePrincipal.h"
+#include "plstr.h"
+
+namespace mozilla {
+namespace net {
+
+/**
+ *  CacheHash::Hash(const char * key, uint32_t initval)
+ *
+ *  See http://burtleburtle.net/bob/hash/evahash.html for more information
+ *  about this hash function.
+ *
+ *  This algorithm is used to check the data integrity.
+ */
+
+static inline void hashmix(uint32_t& a, uint32_t& b, uint32_t& c)
+{
+  a -= b; a -= c; a ^= (c>>13);
+  b -= c; b -= a; b ^= (a<<8);
+  c -= a; c -= b; c ^= (b>>13);
+  a -= b; a -= c; a ^= (c>>12);
+  b -= c; b -= a; b ^= (a<<16);
+  c -= a; c -= b; c ^= (b>>5);
+  a -= b; a -= c; a ^= (c>>3);
+  b -= c; b -= a; b ^= (a<<10);
+  c -= a; c -= b; c ^= (b>>15);
+}
+
+CacheHash::Hash32_t
+CacheHash::Hash(const char *aData, uint32_t aSize, uint32_t aInitval)
+{
+  const uint8_t *k = reinterpret_cast<const uint8_t*>(aData);
+  uint32_t a, b, c, len;
+
+//  length = PL_strlen(key);
+  /* Set up the internal state */
+  len = aSize;
+  a = b = 0x9e3779b9;  /* the golden ratio; an arbitrary value */
+  c = aInitval;        /* variable initialization of internal state */
+
+  /*---------------------------------------- handle most of the key */
+  while (len >= 12)
+  {
+    a += k[0] + (uint32_t(k[1])<<8) + (uint32_t(k[2])<<16) + (uint32_t(k[3])<<24);
+    b += k[4] + (uint32_t(k[5])<<8) + (uint32_t(k[6])<<16) + (uint32_t(k[7])<<24);
+    c += k[8] + (uint32_t(k[9])<<8) + (uint32_t(k[10])<<16) + (uint32_t(k[11])<<24);
+    hashmix(a, b, c);
+    k += 12; len -= 12;
+  }
+
+  /*------------------------------------- handle the last 11 bytes */
+  c += aSize;
+  switch(len) {              /* all the case statements fall through */
+    case 11: c += (uint32_t(k[10])<<24);  MOZ_FALLTHROUGH;
+    case 10: c += (uint32_t(k[9])<<16);   MOZ_FALLTHROUGH;
+    case 9 : c += (uint32_t(k[8])<<8);    MOZ_FALLTHROUGH;
+    /* the low-order byte of c is reserved for the length */
+    case 8 : b += (uint32_t(k[7])<<24);   MOZ_FALLTHROUGH;
+    case 7 : b += (uint32_t(k[6])<<16);   MOZ_FALLTHROUGH;
+    case 6 : b += (uint32_t(k[5])<<8);    MOZ_FALLTHROUGH;
+    case 5 : b += k[4];                   MOZ_FALLTHROUGH;
+    case 4 : a += (uint32_t(k[3])<<24);   MOZ_FALLTHROUGH;
+    case 3 : a += (uint32_t(k[2])<<16);   MOZ_FALLTHROUGH;
+    case 2 : a += (uint32_t(k[1])<<8);    MOZ_FALLTHROUGH;
+    case 1 : a += k[0];
+    /* case 0: nothing left to add */
+  }
+  hashmix(a, b, c);
+
+  return c;
+}
+
+CacheHash::Hash16_t
+CacheHash::Hash16(const char *aData, uint32_t aSize, uint32_t aInitval)
+{
+  Hash32_t hash = Hash(aData, aSize, aInitval);
+  return (hash & 0xFFFF);
+}
+
+NS_IMPL_ISUPPORTS0(CacheHash)
+
+CacheHash::CacheHash(uint32_t aInitval)
+  : mA(0x9e3779b9)
+  , mB(0x9e3779b9)
+  , mC(aInitval)
+  , mPos(0)
+  , mBuf(0)
+  , mBufPos(0)
+  , mLength(0)
+  , mFinalized(false)
+{}
+
+void
+CacheHash::Feed(uint32_t aVal, uint8_t aLen)
+{
+  switch (mPos) {
+  case 0:
+    mA += aVal;
+    mPos ++;
+    break;
+
+  case 1:
+    mB += aVal;
+    mPos ++;
+    break;
+
+  case 2:
+    mPos = 0;
+    if (aLen == 4) {
+      mC += aVal;
+      hashmix(mA, mB, mC);
+    }
+    else {
+      mC += aVal << 8;
+    }
+  }
+
+  mLength += aLen;
+}
+
+void
+CacheHash::Update(const char *aData, uint32_t aLen)
+{
+  const uint8_t *data = reinterpret_cast<const uint8_t*>(aData);
+
+  MOZ_ASSERT(!mFinalized);
+
+  if (mBufPos) {
+    while (mBufPos != 4 && aLen) {
+      mBuf += uint32_t(*data) << 8*mBufPos;
+      data++;
+      mBufPos++;
+      aLen--;
+    }
+
+    if (mBufPos == 4) {
+      mBufPos = 0;
+      Feed(mBuf);
+      mBuf = 0;
+    }
+  }
+
+  if (!aLen)
+    return;
+
+  while (aLen >= 4) {
+    Feed(data[0] + (uint32_t(data[1]) << 8) + (uint32_t(data[2]) << 16) +
+         (uint32_t(data[3]) << 24));
+    data += 4;
+    aLen -= 4;
+  }
+
+  switch (aLen) {
+    case 3: mBuf += data[2] << 16;  MOZ_FALLTHROUGH;
+    case 2: mBuf += data[1] << 8;   MOZ_FALLTHROUGH;
+    case 1: mBuf += data[0];
+  }
+
+  mBufPos = aLen;
+}
+
+CacheHash::Hash32_t
+CacheHash::GetHash()
+{
+  if (!mFinalized)
+  {
+    if (mBufPos) {
+      Feed(mBuf, mBufPos);
+    }
+    mC += mLength;
+    hashmix(mA, mB, mC);
+    mFinalized = true;
+  }
+
+  return mC;
+}
+
+CacheHash::Hash16_t
+CacheHash::GetHash16()
+{
+  Hash32_t hash = GetHash();
+  return (hash & 0xFFFF);
+}
+
+OriginAttrsHash
+GetOriginAttrsHash(const mozilla::OriginAttributes &aOA)
+{
+  nsAutoCString suffix;
+  aOA.CreateSuffix(suffix);
+
+  SHA1Sum sum;
+  SHA1Sum::Hash hash;
+  sum.update(suffix.BeginReading(), suffix.Length());
+  sum.finish(hash);
+
+  return BigEndian::readUint64(&hash);
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheHashUtils.h b/netwerk/cache2/CacheHashUtils.h
new file mode 100644
index 0000000000..2af3fed808
--- /dev/null
+++ b/netwerk/cache2/CacheHashUtils.h
@@ -0,0 +1,67 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheHashUtils__h__
+#define CacheHashUtils__h__
+
+#include "nsISupports.h"
+#include "mozilla/Types.h"
+#include "prnetdb.h"
+#include "nsPrintfCString.h"
+
+#define LOGSHA1(x) \
+    PR_htonl((reinterpret_cast<const uint32_t *>(x))[0]), \
+    PR_htonl((reinterpret_cast<const uint32_t *>(x))[1]), \
+    PR_htonl((reinterpret_cast<const uint32_t *>(x))[2]), \
+    PR_htonl((reinterpret_cast<const uint32_t *>(x))[3]), \
+    PR_htonl((reinterpret_cast<const uint32_t *>(x))[4])
+
+#define SHA1STRING(x) \
+    (nsPrintfCString("%08x%08x%08x%08x%08x", LOGSHA1(x)).get())
+
+namespace mozilla {
+
+class OriginAttributes;
+
+namespace net {
+
+class CacheHash : public nsISupports
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  typedef uint16_t Hash16_t;
+  typedef uint32_t Hash32_t;
+
+  static Hash32_t Hash(const char* aData, uint32_t aSize, uint32_t aInitval=0);
+  static Hash16_t Hash16(const char* aData, uint32_t aSize,
+                         uint32_t aInitval=0);
+
+  explicit CacheHash(uint32_t aInitval=0);
+
+  void     Update(const char *aData, uint32_t aLen);
+  Hash32_t GetHash();
+  Hash16_t GetHash16();
+
+private:
+  virtual ~CacheHash() {}
+
+  void Feed(uint32_t aVal, uint8_t aLen = 4);
+
+  uint32_t mA, mB, mC;
+  uint8_t  mPos;
+  uint32_t mBuf;
+  uint8_t  mBufPos;
+  uint32_t mLength;
+  bool     mFinalized;
+};
+
+typedef uint64_t OriginAttrsHash;
+
+OriginAttrsHash GetOriginAttrsHash(const mozilla::OriginAttributes &aOA);
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheIOThread.cpp b/netwerk/cache2/CacheIOThread.cpp
new file mode 100644
index 0000000000..b96f03216c
--- /dev/null
+++ b/netwerk/cache2/CacheIOThread.cpp
@@ -0,0 +1,646 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheIOThread.h"
+#include "CacheFileIOManager.h"
+
+#include "nsIRunnable.h"
+#include "nsISupportsImpl.h"
+#include "nsPrintfCString.h"
+#include "nsThreadUtils.h"
+#include "mozilla/IOInterposer.h"
+
+#ifdef XP_WIN
+#include <windows.h>
+#endif
+
+namespace mozilla {
+namespace net {
+
+namespace { // anon
+
+class CacheIOTelemetry
+{
+public:
+  typedef CacheIOThread::EventQueue::size_type size_type;
+  static size_type mMinLengthToReport[CacheIOThread::LAST_LEVEL];
+  static void Report(uint32_t aLevel, size_type aLength);
+};
+
+static CacheIOTelemetry::size_type const kGranularity = 30;
+
+CacheIOTelemetry::size_type 
+CacheIOTelemetry::mMinLengthToReport[CacheIOThread::LAST_LEVEL] = {
+  kGranularity, kGranularity, kGranularity, kGranularity,
+  kGranularity, kGranularity, kGranularity, kGranularity
+};
+
+// static
+void CacheIOTelemetry::Report(uint32_t aLevel, CacheIOTelemetry::size_type aLength)
+{
+  if (mMinLengthToReport[aLevel] > aLength) {
+    return;
+  }
+
+  static Telemetry::ID telemetryID[] = {
+    Telemetry::HTTP_CACHE_IO_QUEUE_2_OPEN_PRIORITY,
+    Telemetry::HTTP_CACHE_IO_QUEUE_2_READ_PRIORITY,
+    Telemetry::HTTP_CACHE_IO_QUEUE_2_MANAGEMENT,
+    Telemetry::HTTP_CACHE_IO_QUEUE_2_OPEN,
+    Telemetry::HTTP_CACHE_IO_QUEUE_2_READ,
+    Telemetry::HTTP_CACHE_IO_QUEUE_2_WRITE_PRIORITY,
+    Telemetry::HTTP_CACHE_IO_QUEUE_2_WRITE,
+    Telemetry::HTTP_CACHE_IO_QUEUE_2_INDEX,
+    Telemetry::HTTP_CACHE_IO_QUEUE_2_EVICT
+  };
+
+  // Each bucket is a multiply of kGranularity (30, 60, 90..., 300+)
+  aLength = (aLength / kGranularity);
+  // Next time report only when over the current length + kGranularity
+  mMinLengthToReport[aLevel] = (aLength + 1) * kGranularity;
+
+  // 10 is number of buckets we have in each probe
+  aLength = std::min<size_type>(aLength, 10);
+
+  Telemetry::Accumulate(telemetryID[aLevel], aLength - 1); // counted from 0
+}
+
+} // anon
+
+namespace detail {
+
+/**
+ * Helper class encapsulating platform-specific code to cancel
+ * any pending IO operation taking too long.  Solely used during
+ * shutdown to prevent any IO shutdown hangs.
+ * Mainly designed for using Win32 CancelSynchronousIo function.
+ */
+class BlockingIOWatcher
+{
+#ifdef XP_WIN
+  typedef BOOL(WINAPI* TCancelSynchronousIo)(HANDLE hThread);
+  TCancelSynchronousIo mCancelSynchronousIo;
+  // The native handle to the thread
+  HANDLE mThread;
+  // Event signaling back to the main thread, see NotifyOperationDone.
+  HANDLE mEvent;
+#endif
+
+public:
+  // Created and destroyed on the main thread only
+  BlockingIOWatcher();
+  ~BlockingIOWatcher();
+
+  // Called on the IO thread to grab the platform specific
+  // reference to it.
+  void InitThread();
+  // If there is a blocking operation being handled on the IO
+  // thread, this is called on the main thread during shutdown.
+  // Waits for notification from the IO thread for up to two seconds.
+  // If that times out, it attempts to cancel the IO operation.
+  void WatchAndCancel(Monitor& aMonitor);
+  // Called by the IO thread after each operation has been
+  // finished (after each Run() call).  This wakes the main
+  // thread up and makes WatchAndCancel() early exit and become
+  // a no-op.
+  void NotifyOperationDone();
+};
+
+#ifdef XP_WIN
+
+BlockingIOWatcher::BlockingIOWatcher()
+  : mCancelSynchronousIo(NULL)
+  , mThread(NULL)
+  , mEvent(NULL)
+{
+  HMODULE kernel32_dll = GetModuleHandle("kernel32.dll");
+  if (!kernel32_dll) {
+    return;
+  }
+
+  FARPROC ptr = GetProcAddress(kernel32_dll, "CancelSynchronousIo");
+  if (!ptr) {
+    return;
+  }
+
+  mCancelSynchronousIo = reinterpret_cast<TCancelSynchronousIo>(ptr);
+
+  mEvent = ::CreateEvent(NULL, TRUE, FALSE, NULL);
+}
+
+BlockingIOWatcher::~BlockingIOWatcher()
+{
+  if (mEvent) {
+    CloseHandle(mEvent);
+  }
+  if (mThread) {
+    CloseHandle(mThread);
+  }
+}
+
+void BlockingIOWatcher::InitThread()
+{
+  // GetCurrentThread() only returns a pseudo handle, hence DuplicateHandle
+  BOOL result = ::DuplicateHandle(
+    GetCurrentProcess(),
+    GetCurrentThread(),
+    GetCurrentProcess(),
+    &mThread,
+    0,
+    FALSE,
+    DUPLICATE_SAME_ACCESS);
+}
+
+void BlockingIOWatcher::WatchAndCancel(Monitor& aMonitor)
+{
+  if (!mEvent) {
+    return;
+  }
+
+  // Reset before we enter the monitor to raise the chance we catch
+  // the currently pending IO op completion.
+  ::ResetEvent(mEvent);
+
+  HANDLE thread;
+  {
+    MonitorAutoLock lock(aMonitor);
+    thread = mThread;
+
+    if (!thread) {
+      return;
+    }
+  }
+
+  LOG(("Blocking IO operation pending on IO thread, waiting..."));
+
+  // It seems wise to use the I/O lag time as a maximum time to wait
+  // for an operation to finish.  When that times out and cancelation
+  // succeeds, there will be no other IO operation permitted.  By default
+  // this is two seconds.
+  uint32_t maxLag = std::min<uint32_t>(5, CacheObserver::MaxShutdownIOLag()) * 1000;
+
+  DWORD result = ::WaitForSingleObject(mEvent, maxLag);
+  if (result == WAIT_TIMEOUT) {
+    LOG(("CacheIOThread: Attempting to cancel a long blocking IO operation"));
+    BOOL result = mCancelSynchronousIo(thread);
+    if (result) {
+      LOG(("  cancelation signal succeeded"));
+    } else {
+      DWORD error = GetLastError();
+      LOG(("  cancelation signal failed with GetLastError=%u", error));
+    }
+  }
+}
+
+void BlockingIOWatcher::NotifyOperationDone()
+{
+  if (mEvent) {
+    ::SetEvent(mEvent);
+  }
+}
+
+#else // WIN
+
+// Stub code only (we don't implement IO cancelation for this platform)
+
+BlockingIOWatcher::BlockingIOWatcher() { }
+BlockingIOWatcher::~BlockingIOWatcher() { }
+void BlockingIOWatcher::InitThread() { }
+void BlockingIOWatcher::WatchAndCancel(Monitor&) { }
+void BlockingIOWatcher::NotifyOperationDone() { }
+
+#endif
+
+} // detail
+
+CacheIOThread* CacheIOThread::sSelf = nullptr;
+
+NS_IMPL_ISUPPORTS(CacheIOThread, nsIThreadObserver)
+
+CacheIOThread::CacheIOThread()
+: mMonitor("CacheIOThread")
+, mThread(nullptr)
+, mXPCOMThread(nullptr)
+, mLowestLevelWaiting(LAST_LEVEL)
+, mCurrentlyExecutingLevel(0)
+, mHasXPCOMEvents(false)
+, mRerunCurrentEvent(false)
+, mShutdown(false)
+, mIOCancelableEvents(0)
+#ifdef DEBUG
+, mInsideLoop(true)
+#endif
+{
+  for (uint32_t i = 0; i < LAST_LEVEL; ++i) {
+    mQueueLength[i] = 0;
+  }
+
+  sSelf = this;
+}
+
+CacheIOThread::~CacheIOThread()
+{
+  if (mXPCOMThread) {
+    nsIThread *thread = mXPCOMThread;
+    thread->Release();
+  }
+
+  sSelf = nullptr;
+#ifdef DEBUG
+  for (uint32_t level = 0; level < LAST_LEVEL; ++level) {
+    MOZ_ASSERT(!mEventQueue[level].Length());
+  }
+#endif
+}
+
+nsresult CacheIOThread::Init()
+{
+  {
+    MonitorAutoLock lock(mMonitor);
+    // Yeah, there is not a thread yet, but we want to make sure
+    // the sequencing is correct.
+    mBlockingIOWatcher = MakeUnique<detail::BlockingIOWatcher>();
+  }
+
+  mThread = PR_CreateThread(PR_USER_THREAD, ThreadFunc, this,
+                            PR_PRIORITY_NORMAL, PR_GLOBAL_THREAD,
+                            PR_JOINABLE_THREAD, 128 * 1024);
+  if (!mThread) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+nsresult CacheIOThread::Dispatch(nsIRunnable* aRunnable, uint32_t aLevel)
+{
+  return Dispatch(do_AddRef(aRunnable), aLevel);
+}
+
+nsresult CacheIOThread::Dispatch(already_AddRefed<nsIRunnable> aRunnable,
+				 uint32_t aLevel)
+{
+  NS_ENSURE_ARG(aLevel < LAST_LEVEL);
+
+  nsCOMPtr<nsIRunnable> runnable(aRunnable);
+
+  // Runnable is always expected to be non-null, hard null-check bellow.
+  MOZ_ASSERT(runnable);
+
+  MonitorAutoLock lock(mMonitor);
+
+  if (mShutdown && (PR_GetCurrentThread() != mThread))
+    return NS_ERROR_UNEXPECTED;
+
+  return DispatchInternal(runnable.forget(), aLevel);
+}
+
+nsresult CacheIOThread::DispatchAfterPendingOpens(nsIRunnable* aRunnable)
+{
+  // Runnable is always expected to be non-null, hard null-check bellow.
+  MOZ_ASSERT(aRunnable);
+
+  MonitorAutoLock lock(mMonitor);
+
+  if (mShutdown && (PR_GetCurrentThread() != mThread))
+    return NS_ERROR_UNEXPECTED;
+
+  // Move everything from later executed OPEN level to the OPEN_PRIORITY level
+  // where we post the (eviction) runnable.
+  mQueueLength[OPEN_PRIORITY] += mEventQueue[OPEN].Length();
+  mQueueLength[OPEN] -= mEventQueue[OPEN].Length();
+  mEventQueue[OPEN_PRIORITY].AppendElements(mEventQueue[OPEN]);
+  mEventQueue[OPEN].Clear();
+
+  return DispatchInternal(do_AddRef(aRunnable), OPEN_PRIORITY);
+}
+
+nsresult CacheIOThread::DispatchInternal(already_AddRefed<nsIRunnable> aRunnable,
+					 uint32_t aLevel)
+{
+  nsCOMPtr<nsIRunnable> runnable(aRunnable);
+
+  if (NS_WARN_IF(!runnable))
+    return NS_ERROR_NULL_POINTER;
+
+  mMonitor.AssertCurrentThreadOwns();
+
+  ++mQueueLength[aLevel];
+  mEventQueue[aLevel].AppendElement(runnable.forget());
+  if (mLowestLevelWaiting > aLevel)
+    mLowestLevelWaiting = aLevel;
+
+  mMonitor.NotifyAll();
+
+  return NS_OK;
+}
+
+bool CacheIOThread::IsCurrentThread()
+{
+  return mThread == PR_GetCurrentThread();
+}
+
+uint32_t CacheIOThread::QueueSize(bool highPriority)
+{
+  MonitorAutoLock lock(mMonitor);
+  if (highPriority) {
+    return mQueueLength[OPEN_PRIORITY] + mQueueLength[READ_PRIORITY];
+  }
+
+  return mQueueLength[OPEN_PRIORITY] + mQueueLength[READ_PRIORITY] +
+         mQueueLength[MANAGEMENT] + mQueueLength[OPEN] + mQueueLength[READ];
+}
+
+bool CacheIOThread::YieldInternal()
+{
+  if (!IsCurrentThread()) {
+    NS_WARNING("Trying to yield to priority events on non-cache2 I/O thread? "
+               "You probably do something wrong.");
+    return false;
+  }
+
+  if (mCurrentlyExecutingLevel == XPCOM_LEVEL) {
+    // Doesn't make any sense, since this handler is the one
+    // that would be executed as the next one.
+    return false;
+  }
+
+  if (!EventsPending(mCurrentlyExecutingLevel))
+    return false;
+
+  mRerunCurrentEvent = true;
+  return true;
+}
+
+void CacheIOThread::Shutdown()
+{
+  if (!mThread) {
+    return;
+  }
+
+  {
+    MonitorAutoLock lock(mMonitor);
+    mShutdown = true;
+    mMonitor.NotifyAll();
+  }
+
+  PR_JoinThread(mThread);
+  mThread = nullptr;
+}
+
+void CacheIOThread::CancelBlockingIO()
+{
+  // This is an attempt to cancel any blocking I/O operation taking
+  // too long time.
+  if (!mBlockingIOWatcher) {
+    return;
+  }
+
+  if (!mIOCancelableEvents) {
+    LOG(("CacheIOThread::CancelBlockingIO, no blocking operation to cancel"));
+    return;
+  }
+
+  // OK, when we are here, we are processing an IO on the thread that
+  // can be cancelled.
+  mBlockingIOWatcher->WatchAndCancel(mMonitor);
+}
+
+already_AddRefed<nsIEventTarget> CacheIOThread::Target()
+{
+  nsCOMPtr<nsIEventTarget> target;
+
+  target = mXPCOMThread;
+  if (!target && mThread)
+  {
+    MonitorAutoLock lock(mMonitor);
+    while (!mXPCOMThread) {
+      lock.Wait();
+    }
+
+    target = mXPCOMThread;
+  }
+
+  return target.forget();
+}
+
+// static
+void CacheIOThread::ThreadFunc(void* aClosure)
+{
+  PR_SetCurrentThreadName("Cache2 I/O");
+  mozilla::IOInterposer::RegisterCurrentThread();
+  CacheIOThread* thread = static_cast<CacheIOThread*>(aClosure);
+  thread->ThreadFunc();
+  mozilla::IOInterposer::UnregisterCurrentThread();
+}
+
+void CacheIOThread::ThreadFunc()
+{
+  nsCOMPtr<nsIThreadInternal> threadInternal;
+
+  {
+    MonitorAutoLock lock(mMonitor);
+
+    MOZ_ASSERT(mBlockingIOWatcher);
+    mBlockingIOWatcher->InitThread();
+
+    // This creates nsThread for this PRThread
+    nsCOMPtr<nsIThread> xpcomThread = NS_GetCurrentThread();
+
+    threadInternal = do_QueryInterface(xpcomThread);
+    if (threadInternal)
+      threadInternal->SetObserver(this);
+
+    mXPCOMThread = xpcomThread.forget().take();
+
+    lock.NotifyAll();
+
+    do {
+loopStart:
+      // Reset the lowest level now, so that we can detect a new event on
+      // a lower level (i.e. higher priority) has been scheduled while
+      // executing any previously scheduled event.
+      mLowestLevelWaiting = LAST_LEVEL;
+
+      // Process xpcom events first
+      while (mHasXPCOMEvents) {
+        mHasXPCOMEvents = false;
+        mCurrentlyExecutingLevel = XPCOM_LEVEL;
+
+        MonitorAutoUnlock unlock(mMonitor);
+
+        bool processedEvent;
+        nsresult rv;
+        do {
+          nsIThread *thread = mXPCOMThread;
+          rv = thread->ProcessNextEvent(false, &processedEvent);
+
+          MOZ_ASSERT(mBlockingIOWatcher);
+          mBlockingIOWatcher->NotifyOperationDone();
+        } while (NS_SUCCEEDED(rv) && processedEvent);
+      }
+
+      uint32_t level;
+      for (level = 0; level < LAST_LEVEL; ++level) {
+        if (!mEventQueue[level].Length()) {
+          // no events on this level, go to the next level
+          continue;
+        }
+
+        LoopOneLevel(level);
+
+        // Go to the first (lowest) level again
+        goto loopStart;
+      }
+
+      if (EventsPending()) {
+        continue;
+      }
+
+      if (mShutdown) {
+        break;
+      }
+
+      lock.Wait(PR_INTERVAL_NO_TIMEOUT);
+
+    } while (true);
+
+    MOZ_ASSERT(!EventsPending());
+
+#ifdef DEBUG
+    // This is for correct assertion on XPCOM events dispatch.
+    mInsideLoop = false;
+#endif
+  } // lock
+
+  if (threadInternal)
+    threadInternal->SetObserver(nullptr);
+}
+
+void CacheIOThread::LoopOneLevel(uint32_t aLevel)
+{
+  EventQueue events;
+  events.SwapElements(mEventQueue[aLevel]);
+  EventQueue::size_type length = events.Length();
+
+  mCurrentlyExecutingLevel = aLevel;
+
+  bool returnEvents = false;
+  bool reportTelementry = true;
+
+  EventQueue::size_type index;
+  {
+    MonitorAutoUnlock unlock(mMonitor);
+
+    for (index = 0; index < length; ++index) {
+      if (EventsPending(aLevel)) {
+        // Somebody scheduled a new event on a lower level, break and harry
+        // to execute it!  Don't forget to return what we haven't exec.
+        returnEvents = true;
+        break;
+      }
+
+      if (reportTelementry) {
+        reportTelementry = false;
+        CacheIOTelemetry::Report(aLevel, length);
+      }
+
+      // Drop any previous flagging, only an event on the current level may set
+      // this flag.
+      mRerunCurrentEvent = false;
+
+      events[index]->Run();
+
+      MOZ_ASSERT(mBlockingIOWatcher);
+      mBlockingIOWatcher->NotifyOperationDone();
+
+      if (mRerunCurrentEvent) {
+        // The event handler yields to higher priority events and wants to rerun.
+        returnEvents = true;
+        break;
+      }
+
+      --mQueueLength[aLevel];
+
+      // Release outside the lock.
+      events[index] = nullptr;
+    }
+  }
+
+  if (returnEvents)
+    mEventQueue[aLevel].InsertElementsAt(0, events.Elements() + index, length - index);
+}
+
+bool CacheIOThread::EventsPending(uint32_t aLastLevel)
+{
+  return mLowestLevelWaiting < aLastLevel || mHasXPCOMEvents;
+}
+
+NS_IMETHODIMP CacheIOThread::OnDispatchedEvent(nsIThreadInternal *thread)
+{
+  MonitorAutoLock lock(mMonitor);
+  mHasXPCOMEvents = true;
+  MOZ_ASSERT(mInsideLoop);
+  lock.Notify();
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheIOThread::OnProcessNextEvent(nsIThreadInternal *thread, bool mayWait)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheIOThread::AfterProcessNextEvent(nsIThreadInternal *thread,
+                                                   bool eventWasProcessed)
+{
+  return NS_OK;
+}
+
+// Memory reporting
+
+size_t CacheIOThread::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  MonitorAutoLock lock(const_cast<CacheIOThread*>(this)->mMonitor);
+
+  size_t n = 0;
+  n += mallocSizeOf(mThread);
+  for (uint32_t level = 0; level < LAST_LEVEL; ++level) {
+    n += mEventQueue[level].ShallowSizeOfExcludingThis(mallocSizeOf);
+    // Events referenced by the queues are arbitrary objects we cannot be sure
+    // are reported elsewhere as well as probably not implementing nsISizeOf
+    // interface.  Deliberatly omitting them from reporting here.
+  }
+
+  return n;
+}
+
+size_t CacheIOThread::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+CacheIOThread::Cancelable::Cancelable(bool aCancelable)
+  : mCancelable(aCancelable)
+{
+  // This will only ever be used on the I/O thread,
+  // which is expected to be alive longer than this class.
+  MOZ_ASSERT(CacheIOThread::sSelf);
+  MOZ_ASSERT(CacheIOThread::sSelf->IsCurrentThread());
+
+  if (mCancelable) {
+    ++CacheIOThread::sSelf->mIOCancelableEvents;
+  }
+}
+
+CacheIOThread::Cancelable::~Cancelable()
+{
+  MOZ_ASSERT(CacheIOThread::sSelf);
+
+  if (mCancelable) {
+    --CacheIOThread::sSelf->mIOCancelableEvents;
+  }
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheIOThread.h b/netwerk/cache2/CacheIOThread.h
new file mode 100644
index 0000000000..ea71f7df0a
--- /dev/null
+++ b/netwerk/cache2/CacheIOThread.h
@@ -0,0 +1,147 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheIOThread__h__
+#define CacheIOThread__h__
+
+#include "nsIThreadInternal.h"
+#include "nsISupportsImpl.h"
+#include "prthread.h"
+#include "nsTArray.h"
+#include "nsAutoPtr.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/UniquePtr.h"
+
+class nsIRunnable;
+
+namespace mozilla {
+namespace net {
+
+namespace detail {
+// A class keeping platform specific information needed to watch and
+// cancel any long blocking synchronous IO.  Must be predeclared here
+// since including windows.h breaks stuff with number of macro definition
+// conflicts.
+class BlockingIOWatcher;
+}
+
+class CacheIOThread : public nsIThreadObserver
+{
+  virtual ~CacheIOThread();
+
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITHREADOBSERVER
+
+  CacheIOThread();
+
+  typedef nsTArray<nsCOMPtr<nsIRunnable>> EventQueue;
+
+  enum ELevel : uint32_t {
+    OPEN_PRIORITY,
+    READ_PRIORITY,
+    MANAGEMENT, // Doesn't do any actual I/O
+    OPEN,
+    READ,
+    WRITE_PRIORITY,
+    WRITE,
+    INDEX,
+    EVICT,
+    LAST_LEVEL,
+
+    // This is actually executed as the first level, but we want this enum
+    // value merely as an indicator while other values are used as indexes
+    // to the queue array.  Hence put at end and not as the first.
+    XPCOM_LEVEL
+  };
+
+  nsresult Init();
+  nsresult Dispatch(nsIRunnable* aRunnable, uint32_t aLevel);
+  nsresult Dispatch(already_AddRefed<nsIRunnable>, uint32_t aLevel);
+  // Makes sure that any previously posted event to OPEN or OPEN_PRIORITY
+  // levels (such as file opennings and dooms) are executed before aRunnable
+  // that is intended to evict stuff from the cache.
+  nsresult DispatchAfterPendingOpens(nsIRunnable* aRunnable);
+  bool IsCurrentThread();
+
+  uint32_t QueueSize(bool highPriority);
+
+  /**
+   * Callable only on this thread, checks if there is an event waiting in
+   * the event queue with a higher execution priority.  If so, the result
+   * is true and the current event handler should break it's work and return
+   * from Run() method immediately.  The event handler will be rerun again
+   * when all more priority events are processed.  Events pending after this
+   * handler (i.e. the one that called YieldAndRerun()) will not execute sooner
+   * then this handler is executed w/o a call to YieldAndRerun().
+   */
+  static bool YieldAndRerun()
+  {
+    return sSelf ? sSelf->YieldInternal() : false;
+  }
+
+  void Shutdown();
+  // This method checks if there is a long blocking IO on the
+  // IO thread and tries to cancel it.  It waits maximum of
+  // two seconds.
+  void CancelBlockingIO();
+  already_AddRefed<nsIEventTarget> Target();
+
+  // A stack class used to annotate running interruptable I/O event
+  class Cancelable
+  {
+    bool mCancelable;
+  public:
+    explicit Cancelable(bool aCancelable);
+    ~Cancelable();
+  };
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+private:
+  static void ThreadFunc(void* aClosure);
+  void ThreadFunc();
+  void LoopOneLevel(uint32_t aLevel);
+  bool EventsPending(uint32_t aLastLevel = LAST_LEVEL);
+  nsresult DispatchInternal(already_AddRefed<nsIRunnable> aRunnable, uint32_t aLevel);
+  bool YieldInternal();
+
+  static CacheIOThread* sSelf;
+
+  mozilla::Monitor mMonitor;
+  PRThread* mThread;
+  UniquePtr<detail::BlockingIOWatcher> mBlockingIOWatcher;
+  Atomic<nsIThread *> mXPCOMThread;
+  Atomic<uint32_t, Relaxed> mLowestLevelWaiting;
+  uint32_t mCurrentlyExecutingLevel;
+
+  // Keeps the length of the each event queue, since LoopOneLevel moves all
+  // events into a local array.
+  Atomic<int32_t> mQueueLength[LAST_LEVEL];
+
+  EventQueue mEventQueue[LAST_LEVEL];
+  // Raised when nsIEventTarget.Dispatch() is called on this thread
+  Atomic<bool, Relaxed> mHasXPCOMEvents;
+  // See YieldAndRerun() above
+  bool mRerunCurrentEvent;
+  // Signal to process all pending events and then shutdown
+  // Synchronized by mMonitor
+  bool mShutdown;
+  // If > 0 there is currently an I/O operation on the thread that
+  // can be canceled when after shutdown, see the Shutdown() method
+  // for usage. Made a counter to allow nesting of the Cancelable class.
+  Atomic<uint32_t, Relaxed> mIOCancelableEvents;
+#ifdef DEBUG
+  bool mInsideLoop;
+#endif
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheIndex.cpp b/netwerk/cache2/CacheIndex.cpp
new file mode 100644
index 0000000000..4525bbe6d6
--- /dev/null
+++ b/netwerk/cache2/CacheIndex.cpp
@@ -0,0 +1,3810 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheIndex.h"
+
+#include "CacheLog.h"
+#include "CacheFileIOManager.h"
+#include "CacheFileMetadata.h"
+#include "CacheIndexIterator.h"
+#include "CacheIndexContextIterator.h"
+#include "nsThreadUtils.h"
+#include "nsISimpleEnumerator.h"
+#include "nsIDirectoryEnumerator.h"
+#include "nsISizeOf.h"
+#include "nsPrintfCString.h"
+#include "mozilla/DebugOnly.h"
+#include "prinrval.h"
+#include "nsIFile.h"
+#include "nsITimer.h"
+#include "mozilla/AutoRestore.h"
+#include <algorithm>
+#include "mozilla/Telemetry.h"
+#include "mozilla/Unused.h"
+
+
+#define kMinUnwrittenChanges   300
+#define kMinDumpInterval       20000 // in milliseconds
+#define kMaxBufSize            16384
+#define kIndexVersion          0x00000003
+#define kUpdateIndexStartDelay 50000 // in milliseconds
+
+#define INDEX_NAME      "index"
+#define TEMP_INDEX_NAME "index.tmp"
+#define JOURNAL_NAME    "index.log"
+
+namespace mozilla {
+namespace net {
+
+namespace {
+
+class FrecencyComparator
+{
+public:
+  bool Equals(CacheIndexRecord* a, CacheIndexRecord* b) const {
+    if (!a || !b) {
+      return false;
+    }
+
+    return a->mFrecency == b->mFrecency;
+  }
+  bool LessThan(CacheIndexRecord* a, CacheIndexRecord* b) const {
+    // Removed (=null) entries must be at the end of the array.
+    if (!a) {
+      return false;
+    }
+    if (!b) {
+      return true;
+    }
+
+    // Place entries with frecency 0 at the end of the non-removed entries.
+    if (a->mFrecency == 0) {
+      return false;
+    }
+    if (b->mFrecency == 0) {
+      return true;
+    }
+
+    return a->mFrecency < b->mFrecency;
+  }
+};
+
+} // namespace
+
+/**
+ * This helper class is responsible for keeping CacheIndex::mIndexStats and
+ * CacheIndex::mFrecencyArray up to date.
+ */
+class CacheIndexEntryAutoManage
+{
+public:
+  CacheIndexEntryAutoManage(const SHA1Sum::Hash *aHash, CacheIndex *aIndex)
+    : mIndex(aIndex)
+    , mOldRecord(nullptr)
+    , mOldFrecency(0)
+    , mDoNotSearchInIndex(false)
+    , mDoNotSearchInUpdates(false)
+  {
+    CacheIndex::sLock.AssertCurrentThreadOwns();
+
+    mHash = aHash;
+    const CacheIndexEntry *entry = FindEntry();
+    mIndex->mIndexStats.BeforeChange(entry);
+    if (entry && entry->IsInitialized() && !entry->IsRemoved()) {
+      mOldRecord = entry->mRec;
+      mOldFrecency = entry->mRec->mFrecency;
+    }
+  }
+
+  ~CacheIndexEntryAutoManage()
+  {
+    CacheIndex::sLock.AssertCurrentThreadOwns();
+
+    const CacheIndexEntry *entry = FindEntry();
+    mIndex->mIndexStats.AfterChange(entry);
+    if (!entry || !entry->IsInitialized() || entry->IsRemoved()) {
+      entry = nullptr;
+    }
+
+    if (entry && !mOldRecord) {
+      mIndex->mFrecencyArray.AppendRecord(entry->mRec);
+      mIndex->AddRecordToIterators(entry->mRec);
+    } else if (!entry && mOldRecord) {
+      mIndex->mFrecencyArray.RemoveRecord(mOldRecord);
+      mIndex->RemoveRecordFromIterators(mOldRecord);
+    } else if (entry && mOldRecord) {
+      if (entry->mRec != mOldRecord) {
+        // record has a different address, we have to replace it
+        mIndex->ReplaceRecordInIterators(mOldRecord, entry->mRec);
+
+        if (entry->mRec->mFrecency == mOldFrecency) {
+          // If frecency hasn't changed simply replace the pointer
+          mIndex->mFrecencyArray.ReplaceRecord(mOldRecord, entry->mRec);
+        } else {
+          // Remove old pointer and insert the new one at the end of the array
+          mIndex->mFrecencyArray.RemoveRecord(mOldRecord);
+          mIndex->mFrecencyArray.AppendRecord(entry->mRec);
+        }
+      } else if (entry->mRec->mFrecency != mOldFrecency) {
+        // Move the element at the end of the array
+        mIndex->mFrecencyArray.RemoveRecord(entry->mRec);
+        mIndex->mFrecencyArray.AppendRecord(entry->mRec);
+      }
+    } else {
+      // both entries were removed or not initialized, do nothing
+    }
+  }
+
+  // We cannot rely on nsTHashtable::GetEntry() in case we are removing entries
+  // while iterating. Destructor is called before the entry is removed. Caller
+  // must call one of following methods to skip lookup in the hashtable.
+  void DoNotSearchInIndex()   { mDoNotSearchInIndex = true; }
+  void DoNotSearchInUpdates() { mDoNotSearchInUpdates = true; }
+
+private:
+  const CacheIndexEntry * FindEntry()
+  {
+    const CacheIndexEntry *entry = nullptr;
+
+    switch (mIndex->mState) {
+      case CacheIndex::READING:
+      case CacheIndex::WRITING:
+        if (!mDoNotSearchInUpdates) {
+          entry = mIndex->mPendingUpdates.GetEntry(*mHash);
+        }
+        MOZ_FALLTHROUGH;
+      case CacheIndex::BUILDING:
+      case CacheIndex::UPDATING:
+      case CacheIndex::READY:
+        if (!entry && !mDoNotSearchInIndex) {
+          entry = mIndex->mIndex.GetEntry(*mHash);
+        }
+        break;
+      case CacheIndex::INITIAL:
+      case CacheIndex::SHUTDOWN:
+      default:
+        MOZ_ASSERT(false, "Unexpected state!");
+    }
+
+    return entry;
+  }
+
+  const SHA1Sum::Hash *mHash;
+  RefPtr<CacheIndex> mIndex;
+  CacheIndexRecord    *mOldRecord;
+  uint32_t             mOldFrecency;
+  bool                 mDoNotSearchInIndex;
+  bool                 mDoNotSearchInUpdates;
+};
+
+class FileOpenHelper : public CacheFileIOListener
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  explicit FileOpenHelper(CacheIndex* aIndex)
+    : mIndex(aIndex)
+    , mCanceled(false)
+  {}
+
+  void Cancel() {
+    CacheIndex::sLock.AssertCurrentThreadOwns();
+    mCanceled = true;
+  }
+
+private:
+  virtual ~FileOpenHelper() {}
+
+  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                           nsresult aResult) override {
+    MOZ_CRASH("FileOpenHelper::OnDataWritten should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf,
+                        nsresult aResult) override {
+    MOZ_CRASH("FileOpenHelper::OnDataRead should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) override {
+    MOZ_CRASH("FileOpenHelper::OnFileDoomed should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) override {
+    MOZ_CRASH("FileOpenHelper::OnEOFSet should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) override {
+    MOZ_CRASH("FileOpenHelper::OnFileRenamed should not be called!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  RefPtr<CacheIndex> mIndex;
+  bool                 mCanceled;
+};
+
+NS_IMETHODIMP FileOpenHelper::OnFileOpened(CacheFileHandle *aHandle,
+                                           nsresult aResult)
+{
+  StaticMutexAutoLock lock(CacheIndex::sLock);
+
+  if (mCanceled) {
+    if (aHandle) {
+      CacheFileIOManager::DoomFile(aHandle, nullptr);
+    }
+
+    return NS_OK;
+  }
+
+  mIndex->OnFileOpenedInternal(this, aHandle, aResult);
+
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(FileOpenHelper, CacheFileIOListener);
+
+
+StaticRefPtr<CacheIndex> CacheIndex::gInstance;
+StaticMutex  CacheIndex::sLock;
+
+
+NS_IMPL_ADDREF(CacheIndex)
+NS_IMPL_RELEASE(CacheIndex)
+
+NS_INTERFACE_MAP_BEGIN(CacheIndex)
+  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileIOListener)
+  NS_INTERFACE_MAP_ENTRY(nsIRunnable)
+NS_INTERFACE_MAP_END_THREADSAFE
+
+
+CacheIndex::CacheIndex()
+  : mState(INITIAL)
+  , mShuttingDown(false)
+  , mIndexNeedsUpdate(false)
+  , mRemovingAll(false)
+  , mIndexOnDiskIsValid(false)
+  , mDontMarkIndexClean(false)
+  , mIndexTimeStamp(0)
+  , mUpdateEventPending(false)
+  , mSkipEntries(0)
+  , mProcessEntries(0)
+  , mRWBuf(nullptr)
+  , mRWBufSize(0)
+  , mRWBufPos(0)
+  , mRWPending(false)
+  , mJournalReadSuccessfully(false)
+  , mAsyncGetDiskConsumptionBlocked(false)
+{
+  sLock.AssertCurrentThreadOwns();
+  LOG(("CacheIndex::CacheIndex [this=%p]", this));
+  MOZ_COUNT_CTOR(CacheIndex);
+  MOZ_ASSERT(!gInstance, "multiple CacheIndex instances!");
+}
+
+CacheIndex::~CacheIndex()
+{
+  sLock.AssertCurrentThreadOwns();
+  LOG(("CacheIndex::~CacheIndex [this=%p]", this));
+  MOZ_COUNT_DTOR(CacheIndex);
+
+  ReleaseBuffer();
+}
+
+// static
+nsresult
+CacheIndex::Init(nsIFile *aCacheDirectory)
+{
+  LOG(("CacheIndex::Init()"));
+
+  MOZ_ASSERT(NS_IsMainThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  if (gInstance) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+  RefPtr<CacheIndex> idx = new CacheIndex();
+
+  nsresult rv = idx->InitInternal(aCacheDirectory);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  gInstance = idx.forget();
+  return NS_OK;
+}
+
+nsresult
+CacheIndex::InitInternal(nsIFile *aCacheDirectory)
+{
+  nsresult rv;
+
+  rv = aCacheDirectory->Clone(getter_AddRefs(mCacheDirectory));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mStartTime = TimeStamp::NowLoRes();
+
+  ReadIndexFromDisk();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::PreShutdown()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  LOG(("CacheIndex::PreShutdown() [gInstance=%p]", gInstance.get()));
+
+  nsresult rv;
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  LOG(("CacheIndex::PreShutdown() - [state=%d, indexOnDiskIsValid=%d, "
+       "dontMarkIndexClean=%d]", index->mState, index->mIndexOnDiskIsValid,
+       index->mDontMarkIndexClean));
+
+  LOG(("CacheIndex::PreShutdown() - Closing iterators."));
+  for (uint32_t i = 0; i < index->mIterators.Length(); ) {
+    rv = index->mIterators[i]->CloseInternal(NS_ERROR_FAILURE);
+    if (NS_FAILED(rv)) {
+      // CacheIndexIterator::CloseInternal() removes itself from mIteratos iff
+      // it returns success.
+      LOG(("CacheIndex::PreShutdown() - Failed to remove iterator %p. "
+           "[rv=0x%08x]", rv));
+      i++;
+    }
+  }
+
+  index->mShuttingDown = true;
+
+  if (index->mState == READY) {
+    return NS_OK; // nothing to do
+  }
+
+  nsCOMPtr<nsIRunnable> event;
+  event = NewRunnableMethod(index, &CacheIndex::PreShutdownInternal);
+
+  nsCOMPtr<nsIEventTarget> ioTarget = CacheFileIOManager::IOTarget();
+  MOZ_ASSERT(ioTarget);
+
+  // PreShutdownInternal() will be executed before any queued event on INDEX
+  // level. That's OK since we don't want to wait for any operation in progess.
+  rv = ioTarget->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("CacheIndex::PreShutdown() - Can't dispatch event");
+    LOG(("CacheIndex::PreShutdown() - Can't dispatch event" ));
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+void
+CacheIndex::PreShutdownInternal()
+{
+  StaticMutexAutoLock lock(sLock);
+
+  LOG(("CacheIndex::PreShutdownInternal() - [state=%d, indexOnDiskIsValid=%d, "
+       "dontMarkIndexClean=%d]", mState, mIndexOnDiskIsValid,
+       mDontMarkIndexClean));
+
+  MOZ_ASSERT(mShuttingDown);
+
+  if (mUpdateTimer) {
+    mUpdateTimer = nullptr;
+  }
+
+  switch (mState) {
+    case WRITING:
+      FinishWrite(false);
+      break;
+    case READY:
+      // nothing to do, write the journal in Shutdown()
+      break;
+    case READING:
+      FinishRead(false);
+      break;
+    case BUILDING:
+    case UPDATING:
+      FinishUpdate(false);
+      break;
+    default:
+      MOZ_ASSERT(false, "Implement me!");
+  }
+
+  // We should end up in READY state
+  MOZ_ASSERT(mState == READY);
+}
+
+// static
+nsresult
+CacheIndex::Shutdown()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  LOG(("CacheIndex::Shutdown() [gInstance=%p]", gInstance.get()));
+
+  RefPtr<CacheIndex> index = gInstance.forget();
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  bool sanitize = CacheObserver::ClearCacheOnShutdown();
+
+  LOG(("CacheIndex::Shutdown() - [state=%d, indexOnDiskIsValid=%d, "
+       "dontMarkIndexClean=%d, sanitize=%d]", index->mState,
+       index->mIndexOnDiskIsValid, index->mDontMarkIndexClean, sanitize));
+
+  MOZ_ASSERT(index->mShuttingDown);
+
+  EState oldState = index->mState;
+  index->ChangeState(SHUTDOWN);
+
+  if (oldState != READY) {
+    LOG(("CacheIndex::Shutdown() - Unexpected state. Did posting of "
+         "PreShutdownInternal() fail?"));
+  }
+
+  switch (oldState) {
+    case WRITING:
+      index->FinishWrite(false);
+      MOZ_FALLTHROUGH;
+    case READY:
+      if (index->mIndexOnDiskIsValid && !index->mDontMarkIndexClean) {
+        if (!sanitize && NS_FAILED(index->WriteLogToDisk())) {
+          index->RemoveJournalAndTempFile();
+        }
+      } else {
+        index->RemoveJournalAndTempFile();
+      }
+      break;
+    case READING:
+      index->FinishRead(false);
+      break;
+    case BUILDING:
+    case UPDATING:
+      index->FinishUpdate(false);
+      break;
+    default:
+      MOZ_ASSERT(false, "Unexpected state!");
+  }
+
+  if (sanitize) {
+    index->RemoveAllIndexFiles();
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::AddEntry(const SHA1Sum::Hash *aHash)
+{
+  LOG(("CacheIndex::AddEntry() [hash=%08x%08x%08x%08x%08x]", LOGSHA1(aHash)));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Getters in CacheIndexStats assert when mStateLogged is true since the
+  // information is incomplete between calls to BeforeChange() and AfterChange()
+  // (i.e. while CacheIndexEntryAutoManage exists). We need to check whether
+  // non-fresh entries exists outside the scope of CacheIndexEntryAutoManage.
+  bool updateIfNonFreshEntriesExist = false;
+
+  {
+    CacheIndexEntryAutoManage entryMng(aHash, index);
+
+    CacheIndexEntry *entry = index->mIndex.GetEntry(*aHash);
+    bool entryRemoved = entry && entry->IsRemoved();
+    CacheIndexEntryUpdate *updated = nullptr;
+
+    if (index->mState == READY || index->mState == UPDATING ||
+        index->mState == BUILDING) {
+      MOZ_ASSERT(index->mPendingUpdates.Count() == 0);
+
+      if (entry && !entryRemoved) {
+        // Found entry in index that shouldn't exist.
+
+        if (entry->IsFresh()) {
+          // Someone removed the file on disk while FF is running. Update
+          // process can fix only non-fresh entries (i.e. entries that were not
+          // added within this session). Start update only if we have such
+          // entries.
+          //
+          // TODO: This should be very rare problem. If it turns out not to be
+          // true, change the update process so that it also iterates all
+          // initialized non-empty entries and checks whether the file exists.
+
+          LOG(("CacheIndex::AddEntry() - Cache file was removed outside FF "
+               "process!"));
+
+          updateIfNonFreshEntriesExist = true;
+        } else if (index->mState == READY) {
+          // Index is outdated, update it.
+          LOG(("CacheIndex::AddEntry() - Found entry that shouldn't exist, "
+               "update is needed"));
+          index->mIndexNeedsUpdate = true;
+        } else {
+          // We cannot be here when building index since all entries are fresh
+          // during building.
+          MOZ_ASSERT(index->mState == UPDATING);
+        }
+      }
+
+      if (!entry) {
+        entry = index->mIndex.PutEntry(*aHash);
+      }
+    } else { // WRITING, READING
+      updated = index->mPendingUpdates.GetEntry(*aHash);
+      bool updatedRemoved = updated && updated->IsRemoved();
+
+      if ((updated && !updatedRemoved) ||
+          (!updated && entry && !entryRemoved && entry->IsFresh())) {
+        // Fresh entry found, so the file was removed outside FF
+        LOG(("CacheIndex::AddEntry() - Cache file was removed outside FF "
+             "process!"));
+
+        updateIfNonFreshEntriesExist = true;
+      } else if (!updated && entry && !entryRemoved) {
+        if (index->mState == WRITING) {
+          LOG(("CacheIndex::AddEntry() - Found entry that shouldn't exist, "
+               "update is needed"));
+          index->mIndexNeedsUpdate = true;
+        }
+        // Ignore if state is READING since the index information is partial
+      }
+
+      updated = index->mPendingUpdates.PutEntry(*aHash);
+    }
+
+    if (updated) {
+      updated->InitNew();
+      updated->MarkDirty();
+      updated->MarkFresh();
+    } else {
+      entry->InitNew();
+      entry->MarkDirty();
+      entry->MarkFresh();
+    }
+  }
+
+  if (updateIfNonFreshEntriesExist &&
+      index->mIndexStats.Count() != index->mIndexStats.Fresh()) {
+    index->mIndexNeedsUpdate = true;
+  }
+
+  index->StartUpdatingIndexIfNeeded();
+  index->WriteIndexToDiskIfNeeded();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::EnsureEntryExists(const SHA1Sum::Hash *aHash)
+{
+  LOG(("CacheIndex::EnsureEntryExists() [hash=%08x%08x%08x%08x%08x]",
+       LOGSHA1(aHash)));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  {
+    CacheIndexEntryAutoManage entryMng(aHash, index);
+
+    CacheIndexEntry *entry = index->mIndex.GetEntry(*aHash);
+    bool entryRemoved = entry && entry->IsRemoved();
+
+    if (index->mState == READY || index->mState == UPDATING ||
+        index->mState == BUILDING) {
+      MOZ_ASSERT(index->mPendingUpdates.Count() == 0);
+
+      if (!entry || entryRemoved) {
+        if (entryRemoved && entry->IsFresh()) {
+          // This could happen only if somebody copies files to the entries
+          // directory while FF is running.
+          LOG(("CacheIndex::EnsureEntryExists() - Cache file was added outside "
+               "FF process! Update is needed."));
+          index->mIndexNeedsUpdate = true;
+        } else if (index->mState == READY ||
+                   (entryRemoved && !entry->IsFresh())) {
+          // Removed non-fresh entries can be present as a result of
+          // MergeJournal()
+          LOG(("CacheIndex::EnsureEntryExists() - Didn't find entry that should"
+               " exist, update is needed"));
+          index->mIndexNeedsUpdate = true;
+        }
+
+        if (!entry) {
+          entry = index->mIndex.PutEntry(*aHash);
+        }
+        entry->InitNew();
+        entry->MarkDirty();
+      }
+      entry->MarkFresh();
+    } else { // WRITING, READING
+      CacheIndexEntryUpdate *updated = index->mPendingUpdates.GetEntry(*aHash);
+      bool updatedRemoved = updated && updated->IsRemoved();
+
+      if (updatedRemoved ||
+          (!updated && entryRemoved && entry->IsFresh())) {
+        // Fresh information about missing entry found. This could happen only
+        // if somebody copies files to the entries directory while FF is running.
+        LOG(("CacheIndex::EnsureEntryExists() - Cache file was added outside "
+             "FF process! Update is needed."));
+        index->mIndexNeedsUpdate = true;
+      } else if (!updated && (!entry || entryRemoved)) {
+        if (index->mState == WRITING) {
+          LOG(("CacheIndex::EnsureEntryExists() - Didn't find entry that should"
+               " exist, update is needed"));
+          index->mIndexNeedsUpdate = true;
+        }
+        // Ignore if state is READING since the index information is partial
+      }
+
+      // We don't need entryRemoved and updatedRemoved info anymore
+      if (entryRemoved)   entry = nullptr;
+      if (updatedRemoved) updated = nullptr;
+
+      if (updated) {
+        updated->MarkFresh();
+      } else {
+        if (!entry) {
+          // Create a new entry
+          updated = index->mPendingUpdates.PutEntry(*aHash);
+          updated->InitNew();
+          updated->MarkFresh();
+          updated->MarkDirty();
+        } else {
+          if (!entry->IsFresh()) {
+            // To mark the entry fresh we must make a copy of index entry
+            // since the index is read-only.
+            updated = index->mPendingUpdates.PutEntry(*aHash);
+            *updated = *entry;
+            updated->MarkFresh();
+          }
+        }
+      }
+    }
+  }
+
+  index->StartUpdatingIndexIfNeeded();
+  index->WriteIndexToDiskIfNeeded();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::InitEntry(const SHA1Sum::Hash *aHash,
+                      OriginAttrsHash      aOriginAttrsHash,
+                      bool                 aAnonymous,
+                      bool                 aPinned)
+{
+  LOG(("CacheIndex::InitEntry() [hash=%08x%08x%08x%08x%08x, "
+       "originAttrsHash=%llx, anonymous=%d, pinned=%d]", LOGSHA1(aHash),
+       aOriginAttrsHash, aAnonymous, aPinned));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  {
+    CacheIndexEntryAutoManage entryMng(aHash, index);
+
+    CacheIndexEntry *entry = index->mIndex.GetEntry(*aHash);
+    CacheIndexEntryUpdate *updated = nullptr;
+    bool reinitEntry = false;
+
+    if (entry && entry->IsRemoved()) {
+      entry = nullptr;
+    }
+
+    if (index->mState == READY || index->mState == UPDATING ||
+        index->mState == BUILDING) {
+      MOZ_ASSERT(index->mPendingUpdates.Count() == 0);
+      MOZ_ASSERT(entry);
+      MOZ_ASSERT(entry->IsFresh());
+
+      if (IsCollision(entry, aOriginAttrsHash, aAnonymous)) {
+        index->mIndexNeedsUpdate = true; // TODO Does this really help in case of collision?
+        reinitEntry = true;
+      } else {
+        if (entry->IsInitialized()) {
+          return NS_OK;
+        }
+      }
+    } else {
+      updated = index->mPendingUpdates.GetEntry(*aHash);
+      DebugOnly<bool> removed = updated && updated->IsRemoved();
+
+      MOZ_ASSERT(updated || !removed);
+      MOZ_ASSERT(updated || entry);
+
+      if (updated) {
+        MOZ_ASSERT(updated->IsFresh());
+
+        if (IsCollision(updated, aOriginAttrsHash, aAnonymous)) {
+          index->mIndexNeedsUpdate = true;
+          reinitEntry = true;
+        } else {
+          if (updated->IsInitialized()) {
+            return NS_OK;
+          }
+        }
+      } else {
+        MOZ_ASSERT(entry->IsFresh());
+
+        if (IsCollision(entry, aOriginAttrsHash, aAnonymous)) {
+          index->mIndexNeedsUpdate = true;
+          reinitEntry = true;
+        } else {
+          if (entry->IsInitialized()) {
+            return NS_OK;
+          }
+        }
+
+        // make a copy of a read-only entry
+        updated = index->mPendingUpdates.PutEntry(*aHash);
+        *updated = *entry;
+      }
+    }
+
+    if (reinitEntry) {
+      // There is a collision and we are going to rewrite this entry. Initialize
+      // it as a new entry.
+      if (updated) {
+        updated->InitNew();
+        updated->MarkFresh();
+      } else {
+        entry->InitNew();
+        entry->MarkFresh();
+      }
+    }
+
+    if (updated) {
+      updated->Init(aOriginAttrsHash, aAnonymous, aPinned);
+      updated->MarkDirty();
+    } else {
+      entry->Init(aOriginAttrsHash, aAnonymous, aPinned);
+      entry->MarkDirty();
+    }
+  }
+
+  index->StartUpdatingIndexIfNeeded();
+  index->WriteIndexToDiskIfNeeded();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::RemoveEntry(const SHA1Sum::Hash *aHash)
+{
+  LOG(("CacheIndex::RemoveEntry() [hash=%08x%08x%08x%08x%08x]",
+       LOGSHA1(aHash)));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  {
+    CacheIndexEntryAutoManage entryMng(aHash, index);
+
+    CacheIndexEntry *entry = index->mIndex.GetEntry(*aHash);
+    bool entryRemoved = entry && entry->IsRemoved();
+
+    if (index->mState == READY || index->mState == UPDATING ||
+        index->mState == BUILDING) {
+      MOZ_ASSERT(index->mPendingUpdates.Count() == 0);
+
+      if (!entry || entryRemoved) {
+        if (entryRemoved && entry->IsFresh()) {
+          // This could happen only if somebody copies files to the entries
+          // directory while FF is running.
+          LOG(("CacheIndex::RemoveEntry() - Cache file was added outside FF "
+               "process! Update is needed."));
+          index->mIndexNeedsUpdate = true;
+        } else if (index->mState == READY ||
+                   (entryRemoved && !entry->IsFresh())) {
+          // Removed non-fresh entries can be present as a result of
+          // MergeJournal()
+          LOG(("CacheIndex::RemoveEntry() - Didn't find entry that should exist"
+               ", update is needed"));
+          index->mIndexNeedsUpdate = true;
+        }
+      } else {
+        if (entry) {
+          if (!entry->IsDirty() && entry->IsFileEmpty()) {
+            index->mIndex.RemoveEntry(entry);
+            entry = nullptr;
+          } else {
+            entry->MarkRemoved();
+            entry->MarkDirty();
+            entry->MarkFresh();
+          }
+        }
+      }
+    } else { // WRITING, READING
+      CacheIndexEntryUpdate *updated = index->mPendingUpdates.GetEntry(*aHash);
+      bool updatedRemoved = updated && updated->IsRemoved();
+
+      if (updatedRemoved ||
+          (!updated && entryRemoved && entry->IsFresh())) {
+        // Fresh information about missing entry found. This could happen only
+        // if somebody copies files to the entries directory while FF is running.
+        LOG(("CacheIndex::RemoveEntry() - Cache file was added outside FF "
+             "process! Update is needed."));
+        index->mIndexNeedsUpdate = true;
+      } else if (!updated && (!entry || entryRemoved)) {
+        if (index->mState == WRITING) {
+          LOG(("CacheIndex::RemoveEntry() - Didn't find entry that should exist"
+               ", update is needed"));
+          index->mIndexNeedsUpdate = true;
+        }
+        // Ignore if state is READING since the index information is partial
+      }
+
+      if (!updated) {
+        updated = index->mPendingUpdates.PutEntry(*aHash);
+        updated->InitNew();
+      }
+
+      updated->MarkRemoved();
+      updated->MarkDirty();
+      updated->MarkFresh();
+    }
+  }
+
+  index->StartUpdatingIndexIfNeeded();
+  index->WriteIndexToDiskIfNeeded();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::UpdateEntry(const SHA1Sum::Hash *aHash,
+                        const uint32_t      *aFrecency,
+                        const uint32_t      *aExpirationTime,
+                        const uint32_t      *aSize)
+{
+  LOG(("CacheIndex::UpdateEntry() [hash=%08x%08x%08x%08x%08x, "
+       "frecency=%s, expirationTime=%s, size=%s]", LOGSHA1(aHash),
+       aFrecency ? nsPrintfCString("%u", *aFrecency).get() : "",
+       aExpirationTime ? nsPrintfCString("%u", *aExpirationTime).get() : "",
+       aSize ? nsPrintfCString("%u", *aSize).get() : ""));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  {
+    CacheIndexEntryAutoManage entryMng(aHash, index);
+
+    CacheIndexEntry *entry = index->mIndex.GetEntry(*aHash);
+
+    if (entry && entry->IsRemoved()) {
+      entry = nullptr;
+    }
+
+    if (index->mState == READY || index->mState == UPDATING ||
+        index->mState == BUILDING) {
+      MOZ_ASSERT(index->mPendingUpdates.Count() == 0);
+      MOZ_ASSERT(entry);
+
+      if (!HasEntryChanged(entry, aFrecency, aExpirationTime, aSize)) {
+        return NS_OK;
+      }
+
+      MOZ_ASSERT(entry->IsFresh());
+      MOZ_ASSERT(entry->IsInitialized());
+      entry->MarkDirty();
+
+      if (aFrecency) {
+        entry->SetFrecency(*aFrecency);
+      }
+
+      if (aExpirationTime) {
+        entry->SetExpirationTime(*aExpirationTime);
+      }
+
+      if (aSize) {
+        entry->SetFileSize(*aSize);
+      }
+    } else {
+      CacheIndexEntryUpdate *updated = index->mPendingUpdates.GetEntry(*aHash);
+      DebugOnly<bool> removed = updated && updated->IsRemoved();
+
+      MOZ_ASSERT(updated || !removed);
+      MOZ_ASSERT(updated || entry);
+
+      if (!updated) {
+        if (!entry) {
+          LOG(("CacheIndex::UpdateEntry() - Entry was found neither in mIndex "
+               "nor in mPendingUpdates!"));
+          NS_WARNING(("CacheIndex::UpdateEntry() - Entry was found neither in "
+                      "mIndex nor in mPendingUpdates!"));
+          return NS_ERROR_NOT_AVAILABLE;
+        }
+
+        // make a copy of a read-only entry
+        updated = index->mPendingUpdates.PutEntry(*aHash);
+        *updated = *entry;
+      }
+
+      MOZ_ASSERT(updated->IsFresh());
+      MOZ_ASSERT(updated->IsInitialized());
+      updated->MarkDirty();
+
+      if (aFrecency) {
+        updated->SetFrecency(*aFrecency);
+      }
+
+      if (aExpirationTime) {
+        updated->SetExpirationTime(*aExpirationTime);
+      }
+
+      if (aSize) {
+        updated->SetFileSize(*aSize);
+      }
+    }
+  }
+
+  index->WriteIndexToDiskIfNeeded();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::RemoveAll()
+{
+  LOG(("CacheIndex::RemoveAll()"));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsCOMPtr<nsIFile> file;
+
+  {
+    StaticMutexAutoLock lock(sLock);
+
+    RefPtr<CacheIndex> index = gInstance;
+
+    if (!index) {
+      return NS_ERROR_NOT_INITIALIZED;
+    }
+
+    MOZ_ASSERT(!index->mRemovingAll);
+
+    if (!index->IsIndexUsable()) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    AutoRestore<bool> saveRemovingAll(index->mRemovingAll);
+    index->mRemovingAll = true;
+
+    // Doom index and journal handles but don't null them out since this will be
+    // done in FinishWrite/FinishRead methods.
+    if (index->mIndexHandle) {
+      CacheFileIOManager::DoomFile(index->mIndexHandle, nullptr);
+    } else {
+      // We don't have a handle to index file, so get the file here, but delete
+      // it outside the lock. Ignore the result since this is not fatal.
+      index->GetFile(NS_LITERAL_CSTRING(INDEX_NAME), getter_AddRefs(file));
+    }
+
+    if (index->mJournalHandle) {
+      CacheFileIOManager::DoomFile(index->mJournalHandle, nullptr);
+    }
+
+    switch (index->mState) {
+      case WRITING:
+        index->FinishWrite(false);
+        break;
+      case READY:
+        // nothing to do
+        break;
+      case READING:
+        index->FinishRead(false);
+        break;
+      case BUILDING:
+      case UPDATING:
+        index->FinishUpdate(false);
+        break;
+      default:
+        MOZ_ASSERT(false, "Unexpected state!");
+    }
+
+    // We should end up in READY state
+    MOZ_ASSERT(index->mState == READY);
+
+    // There should not be any handle
+    MOZ_ASSERT(!index->mIndexHandle);
+    MOZ_ASSERT(!index->mJournalHandle);
+
+    index->mIndexOnDiskIsValid = false;
+    index->mIndexNeedsUpdate = false;
+
+    index->mIndexStats.Clear();
+    index->mFrecencyArray.Clear();
+    index->mIndex.Clear();
+
+    for (uint32_t i = 0; i < index->mIterators.Length(); ) {
+      nsresult rv = index->mIterators[i]->CloseInternal(NS_ERROR_NOT_AVAILABLE);
+      if (NS_FAILED(rv)) {
+        // CacheIndexIterator::CloseInternal() removes itself from mIterators
+        // iff it returns success.
+        LOG(("CacheIndex::RemoveAll() - Failed to remove iterator %p. "
+             "[rv=0x%08x]", rv));
+        i++;
+      }
+    }
+  }
+
+  if (file) {
+    // Ignore the result. The file might not exist and the failure is not fatal.
+    file->Remove(false);
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::HasEntry(const nsACString &aKey, EntryStatus *_retval, bool *_pinned)
+{
+  LOG(("CacheIndex::HasEntry() [key=%s]", PromiseFlatCString(aKey).get()));
+
+  SHA1Sum sum;
+  SHA1Sum::Hash hash;
+  sum.update(aKey.BeginReading(), aKey.Length());
+  sum.finish(hash);
+
+  return HasEntry(hash, _retval, _pinned);
+}
+
+// static
+nsresult
+CacheIndex::HasEntry(const SHA1Sum::Hash &hash, EntryStatus *_retval, bool *_pinned)
+{
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (_pinned) {
+    *_pinned = false;
+  }
+
+  const CacheIndexEntry *entry = nullptr;
+
+  switch (index->mState) {
+    case READING:
+    case WRITING:
+      entry = index->mPendingUpdates.GetEntry(hash);
+      MOZ_FALLTHROUGH;
+    case BUILDING:
+    case UPDATING:
+    case READY:
+      if (!entry) {
+        entry = index->mIndex.GetEntry(hash);
+      }
+      break;
+    case INITIAL:
+    case SHUTDOWN:
+      MOZ_ASSERT(false, "Unexpected state!");
+  }
+
+  if (!entry) {
+    if (index->mState == READY || index->mState == WRITING) {
+      *_retval = DOES_NOT_EXIST;
+    } else {
+      *_retval = DO_NOT_KNOW;
+    }
+  } else {
+    if (entry->IsRemoved()) {
+      if (entry->IsFresh()) {
+        *_retval = DOES_NOT_EXIST;
+      } else {
+        *_retval = DO_NOT_KNOW;
+      }
+    } else {
+      *_retval = EXISTS;
+      if (_pinned && entry->IsPinned()) {
+        *_pinned = true;
+      }
+    }
+  }
+
+  LOG(("CacheIndex::HasEntry() - result is %u", *_retval));
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::GetEntryForEviction(bool aIgnoreEmptyEntries, SHA1Sum::Hash *aHash, uint32_t *aCnt)
+{
+  LOG(("CacheIndex::GetEntryForEviction()"));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index)
+    return NS_ERROR_NOT_INITIALIZED;
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  SHA1Sum::Hash hash;
+  CacheIndexRecord *foundRecord = nullptr;
+  uint32_t skipped = 0;
+
+  // find first non-forced valid and unpinned entry with the lowest frecency
+  index->mFrecencyArray.SortIfNeeded();
+
+  for (auto iter = index->mFrecencyArray.Iter(); !iter.Done(); iter.Next()) {
+    CacheIndexRecord *rec = iter.Get();
+
+    memcpy(&hash, rec->mHash, sizeof(SHA1Sum::Hash));
+
+    ++skipped;
+
+    if (IsForcedValidEntry(&hash)) {
+      continue;
+    }
+
+    if (CacheIndexEntry::IsPinned(rec)) {
+      continue;
+    }
+
+    if (aIgnoreEmptyEntries && !CacheIndexEntry::GetFileSize(rec)) {
+      continue;
+    }
+
+    --skipped;
+    foundRecord = rec;
+    break;
+  }
+
+  if (!foundRecord)
+    return NS_ERROR_NOT_AVAILABLE;
+
+  *aCnt = skipped;
+
+  LOG(("CacheIndex::GetEntryForEviction() - returning entry from frecency "
+        "array [hash=%08x%08x%08x%08x%08x, cnt=%u, frecency=%u]",
+        LOGSHA1(&hash), *aCnt, foundRecord->mFrecency));
+
+  memcpy(aHash, &hash, sizeof(SHA1Sum::Hash));
+
+  return NS_OK;
+}
+
+
+// static
+bool CacheIndex::IsForcedValidEntry(const SHA1Sum::Hash *aHash)
+{
+  RefPtr<CacheFileHandle> handle;
+
+  CacheFileIOManager::gInstance->mHandles.GetHandle(
+    aHash, getter_AddRefs(handle));
+
+  if (!handle)
+    return false;
+
+  nsCString hashKey = handle->Key();
+  return CacheStorageService::Self()->IsForcedValidEntry(hashKey);
+}
+
+
+// static
+nsresult
+CacheIndex::GetCacheSize(uint32_t *_retval)
+{
+  LOG(("CacheIndex::GetCacheSize()"));
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index)
+    return NS_ERROR_NOT_INITIALIZED;
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  *_retval = index->mIndexStats.Size();
+  LOG(("CacheIndex::GetCacheSize() - returning %u", *_retval));
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::GetEntryFileCount(uint32_t *_retval)
+{
+  LOG(("CacheIndex::GetEntryFileCount()"));
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  *_retval = index->mIndexStats.ActiveEntriesCount();
+  LOG(("CacheIndex::GetEntryFileCount() - returning %u", *_retval));
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::GetCacheStats(nsILoadContextInfo *aInfo, uint32_t *aSize, uint32_t *aCount)
+{
+  LOG(("CacheIndex::GetCacheStats() [info=%p]", aInfo));
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (!aInfo) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  *aSize = 0;
+  *aCount = 0;
+
+  for (auto iter = index->mFrecencyArray.Iter(); !iter.Done(); iter.Next()) {
+    CacheIndexRecord *record = iter.Get();
+    if (!CacheIndexEntry::RecordMatchesLoadContextInfo(record, aInfo))
+      continue;
+
+    *aSize += CacheIndexEntry::GetFileSize(record);
+    ++*aCount;
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::AsyncGetDiskConsumption(nsICacheStorageConsumptionObserver* aObserver)
+{
+  LOG(("CacheIndex::AsyncGetDiskConsumption()"));
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  RefPtr<DiskConsumptionObserver> observer =
+    DiskConsumptionObserver::Init(aObserver);
+
+  NS_ENSURE_ARG(observer);
+
+  if ((index->mState == READY || index->mState == WRITING) &&
+      !index->mAsyncGetDiskConsumptionBlocked) {
+    LOG(("CacheIndex::AsyncGetDiskConsumption - calling immediately"));
+    // Safe to call the callback under the lock,
+    // we always post to the main thread.
+    observer->OnDiskConsumption(index->mIndexStats.Size() << 10);
+    return NS_OK;
+  }
+
+  LOG(("CacheIndex::AsyncGetDiskConsumption - remembering callback"));
+  // Will be called when the index get to the READY state.
+  index->mDiskConsumptionObservers.AppendElement(observer);
+
+  // Move forward with index re/building if it is pending
+  RefPtr<CacheIOThread> ioThread = CacheFileIOManager::IOThread();
+  if (ioThread) {
+    ioThread->Dispatch(NS_NewRunnableFunction([]() -> void {
+      StaticMutexAutoLock lock(sLock);
+
+      RefPtr<CacheIndex> index = gInstance;
+      if (index && index->mUpdateTimer) {
+        index->mUpdateTimer->Cancel();
+        index->DelayedUpdateLocked();
+      }
+    }), CacheIOThread::INDEX);
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::GetIterator(nsILoadContextInfo *aInfo, bool aAddNew,
+                        CacheIndexIterator **_retval)
+{
+  LOG(("CacheIndex::GetIterator() [info=%p, addNew=%d]", aInfo, aAddNew));
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  RefPtr<CacheIndexIterator> idxIter;
+  if (aInfo) {
+    idxIter = new CacheIndexContextIterator(index, aAddNew, aInfo);
+  } else {
+    idxIter = new CacheIndexIterator(index, aAddNew);
+  }
+
+  index->mFrecencyArray.SortIfNeeded();
+
+  for (auto iter = index->mFrecencyArray.Iter(); !iter.Done(); iter.Next()) {
+    idxIter->AddRecord(iter.Get());
+  }
+
+  index->mIterators.AppendElement(idxIter);
+  idxIter.swap(*_retval);
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheIndex::IsUpToDate(bool *_retval)
+{
+  LOG(("CacheIndex::IsUpToDate()"));
+
+  StaticMutexAutoLock lock(sLock);
+
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!index->IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  *_retval = (index->mState == READY || index->mState == WRITING) &&
+             !index->mIndexNeedsUpdate && !index->mShuttingDown;
+
+  LOG(("CacheIndex::IsUpToDate() - returning %p", *_retval));
+  return NS_OK;
+}
+
+bool
+CacheIndex::IsIndexUsable()
+{
+  MOZ_ASSERT(mState != INITIAL);
+
+  switch (mState) {
+    case INITIAL:
+    case SHUTDOWN:
+      return false;
+
+    case READING:
+    case WRITING:
+    case BUILDING:
+    case UPDATING:
+    case READY:
+      break;
+  }
+
+  return true;
+}
+
+// static
+bool
+CacheIndex::IsCollision(CacheIndexEntry *aEntry,
+                        OriginAttrsHash  aOriginAttrsHash,
+                        bool             aAnonymous)
+{
+  if (!aEntry->IsInitialized()) {
+    return false;
+  }
+
+  if (aEntry->Anonymous() != aAnonymous ||
+      aEntry->OriginAttrsHash() != aOriginAttrsHash) {
+    LOG(("CacheIndex::IsCollision() - Collision detected for entry hash=%08x"
+         "%08x%08x%08x%08x, expected values: originAttrsHash=%llx, "
+         "anonymous=%d; actual values: originAttrsHash=%llx, anonymous=%d]",
+         LOGSHA1(aEntry->Hash()), aOriginAttrsHash, aAnonymous,
+         aEntry->OriginAttrsHash(), aEntry->Anonymous()));
+    return true;
+  }
+
+  return false;
+}
+
+// static
+bool
+CacheIndex::HasEntryChanged(CacheIndexEntry *aEntry,
+                            const uint32_t  *aFrecency,
+                            const uint32_t  *aExpirationTime,
+                            const uint32_t  *aSize)
+{
+  if (aFrecency && *aFrecency != aEntry->GetFrecency()) {
+    return true;
+  }
+
+  if (aExpirationTime && *aExpirationTime != aEntry->GetExpirationTime()) {
+    return true;
+  }
+
+  if (aSize &&
+      (*aSize & CacheIndexEntry::kFileSizeMask) != aEntry->GetFileSize()) {
+    return true;
+  }
+
+  return false;
+}
+
+void
+CacheIndex::ProcessPendingOperations()
+{
+  LOG(("CacheIndex::ProcessPendingOperations()"));
+
+  sLock.AssertCurrentThreadOwns();
+
+  for (auto iter = mPendingUpdates.Iter(); !iter.Done(); iter.Next()) {
+    CacheIndexEntryUpdate* update = iter.Get();
+
+    LOG(("CacheIndex::ProcessPendingOperations() [hash=%08x%08x%08x%08x%08x]",
+         LOGSHA1(update->Hash())));
+
+    MOZ_ASSERT(update->IsFresh());
+
+    CacheIndexEntry* entry = mIndex.GetEntry(*update->Hash());
+
+    {
+      CacheIndexEntryAutoManage emng(update->Hash(), this);
+      emng.DoNotSearchInUpdates();
+
+      if (update->IsRemoved()) {
+        if (entry) {
+          if (entry->IsRemoved()) {
+            MOZ_ASSERT(entry->IsFresh());
+            MOZ_ASSERT(entry->IsDirty());
+          } else if (!entry->IsDirty() && entry->IsFileEmpty()) {
+            // Entries with empty file are not stored in index on disk. Just
+            // remove the entry, but only in case the entry is not dirty, i.e.
+            // the entry file was empty when we wrote the index.
+            mIndex.RemoveEntry(*update->Hash());
+            entry = nullptr;
+          } else {
+            entry->MarkRemoved();
+            entry->MarkDirty();
+            entry->MarkFresh();
+          }
+        }
+      } else if (entry) {
+        // Some information in mIndex can be newer than in mPendingUpdates (see
+        // bug 1074832). This will copy just those values that were really
+        // updated.
+        update->ApplyUpdate(entry);
+      } else {
+        // There is no entry in mIndex, copy all information from
+        // mPendingUpdates to mIndex.
+        entry = mIndex.PutEntry(*update->Hash());
+        *entry = *update;
+      }
+    }
+
+    iter.Remove();
+  }
+
+  MOZ_ASSERT(mPendingUpdates.Count() == 0);
+
+  EnsureCorrectStats();
+}
+
+bool
+CacheIndex::WriteIndexToDiskIfNeeded()
+{
+  if (mState != READY || mShuttingDown || mRWPending) {
+    return false;
+  }
+
+  if (!mLastDumpTime.IsNull() &&
+      (TimeStamp::NowLoRes() - mLastDumpTime).ToMilliseconds() <
+      kMinDumpInterval) {
+    return false;
+  }
+
+  if (mIndexStats.Dirty() < kMinUnwrittenChanges) {
+    return false;
+  }
+
+  WriteIndexToDisk();
+  return true;
+}
+
+void
+CacheIndex::WriteIndexToDisk()
+{
+  LOG(("CacheIndex::WriteIndexToDisk()"));
+  mIndexStats.Log();
+
+  nsresult rv;
+
+  sLock.AssertCurrentThreadOwns();
+  MOZ_ASSERT(mState == READY);
+  MOZ_ASSERT(!mRWBuf);
+  MOZ_ASSERT(!mRWHash);
+  MOZ_ASSERT(!mRWPending);
+
+  ChangeState(WRITING);
+
+  mProcessEntries = mIndexStats.ActiveEntriesCount();
+
+  mIndexFileOpener = new FileOpenHelper(this);
+  rv = CacheFileIOManager::OpenFile(NS_LITERAL_CSTRING(TEMP_INDEX_NAME),
+                                    CacheFileIOManager::SPECIAL_FILE |
+                                    CacheFileIOManager::CREATE,
+                                    mIndexFileOpener);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheIndex::WriteIndexToDisk() - Can't open file [rv=0x%08x]", rv));
+    FinishWrite(false);
+    return;
+  }
+
+  // Write index header to a buffer, it will be written to disk together with
+  // records in WriteRecords() once we open the file successfully.
+  AllocBuffer();
+  mRWHash = new CacheHash();
+
+  mRWBufPos = 0;
+  // index version
+  NetworkEndian::writeUint32(mRWBuf + mRWBufPos, kIndexVersion);
+  mRWBufPos += sizeof(uint32_t);
+  // timestamp
+  NetworkEndian::writeUint32(mRWBuf + mRWBufPos,
+                             static_cast<uint32_t>(PR_Now() / PR_USEC_PER_SEC));
+  mRWBufPos += sizeof(uint32_t);
+  // dirty flag
+  NetworkEndian::writeUint32(mRWBuf + mRWBufPos, 1);
+  mRWBufPos += sizeof(uint32_t);
+
+  mSkipEntries = 0;
+}
+
+void
+CacheIndex::WriteRecords()
+{
+  LOG(("CacheIndex::WriteRecords()"));
+
+  nsresult rv;
+
+  sLock.AssertCurrentThreadOwns();
+  MOZ_ASSERT(mState == WRITING);
+  MOZ_ASSERT(!mRWPending);
+
+  int64_t fileOffset;
+
+  if (mSkipEntries) {
+    MOZ_ASSERT(mRWBufPos == 0);
+    fileOffset = sizeof(CacheIndexHeader);
+    fileOffset += sizeof(CacheIndexRecord) * mSkipEntries;
+  } else {
+    MOZ_ASSERT(mRWBufPos == sizeof(CacheIndexHeader));
+    fileOffset = 0;
+  }
+  uint32_t hashOffset = mRWBufPos;
+
+  char* buf = mRWBuf + mRWBufPos;
+  uint32_t skip = mSkipEntries;
+  uint32_t processMax = (mRWBufSize - mRWBufPos) / sizeof(CacheIndexRecord);
+  MOZ_ASSERT(processMax != 0 || mProcessEntries == 0); // TODO make sure we can write an empty index
+  uint32_t processed = 0;
+#ifdef DEBUG
+  bool hasMore = false;
+#endif
+  for (auto iter = mIndex.Iter(); !iter.Done(); iter.Next()) {
+    CacheIndexEntry* entry = iter.Get();
+    if (entry->IsRemoved() ||
+        !entry->IsInitialized() ||
+        entry->IsFileEmpty()) {
+      continue;
+    }
+
+    if (skip) {
+      skip--;
+      continue;
+    }
+
+    if (processed == processMax) {
+  #ifdef DEBUG
+      hasMore = true;
+  #endif
+      break;
+    }
+
+    entry->WriteToBuf(buf);
+    buf += sizeof(CacheIndexRecord);
+    processed++;
+  }
+
+  MOZ_ASSERT(mRWBufPos != static_cast<uint32_t>(buf - mRWBuf) ||
+             mProcessEntries == 0);
+  mRWBufPos = buf - mRWBuf;
+  mSkipEntries += processed;
+  MOZ_ASSERT(mSkipEntries <= mProcessEntries);
+
+  mRWHash->Update(mRWBuf + hashOffset, mRWBufPos - hashOffset);
+
+  if (mSkipEntries == mProcessEntries) {
+    MOZ_ASSERT(!hasMore);
+
+    // We've processed all records
+    if (mRWBufPos + sizeof(CacheHash::Hash32_t) > mRWBufSize) {
+      // realloc buffer to spare another write cycle
+      mRWBufSize = mRWBufPos + sizeof(CacheHash::Hash32_t);
+      mRWBuf = static_cast<char *>(moz_xrealloc(mRWBuf, mRWBufSize));
+    }
+
+    NetworkEndian::writeUint32(mRWBuf + mRWBufPos, mRWHash->GetHash());
+    mRWBufPos += sizeof(CacheHash::Hash32_t);
+  } else {
+    MOZ_ASSERT(hasMore);
+  }
+
+  rv = CacheFileIOManager::Write(mIndexHandle, fileOffset, mRWBuf, mRWBufPos,
+                                 mSkipEntries == mProcessEntries, false, this);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheIndex::WriteRecords() - CacheFileIOManager::Write() failed "
+         "synchronously [rv=0x%08x]", rv));
+    FinishWrite(false);
+  } else {
+    mRWPending = true;
+  }
+
+  mRWBufPos = 0;
+}
+
+void
+CacheIndex::FinishWrite(bool aSucceeded)
+{
+  LOG(("CacheIndex::FinishWrite() [succeeded=%d]", aSucceeded));
+
+  MOZ_ASSERT((!aSucceeded && mState == SHUTDOWN) || mState == WRITING);
+
+  sLock.AssertCurrentThreadOwns();
+
+  // If there is write operation pending we must be cancelling writing of the
+  // index when shutting down or removing the whole index.
+  MOZ_ASSERT(!mRWPending || (!aSucceeded && (mShuttingDown || mRemovingAll)));
+
+  mIndexHandle = nullptr;
+  mRWHash = nullptr;
+  ReleaseBuffer();
+
+  if (aSucceeded) {
+    // Opening of the file must not be in progress if writing succeeded.
+    MOZ_ASSERT(!mIndexFileOpener);
+
+    for (auto iter = mIndex.Iter(); !iter.Done(); iter.Next()) {
+      CacheIndexEntry* entry = iter.Get();
+
+      bool remove = false;
+      {
+        CacheIndexEntryAutoManage emng(entry->Hash(), this);
+
+        if (entry->IsRemoved()) {
+          emng.DoNotSearchInIndex();
+          remove = true;
+        } else if (entry->IsDirty()) {
+          entry->ClearDirty();
+        }
+      }
+      if (remove) {
+        iter.Remove();
+      }
+    }
+
+    mIndexOnDiskIsValid = true;
+  } else {
+    if (mIndexFileOpener) {
+      // If opening of the file is still in progress (e.g. WRITE process was
+      // canceled by RemoveAll()) then we need to cancel the opener to make sure
+      // that OnFileOpenedInternal() won't be called.
+      mIndexFileOpener->Cancel();
+      mIndexFileOpener = nullptr;
+    }
+  }
+
+  ProcessPendingOperations();
+  mIndexStats.Log();
+
+  if (mState == WRITING) {
+    ChangeState(READY);
+    mLastDumpTime = TimeStamp::NowLoRes();
+  }
+}
+
+nsresult
+CacheIndex::GetFile(const nsACString &aName, nsIFile **_retval)
+{
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(aName);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  file.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheIndex::RemoveFile(const nsACString &aName)
+{
+  MOZ_ASSERT(mState == SHUTDOWN);
+
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> file;
+  rv = GetFile(aName, getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool exists;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (exists) {
+    rv = file->Remove(false);
+    if (NS_FAILED(rv)) {
+      LOG(("CacheIndex::RemoveFile() - Cannot remove old entry file from disk."
+           "[name=%s]", PromiseFlatCString(aName).get()));
+      NS_WARNING("Cannot remove old entry file from the disk");
+      return rv;
+    }
+  }
+
+  return NS_OK;
+}
+
+void
+CacheIndex::RemoveAllIndexFiles()
+{
+  LOG(("CacheIndex::RemoveAllIndexFiles()"));
+  RemoveFile(NS_LITERAL_CSTRING(INDEX_NAME));
+  RemoveJournalAndTempFile();
+}
+
+void
+CacheIndex::RemoveJournalAndTempFile()
+{
+  LOG(("CacheIndex::RemoveJournalAndTempFile()"));
+  RemoveFile(NS_LITERAL_CSTRING(TEMP_INDEX_NAME));
+  RemoveFile(NS_LITERAL_CSTRING(JOURNAL_NAME));
+}
+
+class WriteLogHelper
+{
+public:
+  explicit WriteLogHelper(PRFileDesc *aFD)
+    : mFD(aFD)
+    , mBufSize(kMaxBufSize)
+    , mBufPos(0)
+  {
+    mHash = new CacheHash();
+    mBuf = static_cast<char *>(moz_xmalloc(mBufSize));
+  }
+
+  ~WriteLogHelper() {
+    free(mBuf);
+  }
+
+  nsresult AddEntry(CacheIndexEntry *aEntry);
+  nsresult Finish();
+
+private:
+
+  nsresult FlushBuffer();
+
+  PRFileDesc       *mFD;
+  char             *mBuf;
+  uint32_t          mBufSize;
+  int32_t           mBufPos;
+  RefPtr<CacheHash> mHash;
+};
+
+nsresult
+WriteLogHelper::AddEntry(CacheIndexEntry *aEntry)
+{
+  nsresult rv;
+
+  if (mBufPos + sizeof(CacheIndexRecord) > mBufSize) {
+    mHash->Update(mBuf, mBufPos);
+
+    rv = FlushBuffer();
+    NS_ENSURE_SUCCESS(rv, rv);
+    MOZ_ASSERT(mBufPos + sizeof(CacheIndexRecord) <= mBufSize);
+  }
+
+  aEntry->WriteToBuf(mBuf + mBufPos);
+  mBufPos += sizeof(CacheIndexRecord);
+
+  return NS_OK;
+}
+
+nsresult
+WriteLogHelper::Finish()
+{
+  nsresult rv;
+
+  mHash->Update(mBuf, mBufPos);
+  if (mBufPos + sizeof(CacheHash::Hash32_t) > mBufSize) {
+    rv = FlushBuffer();
+    NS_ENSURE_SUCCESS(rv, rv);
+    MOZ_ASSERT(mBufPos + sizeof(CacheHash::Hash32_t) <= mBufSize);
+  }
+
+  NetworkEndian::writeUint32(mBuf + mBufPos, mHash->GetHash());
+  mBufPos += sizeof(CacheHash::Hash32_t);
+
+  rv = FlushBuffer();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+WriteLogHelper::FlushBuffer()
+{
+  if (CacheObserver::IsPastShutdownIOLag()) {
+    LOG(("WriteLogHelper::FlushBuffer() - Interrupting writing journal."));
+    return NS_ERROR_FAILURE;
+  }
+
+  int32_t bytesWritten = PR_Write(mFD, mBuf, mBufPos);
+
+  if (bytesWritten != mBufPos) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mBufPos = 0;
+  return NS_OK;
+}
+
+nsresult
+CacheIndex::WriteLogToDisk()
+{
+  LOG(("CacheIndex::WriteLogToDisk()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mPendingUpdates.Count() == 0);
+  MOZ_ASSERT(mState == SHUTDOWN);
+
+  if (CacheObserver::IsPastShutdownIOLag()) {
+    LOG(("CacheIndex::WriteLogToDisk() - Skipping writing journal."));
+    return NS_ERROR_FAILURE;
+  }
+
+  RemoveFile(NS_LITERAL_CSTRING(TEMP_INDEX_NAME));
+
+  nsCOMPtr<nsIFile> indexFile;
+  rv = GetFile(NS_LITERAL_CSTRING(INDEX_NAME), getter_AddRefs(indexFile));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIFile> logFile;
+  rv = GetFile(NS_LITERAL_CSTRING(JOURNAL_NAME), getter_AddRefs(logFile));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mIndexStats.Log();
+
+  PRFileDesc *fd = nullptr;
+  rv = logFile->OpenNSPRFileDesc(PR_RDWR | PR_CREATE_FILE | PR_TRUNCATE,
+                                 0600, &fd);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  WriteLogHelper wlh(fd);
+  for (auto iter = mIndex.Iter(); !iter.Done(); iter.Next()) {
+    CacheIndexEntry* entry = iter.Get();
+    if (entry->IsRemoved() || entry->IsDirty()) {
+      rv = wlh.AddEntry(entry);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
+  }
+
+  rv = wlh.Finish();
+  PR_Close(fd);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = indexFile->OpenNSPRFileDesc(PR_RDWR, 0600, &fd);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Seek to dirty flag in the index header and clear it.
+  static_assert(2 * sizeof(uint32_t) == offsetof(CacheIndexHeader, mIsDirty),
+                "Unexpected offset of CacheIndexHeader::mIsDirty");
+  int64_t offset = PR_Seek64(fd, 2 * sizeof(uint32_t), PR_SEEK_SET);
+  if (offset == -1) {
+    PR_Close(fd);
+    return NS_ERROR_FAILURE;
+  }
+
+  uint32_t isDirty = 0;
+  int32_t bytesWritten = PR_Write(fd, &isDirty, sizeof(isDirty));
+  PR_Close(fd);
+  if (bytesWritten != sizeof(isDirty)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+void
+CacheIndex::ReadIndexFromDisk()
+{
+  LOG(("CacheIndex::ReadIndexFromDisk()"));
+
+  nsresult rv;
+
+  sLock.AssertCurrentThreadOwns();
+  MOZ_ASSERT(mState == INITIAL);
+
+  ChangeState(READING);
+
+  mIndexFileOpener = new FileOpenHelper(this);
+  rv = CacheFileIOManager::OpenFile(NS_LITERAL_CSTRING(INDEX_NAME),
+                                    CacheFileIOManager::SPECIAL_FILE |
+                                    CacheFileIOManager::OPEN,
+                                    mIndexFileOpener);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheIndex::ReadIndexFromDisk() - CacheFileIOManager::OpenFile() "
+         "failed [rv=0x%08x, file=%s]", rv, INDEX_NAME));
+    FinishRead(false);
+    return;
+  }
+
+  mJournalFileOpener = new FileOpenHelper(this);
+  rv = CacheFileIOManager::OpenFile(NS_LITERAL_CSTRING(JOURNAL_NAME),
+                                    CacheFileIOManager::SPECIAL_FILE |
+                                    CacheFileIOManager::OPEN,
+                                    mJournalFileOpener);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheIndex::ReadIndexFromDisk() - CacheFileIOManager::OpenFile() "
+         "failed [rv=0x%08x, file=%s]", rv, JOURNAL_NAME));
+    FinishRead(false);
+  }
+
+  mTmpFileOpener = new FileOpenHelper(this);
+  rv = CacheFileIOManager::OpenFile(NS_LITERAL_CSTRING(TEMP_INDEX_NAME),
+                                    CacheFileIOManager::SPECIAL_FILE |
+                                    CacheFileIOManager::OPEN,
+                                    mTmpFileOpener);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheIndex::ReadIndexFromDisk() - CacheFileIOManager::OpenFile() "
+         "failed [rv=0x%08x, file=%s]", rv, TEMP_INDEX_NAME));
+    FinishRead(false);
+  }
+}
+
+void
+CacheIndex::StartReadingIndex()
+{
+  LOG(("CacheIndex::StartReadingIndex()"));
+
+  nsresult rv;
+
+  sLock.AssertCurrentThreadOwns();
+
+  MOZ_ASSERT(mIndexHandle);
+  MOZ_ASSERT(mState == READING);
+  MOZ_ASSERT(!mIndexOnDiskIsValid);
+  MOZ_ASSERT(!mDontMarkIndexClean);
+  MOZ_ASSERT(!mJournalReadSuccessfully);
+  MOZ_ASSERT(mIndexHandle->FileSize() >= 0);
+  MOZ_ASSERT(!mRWPending);
+
+  int64_t entriesSize = mIndexHandle->FileSize() - sizeof(CacheIndexHeader) -
+                        sizeof(CacheHash::Hash32_t);
+
+  if (entriesSize < 0 || entriesSize % sizeof(CacheIndexRecord)) {
+    LOG(("CacheIndex::StartReadingIndex() - Index is corrupted"));
+    FinishRead(false);
+    return;
+  }
+
+  AllocBuffer();
+  mSkipEntries = 0;
+  mRWHash = new CacheHash();
+
+  mRWBufPos = std::min(mRWBufSize,
+                       static_cast<uint32_t>(mIndexHandle->FileSize()));
+
+  rv = CacheFileIOManager::Read(mIndexHandle, 0, mRWBuf, mRWBufPos, this);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheIndex::StartReadingIndex() - CacheFileIOManager::Read() failed "
+         "synchronously [rv=0x%08x]", rv));
+    FinishRead(false);
+  } else {
+    mRWPending = true;
+  }
+}
+
+void
+CacheIndex::ParseRecords()
+{
+  LOG(("CacheIndex::ParseRecords()"));
+
+  nsresult rv;
+
+  sLock.AssertCurrentThreadOwns();
+
+  MOZ_ASSERT(!mRWPending);
+
+  uint32_t entryCnt = (mIndexHandle->FileSize() - sizeof(CacheIndexHeader) -
+                     sizeof(CacheHash::Hash32_t)) / sizeof(CacheIndexRecord);
+  uint32_t pos = 0;
+
+  if (!mSkipEntries) {
+    if (NetworkEndian::readUint32(mRWBuf + pos) != kIndexVersion) {
+      FinishRead(false);
+      return;
+    }
+    pos += sizeof(uint32_t);
+
+    mIndexTimeStamp = NetworkEndian::readUint32(mRWBuf + pos);
+    pos += sizeof(uint32_t);
+
+    if (NetworkEndian::readUint32(mRWBuf + pos)) {
+      if (mJournalHandle) {
+        CacheFileIOManager::DoomFile(mJournalHandle, nullptr);
+        mJournalHandle = nullptr;
+      }
+    } else {
+      uint32_t * isDirty = reinterpret_cast<uint32_t *>(
+                             moz_xmalloc(sizeof(uint32_t)));
+      NetworkEndian::writeUint32(isDirty, 1);
+
+      // Mark index dirty. The buffer is freed by CacheFileIOManager when
+      // nullptr is passed as the listener and the call doesn't fail
+      // synchronously.
+      rv = CacheFileIOManager::Write(mIndexHandle, 2 * sizeof(uint32_t),
+                                     reinterpret_cast<char *>(isDirty),
+                                     sizeof(uint32_t), true, false, nullptr);
+      if (NS_FAILED(rv)) {
+        // This is not fatal, just free the memory
+        free(isDirty);
+      }
+    }
+    pos += sizeof(uint32_t);
+  }
+
+  uint32_t hashOffset = pos;
+
+  while (pos + sizeof(CacheIndexRecord) <= mRWBufPos &&
+         mSkipEntries != entryCnt) {
+    CacheIndexRecord *rec = reinterpret_cast<CacheIndexRecord *>(mRWBuf + pos);
+    CacheIndexEntry tmpEntry(&rec->mHash);
+    tmpEntry.ReadFromBuf(mRWBuf + pos);
+
+    if (tmpEntry.IsDirty() || !tmpEntry.IsInitialized() ||
+        tmpEntry.IsFileEmpty() || tmpEntry.IsFresh() || tmpEntry.IsRemoved()) {
+      LOG(("CacheIndex::ParseRecords() - Invalid entry found in index, removing"
+           " whole index [dirty=%d, initialized=%d, fileEmpty=%d, fresh=%d, "
+           "removed=%d]", tmpEntry.IsDirty(), tmpEntry.IsInitialized(),
+           tmpEntry.IsFileEmpty(), tmpEntry.IsFresh(), tmpEntry.IsRemoved()));
+      FinishRead(false);
+      return;
+    }
+
+    CacheIndexEntryAutoManage emng(tmpEntry.Hash(), this);
+
+    CacheIndexEntry *entry = mIndex.PutEntry(*tmpEntry.Hash());
+    *entry = tmpEntry;
+
+    pos += sizeof(CacheIndexRecord);
+    mSkipEntries++;
+  }
+
+  mRWHash->Update(mRWBuf + hashOffset, pos - hashOffset);
+
+  if (pos != mRWBufPos) {
+    memmove(mRWBuf, mRWBuf + pos, mRWBufPos - pos);
+  }
+
+  mRWBufPos -= pos;
+  pos = 0;
+
+  int64_t fileOffset = sizeof(CacheIndexHeader) +
+                       mSkipEntries * sizeof(CacheIndexRecord) + mRWBufPos;
+
+  MOZ_ASSERT(fileOffset <= mIndexHandle->FileSize());
+  if (fileOffset == mIndexHandle->FileSize()) {
+    uint32_t expectedHash = NetworkEndian::readUint32(mRWBuf);
+    if (mRWHash->GetHash() != expectedHash) {
+      LOG(("CacheIndex::ParseRecords() - Hash mismatch, [is %x, should be %x]",
+           mRWHash->GetHash(), expectedHash));
+      FinishRead(false);
+      return;
+    }
+
+    mIndexOnDiskIsValid = true;
+    mJournalReadSuccessfully = false;
+
+    if (mJournalHandle) {
+      StartReadingJournal();
+    } else {
+      FinishRead(false);
+    }
+
+    return;
+  }
+
+  pos = mRWBufPos;
+  uint32_t toRead = std::min(mRWBufSize - pos,
+                             static_cast<uint32_t>(mIndexHandle->FileSize() -
+                                                   fileOffset));
+  mRWBufPos = pos + toRead;
+
+  rv = CacheFileIOManager::Read(mIndexHandle, fileOffset, mRWBuf + pos, toRead,
+                                this);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheIndex::ParseRecords() - CacheFileIOManager::Read() failed "
+         "synchronously [rv=0x%08x]", rv));
+    FinishRead(false);
+    return;
+  } else {
+    mRWPending = true;
+  }
+}
+
+void
+CacheIndex::StartReadingJournal()
+{
+  LOG(("CacheIndex::StartReadingJournal()"));
+
+  nsresult rv;
+
+  sLock.AssertCurrentThreadOwns();
+
+  MOZ_ASSERT(mJournalHandle);
+  MOZ_ASSERT(mIndexOnDiskIsValid);
+  MOZ_ASSERT(mTmpJournal.Count() == 0);
+  MOZ_ASSERT(mJournalHandle->FileSize() >= 0);
+  MOZ_ASSERT(!mRWPending);
+
+  int64_t entriesSize = mJournalHandle->FileSize() -
+                        sizeof(CacheHash::Hash32_t);
+
+  if (entriesSize < 0 || entriesSize % sizeof(CacheIndexRecord)) {
+    LOG(("CacheIndex::StartReadingJournal() - Journal is corrupted"));
+    FinishRead(false);
+    return;
+  }
+
+  mSkipEntries = 0;
+  mRWHash = new CacheHash();
+
+  mRWBufPos = std::min(mRWBufSize,
+                       static_cast<uint32_t>(mJournalHandle->FileSize()));
+
+  rv = CacheFileIOManager::Read(mJournalHandle, 0, mRWBuf, mRWBufPos, this);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheIndex::StartReadingJournal() - CacheFileIOManager::Read() failed"
+         " synchronously [rv=0x%08x]", rv));
+    FinishRead(false);
+  } else {
+    mRWPending = true;
+  }
+}
+
+void
+CacheIndex::ParseJournal()
+{
+  LOG(("CacheIndex::ParseJournal()"));
+
+  nsresult rv;
+
+  sLock.AssertCurrentThreadOwns();
+
+  MOZ_ASSERT(!mRWPending);
+
+  uint32_t entryCnt = (mJournalHandle->FileSize() -
+                       sizeof(CacheHash::Hash32_t)) / sizeof(CacheIndexRecord);
+
+  uint32_t pos = 0;
+
+  while (pos + sizeof(CacheIndexRecord) <= mRWBufPos &&
+         mSkipEntries != entryCnt) {
+    CacheIndexEntry tmpEntry(reinterpret_cast<SHA1Sum::Hash *>(mRWBuf + pos));
+    tmpEntry.ReadFromBuf(mRWBuf + pos);
+
+    CacheIndexEntry *entry = mTmpJournal.PutEntry(*tmpEntry.Hash());
+    *entry = tmpEntry;
+
+    if (entry->IsDirty() || entry->IsFresh()) {
+      LOG(("CacheIndex::ParseJournal() - Invalid entry found in journal, "
+           "ignoring whole journal [dirty=%d, fresh=%d]", entry->IsDirty(),
+           entry->IsFresh()));
+      FinishRead(false);
+      return;
+    }
+
+    pos += sizeof(CacheIndexRecord);
+    mSkipEntries++;
+  }
+
+  mRWHash->Update(mRWBuf, pos);
+
+  if (pos != mRWBufPos) {
+    memmove(mRWBuf, mRWBuf + pos, mRWBufPos - pos);
+  }
+
+  mRWBufPos -= pos;
+  pos = 0;
+
+  int64_t fileOffset = mSkipEntries * sizeof(CacheIndexRecord) + mRWBufPos;
+
+  MOZ_ASSERT(fileOffset <= mJournalHandle->FileSize());
+  if (fileOffset == mJournalHandle->FileSize()) {
+    uint32_t expectedHash = NetworkEndian::readUint32(mRWBuf);
+    if (mRWHash->GetHash() != expectedHash) {
+      LOG(("CacheIndex::ParseJournal() - Hash mismatch, [is %x, should be %x]",
+           mRWHash->GetHash(), expectedHash));
+      FinishRead(false);
+      return;
+    }
+
+    mJournalReadSuccessfully = true;
+    FinishRead(true);
+    return;
+  }
+
+  pos = mRWBufPos;
+  uint32_t toRead = std::min(mRWBufSize - pos,
+                             static_cast<uint32_t>(mJournalHandle->FileSize() -
+                                                   fileOffset));
+  mRWBufPos = pos + toRead;
+
+  rv = CacheFileIOManager::Read(mJournalHandle, fileOffset, mRWBuf + pos,
+                                toRead, this);
+  if (NS_FAILED(rv)) {
+    LOG(("CacheIndex::ParseJournal() - CacheFileIOManager::Read() failed "
+         "synchronously [rv=0x%08x]", rv));
+    FinishRead(false);
+    return;
+  } else {
+    mRWPending = true;
+  }
+}
+
+void
+CacheIndex::MergeJournal()
+{
+  LOG(("CacheIndex::MergeJournal()"));
+
+  sLock.AssertCurrentThreadOwns();
+
+  for (auto iter = mTmpJournal.Iter(); !iter.Done(); iter.Next()) {
+    CacheIndexEntry* entry = iter.Get();
+
+    LOG(("CacheIndex::MergeJournal() [hash=%08x%08x%08x%08x%08x]",
+         LOGSHA1(entry->Hash())));
+
+    CacheIndexEntry* entry2 = mIndex.GetEntry(*entry->Hash());
+    {
+      CacheIndexEntryAutoManage emng(entry->Hash(), this);
+      if (entry->IsRemoved()) {
+        if (entry2) {
+          entry2->MarkRemoved();
+          entry2->MarkDirty();
+        }
+      } else {
+        if (!entry2) {
+          entry2 = mIndex.PutEntry(*entry->Hash());
+        }
+
+        *entry2 = *entry;
+        entry2->MarkDirty();
+      }
+    }
+    iter.Remove();
+  }
+
+  MOZ_ASSERT(mTmpJournal.Count() == 0);
+}
+
+void
+CacheIndex::EnsureNoFreshEntry()
+{
+#ifdef DEBUG_STATS
+  CacheIndexStats debugStats;
+  debugStats.DisableLogging();
+  for (auto iter = mIndex.Iter(); !iter.Done(); iter.Next()) {
+    debugStats.BeforeChange(nullptr);
+    debugStats.AfterChange(iter.Get());
+  }
+  MOZ_ASSERT(debugStats.Fresh() == 0);
+#endif
+}
+
+void
+CacheIndex::EnsureCorrectStats()
+{
+#ifdef DEBUG_STATS
+  MOZ_ASSERT(mPendingUpdates.Count() == 0);
+  CacheIndexStats debugStats;
+  debugStats.DisableLogging();
+  for (auto iter = mIndex.Iter(); !iter.Done(); iter.Next()) {
+    debugStats.BeforeChange(nullptr);
+    debugStats.AfterChange(iter.Get());
+  }
+  MOZ_ASSERT(debugStats == mIndexStats);
+#endif
+}
+
+void
+CacheIndex::FinishRead(bool aSucceeded)
+{
+  LOG(("CacheIndex::FinishRead() [succeeded=%d]", aSucceeded));
+  sLock.AssertCurrentThreadOwns();
+
+  MOZ_ASSERT((!aSucceeded && mState == SHUTDOWN) || mState == READING);
+
+  MOZ_ASSERT(
+    // -> rebuild
+    (!aSucceeded && !mIndexOnDiskIsValid && !mJournalReadSuccessfully) ||
+    // -> update
+    (!aSucceeded && mIndexOnDiskIsValid && !mJournalReadSuccessfully) ||
+    // -> ready
+    (aSucceeded && mIndexOnDiskIsValid && mJournalReadSuccessfully));
+
+  // If there is read operation pending we must be cancelling reading of the
+  // index when shutting down or removing the whole index.
+  MOZ_ASSERT(!mRWPending || (!aSucceeded && (mShuttingDown || mRemovingAll)));
+
+  if (mState == SHUTDOWN) {
+    RemoveFile(NS_LITERAL_CSTRING(TEMP_INDEX_NAME));
+    RemoveFile(NS_LITERAL_CSTRING(JOURNAL_NAME));
+  } else {
+    if (mIndexHandle && !mIndexOnDiskIsValid) {
+      CacheFileIOManager::DoomFile(mIndexHandle, nullptr);
+    }
+
+    if (mJournalHandle) {
+      CacheFileIOManager::DoomFile(mJournalHandle, nullptr);
+    }
+  }
+
+  if (mIndexFileOpener) {
+    mIndexFileOpener->Cancel();
+    mIndexFileOpener = nullptr;
+  }
+  if (mJournalFileOpener) {
+    mJournalFileOpener->Cancel();
+    mJournalFileOpener = nullptr;
+  }
+  if (mTmpFileOpener) {
+    mTmpFileOpener->Cancel();
+    mTmpFileOpener = nullptr;
+  }
+
+  mIndexHandle = nullptr;
+  mJournalHandle = nullptr;
+  mRWHash = nullptr;
+  ReleaseBuffer();
+
+  if (mState == SHUTDOWN) {
+    return;
+  }
+
+  if (!mIndexOnDiskIsValid) {
+    MOZ_ASSERT(mTmpJournal.Count() == 0);
+    EnsureNoFreshEntry();
+    ProcessPendingOperations();
+    // Remove all entries that we haven't seen during this session
+    RemoveNonFreshEntries();
+    StartUpdatingIndex(true);
+    return;
+  }
+
+  if (!mJournalReadSuccessfully) {
+    mTmpJournal.Clear();
+    EnsureNoFreshEntry();
+    ProcessPendingOperations();
+    StartUpdatingIndex(false);
+    return;
+  }
+
+  MergeJournal();
+  EnsureNoFreshEntry();
+  ProcessPendingOperations();
+  mIndexStats.Log();
+
+  ChangeState(READY);
+  mLastDumpTime = TimeStamp::NowLoRes(); // Do not dump new index immediately
+}
+
+// static
+void
+CacheIndex::DelayedUpdate(nsITimer *aTimer, void *aClosure)
+{
+  LOG(("CacheIndex::DelayedUpdate()"));
+
+  StaticMutexAutoLock lock(sLock);
+  RefPtr<CacheIndex> index = gInstance;
+
+  if (!index) {
+    return;
+  }
+
+  index->DelayedUpdateLocked();
+}
+
+// static
+void
+CacheIndex::DelayedUpdateLocked()
+{
+  LOG(("CacheIndex::DelayedUpdateLocked()"));
+
+  sLock.AssertCurrentThreadOwns();
+
+  nsresult rv;
+
+  mUpdateTimer = nullptr;
+
+  if (!IsIndexUsable()) {
+    return;
+  }
+
+  if (mState == READY && mShuttingDown) {
+    return;
+  }
+
+  // mUpdateEventPending must be false here since StartUpdatingIndex() won't
+  // schedule timer if it is true.
+  MOZ_ASSERT(!mUpdateEventPending);
+  if (mState != BUILDING && mState != UPDATING) {
+    LOG(("CacheIndex::DelayedUpdateLocked() - Update was canceled"));
+    return;
+  }
+
+  // We need to redispatch to run with lower priority
+  RefPtr<CacheIOThread> ioThread = CacheFileIOManager::IOThread();
+  MOZ_ASSERT(ioThread);
+
+  mUpdateEventPending = true;
+  rv = ioThread->Dispatch(this, CacheIOThread::INDEX);
+  if (NS_FAILED(rv)) {
+    mUpdateEventPending = false;
+    NS_WARNING("CacheIndex::DelayedUpdateLocked() - Can't dispatch event");
+    LOG(("CacheIndex::DelayedUpdate() - Can't dispatch event" ));
+    FinishUpdate(false);
+  }
+}
+
+nsresult
+CacheIndex::ScheduleUpdateTimer(uint32_t aDelay)
+{
+  LOG(("CacheIndex::ScheduleUpdateTimer() [delay=%u]", aDelay));
+
+  MOZ_ASSERT(!mUpdateTimer);
+
+  nsresult rv;
+
+  nsCOMPtr<nsITimer> timer = do_CreateInstance("@mozilla.org/timer;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIEventTarget> ioTarget = CacheFileIOManager::IOTarget();
+  MOZ_ASSERT(ioTarget);
+
+  rv = timer->SetTarget(ioTarget);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = timer->InitWithFuncCallback(CacheIndex::DelayedUpdate, nullptr,
+                                   aDelay, nsITimer::TYPE_ONE_SHOT);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mUpdateTimer.swap(timer);
+  return NS_OK;
+}
+
+nsresult
+CacheIndex::SetupDirectoryEnumerator()
+{
+  MOZ_ASSERT(!NS_IsMainThread());
+  MOZ_ASSERT(!mDirEnumerator);
+
+  nsresult rv;
+  nsCOMPtr<nsIFile> file;
+
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(NS_LITERAL_CSTRING(ENTRIES_DIR));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool exists;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!exists) {
+    NS_WARNING("CacheIndex::SetupDirectoryEnumerator() - Entries directory "
+               "doesn't exist!");
+    LOG(("CacheIndex::SetupDirectoryEnumerator() - Entries directory doesn't "
+          "exist!" ));
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsCOMPtr<nsISimpleEnumerator> enumerator;
+  rv = file->GetDirectoryEntries(getter_AddRefs(enumerator));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mDirEnumerator = do_QueryInterface(enumerator, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+void
+CacheIndex::InitEntryFromDiskData(CacheIndexEntry *aEntry,
+                                  CacheFileMetadata *aMetaData,
+                                  int64_t aFileSize)
+{
+  aEntry->InitNew();
+  aEntry->MarkDirty();
+  aEntry->MarkFresh();
+
+  aEntry->Init(GetOriginAttrsHash(aMetaData->OriginAttributes()),
+               aMetaData->IsAnonymous(),
+               aMetaData->Pinned());
+
+  uint32_t expirationTime;
+  aMetaData->GetExpirationTime(&expirationTime);
+  aEntry->SetExpirationTime(expirationTime);
+
+  uint32_t frecency;
+  aMetaData->GetFrecency(&frecency);
+  aEntry->SetFrecency(frecency);
+
+  aEntry->SetFileSize(static_cast<uint32_t>(
+                        std::min(static_cast<int64_t>(PR_UINT32_MAX),
+                                 (aFileSize + 0x3FF) >> 10)));
+}
+
+bool
+CacheIndex::IsUpdatePending()
+{
+  sLock.AssertCurrentThreadOwns();
+
+  if (mUpdateTimer || mUpdateEventPending) {
+    return true;
+  }
+
+  return false;
+}
+
+void
+CacheIndex::BuildIndex()
+{
+  LOG(("CacheIndex::BuildIndex()"));
+
+  sLock.AssertCurrentThreadOwns();
+
+  MOZ_ASSERT(mPendingUpdates.Count() == 0);
+
+  nsresult rv;
+
+  if (!mDirEnumerator) {
+    {
+      // Do not do IO under the lock.
+      StaticMutexAutoUnlock unlock(sLock);
+      rv = SetupDirectoryEnumerator();
+    }
+    if (mState == SHUTDOWN) {
+      // The index was shut down while we released the lock. FinishUpdate() was
+      // already called from Shutdown(), so just simply return here.
+      return;
+    }
+
+    if (NS_FAILED(rv)) {
+      FinishUpdate(false);
+      return;
+    }
+  }
+
+  while (true) {
+    if (CacheIOThread::YieldAndRerun()) {
+      LOG(("CacheIndex::BuildIndex() - Breaking loop for higher level events."));
+      mUpdateEventPending = true;
+      return;
+    }
+
+    nsCOMPtr<nsIFile> file;
+    {
+      // Do not do IO under the lock.
+      StaticMutexAutoUnlock unlock(sLock);
+      rv = mDirEnumerator->GetNextFile(getter_AddRefs(file));
+    }
+    if (mState == SHUTDOWN) {
+      return;
+    }
+    if (!file) {
+      FinishUpdate(NS_SUCCEEDED(rv));
+      return;
+    }
+
+    nsAutoCString leaf;
+    rv = file->GetNativeLeafName(leaf);
+    if (NS_FAILED(rv)) {
+      LOG(("CacheIndex::BuildIndex() - GetNativeLeafName() failed! Skipping "
+           "file."));
+      mDontMarkIndexClean = true;
+      continue;
+    }
+
+    SHA1Sum::Hash hash;
+    rv = CacheFileIOManager::StrToHash(leaf, &hash);
+    if (NS_FAILED(rv)) {
+      LOG(("CacheIndex::BuildIndex() - Filename is not a hash, removing file. "
+           "[name=%s]", leaf.get()));
+      file->Remove(false);
+      continue;
+    }
+
+    CacheIndexEntry *entry = mIndex.GetEntry(hash);
+    if (entry && entry->IsRemoved()) {
+      LOG(("CacheIndex::BuildIndex() - Found file that should not exist. "
+           "[name=%s]", leaf.get()));
+      entry->Log();
+      MOZ_ASSERT(entry->IsFresh());
+      entry = nullptr;
+    }
+
+#ifdef DEBUG
+    RefPtr<CacheFileHandle> handle;
+    CacheFileIOManager::gInstance->mHandles.GetHandle(&hash,
+                                                      getter_AddRefs(handle));
+#endif
+
+    if (entry) {
+      // the entry is up to date
+      LOG(("CacheIndex::BuildIndex() - Skipping file because the entry is up to"
+           " date. [name=%s]", leaf.get()));
+      entry->Log();
+      MOZ_ASSERT(entry->IsFresh()); // The entry must be from this session
+      // there must be an active CacheFile if the entry is not initialized
+      MOZ_ASSERT(entry->IsInitialized() || handle);
+      continue;
+    }
+
+    MOZ_ASSERT(!handle);
+
+    RefPtr<CacheFileMetadata> meta = new CacheFileMetadata();
+    int64_t size = 0;
+
+    {
+      // Do not do IO under the lock.
+      StaticMutexAutoUnlock unlock(sLock);
+      rv = meta->SyncReadMetadata(file);
+
+      if (NS_SUCCEEDED(rv)) {
+        rv = file->GetFileSize(&size);
+        if (NS_FAILED(rv)) {
+          LOG(("CacheIndex::BuildIndex() - Cannot get filesize of file that was"
+               " successfully parsed. [name=%s]", leaf.get()));
+        }
+      }
+    }
+    if (mState == SHUTDOWN) {
+      return;
+    }
+
+    // Nobody could add the entry while the lock was released since we modify
+    // the index only on IO thread and this loop is executed on IO thread too.
+    entry = mIndex.GetEntry(hash);
+    MOZ_ASSERT(!entry || entry->IsRemoved());
+
+    if (NS_FAILED(rv)) {
+      LOG(("CacheIndex::BuildIndex() - CacheFileMetadata::SyncReadMetadata() "
+           "failed, removing file. [name=%s]", leaf.get()));
+      file->Remove(false);
+    } else {
+      CacheIndexEntryAutoManage entryMng(&hash, this);
+      entry = mIndex.PutEntry(hash);
+      InitEntryFromDiskData(entry, meta, size);
+      LOG(("CacheIndex::BuildIndex() - Added entry to index. [hash=%s]",
+           leaf.get()));
+      entry->Log();
+    }
+  }
+
+  NS_NOTREACHED("We should never get here");
+}
+
+bool
+CacheIndex::StartUpdatingIndexIfNeeded(bool aSwitchingToReadyState)
+{
+  // Start updating process when we are in or we are switching to READY state
+  // and index needs update, but not during shutdown or when removing all
+  // entries.
+  if ((mState == READY || aSwitchingToReadyState) && mIndexNeedsUpdate &&
+      !mShuttingDown && !mRemovingAll) {
+    LOG(("CacheIndex::StartUpdatingIndexIfNeeded() - starting update process"));
+    mIndexNeedsUpdate = false;
+    StartUpdatingIndex(false);
+    return true;
+  }
+
+  return false;
+}
+
+void
+CacheIndex::StartUpdatingIndex(bool aRebuild)
+{
+  LOG(("CacheIndex::StartUpdatingIndex() [rebuild=%d]", aRebuild));
+
+  sLock.AssertCurrentThreadOwns();
+
+  nsresult rv;
+
+  mIndexStats.Log();
+
+  ChangeState(aRebuild ? BUILDING : UPDATING);
+  mDontMarkIndexClean = false;
+
+  if (mShuttingDown || mRemovingAll) {
+    FinishUpdate(false);
+    return;
+  }
+
+  if (IsUpdatePending()) {
+    LOG(("CacheIndex::StartUpdatingIndex() - Update is already pending"));
+    return;
+  }
+
+  uint32_t elapsed = (TimeStamp::NowLoRes() - mStartTime).ToMilliseconds();
+  if (elapsed < kUpdateIndexStartDelay) {
+    LOG(("CacheIndex::StartUpdatingIndex() - %u ms elapsed since startup, "
+         "scheduling timer to fire in %u ms.", elapsed,
+         kUpdateIndexStartDelay - elapsed));
+    rv = ScheduleUpdateTimer(kUpdateIndexStartDelay - elapsed);
+    if (NS_SUCCEEDED(rv)) {
+      return;
+    }
+
+    LOG(("CacheIndex::StartUpdatingIndex() - ScheduleUpdateTimer() failed. "
+         "Starting update immediately."));
+  } else {
+    LOG(("CacheIndex::StartUpdatingIndex() - %u ms elapsed since startup, "
+         "starting update now.", elapsed));
+  }
+
+  RefPtr<CacheIOThread> ioThread = CacheFileIOManager::IOThread();
+  MOZ_ASSERT(ioThread);
+
+  // We need to dispatch an event even if we are on IO thread since we need to
+  // update the index with the correct priority.
+  mUpdateEventPending = true;
+  rv = ioThread->Dispatch(this, CacheIOThread::INDEX);
+  if (NS_FAILED(rv)) {
+    mUpdateEventPending = false;
+    NS_WARNING("CacheIndex::StartUpdatingIndex() - Can't dispatch event");
+    LOG(("CacheIndex::StartUpdatingIndex() - Can't dispatch event" ));
+    FinishUpdate(false);
+  }
+}
+
+void
+CacheIndex::UpdateIndex()
+{
+  LOG(("CacheIndex::UpdateIndex()"));
+
+  sLock.AssertCurrentThreadOwns();
+
+  MOZ_ASSERT(mPendingUpdates.Count() == 0);
+
+  nsresult rv;
+
+  if (!mDirEnumerator) {
+    {
+      // Do not do IO under the lock.
+      StaticMutexAutoUnlock unlock(sLock);
+      rv = SetupDirectoryEnumerator();
+    }
+    if (mState == SHUTDOWN) {
+      // The index was shut down while we released the lock. FinishUpdate() was
+      // already called from Shutdown(), so just simply return here.
+      return;
+    }
+
+    if (NS_FAILED(rv)) {
+      FinishUpdate(false);
+      return;
+    }
+  }
+
+  while (true) {
+    if (CacheIOThread::YieldAndRerun()) {
+      LOG(("CacheIndex::UpdateIndex() - Breaking loop for higher level "
+           "events."));
+      mUpdateEventPending = true;
+      return;
+    }
+
+    nsCOMPtr<nsIFile> file;
+    {
+      // Do not do IO under the lock.
+      StaticMutexAutoUnlock unlock(sLock);
+      rv = mDirEnumerator->GetNextFile(getter_AddRefs(file));
+    }
+    if (mState == SHUTDOWN) {
+      return;
+    }
+    if (!file) {
+      FinishUpdate(NS_SUCCEEDED(rv));
+      return;
+    }
+
+    nsAutoCString leaf;
+    rv = file->GetNativeLeafName(leaf);
+    if (NS_FAILED(rv)) {
+      LOG(("CacheIndex::UpdateIndex() - GetNativeLeafName() failed! Skipping "
+           "file."));
+      mDontMarkIndexClean = true;
+      continue;
+    }
+
+    SHA1Sum::Hash hash;
+    rv = CacheFileIOManager::StrToHash(leaf, &hash);
+    if (NS_FAILED(rv)) {
+      LOG(("CacheIndex::UpdateIndex() - Filename is not a hash, removing file. "
+           "[name=%s]", leaf.get()));
+      file->Remove(false);
+      continue;
+    }
+
+    CacheIndexEntry *entry = mIndex.GetEntry(hash);
+    if (entry && entry->IsRemoved()) {
+      if (entry->IsFresh()) {
+        LOG(("CacheIndex::UpdateIndex() - Found file that should not exist. "
+             "[name=%s]", leaf.get()));
+        entry->Log();
+      }
+      entry = nullptr;
+    }
+
+#ifdef DEBUG
+    RefPtr<CacheFileHandle> handle;
+    CacheFileIOManager::gInstance->mHandles.GetHandle(&hash,
+                                                      getter_AddRefs(handle));
+#endif
+
+    if (entry && entry->IsFresh()) {
+      // the entry is up to date
+      LOG(("CacheIndex::UpdateIndex() - Skipping file because the entry is up "
+           " to date. [name=%s]", leaf.get()));
+      entry->Log();
+      // there must be an active CacheFile if the entry is not initialized
+      MOZ_ASSERT(entry->IsInitialized() || handle);
+      continue;
+    }
+
+    MOZ_ASSERT(!handle);
+
+    if (entry) {
+      PRTime lastModifiedTime;
+      {
+        // Do not do IO under the lock.
+        StaticMutexAutoUnlock unlock(sLock);
+        rv = file->GetLastModifiedTime(&lastModifiedTime);
+      }
+      if (mState == SHUTDOWN) {
+        return;
+      }
+      if (NS_FAILED(rv)) {
+        LOG(("CacheIndex::UpdateIndex() - Cannot get lastModifiedTime. "
+             "[name=%s]", leaf.get()));
+        // Assume the file is newer than index
+      } else {
+        if (mIndexTimeStamp > (lastModifiedTime / PR_MSEC_PER_SEC)) {
+          LOG(("CacheIndex::UpdateIndex() - Skipping file because of last "
+               "modified time. [name=%s, indexTimeStamp=%u, "
+               "lastModifiedTime=%u]", leaf.get(), mIndexTimeStamp,
+               lastModifiedTime / PR_MSEC_PER_SEC));
+
+          CacheIndexEntryAutoManage entryMng(&hash, this);
+          entry->MarkFresh();
+          continue;
+        }
+      }
+    }
+
+    RefPtr<CacheFileMetadata> meta = new CacheFileMetadata();
+    int64_t size = 0;
+
+    {
+      // Do not do IO under the lock.
+      StaticMutexAutoUnlock unlock(sLock);
+      rv = meta->SyncReadMetadata(file);
+
+      if (NS_SUCCEEDED(rv)) {
+        rv = file->GetFileSize(&size);
+        if (NS_FAILED(rv)) {
+          LOG(("CacheIndex::UpdateIndex() - Cannot get filesize of file that "
+               "was successfully parsed. [name=%s]", leaf.get()));
+        }
+      }
+    }
+    if (mState == SHUTDOWN) {
+      return;
+    }
+
+    // Nobody could add the entry while the lock was released since we modify
+    // the index only on IO thread and this loop is executed on IO thread too.
+    entry = mIndex.GetEntry(hash);
+    MOZ_ASSERT(!entry || !entry->IsFresh());
+
+    CacheIndexEntryAutoManage entryMng(&hash, this);
+
+    if (NS_FAILED(rv)) {
+      LOG(("CacheIndex::UpdateIndex() - CacheFileMetadata::SyncReadMetadata() "
+           "failed, removing file. [name=%s]", leaf.get()));
+      file->Remove(false);
+      if (entry) {
+        entry->MarkRemoved();
+        entry->MarkFresh();
+        entry->MarkDirty();
+      }
+    } else {
+      entry = mIndex.PutEntry(hash);
+      InitEntryFromDiskData(entry, meta, size);
+      LOG(("CacheIndex::UpdateIndex() - Added/updated entry to/in index. "
+           "[hash=%s]", leaf.get()));
+      entry->Log();
+    }
+  }
+
+  NS_NOTREACHED("We should never get here");
+}
+
+void
+CacheIndex::FinishUpdate(bool aSucceeded)
+{
+  LOG(("CacheIndex::FinishUpdate() [succeeded=%d]", aSucceeded));
+
+  MOZ_ASSERT(mState == UPDATING || mState == BUILDING ||
+             (!aSucceeded && mState == SHUTDOWN));
+
+  sLock.AssertCurrentThreadOwns();
+
+  if (mDirEnumerator) {
+    if (NS_IsMainThread()) {
+      LOG(("CacheIndex::FinishUpdate() - posting of PreShutdownInternal failed?"
+           " Cannot safely release mDirEnumerator, leaking it!"));
+      NS_WARNING(("CacheIndex::FinishUpdate() - Leaking mDirEnumerator!"));
+      // This can happen only in case dispatching event to IO thread failed in
+      // CacheIndex::PreShutdown().
+      Unused << mDirEnumerator.forget(); // Leak it since dir enumerator is not threadsafe
+    } else {
+      mDirEnumerator->Close();
+      mDirEnumerator = nullptr;
+    }
+  }
+
+  if (!aSucceeded) {
+    mDontMarkIndexClean = true;
+  }
+
+  if (mState == SHUTDOWN) {
+    return;
+  }
+
+  if (mState == UPDATING && aSucceeded) {
+    // If we've iterated over all entries successfully then all entries that
+    // really exist on the disk are now marked as fresh. All non-fresh entries
+    // don't exist anymore and must be removed from the index.
+    RemoveNonFreshEntries();
+  }
+
+  // Make sure we won't start update. If the build or update failed, there is no
+  // reason to believe that it will succeed next time.
+  mIndexNeedsUpdate = false;
+
+  ChangeState(READY);
+  mLastDumpTime = TimeStamp::NowLoRes(); // Do not dump new index immediately
+}
+
+void
+CacheIndex::RemoveNonFreshEntries()
+{
+  for (auto iter = mIndex.Iter(); !iter.Done(); iter.Next()) {
+    CacheIndexEntry* entry = iter.Get();
+    if (entry->IsFresh()) {
+      continue;
+    }
+
+    LOG(("CacheIndex::RemoveNonFreshEntries() - Removing entry. "
+         "[hash=%08x%08x%08x%08x%08x]", LOGSHA1(entry->Hash())));
+
+    {
+      CacheIndexEntryAutoManage emng(entry->Hash(), this);
+      emng.DoNotSearchInIndex();
+    }
+
+    iter.Remove();
+  }
+}
+
+// static
+char const *
+CacheIndex::StateString(EState aState)
+{
+  switch (aState) {
+    case INITIAL:  return "INITIAL";
+    case READING:  return "READING";
+    case WRITING:  return "WRITING";
+    case BUILDING: return "BUILDING";
+    case UPDATING: return "UPDATING";
+    case READY:    return "READY";
+    case SHUTDOWN: return "SHUTDOWN";
+  }
+
+  MOZ_ASSERT(false, "Unexpected state!");
+  return "?";
+}
+
+void
+CacheIndex::ChangeState(EState aNewState)
+{
+  LOG(("CacheIndex::ChangeState() changing state %s -> %s", StateString(mState),
+       StateString(aNewState)));
+
+  // All pending updates should be processed before changing state
+  MOZ_ASSERT(mPendingUpdates.Count() == 0);
+
+  // PreShutdownInternal() should change the state to READY from every state. It
+  // may go through different states, but once we are in READY state the only
+  // possible transition is to SHUTDOWN state.
+  MOZ_ASSERT(!mShuttingDown || mState != READY || aNewState == SHUTDOWN);
+
+  // Start updating process when switching to READY state if needed
+  if (aNewState == READY && StartUpdatingIndexIfNeeded(true)) {
+    return;
+  }
+
+  if ((mState == READING || mState == BUILDING || mState == UPDATING) &&
+      aNewState == READY) {
+    ReportHashStats();
+  }
+
+  // Try to evict entries over limit everytime we're leaving state READING,
+  // BUILDING or UPDATING, but not during shutdown or when removing all
+  // entries.
+  if (!mShuttingDown && !mRemovingAll && aNewState != SHUTDOWN &&
+      (mState == READING || mState == BUILDING || mState == UPDATING))  {
+    CacheFileIOManager::EvictIfOverLimit();
+  }
+
+  mState = aNewState;
+
+  if (mState != SHUTDOWN) {
+    CacheFileIOManager::CacheIndexStateChanged();
+  }
+
+  NotifyAsyncGetDiskConsumptionCallbacks();
+}
+
+void
+CacheIndex::NotifyAsyncGetDiskConsumptionCallbacks()
+{
+  if ((mState == READY || mState == WRITING) && !mAsyncGetDiskConsumptionBlocked && mDiskConsumptionObservers.Length()) {
+    for (uint32_t i = 0; i < mDiskConsumptionObservers.Length(); ++i) {
+      DiskConsumptionObserver* o = mDiskConsumptionObservers[i];
+      // Safe to call under the lock.  We always post to the main thread.
+      o->OnDiskConsumption(mIndexStats.Size() << 10);
+    }
+
+    mDiskConsumptionObservers.Clear();
+  }
+}
+
+void
+CacheIndex::AllocBuffer()
+{
+  switch (mState) {
+    case WRITING:
+      mRWBufSize = sizeof(CacheIndexHeader) + sizeof(CacheHash::Hash32_t) +
+                   mProcessEntries * sizeof(CacheIndexRecord);
+      if (mRWBufSize > kMaxBufSize) {
+        mRWBufSize = kMaxBufSize;
+      }
+      break;
+    case READING:
+      mRWBufSize = kMaxBufSize;
+      break;
+    default:
+      MOZ_ASSERT(false, "Unexpected state!");
+  }
+
+  mRWBuf = static_cast<char *>(moz_xmalloc(mRWBufSize));
+}
+
+void
+CacheIndex::ReleaseBuffer()
+{
+  sLock.AssertCurrentThreadOwns();
+
+  if (!mRWBuf || mRWPending) {
+    return;
+  }
+
+  LOG(("CacheIndex::ReleaseBuffer() releasing buffer"));
+
+  free(mRWBuf);
+  mRWBuf = nullptr;
+  mRWBufSize = 0;
+  mRWBufPos = 0;
+}
+
+void
+CacheIndex::FrecencyArray::AppendRecord(CacheIndexRecord *aRecord)
+{
+  LOG(("CacheIndex::FrecencyArray::AppendRecord() [record=%p, hash=%08x%08x%08x"
+       "%08x%08x]", aRecord, LOGSHA1(aRecord->mHash)));
+
+  MOZ_ASSERT(!mRecs.Contains(aRecord));
+  mRecs.AppendElement(aRecord);
+
+  // If the new frecency is 0, the element should be at the end of the array,
+  // i.e. this change doesn't affect order of the array
+  if (aRecord->mFrecency != 0) {
+    ++mUnsortedElements;
+  }
+}
+
+void
+CacheIndex::FrecencyArray::RemoveRecord(CacheIndexRecord *aRecord)
+{
+  LOG(("CacheIndex::FrecencyArray::RemoveRecord() [record=%p]", aRecord));
+
+  decltype(mRecs)::index_type idx;
+  idx = mRecs.IndexOf(aRecord);
+  MOZ_RELEASE_ASSERT(idx != mRecs.NoIndex);
+  mRecs[idx] = nullptr;
+  ++mRemovedElements;
+
+  // Calling SortIfNeeded ensures that we get rid of removed elements in the
+  // array once we hit the limit.
+  SortIfNeeded();
+}
+
+void
+CacheIndex::FrecencyArray::ReplaceRecord(CacheIndexRecord *aOldRecord,
+                                         CacheIndexRecord *aNewRecord)
+{
+  LOG(("CacheIndex::FrecencyArray::ReplaceRecord() [oldRecord=%p, "
+       "newRecord=%p]", aOldRecord, aNewRecord));
+
+  decltype(mRecs)::index_type idx;
+  idx = mRecs.IndexOf(aOldRecord);
+  MOZ_RELEASE_ASSERT(idx != mRecs.NoIndex);
+  mRecs[idx] = aNewRecord;
+}
+
+void
+CacheIndex::FrecencyArray::SortIfNeeded()
+{
+  const uint32_t kMaxUnsortedCount = 512;
+  const uint32_t kMaxUnsortedPercent = 10;
+  const uint32_t kMaxRemovedCount = 512;
+
+  uint32_t unsortedLimit =
+    std::min<uint32_t>(kMaxUnsortedCount, Length() * kMaxUnsortedPercent / 100);
+
+  if (mUnsortedElements > unsortedLimit ||
+      mRemovedElements > kMaxRemovedCount) {
+    LOG(("CacheIndex::FrecencyArray::SortIfNeeded() - Sorting array "
+       "[unsortedElements=%u, unsortedLimit=%u, removedElements=%u, "
+       "maxRemovedCount=%u]", mUnsortedElements, unsortedLimit,
+       mRemovedElements, kMaxRemovedCount));
+
+    mRecs.Sort(FrecencyComparator());
+    mUnsortedElements = 0;
+    if (mRemovedElements) {
+#ifdef DEBUG
+      for (uint32_t i = Length(); i < mRecs.Length(); ++i) {
+        MOZ_ASSERT(!mRecs[i]);
+      }
+#endif
+      // Removed elements are at the end after sorting.
+      mRecs.RemoveElementsAt(Length(), mRemovedElements);
+      mRemovedElements = 0;
+    }
+  }
+}
+
+void
+CacheIndex::AddRecordToIterators(CacheIndexRecord *aRecord)
+{
+  sLock.AssertCurrentThreadOwns();
+
+  for (uint32_t i = 0; i < mIterators.Length(); ++i) {
+    // Add a new record only when iterator is supposed to be updated.
+    if (mIterators[i]->ShouldBeNewAdded()) {
+      mIterators[i]->AddRecord(aRecord);
+    }
+  }
+}
+
+void
+CacheIndex::RemoveRecordFromIterators(CacheIndexRecord *aRecord)
+{
+  sLock.AssertCurrentThreadOwns();
+
+  for (uint32_t i = 0; i < mIterators.Length(); ++i) {
+    // Remove the record from iterator always, it makes no sence to return
+    // non-existing entries. Also the pointer to the record is no longer valid
+    // once the entry is removed from index.
+    mIterators[i]->RemoveRecord(aRecord);
+  }
+}
+
+void
+CacheIndex::ReplaceRecordInIterators(CacheIndexRecord *aOldRecord,
+                                     CacheIndexRecord *aNewRecord)
+{
+  sLock.AssertCurrentThreadOwns();
+
+  for (uint32_t i = 0; i < mIterators.Length(); ++i) {
+    // We have to replace the record always since the pointer is no longer
+    // valid after this point. NOTE: Replacing the record doesn't mean that
+    // a new entry was added, it just means that the data in the entry was
+    // changed (e.g. a file size) and we had to track this change in
+    // mPendingUpdates since mIndex was read-only.
+    mIterators[i]->ReplaceRecord(aOldRecord, aNewRecord);
+  }
+}
+
+nsresult
+CacheIndex::Run()
+{
+  LOG(("CacheIndex::Run()"));
+
+  StaticMutexAutoLock lock(sLock);
+
+  if (!IsIndexUsable()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (mState == READY && mShuttingDown) {
+    return NS_OK;
+  }
+
+  mUpdateEventPending = false;
+
+  switch (mState) {
+    case BUILDING:
+      BuildIndex();
+      break;
+    case UPDATING:
+      UpdateIndex();
+      break;
+    default:
+      LOG(("CacheIndex::Run() - Update/Build was canceled"));
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheIndex::OnFileOpenedInternal(FileOpenHelper *aOpener,
+                                 CacheFileHandle *aHandle, nsresult aResult)
+{
+  LOG(("CacheIndex::OnFileOpenedInternal() [opener=%p, handle=%p, "
+       "result=0x%08x]", aOpener, aHandle, aResult));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsresult rv;
+
+  sLock.AssertCurrentThreadOwns();
+
+  MOZ_RELEASE_ASSERT(IsIndexUsable());
+
+  if (mState == READY && mShuttingDown) {
+    return NS_OK;
+  }
+
+  switch (mState) {
+    case WRITING:
+      MOZ_ASSERT(aOpener == mIndexFileOpener);
+      mIndexFileOpener = nullptr;
+
+      if (NS_FAILED(aResult)) {
+        LOG(("CacheIndex::OnFileOpenedInternal() - Can't open index file for "
+             "writing [rv=0x%08x]", aResult));
+        FinishWrite(false);
+      } else {
+        mIndexHandle = aHandle;
+        WriteRecords();
+      }
+      break;
+    case READING:
+      if (aOpener == mIndexFileOpener) {
+        mIndexFileOpener = nullptr;
+
+        if (NS_SUCCEEDED(aResult)) {
+          if (aHandle->FileSize() == 0) {
+            FinishRead(false);
+            CacheFileIOManager::DoomFile(aHandle, nullptr);
+            break;
+          } else {
+            mIndexHandle = aHandle;
+          }
+        } else {
+          FinishRead(false);
+          break;
+        }
+      } else if (aOpener == mJournalFileOpener) {
+        mJournalFileOpener = nullptr;
+        mJournalHandle = aHandle;
+      } else if (aOpener == mTmpFileOpener) {
+        mTmpFileOpener = nullptr;
+        mTmpHandle = aHandle;
+      } else {
+        MOZ_ASSERT(false, "Unexpected state!");
+      }
+
+      if (mIndexFileOpener || mJournalFileOpener || mTmpFileOpener) {
+        // Some opener still didn't finish
+        break;
+      }
+
+      // We fail and cancel all other openers when we opening index file fails.
+      MOZ_ASSERT(mIndexHandle);
+
+      if (mTmpHandle) {
+        CacheFileIOManager::DoomFile(mTmpHandle, nullptr);
+        mTmpHandle = nullptr;
+
+        if (mJournalHandle) { // this shouldn't normally happen
+          LOG(("CacheIndex::OnFileOpenedInternal() - Unexpected state, all "
+               "files [%s, %s, %s] should never exist. Removing whole index.",
+               INDEX_NAME, JOURNAL_NAME, TEMP_INDEX_NAME));
+          FinishRead(false);
+          break;
+        }
+      }
+
+      if (mJournalHandle) {
+        // Rename journal to make sure we update index on next start in case
+        // firefox crashes
+        rv = CacheFileIOManager::RenameFile(
+          mJournalHandle, NS_LITERAL_CSTRING(TEMP_INDEX_NAME), this);
+        if (NS_FAILED(rv)) {
+          LOG(("CacheIndex::OnFileOpenedInternal() - CacheFileIOManager::"
+               "RenameFile() failed synchronously [rv=0x%08x]", rv));
+          FinishRead(false);
+          break;
+        }
+      } else {
+        StartReadingIndex();
+      }
+
+      break;
+    default:
+      MOZ_ASSERT(false, "Unexpected state!");
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheIndex::OnFileOpened(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheIndex::OnFileOpened should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheIndex::OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                          nsresult aResult)
+{
+  LOG(("CacheIndex::OnDataWritten() [handle=%p, result=0x%08x]", aHandle,
+       aResult));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsresult rv;
+
+  StaticMutexAutoLock lock(sLock);
+
+  MOZ_RELEASE_ASSERT(IsIndexUsable());
+  MOZ_RELEASE_ASSERT(mRWPending);
+  mRWPending = false;
+
+  if (mState == READY && mShuttingDown) {
+    return NS_OK;
+  }
+
+  switch (mState) {
+    case WRITING:
+      MOZ_ASSERT(mIndexHandle == aHandle);
+
+      if (NS_FAILED(aResult)) {
+        FinishWrite(false);
+      } else {
+        if (mSkipEntries == mProcessEntries) {
+          rv = CacheFileIOManager::RenameFile(mIndexHandle,
+                                              NS_LITERAL_CSTRING(INDEX_NAME),
+                                              this);
+          if (NS_FAILED(rv)) {
+            LOG(("CacheIndex::OnDataWritten() - CacheFileIOManager::"
+                 "RenameFile() failed synchronously [rv=0x%08x]", rv));
+            FinishWrite(false);
+          }
+        } else {
+          WriteRecords();
+        }
+      }
+      break;
+    default:
+      // Writing was canceled.
+      LOG(("CacheIndex::OnDataWritten() - ignoring notification since the "
+           "operation was previously canceled [state=%d]", mState));
+      ReleaseBuffer();
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheIndex::OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult)
+{
+  LOG(("CacheIndex::OnDataRead() [handle=%p, result=0x%08x]", aHandle,
+       aResult));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  MOZ_RELEASE_ASSERT(IsIndexUsable());
+  MOZ_RELEASE_ASSERT(mRWPending);
+  mRWPending = false;
+
+  switch (mState) {
+    case READING:
+      MOZ_ASSERT(mIndexHandle == aHandle || mJournalHandle == aHandle);
+
+      if (NS_FAILED(aResult)) {
+        FinishRead(false);
+      } else {
+        if (!mIndexOnDiskIsValid) {
+          ParseRecords();
+        } else {
+          ParseJournal();
+        }
+      }
+      break;
+    default:
+      // Reading was canceled.
+      LOG(("CacheIndex::OnDataRead() - ignoring notification since the "
+           "operation was previously canceled [state=%d]", mState));
+      ReleaseBuffer();
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheIndex::OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheIndex::OnFileDoomed should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheIndex::OnEOFSet(CacheFileHandle *aHandle, nsresult aResult)
+{
+  MOZ_CRASH("CacheIndex::OnEOFSet should not be called!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+nsresult
+CacheIndex::OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult)
+{
+  LOG(("CacheIndex::OnFileRenamed() [handle=%p, result=0x%08x]", aHandle,
+       aResult));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  StaticMutexAutoLock lock(sLock);
+
+  MOZ_RELEASE_ASSERT(IsIndexUsable());
+
+  if (mState == READY && mShuttingDown) {
+    return NS_OK;
+  }
+
+  switch (mState) {
+    case WRITING:
+      // This is a result of renaming the new index written to tmpfile to index
+      // file. This is the last step when writing the index and the whole
+      // writing process is successful iff renaming was successful.
+
+      if (mIndexHandle != aHandle) {
+        LOG(("CacheIndex::OnFileRenamed() - ignoring notification since it "
+             "belongs to previously canceled operation [state=%d]", mState));
+        break;
+      }
+
+      FinishWrite(NS_SUCCEEDED(aResult));
+      break;
+    case READING:
+      // This is a result of renaming journal file to tmpfile. It is renamed
+      // before we start reading index and journal file and it should normally
+      // succeed. If it fails give up reading of index.
+
+      if (mJournalHandle != aHandle) {
+        LOG(("CacheIndex::OnFileRenamed() - ignoring notification since it "
+             "belongs to previously canceled operation [state=%d]", mState));
+        break;
+      }
+
+      if (NS_FAILED(aResult)) {
+        FinishRead(false);
+      } else {
+        StartReadingIndex();
+      }
+      break;
+    default:
+      // Reading/writing was canceled.
+      LOG(("CacheIndex::OnFileRenamed() - ignoring notification since the "
+           "operation was previously canceled [state=%d]", mState));
+  }
+
+  return NS_OK;
+}
+
+// Memory reporting
+
+size_t
+CacheIndex::SizeOfExcludingThisInternal(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  sLock.AssertCurrentThreadOwns();
+
+  size_t n = 0;
+  nsCOMPtr<nsISizeOf> sizeOf;
+
+  // mIndexHandle and mJournalHandle are reported via SizeOfHandlesRunnable
+  // in CacheFileIOManager::SizeOfExcludingThisInternal as part of special
+  // handles array.
+
+  sizeOf = do_QueryInterface(mCacheDirectory);
+  if (sizeOf) {
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  sizeOf = do_QueryInterface(mUpdateTimer);
+  if (sizeOf) {
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  n += mallocSizeOf(mRWBuf);
+  n += mallocSizeOf(mRWHash);
+
+  n += mIndex.SizeOfExcludingThis(mallocSizeOf);
+  n += mPendingUpdates.SizeOfExcludingThis(mallocSizeOf);
+  n += mTmpJournal.SizeOfExcludingThis(mallocSizeOf);
+
+  // mFrecencyArray items are reported by mIndex/mPendingUpdates
+  n += mFrecencyArray.mRecs.ShallowSizeOfExcludingThis(mallocSizeOf);
+  n += mDiskConsumptionObservers.ShallowSizeOfExcludingThis(mallocSizeOf);
+
+  return n;
+}
+
+// static
+size_t
+CacheIndex::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+  sLock.AssertCurrentThreadOwns();
+
+  if (!gInstance)
+    return 0;
+
+  return gInstance->SizeOfExcludingThisInternal(mallocSizeOf);
+}
+
+// static
+size_t
+CacheIndex::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+  StaticMutexAutoLock lock(sLock);
+
+  return mallocSizeOf(gInstance) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+namespace {
+
+class HashComparator
+{
+public:
+  bool Equals(CacheIndexRecord* a, CacheIndexRecord* b) const {
+    return memcmp(&a->mHash, &b->mHash, sizeof(SHA1Sum::Hash)) == 0;
+  }
+  bool LessThan(CacheIndexRecord* a, CacheIndexRecord* b) const {
+    return memcmp(&a->mHash, &b->mHash, sizeof(SHA1Sum::Hash)) < 0;
+  }
+};
+
+void
+ReportHashSizeMatch(const SHA1Sum::Hash *aHash1, const SHA1Sum::Hash *aHash2)
+{
+  const uint32_t *h1 = reinterpret_cast<const uint32_t *>(aHash1);
+  const uint32_t *h2 = reinterpret_cast<const uint32_t *>(aHash2);
+
+  for (uint32_t i = 0; i < 5; ++i) {
+    if (h1[i] != h2[i]) {
+      uint32_t bitsDiff = h1[i] ^ h2[i];
+      bitsDiff = NetworkEndian::readUint32(&bitsDiff);
+
+      // count leading zeros in bitsDiff
+      static const uint8_t debruijn32[32] =
+        { 0, 31, 9, 30, 3, 8, 13, 29, 2, 5, 7, 21, 12, 24, 28, 19,
+          1, 10, 4, 14, 6, 22, 25, 20, 11, 15, 23, 26, 16, 27, 17, 18};
+
+      bitsDiff |= bitsDiff>>1;
+      bitsDiff |= bitsDiff>>2;
+      bitsDiff |= bitsDiff>>4;
+      bitsDiff |= bitsDiff>>8;
+      bitsDiff |= bitsDiff>>16;
+      bitsDiff++;
+
+      uint8_t hashSizeMatch = debruijn32[bitsDiff*0x076be629>>27] + (i<<5);
+      Telemetry::Accumulate(Telemetry::NETWORK_CACHE_HASH_STATS, hashSizeMatch);
+
+      return;
+    }
+  }
+
+  MOZ_ASSERT(false, "Found a collision in the index!");
+}
+
+} // namespace
+
+void
+CacheIndex::ReportHashStats()
+{
+  // We're gathering the hash stats only once, exclude too small caches.
+  if (CacheObserver::HashStatsReported() || mFrecencyArray.Length() < 15000) {
+    return;
+  }
+
+  nsTArray<CacheIndexRecord *> records;
+  for (auto iter = mFrecencyArray.Iter(); !iter.Done(); iter.Next()) {
+    records.AppendElement(iter.Get());
+  }
+
+  records.Sort(HashComparator());
+
+  for (uint32_t i = 1; i < records.Length(); i++) {
+    ReportHashSizeMatch(&records[i-1]->mHash, &records[i]->mHash);
+  }
+
+  CacheObserver::SetHashStatsReported();
+}
+
+// static
+void
+CacheIndex::OnAsyncEviction(bool aEvicting)
+{
+  RefPtr<CacheIndex> index = gInstance;
+  if (!index) {
+    return;
+  }
+
+  StaticMutexAutoLock lock(sLock);
+  index->mAsyncGetDiskConsumptionBlocked = aEvicting;
+  if (!aEvicting) {
+    index->NotifyAsyncGetDiskConsumptionCallbacks();
+  }
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheIndex.h b/netwerk/cache2/CacheIndex.h
new file mode 100644
index 0000000000..dc72c346f7
--- /dev/null
+++ b/netwerk/cache2/CacheIndex.h
@@ -0,0 +1,1153 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheIndex__h__
+#define CacheIndex__h__
+
+#include "CacheLog.h"
+#include "CacheFileIOManager.h"
+#include "nsIRunnable.h"
+#include "CacheHashUtils.h"
+#include "nsICacheStorageService.h"
+#include "nsICacheEntry.h"
+#include "nsILoadContextInfo.h"
+#include "nsTHashtable.h"
+#include "nsThreadUtils.h"
+#include "nsWeakReference.h"
+#include "mozilla/SHA1.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/TimeStamp.h"
+
+class nsIFile;
+class nsIDirectoryEnumerator;
+class nsITimer;
+
+
+#ifdef DEBUG
+#define DEBUG_STATS 1
+#endif
+
+namespace mozilla {
+namespace net {
+
+class CacheFileMetadata;
+class FileOpenHelper;
+class CacheIndexIterator;
+
+typedef struct {
+  // Version of the index. The index must be ignored and deleted when the file
+  // on disk was written with a newer version.
+  uint32_t mVersion;
+
+  // Timestamp of time when the last successful write of the index started.
+  // During update process we use this timestamp for a quick validation of entry
+  // files. If last modified time of the file is lower than this timestamp, we
+  // skip parsing of such file since the information in index should be up to
+  // date.
+  uint32_t mTimeStamp;
+
+  // We set this flag as soon as possible after parsing index during startup
+  // and clean it after we write journal to disk during shutdown. We ignore the
+  // journal and start update process whenever this flag is set during index
+  // parsing.
+  uint32_t mIsDirty;
+} CacheIndexHeader;
+
+static_assert(
+  sizeof(CacheIndexHeader::mVersion) + sizeof(CacheIndexHeader::mTimeStamp) +
+  sizeof(CacheIndexHeader::mIsDirty) == sizeof(CacheIndexHeader),
+  "Unexpected sizeof(CacheIndexHeader)!");
+
+struct CacheIndexRecord {
+  SHA1Sum::Hash   mHash;
+  uint32_t        mFrecency;
+  OriginAttrsHash mOriginAttrsHash;
+  uint32_t        mExpirationTime;
+
+  /*
+   *    1000 0000 0000 0000 0000 0000 0000 0000 : initialized
+   *    0100 0000 0000 0000 0000 0000 0000 0000 : anonymous
+   *    0010 0000 0000 0000 0000 0000 0000 0000 : removed
+   *    0001 0000 0000 0000 0000 0000 0000 0000 : dirty
+   *    0000 1000 0000 0000 0000 0000 0000 0000 : fresh
+   *    0000 0100 0000 0000 0000 0000 0000 0000 : pinned
+   *    0000 0011 0000 0000 0000 0000 0000 0000 : reserved
+   *    0000 0000 1111 1111 1111 1111 1111 1111 : file size (in kB)
+   */
+  uint32_t        mFlags;
+
+  CacheIndexRecord()
+    : mFrecency(0)
+    , mOriginAttrsHash(0)
+    , mExpirationTime(nsICacheEntry::NO_EXPIRATION_TIME)
+    , mFlags(0)
+  {}
+};
+
+static_assert(
+  sizeof(CacheIndexRecord::mHash) + sizeof(CacheIndexRecord::mFrecency) +
+  sizeof(CacheIndexRecord::mOriginAttrsHash) + sizeof(CacheIndexRecord::mExpirationTime) +
+  sizeof(CacheIndexRecord::mFlags) == sizeof(CacheIndexRecord),
+  "Unexpected sizeof(CacheIndexRecord)!");
+
+class CacheIndexEntry : public PLDHashEntryHdr
+{
+public:
+  typedef const SHA1Sum::Hash& KeyType;
+  typedef const SHA1Sum::Hash* KeyTypePointer;
+
+  explicit CacheIndexEntry(KeyTypePointer aKey)
+  {
+    MOZ_COUNT_CTOR(CacheIndexEntry);
+    mRec = new CacheIndexRecord();
+    LOG(("CacheIndexEntry::CacheIndexEntry() - Created record [rec=%p]", mRec.get()));
+    memcpy(&mRec->mHash, aKey, sizeof(SHA1Sum::Hash));
+  }
+  CacheIndexEntry(const CacheIndexEntry& aOther)
+  {
+    NS_NOTREACHED("CacheIndexEntry copy constructor is forbidden!");
+  }
+  ~CacheIndexEntry()
+  {
+    MOZ_COUNT_DTOR(CacheIndexEntry);
+    LOG(("CacheIndexEntry::~CacheIndexEntry() - Deleting record [rec=%p]",
+         mRec.get()));
+  }
+
+  // KeyEquals(): does this entry match this key?
+  bool KeyEquals(KeyTypePointer aKey) const
+  {
+    return memcmp(&mRec->mHash, aKey, sizeof(SHA1Sum::Hash)) == 0;
+  }
+
+  // KeyToPointer(): Convert KeyType to KeyTypePointer
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+
+  // HashKey(): calculate the hash number
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    return (reinterpret_cast<const uint32_t *>(aKey))[0];
+  }
+
+  // ALLOW_MEMMOVE can we move this class with memmove(), or do we have
+  // to use the copy constructor?
+  enum { ALLOW_MEMMOVE = true };
+
+  bool operator==(const CacheIndexEntry& aOther) const
+  {
+    return KeyEquals(&aOther.mRec->mHash);
+  }
+
+  CacheIndexEntry& operator=(const CacheIndexEntry& aOther)
+  {
+    MOZ_ASSERT(memcmp(&mRec->mHash, &aOther.mRec->mHash,
+               sizeof(SHA1Sum::Hash)) == 0);
+    mRec->mFrecency = aOther.mRec->mFrecency;
+    mRec->mExpirationTime = aOther.mRec->mExpirationTime;
+    mRec->mOriginAttrsHash = aOther.mRec->mOriginAttrsHash;
+    mRec->mFlags = aOther.mRec->mFlags;
+    return *this;
+  }
+
+  void InitNew()
+  {
+    mRec->mFrecency = 0;
+    mRec->mExpirationTime = nsICacheEntry::NO_EXPIRATION_TIME;
+    mRec->mOriginAttrsHash = 0;
+    mRec->mFlags = 0;
+  }
+
+  void Init(OriginAttrsHash aOriginAttrsHash, bool aAnonymous, bool aPinned)
+  {
+    MOZ_ASSERT(mRec->mFrecency == 0);
+    MOZ_ASSERT(mRec->mExpirationTime == nsICacheEntry::NO_EXPIRATION_TIME);
+    MOZ_ASSERT(mRec->mOriginAttrsHash == 0);
+    // When we init the entry it must be fresh and may be dirty
+    MOZ_ASSERT((mRec->mFlags & ~kDirtyMask) == kFreshMask);
+
+    mRec->mOriginAttrsHash = aOriginAttrsHash;
+    mRec->mFlags |= kInitializedMask;
+    if (aAnonymous) {
+      mRec->mFlags |= kAnonymousMask;
+    }
+    if (aPinned) {
+      mRec->mFlags |= kPinnedMask;
+    }
+  }
+
+  const SHA1Sum::Hash * Hash() const { return &mRec->mHash; }
+
+  bool IsInitialized() const { return !!(mRec->mFlags & kInitializedMask); }
+
+  mozilla::net::OriginAttrsHash OriginAttrsHash() const { return mRec->mOriginAttrsHash; }
+
+  bool Anonymous() const { return !!(mRec->mFlags & kAnonymousMask); }
+
+  bool IsRemoved() const { return !!(mRec->mFlags & kRemovedMask); }
+  void MarkRemoved() { mRec->mFlags |= kRemovedMask; }
+
+  bool IsDirty() const { return !!(mRec->mFlags & kDirtyMask); }
+  void MarkDirty() { mRec->mFlags |= kDirtyMask; }
+  void ClearDirty() { mRec->mFlags &= ~kDirtyMask; }
+
+  bool IsFresh() const { return !!(mRec->mFlags & kFreshMask); }
+  void MarkFresh() { mRec->mFlags |= kFreshMask; }
+
+  bool IsPinned() const { return !!(mRec->mFlags & kPinnedMask); }
+
+  void     SetFrecency(uint32_t aFrecency) { mRec->mFrecency = aFrecency; }
+  uint32_t GetFrecency() const { return mRec->mFrecency; }
+
+  void     SetExpirationTime(uint32_t aExpirationTime)
+  {
+    mRec->mExpirationTime = aExpirationTime;
+  }
+  uint32_t GetExpirationTime() const { return mRec->mExpirationTime; }
+
+  // Sets filesize in kilobytes.
+  void     SetFileSize(uint32_t aFileSize)
+  {
+    if (aFileSize > kFileSizeMask) {
+      LOG(("CacheIndexEntry::SetFileSize() - FileSize is too large, "
+           "truncating to %u", kFileSizeMask));
+      aFileSize = kFileSizeMask;
+    }
+    mRec->mFlags &= ~kFileSizeMask;
+    mRec->mFlags |= aFileSize;
+  }
+  // Returns filesize in kilobytes.
+  uint32_t GetFileSize() const { return GetFileSize(mRec); }
+  static uint32_t GetFileSize(CacheIndexRecord *aRec)
+  {
+    return aRec->mFlags & kFileSizeMask;
+  }
+  static uint32_t IsPinned(CacheIndexRecord *aRec)
+  {
+    return aRec->mFlags & kPinnedMask;
+  }
+  bool     IsFileEmpty() const { return GetFileSize() == 0; }
+
+  void WriteToBuf(void *aBuf)
+  {
+    uint8_t* ptr = static_cast<uint8_t*>(aBuf);
+    memcpy(ptr, mRec->mHash, sizeof(SHA1Sum::Hash)); ptr += sizeof(SHA1Sum::Hash);
+    NetworkEndian::writeUint32(ptr, mRec->mFrecency); ptr += sizeof(uint32_t);
+    NetworkEndian::writeUint64(ptr, mRec->mOriginAttrsHash); ptr += sizeof(uint64_t);
+    NetworkEndian::writeUint32(ptr, mRec->mExpirationTime); ptr += sizeof(uint32_t);
+    // Dirty and fresh flags should never go to disk, since they make sense only
+    // during current session.
+    NetworkEndian::writeUint32(ptr, mRec->mFlags & ~(kDirtyMask | kFreshMask));
+  }
+
+  void ReadFromBuf(void *aBuf)
+  {
+    const uint8_t* ptr = static_cast<const uint8_t*>(aBuf);
+    MOZ_ASSERT(memcmp(&mRec->mHash, ptr, sizeof(SHA1Sum::Hash)) == 0); ptr += sizeof(SHA1Sum::Hash);
+    mRec->mFrecency = NetworkEndian::readUint32(ptr); ptr += sizeof(uint32_t);
+    mRec->mOriginAttrsHash = NetworkEndian::readUint64(ptr); ptr += sizeof(uint64_t);
+    mRec->mExpirationTime = NetworkEndian::readUint32(ptr); ptr += sizeof(uint32_t);
+    mRec->mFlags = NetworkEndian::readUint32(ptr);
+  }
+
+  void Log() const {
+    LOG(("CacheIndexEntry::Log() [this=%p, hash=%08x%08x%08x%08x%08x, fresh=%u,"
+         " initialized=%u, removed=%u, dirty=%u, anonymous=%u, "
+         "originAttrsHash=%llx, frecency=%u, expirationTime=%u, size=%u]",
+         this, LOGSHA1(mRec->mHash), IsFresh(), IsInitialized(), IsRemoved(),
+         IsDirty(), Anonymous(), OriginAttrsHash(), GetFrecency(),
+         GetExpirationTime(), GetFileSize()));
+  }
+
+  static bool RecordMatchesLoadContextInfo(CacheIndexRecord *aRec,
+                                           nsILoadContextInfo *aInfo)
+  {
+    if (!aInfo->IsPrivate() &&
+        GetOriginAttrsHash(*aInfo->OriginAttributesPtr()) == aRec->mOriginAttrsHash &&
+        aInfo->IsAnonymous() == !!(aRec->mFlags & kAnonymousMask)) {
+      return true;
+    }
+
+    return false;
+  }
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+  {
+    return mallocSizeOf(mRec.get());
+  }
+
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+  {
+    return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
+  }
+
+private:
+  friend class CacheIndexEntryUpdate;
+  friend class CacheIndex;
+  friend class CacheIndexEntryAutoManage;
+
+  static const uint32_t kInitializedMask = 0x80000000;
+  static const uint32_t kAnonymousMask   = 0x40000000;
+
+  // This flag is set when the entry was removed. We need to keep this
+  // information in memory until we write the index file.
+  static const uint32_t kRemovedMask     = 0x20000000;
+
+  // This flag is set when the information in memory is not in sync with the
+  // information in index file on disk.
+  static const uint32_t kDirtyMask       = 0x10000000;
+
+  // This flag is set when the information about the entry is fresh, i.e.
+  // we've created or opened this entry during this session, or we've seen
+  // this entry during update or build process.
+  static const uint32_t kFreshMask       = 0x08000000;
+
+  // Indicates a pinned entry.
+  static const uint32_t kPinnedMask      = 0x04000000;
+
+  static const uint32_t kReservedMask    = 0x03000000;
+
+  // FileSize in kilobytes
+  static const uint32_t kFileSizeMask    = 0x00FFFFFF;
+
+  nsAutoPtr<CacheIndexRecord> mRec;
+};
+
+class CacheIndexEntryUpdate : public CacheIndexEntry
+{
+public:
+  explicit CacheIndexEntryUpdate(CacheIndexEntry::KeyTypePointer aKey)
+    : CacheIndexEntry(aKey)
+    , mUpdateFlags(0)
+  {
+    MOZ_COUNT_CTOR(CacheIndexEntryUpdate);
+    LOG(("CacheIndexEntryUpdate::CacheIndexEntryUpdate()"));
+  }
+  ~CacheIndexEntryUpdate()
+  {
+    MOZ_COUNT_DTOR(CacheIndexEntryUpdate);
+    LOG(("CacheIndexEntryUpdate::~CacheIndexEntryUpdate()"));
+  }
+
+  CacheIndexEntryUpdate& operator=(const CacheIndexEntry& aOther)
+  {
+    MOZ_ASSERT(memcmp(&mRec->mHash, &aOther.mRec->mHash,
+               sizeof(SHA1Sum::Hash)) == 0);
+    mUpdateFlags = 0;
+    *(static_cast<CacheIndexEntry *>(this)) = aOther;
+    return *this;
+  }
+
+  void InitNew()
+  {
+    mUpdateFlags = kFrecencyUpdatedMask | kExpirationUpdatedMask |
+                   kFileSizeUpdatedMask;
+    CacheIndexEntry::InitNew();
+  }
+
+  void SetFrecency(uint32_t aFrecency)
+  {
+    mUpdateFlags |= kFrecencyUpdatedMask;
+    CacheIndexEntry::SetFrecency(aFrecency);
+  }
+
+  void SetExpirationTime(uint32_t aExpirationTime)
+  {
+    mUpdateFlags |= kExpirationUpdatedMask;
+    CacheIndexEntry::SetExpirationTime(aExpirationTime);
+  }
+
+  void SetFileSize(uint32_t aFileSize)
+  {
+    mUpdateFlags |= kFileSizeUpdatedMask;
+    CacheIndexEntry::SetFileSize(aFileSize);
+  }
+
+  void ApplyUpdate(CacheIndexEntry *aDst) {
+    MOZ_ASSERT(memcmp(&mRec->mHash, &aDst->mRec->mHash,
+               sizeof(SHA1Sum::Hash)) == 0);
+    if (mUpdateFlags & kFrecencyUpdatedMask) {
+      aDst->mRec->mFrecency = mRec->mFrecency;
+    }
+    if (mUpdateFlags & kExpirationUpdatedMask) {
+      aDst->mRec->mExpirationTime = mRec->mExpirationTime;
+    }
+    aDst->mRec->mOriginAttrsHash = mRec->mOriginAttrsHash;
+    if (mUpdateFlags & kFileSizeUpdatedMask) {
+      aDst->mRec->mFlags = mRec->mFlags;
+    } else {
+      // Copy all flags except file size.
+      aDst->mRec->mFlags &= kFileSizeMask;
+      aDst->mRec->mFlags |= (mRec->mFlags & ~kFileSizeMask);
+    }
+  }
+
+private:
+  static const uint32_t kFrecencyUpdatedMask = 0x00000001;
+  static const uint32_t kExpirationUpdatedMask = 0x00000002;
+  static const uint32_t kFileSizeUpdatedMask = 0x00000004;
+
+  uint32_t mUpdateFlags;
+};
+
+class CacheIndexStats
+{
+public:
+  CacheIndexStats()
+    : mCount(0)
+    , mNotInitialized(0)
+    , mRemoved(0)
+    , mDirty(0)
+    , mFresh(0)
+    , mEmpty(0)
+    , mSize(0)
+#ifdef DEBUG
+    , mStateLogged(false)
+    , mDisableLogging(false)
+#endif
+  {
+  }
+
+  bool operator==(const CacheIndexStats& aOther) const
+  {
+    return
+#ifdef DEBUG
+           aOther.mStateLogged == mStateLogged &&
+#endif
+           aOther.mCount == mCount &&
+           aOther.mNotInitialized == mNotInitialized &&
+           aOther.mRemoved == mRemoved &&
+           aOther.mDirty == mDirty &&
+           aOther.mFresh == mFresh &&
+           aOther.mEmpty == mEmpty &&
+           aOther.mSize == mSize;
+  }
+
+#ifdef DEBUG
+  void DisableLogging() {
+    mDisableLogging = true;
+  }
+#endif
+
+  void Log() {
+    LOG(("CacheIndexStats::Log() [count=%u, notInitialized=%u, removed=%u, "
+         "dirty=%u, fresh=%u, empty=%u, size=%u]", mCount, mNotInitialized,
+         mRemoved, mDirty, mFresh, mEmpty, mSize));
+  }
+
+  void Clear() {
+    MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Clear() - state logged!");
+
+    mCount = 0;
+    mNotInitialized = 0;
+    mRemoved = 0;
+    mDirty = 0;
+    mFresh = 0;
+    mEmpty = 0;
+    mSize = 0;
+  }
+
+#ifdef DEBUG
+  bool StateLogged() {
+    return mStateLogged;
+  }
+#endif
+
+  uint32_t Count() {
+    MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Count() - state logged!");
+    return mCount;
+  }
+
+  uint32_t Dirty() {
+    MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Dirty() - state logged!");
+    return mDirty;
+  }
+
+  uint32_t Fresh() {
+    MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Fresh() - state logged!");
+    return mFresh;
+  }
+
+  uint32_t ActiveEntriesCount() {
+    MOZ_ASSERT(!mStateLogged, "CacheIndexStats::ActiveEntriesCount() - state "
+               "logged!");
+    return mCount - mRemoved - mNotInitialized - mEmpty;
+  }
+
+  uint32_t Size() {
+    MOZ_ASSERT(!mStateLogged, "CacheIndexStats::Size() - state logged!");
+    return mSize;
+  }
+
+  void BeforeChange(const CacheIndexEntry *aEntry) {
+#ifdef DEBUG_STATS
+    if (!mDisableLogging) {
+      LOG(("CacheIndexStats::BeforeChange()"));
+      Log();
+    }
+#endif
+
+    MOZ_ASSERT(!mStateLogged, "CacheIndexStats::BeforeChange() - state "
+               "logged!");
+#ifdef DEBUG
+    mStateLogged = true;
+#endif
+    if (aEntry) {
+      MOZ_ASSERT(mCount);
+      mCount--;
+      if (aEntry->IsDirty()) {
+        MOZ_ASSERT(mDirty);
+        mDirty--;
+      }
+      if (aEntry->IsFresh()) {
+        MOZ_ASSERT(mFresh);
+        mFresh--;
+      }
+      if (aEntry->IsRemoved()) {
+        MOZ_ASSERT(mRemoved);
+        mRemoved--;
+      } else {
+        if (!aEntry->IsInitialized()) {
+          MOZ_ASSERT(mNotInitialized);
+          mNotInitialized--;
+        } else {
+          if (aEntry->IsFileEmpty()) {
+            MOZ_ASSERT(mEmpty);
+            mEmpty--;
+          } else {
+            MOZ_ASSERT(mSize >= aEntry->GetFileSize());
+            mSize -= aEntry->GetFileSize();
+          }
+        }
+      }
+    }
+  }
+
+  void AfterChange(const CacheIndexEntry *aEntry) {
+    MOZ_ASSERT(mStateLogged, "CacheIndexStats::AfterChange() - state not "
+               "logged!");
+#ifdef DEBUG
+    mStateLogged = false;
+#endif
+    if (aEntry) {
+      ++mCount;
+      if (aEntry->IsDirty()) {
+        mDirty++;
+      }
+      if (aEntry->IsFresh()) {
+        mFresh++;
+      }
+      if (aEntry->IsRemoved()) {
+        mRemoved++;
+      } else {
+        if (!aEntry->IsInitialized()) {
+          mNotInitialized++;
+        } else {
+          if (aEntry->IsFileEmpty()) {
+            mEmpty++;
+          } else {
+            mSize += aEntry->GetFileSize();
+          }
+        }
+      }
+    }
+
+#ifdef DEBUG_STATS
+    if (!mDisableLogging) {
+      LOG(("CacheIndexStats::AfterChange()"));
+      Log();
+    }
+#endif
+  }
+
+private:
+  uint32_t mCount;
+  uint32_t mNotInitialized;
+  uint32_t mRemoved;
+  uint32_t mDirty;
+  uint32_t mFresh;
+  uint32_t mEmpty;
+  uint32_t mSize;
+#ifdef DEBUG
+  // We completely remove the data about an entry from the stats in
+  // BeforeChange() and set this flag to true. The entry is then modified,
+  // deleted or created and the data is again put into the stats and this flag
+  // set to false. Statistics must not be read during this time since the
+  // information is not correct.
+  bool     mStateLogged;
+
+  // Disables logging in this instance of CacheIndexStats
+  bool     mDisableLogging;
+#endif
+};
+
+class CacheIndex : public CacheFileIOListener
+                 , public nsIRunnable
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIRUNNABLE
+
+  CacheIndex();
+
+  static nsresult Init(nsIFile *aCacheDirectory);
+  static nsresult PreShutdown();
+  static nsresult Shutdown();
+
+  // Following methods can be called only on IO thread.
+
+  // Add entry to the index. The entry shouldn't be present in index. This
+  // method is called whenever a new handle for a new entry file is created. The
+  // newly created entry is not initialized and it must be either initialized
+  // with InitEntry() or removed with RemoveEntry().
+  static nsresult AddEntry(const SHA1Sum::Hash *aHash);
+
+  // Inform index about an existing entry that should be present in index. This
+  // method is called whenever a new handle for an existing entry file is
+  // created. Like in case of AddEntry(), either InitEntry() or RemoveEntry()
+  // must be called on the entry, since the entry is not initizlized if the
+  // index is outdated.
+  static nsresult EnsureEntryExists(const SHA1Sum::Hash *aHash);
+
+  // Initialize the entry. It MUST be present in index. Call to AddEntry() or
+  // EnsureEntryExists() must precede the call to this method.
+  static nsresult InitEntry(const SHA1Sum::Hash *aHash,
+                            OriginAttrsHash      aOriginAttrsHash,
+                            bool                 aAnonymous,
+                            bool                 aPinned);
+
+  // Remove entry from index. The entry should be present in index.
+  static nsresult RemoveEntry(const SHA1Sum::Hash *aHash);
+
+  // Update some information in entry. The entry MUST be present in index and
+  // MUST be initialized. Call to AddEntry() or EnsureEntryExists() and to
+  // InitEntry() must precede the call to this method.
+  // Pass nullptr if the value didn't change.
+  static nsresult UpdateEntry(const SHA1Sum::Hash *aHash,
+                              const uint32_t      *aFrecency,
+                              const uint32_t      *aExpirationTime,
+                              const uint32_t      *aSize);
+
+  // Remove all entries from the index. Called when clearing the whole cache.
+  static nsresult RemoveAll();
+
+  enum EntryStatus {
+    EXISTS         = 0,
+    DOES_NOT_EXIST = 1,
+    DO_NOT_KNOW    = 2
+  };
+
+  // Returns status of the entry in index for the given key. It can be called
+  // on any thread.
+  // If _pinned is non-null, it's filled with pinning status of the entry.
+  static nsresult HasEntry(const nsACString &aKey, EntryStatus *_retval,
+                           bool *_pinned = nullptr);
+  static nsresult HasEntry(const SHA1Sum::Hash &hash, EntryStatus *_retval,
+                           bool *_pinned = nullptr);
+
+  // Returns a hash of the least important entry that should be evicted if the
+  // cache size is over limit and also returns a total number of all entries in
+  // the index minus the number of forced valid entries and unpinned entries
+  // that we encounter when searching (see below)
+  static nsresult GetEntryForEviction(bool aIgnoreEmptyEntries, SHA1Sum::Hash *aHash, uint32_t *aCnt);
+
+  // Checks if a cache entry is currently forced valid. Used to prevent an entry
+  // (that has been forced valid) from being evicted when the cache size reaches
+  // its limit.
+  static bool IsForcedValidEntry(const SHA1Sum::Hash *aHash);
+
+  // Returns cache size in kB.
+  static nsresult GetCacheSize(uint32_t *_retval);
+
+  // Returns number of entry files in the cache
+  static nsresult GetEntryFileCount(uint32_t *_retval);
+
+  // Synchronously returns the disk occupation and number of entries per-context.
+  // Callable on any thread.
+  static nsresult GetCacheStats(nsILoadContextInfo *aInfo, uint32_t *aSize, uint32_t *aCount);
+
+  // Asynchronously gets the disk cache size, used for display in the UI.
+  static nsresult AsyncGetDiskConsumption(nsICacheStorageConsumptionObserver* aObserver);
+
+  // Returns an iterator that returns entries matching a given context that were
+  // present in the index at the time this method was called. If aAddNew is true
+  // then the iterator will also return entries created after this call.
+  // NOTE: When some entry is removed from index it is removed also from the
+  // iterator regardless what aAddNew was passed.
+  static nsresult GetIterator(nsILoadContextInfo *aInfo, bool aAddNew,
+                              CacheIndexIterator **_retval);
+
+  // Returns true if we _think_ that the index is up to date. I.e. the state is
+  // READY or WRITING and mIndexNeedsUpdate as well as mShuttingDown is false.
+  static nsresult IsUpToDate(bool *_retval);
+
+  // Called from CacheStorageService::Clear() and CacheFileContextEvictor::EvictEntries(),
+  // sets a flag that blocks notification to AsyncGetDiskConsumption.
+  static void OnAsyncEviction(bool aEvicting);
+
+  // Memory reporting
+  static size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf);
+  static size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf);
+
+private:
+  friend class CacheIndexEntryAutoManage;
+  friend class FileOpenHelper;
+  friend class CacheIndexIterator;
+
+  virtual ~CacheIndex();
+
+  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) override;
+  nsresult   OnFileOpenedInternal(FileOpenHelper *aOpener,
+                                  CacheFileHandle *aHandle, nsresult aResult);
+  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                           nsresult aResult) override;
+  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult) override;
+  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) override;
+
+  nsresult InitInternal(nsIFile *aCacheDirectory);
+  void     PreShutdownInternal();
+
+  // This method returns false when index is not initialized or is shut down.
+  bool IsIndexUsable();
+
+  // This method checks whether the entry has the same values of
+  // originAttributes and isAnonymous. We don't expect to find a collision
+  // since these values are part of the key that we hash and we use a strong
+  // hash function.
+  static bool IsCollision(CacheIndexEntry *aEntry,
+                          OriginAttrsHash  aOriginAttrsHash,
+                          bool             aAnonymous);
+
+  // Checks whether any of the information about the entry has changed.
+  static bool HasEntryChanged(CacheIndexEntry *aEntry,
+                              const uint32_t  *aFrecency,
+                              const uint32_t  *aExpirationTime,
+                              const uint32_t  *aSize);
+
+  // Merge all pending operations from mPendingUpdates into mIndex.
+  void ProcessPendingOperations();
+
+  // Following methods perform writing of the index file.
+  //
+  // The index is written periodically, but not earlier than once in
+  // kMinDumpInterval and there must be at least kMinUnwrittenChanges
+  // differences between index on disk and in memory. Index is always first
+  // written to a temporary file and the old index file is replaced when the
+  // writing process succeeds.
+  //
+  // Starts writing of index when both limits (minimal delay between writes and
+  // minimum number of changes in index) were exceeded.
+  bool WriteIndexToDiskIfNeeded();
+  // Starts writing of index file.
+  void WriteIndexToDisk();
+  // Serializes part of mIndex hashtable to the write buffer a writes the buffer
+  // to the file.
+  void WriteRecords();
+  // Finalizes writing process.
+  void FinishWrite(bool aSucceeded);
+
+  // Following methods perform writing of the journal during shutdown. All these
+  // methods must be called only during shutdown since they write/delete files
+  // directly on the main thread instead of using CacheFileIOManager that does
+  // it asynchronously on IO thread. Journal contains only entries that are
+  // dirty, i.e. changes that are not present in the index file on the disk.
+  // When the log is written successfully, the dirty flag in index file is
+  // cleared.
+  nsresult GetFile(const nsACString &aName, nsIFile **_retval);
+  nsresult RemoveFile(const nsACString &aName);
+  void     RemoveAllIndexFiles();
+  void     RemoveJournalAndTempFile();
+  // Writes journal to the disk and clears dirty flag in index header.
+  nsresult WriteLogToDisk();
+
+  // Following methods perform reading of the index from the disk.
+  //
+  // Index is read at startup just after initializing the CacheIndex. There are
+  // 3 files used when manipulating with index: index file, journal file and
+  // a temporary file. All files contain the hash of the data, so we can check
+  // whether the content is valid and complete. Index file contains also a dirty
+  // flag in the index header which is unset on a clean shutdown. During opening
+  // and reading of the files we determine the status of the whole index from
+  // the states of the separate files. Following table shows all possible
+  // combinations:
+  //
+  // index, journal, tmpfile
+  // M      *        *       - index is missing    -> BUILD
+  // I      *        *       - index is invalid    -> BUILD
+  // D      *        *       - index is dirty      -> UPDATE
+  // C      M        *       - index is dirty      -> UPDATE
+  // C      I        *       - unexpected state    -> UPDATE
+  // C      V        E       - unexpected state    -> UPDATE
+  // C      V        M       - index is up to date -> READY
+  //
+  // where the letters mean:
+  //   * - any state
+  //   E - file exists
+  //   M - file is missing
+  //   I - data is invalid (parsing failed or hash didn't match)
+  //   D - dirty (data in index file is correct, but dirty flag is set)
+  //   C - clean (index file is clean)
+  //   V - valid (data in journal file is correct)
+  //
+  // Note: We accept the data from journal only when the index is up to date as
+  // a whole (i.e. C,V,M state).
+  //
+  // We rename the journal file to the temporary file as soon as possible after
+  // initial test to ensure that we start update process on the next startup if
+  // FF crashes during parsing of the index.
+  //
+  // Initiates reading index from disk.
+  void ReadIndexFromDisk();
+  // Starts reading data from index file.
+  void StartReadingIndex();
+  // Parses data read from index file.
+  void ParseRecords();
+  // Starts reading data from journal file.
+  void StartReadingJournal();
+  // Parses data read from journal file.
+  void ParseJournal();
+  // Merges entries from journal into mIndex.
+  void MergeJournal();
+  // In debug build this method checks that we have no fresh entry in mIndex
+  // after we finish reading index and before we process pending operations.
+  void EnsureNoFreshEntry();
+  // In debug build this method is called after processing pending operations
+  // to make sure mIndexStats contains correct information.
+  void EnsureCorrectStats();
+  // Finalizes reading process.
+  void FinishRead(bool aSucceeded);
+
+  // Following methods perform updating and building of the index.
+  // Timer callback that starts update or build process.
+  static void DelayedUpdate(nsITimer *aTimer, void *aClosure);
+  void DelayedUpdateLocked();
+  // Posts timer event that start update or build process.
+  nsresult ScheduleUpdateTimer(uint32_t aDelay);
+  nsresult SetupDirectoryEnumerator();
+  void InitEntryFromDiskData(CacheIndexEntry *aEntry,
+                             CacheFileMetadata *aMetaData,
+                             int64_t aFileSize);
+  // Returns true when either a timer is scheduled or event is posted.
+  bool IsUpdatePending();
+  // Iterates through all files in entries directory that we didn't create/open
+  // during this session, parses them and adds the entries to the index.
+  void BuildIndex();
+
+  bool StartUpdatingIndexIfNeeded(bool aSwitchingToReadyState = false);
+  // Starts update or build process or fires a timer when it is too early after
+  // startup.
+  void StartUpdatingIndex(bool aRebuild);
+  // Iterates through all files in entries directory that we didn't create/open
+  // during this session and theirs last modified time is newer than timestamp
+  // in the index header. Parses the files and adds the entries to the index.
+  void UpdateIndex();
+  // Finalizes update or build process.
+  void FinishUpdate(bool aSucceeded);
+
+  void RemoveNonFreshEntries();
+
+  enum EState {
+    // Initial state in which the index is not usable
+    // Possible transitions:
+    //  -> READING
+    INITIAL  = 0,
+
+    // Index is being read from the disk.
+    // Possible transitions:
+    //  -> INITIAL  - We failed to dispatch a read event.
+    //  -> BUILDING - No or corrupted index file was found.
+    //  -> UPDATING - No or corrupted journal file was found.
+    //              - Dirty flag was set in index header.
+    //  -> READY    - Index was read successfully or was interrupted by
+    //                pre-shutdown.
+    //  -> SHUTDOWN - This could happen only in case of pre-shutdown failure.
+    READING  = 1,
+
+    // Index is being written to the disk.
+    // Possible transitions:
+    //  -> READY    - Writing of index finished or was interrupted by
+    //                pre-shutdown..
+    //  -> UPDATING - Writing of index finished, but index was found outdated
+    //                during writing.
+    //  -> SHUTDOWN - This could happen only in case of pre-shutdown failure.
+    WRITING  = 2,
+
+    // Index is being build.
+    // Possible transitions:
+    //  -> READY    - Building of index finished or was interrupted by
+    //                pre-shutdown.
+    //  -> SHUTDOWN - This could happen only in case of pre-shutdown failure.
+    BUILDING = 3,
+
+    // Index is being updated.
+    // Possible transitions:
+    //  -> READY    - Updating of index finished or was interrupted by
+    //                pre-shutdown.
+    //  -> SHUTDOWN - This could happen only in case of pre-shutdown failure.
+    UPDATING = 4,
+
+    // Index is ready.
+    // Possible transitions:
+    //  -> UPDATING - Index was found outdated.
+    //  -> SHUTDOWN - Index is shutting down.
+    READY    = 5,
+
+    // Index is shutting down.
+    SHUTDOWN = 6
+  };
+
+  static char const * StateString(EState aState);
+  void ChangeState(EState aNewState);
+  void NotifyAsyncGetDiskConsumptionCallbacks();
+
+  // Allocates and releases buffer used for reading and writing index.
+  void AllocBuffer();
+  void ReleaseBuffer();
+
+  // Methods used by CacheIndexEntryAutoManage to keep the iterators up to date.
+  void AddRecordToIterators(CacheIndexRecord *aRecord);
+  void RemoveRecordFromIterators(CacheIndexRecord *aRecord);
+  void ReplaceRecordInIterators(CacheIndexRecord *aOldRecord,
+                                CacheIndexRecord *aNewRecord);
+
+  // Memory reporting (private part)
+  size_t SizeOfExcludingThisInternal(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  void ReportHashStats();
+
+  static mozilla::StaticRefPtr<CacheIndex> gInstance;
+  static StaticMutex sLock;
+
+  nsCOMPtr<nsIFile> mCacheDirectory;
+
+  EState         mState;
+  // Timestamp of time when the index was initialized. We use it to delay
+  // initial update or build of index.
+  TimeStamp      mStartTime;
+  // Set to true in PreShutdown(), it is checked on variaous places to prevent
+  // starting any process (write, update, etc.) during shutdown.
+  bool           mShuttingDown;
+  // When set to true, update process should start as soon as possible. This
+  // flag is set whenever we find some inconsistency which would be fixed by
+  // update process. The flag is checked always when switching to READY state.
+  // To make sure we start the update process as soon as possible, methods that
+  // set this flag should also call StartUpdatingIndexIfNeeded() to cover the
+  // case when we are currently in READY state.
+  bool           mIndexNeedsUpdate;
+  // Set at the beginning of RemoveAll() which clears the whole index. When
+  // removing all entries we must stop any pending reading, writing, updating or
+  // building operation. This flag is checked at various places and it prevents
+  // we won't start another operation (e.g. canceling reading of the index would
+  // normally start update or build process)
+  bool           mRemovingAll;
+  // Whether the index file on disk exists and is valid.
+  bool           mIndexOnDiskIsValid;
+  // When something goes wrong during updating or building process, we don't
+  // mark index clean (and also don't write journal) to ensure that update or
+  // build will be initiated on the next start.
+  bool           mDontMarkIndexClean;
+  // Timestamp value from index file. It is used during update process to skip
+  // entries that were last modified before this timestamp.
+  uint32_t       mIndexTimeStamp;
+  // Timestamp of last time the index was dumped to disk.
+  // NOTE: The index might not be necessarily dumped at this time. The value
+  // is used to schedule next dump of the index.
+  TimeStamp      mLastDumpTime;
+
+  // Timer of delayed update/build.
+  nsCOMPtr<nsITimer> mUpdateTimer;
+  // True when build or update event is posted
+  bool               mUpdateEventPending;
+
+  // Helper members used when reading/writing index from/to disk.
+  // Contains number of entries that should be skipped:
+  //  - in hashtable when writing index because they were already written
+  //  - in index file when reading index because they were already read
+  uint32_t                  mSkipEntries;
+  // Number of entries that should be written to disk. This is number of entries
+  // in hashtable that are initialized and are not marked as removed when writing
+  // begins.
+  uint32_t                  mProcessEntries;
+  char                     *mRWBuf;
+  uint32_t                  mRWBufSize;
+  uint32_t                  mRWBufPos;
+  RefPtr<CacheHash>         mRWHash;
+
+  // True if read or write operation is pending. It is used to ensure that
+  // mRWBuf is not freed until OnDataRead or OnDataWritten is called.
+  bool                      mRWPending;
+
+  // Reading of journal succeeded if true.
+  bool                      mJournalReadSuccessfully;
+
+  // Handle used for writing and reading index file.
+  RefPtr<CacheFileHandle> mIndexHandle;
+  // Handle used for reading journal file.
+  RefPtr<CacheFileHandle> mJournalHandle;
+  // Used to check the existence of the file during reading process.
+  RefPtr<CacheFileHandle> mTmpHandle;
+
+  RefPtr<FileOpenHelper>    mIndexFileOpener;
+  RefPtr<FileOpenHelper>    mJournalFileOpener;
+  RefPtr<FileOpenHelper>    mTmpFileOpener;
+
+  // Directory enumerator used when building and updating index.
+  nsCOMPtr<nsIDirectoryEnumerator> mDirEnumerator;
+
+  // Main index hashtable.
+  nsTHashtable<CacheIndexEntry> mIndex;
+
+  // We cannot add, remove or change any entry in mIndex in states READING and
+  // WRITING. We track all changes in mPendingUpdates during these states.
+  nsTHashtable<CacheIndexEntryUpdate> mPendingUpdates;
+
+  // Contains information statistics for mIndex + mPendingUpdates.
+  CacheIndexStats               mIndexStats;
+
+  // When reading journal, we must first parse the whole file and apply the
+  // changes iff the journal was read successfully. mTmpJournal is used to store
+  // entries from the journal file. We throw away all these entries if parsing
+  // of the journal fails or the hash does not match.
+  nsTHashtable<CacheIndexEntry> mTmpJournal;
+
+  // FrecencyArray maintains order of entry records for eviction. Ideally, the
+  // records would be ordered by frecency all the time, but since this would be
+  // quite expensive, we allow certain amount of entries to be out of order.
+  // When the frecency is updated the new value is always bigger than the old
+  // one. Instead of keeping updated entries at the same position, we move them
+  // at the end of the array. This protects recently updated entries from
+  // eviction. The array is sorted once we hit the limit of maximum unsorted
+  // entries.
+  class FrecencyArray
+  {
+    class Iterator
+    {
+    public:
+      explicit Iterator(nsTArray<CacheIndexRecord *> *aRecs)
+        : mRecs(aRecs)
+        , mIdx(0)
+      {
+        while (!Done() && !(*mRecs)[mIdx]) {
+          mIdx++;
+        }
+      }
+
+      bool Done() const { return mIdx == mRecs->Length(); }
+
+      CacheIndexRecord* Get() const
+      {
+        MOZ_ASSERT(!Done());
+        return (*mRecs)[mIdx];
+      }
+
+      void Next()
+      {
+        MOZ_ASSERT(!Done());
+        ++mIdx;
+        while (!Done() && !(*mRecs)[mIdx]) {
+          mIdx++;
+        }
+      }
+
+    private:
+      nsTArray<CacheIndexRecord *> *mRecs;
+      uint32_t mIdx;
+    };
+
+  public:
+    Iterator Iter() { return Iterator(&mRecs); }
+
+    FrecencyArray() : mUnsortedElements(0)
+                    , mRemovedElements(0) {}
+
+    // Methods used by CacheIndexEntryAutoManage to keep the array up to date.
+    void AppendRecord(CacheIndexRecord *aRecord);
+    void RemoveRecord(CacheIndexRecord *aRecord);
+    void ReplaceRecord(CacheIndexRecord *aOldRecord,
+                       CacheIndexRecord *aNewRecord);
+    void SortIfNeeded();
+
+    size_t Length() const { return mRecs.Length() - mRemovedElements; }
+    void Clear() { mRecs.Clear(); }
+
+  private:
+    friend class CacheIndex;
+
+    nsTArray<CacheIndexRecord *> mRecs;
+    uint32_t                     mUnsortedElements;
+    // Instead of removing elements from the array immediately, we null them out
+    // and the iterator skips them when accessing the array. The null pointers
+    // are placed at the end during sorting and we strip them out all at once.
+    // This saves moving a lot of memory in nsTArray::RemoveElementsAt.
+    uint32_t                     mRemovedElements;
+  };
+
+  FrecencyArray mFrecencyArray;
+
+  nsTArray<CacheIndexIterator *> mIterators;
+
+  // This flag is true iff we are between CacheStorageService:Clear() and processing
+  // all contexts to be evicted.  It will make UI to show "calculating" instead of
+  // any intermediate cache size.
+  bool mAsyncGetDiskConsumptionBlocked;
+
+  class DiskConsumptionObserver : public Runnable
+  {
+  public:
+    static DiskConsumptionObserver* Init(nsICacheStorageConsumptionObserver* aObserver)
+    {
+      nsWeakPtr observer = do_GetWeakReference(aObserver);
+      if (!observer)
+        return nullptr;
+
+      return new DiskConsumptionObserver(observer);
+    }
+
+    void OnDiskConsumption(int64_t aSize)
+    {
+      mSize = aSize;
+      NS_DispatchToMainThread(this);
+    }
+
+  private:
+    explicit DiskConsumptionObserver(nsWeakPtr const &aWeakObserver)
+      : mObserver(aWeakObserver) { }
+    virtual ~DiskConsumptionObserver() {
+      if (mObserver && !NS_IsMainThread()) {
+        NS_ReleaseOnMainThread(mObserver.forget());
+      }
+    }
+
+    NS_IMETHOD Run() override
+    {
+      MOZ_ASSERT(NS_IsMainThread());
+
+      nsCOMPtr<nsICacheStorageConsumptionObserver> observer =
+        do_QueryReferent(mObserver);
+
+      mObserver = nullptr;
+
+      if (observer) {
+        observer->OnNetworkCacheDiskConsumption(mSize);
+      }
+
+      return NS_OK;
+    }
+
+    nsWeakPtr mObserver;
+    int64_t mSize;
+  };
+
+  // List of async observers that want to get disk consumption information
+  nsTArray<RefPtr<DiskConsumptionObserver> > mDiskConsumptionObservers;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheIndexContextIterator.cpp b/netwerk/cache2/CacheIndexContextIterator.cpp
new file mode 100644
index 0000000000..5f3cb7bd7c
--- /dev/null
+++ b/netwerk/cache2/CacheIndexContextIterator.cpp
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheIndexContextIterator.h"
+#include "CacheIndex.h"
+#include "nsString.h"
+
+
+namespace mozilla {
+namespace net {
+
+CacheIndexContextIterator::CacheIndexContextIterator(CacheIndex *aIndex,
+                                                     bool aAddNew,
+                                                     nsILoadContextInfo *aInfo)
+  : CacheIndexIterator(aIndex, aAddNew)
+  , mInfo(aInfo)
+{
+}
+
+CacheIndexContextIterator::~CacheIndexContextIterator()
+{
+}
+
+void
+CacheIndexContextIterator::AddRecord(CacheIndexRecord *aRecord)
+{
+  if (CacheIndexEntry::RecordMatchesLoadContextInfo(aRecord, mInfo)) {
+    CacheIndexIterator::AddRecord(aRecord);
+  }
+}
+
+void
+CacheIndexContextIterator::AddRecords(
+  const nsTArray<CacheIndexRecord *> &aRecords)
+{
+  // We need to add one by one so that those with wrong context are ignored.
+  for (uint32_t i = 0; i < aRecords.Length(); ++i) {
+    AddRecord(aRecords[i]);
+  }
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheIndexContextIterator.h b/netwerk/cache2/CacheIndexContextIterator.h
new file mode 100644
index 0000000000..32eb9c4789
--- /dev/null
+++ b/netwerk/cache2/CacheIndexContextIterator.h
@@ -0,0 +1,32 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheIndexContextIterator__h__
+#define CacheIndexContextIterator__h__
+
+#include "CacheIndexIterator.h"
+
+class nsILoadContextInfo;
+
+namespace mozilla {
+namespace net {
+
+class CacheIndexContextIterator : public CacheIndexIterator
+{
+public:
+  CacheIndexContextIterator(CacheIndex *aIndex, bool aAddNew,
+                            nsILoadContextInfo *aInfo);
+  virtual ~CacheIndexContextIterator();
+
+private:
+  virtual void AddRecord(CacheIndexRecord *aRecord);
+  virtual void AddRecords(const nsTArray<CacheIndexRecord *> &aRecords);
+
+  nsCOMPtr<nsILoadContextInfo> mInfo;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheIndexIterator.cpp b/netwerk/cache2/CacheIndexIterator.cpp
new file mode 100644
index 0000000000..0d56ec81f5
--- /dev/null
+++ b/netwerk/cache2/CacheIndexIterator.cpp
@@ -0,0 +1,118 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheIndexIterator.h"
+#include "CacheIndex.h"
+#include "nsString.h"
+#include "mozilla/DebugOnly.h"
+
+
+namespace mozilla {
+namespace net {
+
+CacheIndexIterator::CacheIndexIterator(CacheIndex *aIndex, bool aAddNew)
+  : mStatus(NS_OK)
+  , mIndex(aIndex)
+  , mAddNew(aAddNew)
+{
+  LOG(("CacheIndexIterator::CacheIndexIterator() [this=%p]", this));
+}
+
+CacheIndexIterator::~CacheIndexIterator()
+{
+  LOG(("CacheIndexIterator::~CacheIndexIterator() [this=%p]", this));
+
+  Close();
+}
+
+nsresult
+CacheIndexIterator::GetNextHash(SHA1Sum::Hash *aHash)
+{
+  LOG(("CacheIndexIterator::GetNextHash() [this=%p]", this));
+
+  StaticMutexAutoLock lock(CacheIndex::sLock);
+
+  if (NS_FAILED(mStatus)) {
+    return mStatus;
+  }
+
+  if (!mRecords.Length()) {
+    CloseInternal(NS_ERROR_NOT_AVAILABLE);
+    return mStatus;
+  }
+
+  memcpy(aHash, mRecords[mRecords.Length() - 1]->mHash, sizeof(SHA1Sum::Hash));
+  mRecords.RemoveElementAt(mRecords.Length() - 1);
+
+  return NS_OK;
+}
+
+nsresult
+CacheIndexIterator::Close()
+{
+  LOG(("CacheIndexIterator::Close() [this=%p]", this));
+
+  StaticMutexAutoLock lock(CacheIndex::sLock);
+
+  return CloseInternal(NS_ERROR_NOT_AVAILABLE);
+}
+
+nsresult
+CacheIndexIterator::CloseInternal(nsresult aStatus)
+{
+  LOG(("CacheIndexIterator::CloseInternal() [this=%p, status=0x%08x]", this,
+       aStatus));
+
+  // Make sure status will be a failure
+  MOZ_ASSERT(NS_FAILED(aStatus));
+  if (NS_SUCCEEDED(aStatus)) {
+    aStatus = NS_ERROR_UNEXPECTED;
+  }
+
+  if (NS_FAILED(mStatus)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  DebugOnly<bool> removed = mIndex->mIterators.RemoveElement(this);
+  MOZ_ASSERT(removed);
+  mStatus = aStatus;
+
+  return NS_OK;
+}
+
+void
+CacheIndexIterator::AddRecord(CacheIndexRecord *aRecord)
+{
+  LOG(("CacheIndexIterator::AddRecord() [this=%p, record=%p]", this, aRecord));
+
+  mRecords.AppendElement(aRecord);
+}
+
+bool
+CacheIndexIterator::RemoveRecord(CacheIndexRecord *aRecord)
+{
+  LOG(("CacheIndexIterator::RemoveRecord() [this=%p, record=%p]", this,
+       aRecord));
+
+  return mRecords.RemoveElement(aRecord);
+}
+
+bool
+CacheIndexIterator::ReplaceRecord(CacheIndexRecord *aOldRecord,
+                                  CacheIndexRecord *aNewRecord)
+{
+  LOG(("CacheIndexIterator::ReplaceRecord() [this=%p, oldRecord=%p, "
+       "newRecord=%p]", this, aOldRecord, aNewRecord));
+
+  if (RemoveRecord(aOldRecord)) {
+    AddRecord(aNewRecord);
+    return true;
+  }
+
+  return false;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheIndexIterator.h b/netwerk/cache2/CacheIndexIterator.h
new file mode 100644
index 0000000000..9fe96989ec
--- /dev/null
+++ b/netwerk/cache2/CacheIndexIterator.h
@@ -0,0 +1,59 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheIndexIterator__h__
+#define CacheIndexIterator__h__
+
+#include "nsTArray.h"
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+#include "mozilla/SHA1.h"
+
+namespace mozilla {
+namespace net {
+
+class CacheIndex;
+struct CacheIndexRecord;
+
+class CacheIndexIterator
+{
+public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CacheIndexIterator)
+
+  CacheIndexIterator(CacheIndex *aIndex, bool aAddNew);
+
+protected:
+  virtual ~CacheIndexIterator();
+
+public:
+  // Returns a hash of a next entry. If there is no entry NS_ERROR_NOT_AVAILABLE
+  // is returned and the iterator is closed. Other error is returned when the
+  // iterator is closed for other reason, e.g. shutdown.
+  nsresult GetNextHash(SHA1Sum::Hash *aHash);
+
+  // Closes the iterator. This means the iterator is removed from the list of
+  // iterators in CacheIndex.
+  nsresult Close();
+
+protected:
+  friend class CacheIndex;
+
+  nsresult CloseInternal(nsresult aStatus);
+
+  bool ShouldBeNewAdded() { return mAddNew; }
+  virtual void AddRecord(CacheIndexRecord *aRecord);
+  bool RemoveRecord(CacheIndexRecord *aRecord);
+  bool ReplaceRecord(CacheIndexRecord *aOldRecord,
+                     CacheIndexRecord *aNewRecord);
+
+  nsresult                     mStatus;
+  RefPtr<CacheIndex>           mIndex;
+  nsTArray<CacheIndexRecord *> mRecords;
+  bool                         mAddNew;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheLog.cpp b/netwerk/cache2/CacheLog.cpp
new file mode 100644
index 0000000000..862c3316ff
--- /dev/null
+++ b/netwerk/cache2/CacheLog.cpp
@@ -0,0 +1,22 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+
+namespace mozilla {
+namespace net {
+
+// Log module for cache2 (2013) cache implementation logging...
+//
+// To enable logging (see prlog.h for full details):
+//
+//    set MOZ_LOG=cache2:5
+//    set MOZ_LOG_FILE=network.log
+//
+// This enables LogLevel::Debug level information and places all output in
+// the file network.log.
+LazyLogModule gCache2Log("cache2");
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheLog.h b/netwerk/cache2/CacheLog.h
new file mode 100644
index 0000000000..7191d47926
--- /dev/null
+++ b/netwerk/cache2/CacheLog.h
@@ -0,0 +1,20 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef Cache2Log__h__
+#define Cache2Log__h__
+
+#include "mozilla/Logging.h"
+
+namespace mozilla {
+namespace net {
+
+extern LazyLogModule gCache2Log;
+#define LOG(x)  MOZ_LOG(gCache2Log, mozilla::LogLevel::Debug, x)
+#define LOG_ENABLED() MOZ_LOG_TEST(gCache2Log, mozilla::LogLevel::Debug)
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheObserver.cpp b/netwerk/cache2/CacheObserver.cpp
new file mode 100644
index 0000000000..1eb76e8c5b
--- /dev/null
+++ b/netwerk/cache2/CacheObserver.cpp
@@ -0,0 +1,581 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheObserver.h"
+
+#include "CacheStorageService.h"
+#include "CacheFileIOManager.h"
+#include "LoadContextInfo.h"
+#include "nsICacheStorage.h"
+#include "nsIObserverService.h"
+#include "mozilla/Services.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/TimeStamp.h"
+#include "nsServiceManagerUtils.h"
+#include "mozilla/net/NeckoCommon.h"
+#include "prsystem.h"
+#include <time.h>
+#include <math.h>
+
+namespace mozilla {
+namespace net {
+
+CacheObserver* CacheObserver::sSelf = nullptr;
+
+static uint32_t const kDefaultUseNewCache = 1; // Use the new cache by default
+uint32_t CacheObserver::sUseNewCache = kDefaultUseNewCache;
+
+static bool sUseNewCacheTemp = false; // Temp trigger to not lose early adopters
+
+static int32_t const kAutoDeleteCacheVersion = -1; // Auto-delete off by default
+static int32_t sAutoDeleteCacheVersion = kAutoDeleteCacheVersion;
+
+static int32_t const kDefaultHalfLifeExperiment = -1; // Disabled
+int32_t CacheObserver::sHalfLifeExperiment = kDefaultHalfLifeExperiment;
+
+static float const kDefaultHalfLifeHours = 1.0F; // 1 hour
+float CacheObserver::sHalfLifeHours = kDefaultHalfLifeHours;
+
+static bool const kDefaultUseDiskCache = true;
+bool CacheObserver::sUseDiskCache = kDefaultUseDiskCache;
+
+static bool const kDefaultUseMemoryCache = true;
+bool CacheObserver::sUseMemoryCache = kDefaultUseMemoryCache;
+
+static uint32_t const kDefaultMetadataMemoryLimit = 250; // 0.25 MB
+uint32_t CacheObserver::sMetadataMemoryLimit = kDefaultMetadataMemoryLimit;
+
+static int32_t const kDefaultMemoryCacheCapacity = -1; // autodetect
+int32_t CacheObserver::sMemoryCacheCapacity = kDefaultMemoryCacheCapacity;
+// Cache of the calculated memory capacity based on the system memory size
+int32_t CacheObserver::sAutoMemoryCacheCapacity = -1;
+
+static uint32_t const kDefaultDiskCacheCapacity = 250 * 1024; // 250 MB
+Atomic<uint32_t,Relaxed> CacheObserver::sDiskCacheCapacity
+                                           (kDefaultDiskCacheCapacity);
+
+static uint32_t const kDefaultDiskFreeSpaceSoftLimit = 5 * 1024; // 5MB
+uint32_t CacheObserver::sDiskFreeSpaceSoftLimit = kDefaultDiskFreeSpaceSoftLimit;
+
+static uint32_t const kDefaultDiskFreeSpaceHardLimit = 1024; // 1MB
+uint32_t CacheObserver::sDiskFreeSpaceHardLimit = kDefaultDiskFreeSpaceHardLimit;
+
+static bool const kDefaultSmartCacheSizeEnabled = false;
+bool CacheObserver::sSmartCacheSizeEnabled = kDefaultSmartCacheSizeEnabled;
+
+static uint32_t const kDefaultPreloadChunkCount = 4;
+uint32_t CacheObserver::sPreloadChunkCount = kDefaultPreloadChunkCount;
+
+static int32_t const kDefaultMaxMemoryEntrySize = 4 * 1024; // 4 MB
+int32_t CacheObserver::sMaxMemoryEntrySize = kDefaultMaxMemoryEntrySize;
+
+static int32_t const kDefaultMaxDiskEntrySize = 50 * 1024; // 50 MB
+int32_t CacheObserver::sMaxDiskEntrySize = kDefaultMaxDiskEntrySize;
+
+static uint32_t const kDefaultMaxDiskChunksMemoryUsage = 10 * 1024; // 10MB
+uint32_t CacheObserver::sMaxDiskChunksMemoryUsage = kDefaultMaxDiskChunksMemoryUsage;
+
+static uint32_t const kDefaultMaxDiskPriorityChunksMemoryUsage = 10 * 1024; // 10MB
+uint32_t CacheObserver::sMaxDiskPriorityChunksMemoryUsage = kDefaultMaxDiskPriorityChunksMemoryUsage;
+
+static uint32_t const kDefaultCompressionLevel = 1;
+uint32_t CacheObserver::sCompressionLevel = kDefaultCompressionLevel;
+
+static bool kDefaultSanitizeOnShutdown = false;
+bool CacheObserver::sSanitizeOnShutdown = kDefaultSanitizeOnShutdown;
+
+static bool kDefaultClearCacheOnShutdown = false;
+bool CacheObserver::sClearCacheOnShutdown = kDefaultClearCacheOnShutdown;
+
+static bool kDefaultCacheFSReported = false;
+bool CacheObserver::sCacheFSReported = kDefaultCacheFSReported;
+
+static bool kDefaultHashStatsReported = false;
+bool CacheObserver::sHashStatsReported = kDefaultHashStatsReported;
+
+static uint32_t const kDefaultMaxShutdownIOLag = 2; // seconds
+Atomic<uint32_t, Relaxed> CacheObserver::sMaxShutdownIOLag(kDefaultMaxShutdownIOLag);
+
+Atomic<PRIntervalTime> CacheObserver::sShutdownDemandedTime(PR_INTERVAL_NO_TIMEOUT);
+
+NS_IMPL_ISUPPORTS(CacheObserver,
+                  nsIObserver,
+                  nsISupportsWeakReference)
+
+// static
+nsresult
+CacheObserver::Init()
+{
+  if (IsNeckoChild()) {
+    return NS_OK;
+  }
+
+  if (sSelf) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (!obs) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  sSelf = new CacheObserver();
+  NS_ADDREF(sSelf);
+
+  obs->AddObserver(sSelf, "prefservice:after-app-defaults", true);
+  obs->AddObserver(sSelf, "profile-do-change", true);
+  obs->AddObserver(sSelf, "browser-delayed-startup-finished", true);
+  obs->AddObserver(sSelf, "profile-before-change", true);
+  obs->AddObserver(sSelf, "xpcom-shutdown", true);
+  obs->AddObserver(sSelf, "last-pb-context-exited", true);
+  obs->AddObserver(sSelf, "clear-origin-attributes-data", true);
+  obs->AddObserver(sSelf, "memory-pressure", true);
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheObserver::Shutdown()
+{
+  if (!sSelf) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  NS_RELEASE(sSelf);
+  return NS_OK;
+}
+
+void
+CacheObserver::AttachToPreferences()
+{
+  sAutoDeleteCacheVersion = mozilla::Preferences::GetInt(
+    "browser.cache.auto_delete_cache_version", kAutoDeleteCacheVersion);
+
+  mozilla::Preferences::AddUintVarCache(
+    &sUseNewCache, "browser.cache.use_new_backend", kDefaultUseNewCache);
+  mozilla::Preferences::AddBoolVarCache(
+    &sUseNewCacheTemp, "browser.cache.use_new_backend_temp", false);
+
+  mozilla::Preferences::AddBoolVarCache(
+    &sUseDiskCache, "browser.cache.disk.enable", kDefaultUseDiskCache);
+  mozilla::Preferences::AddBoolVarCache(
+    &sUseMemoryCache, "browser.cache.memory.enable", kDefaultUseMemoryCache);
+
+  mozilla::Preferences::AddUintVarCache(
+    &sMetadataMemoryLimit, "browser.cache.disk.metadata_memory_limit", kDefaultMetadataMemoryLimit);
+
+  mozilla::Preferences::AddAtomicUintVarCache(
+    &sDiskCacheCapacity, "browser.cache.disk.capacity", kDefaultDiskCacheCapacity);
+  mozilla::Preferences::AddBoolVarCache(
+    &sSmartCacheSizeEnabled, "browser.cache.disk.smart_size.enabled", kDefaultSmartCacheSizeEnabled);
+  mozilla::Preferences::AddIntVarCache(
+    &sMemoryCacheCapacity, "browser.cache.memory.capacity", kDefaultMemoryCacheCapacity);
+
+  mozilla::Preferences::AddUintVarCache(
+    &sDiskFreeSpaceSoftLimit, "browser.cache.disk.free_space_soft_limit", kDefaultDiskFreeSpaceSoftLimit);
+  mozilla::Preferences::AddUintVarCache(
+    &sDiskFreeSpaceHardLimit, "browser.cache.disk.free_space_hard_limit", kDefaultDiskFreeSpaceHardLimit);
+
+  mozilla::Preferences::AddUintVarCache(
+    &sPreloadChunkCount, "browser.cache.disk.preload_chunk_count", kDefaultPreloadChunkCount);
+
+  mozilla::Preferences::AddIntVarCache(
+    &sMaxDiskEntrySize, "browser.cache.disk.max_entry_size", kDefaultMaxDiskEntrySize);
+  mozilla::Preferences::AddIntVarCache(
+    &sMaxMemoryEntrySize, "browser.cache.memory.max_entry_size", kDefaultMaxMemoryEntrySize);
+
+  mozilla::Preferences::AddUintVarCache(
+    &sMaxDiskChunksMemoryUsage, "browser.cache.disk.max_chunks_memory_usage", kDefaultMaxDiskChunksMemoryUsage);
+  mozilla::Preferences::AddUintVarCache(
+    &sMaxDiskPriorityChunksMemoryUsage, "browser.cache.disk.max_priority_chunks_memory_usage", kDefaultMaxDiskPriorityChunksMemoryUsage);
+
+  // http://mxr.mozilla.org/mozilla-central/source/netwerk/cache/nsCacheEntryDescriptor.cpp#367
+  mozilla::Preferences::AddUintVarCache(
+    &sCompressionLevel, "browser.cache.compression_level", kDefaultCompressionLevel);
+
+  mozilla::Preferences::GetComplex(
+    "browser.cache.disk.parent_directory", NS_GET_IID(nsIFile),
+    getter_AddRefs(mCacheParentDirectoryOverride));
+
+  // First check the default value.  If it is at -1, the experient
+  // is turned off.  If it is at 0, then use the user pref value
+  // instead.
+  sHalfLifeExperiment = mozilla::Preferences::GetDefaultInt(
+    "browser.cache.frecency_experiment", kDefaultHalfLifeExperiment);
+
+  if (sHalfLifeExperiment == 0) {
+    // Default preferences indicate we want to run the experiment,
+    // hence read the user value.
+    sHalfLifeExperiment = mozilla::Preferences::GetInt(
+      "browser.cache.frecency_experiment", sHalfLifeExperiment);
+  }
+
+  if (sHalfLifeExperiment == 0) {
+    // The experiment has not yet been initialized but is engaged, do
+    // the initialization now.
+    srand(time(NULL));
+    sHalfLifeExperiment = (rand() % 4) + 1;
+    // Store the experiemnt value, since we need it not to change between
+    // browser sessions.
+    mozilla::Preferences::SetInt(
+      "browser.cache.frecency_experiment", sHalfLifeExperiment);
+  }
+
+  switch (sHalfLifeExperiment) {
+  case 1: // The experiment is engaged
+    sHalfLifeHours = 0.083F; // ~5 mintues
+    break;
+  case 2:
+    sHalfLifeHours = 0.25F; // 15 mintues
+    break;
+  case 3:
+    sHalfLifeHours = 1.0F;
+    break;
+  case 4:
+    sHalfLifeHours = 6.0F;
+    break;
+
+  case -1:
+  default: // The experiment is off or broken
+    sHalfLifeExperiment = -1;
+    sHalfLifeHours = std::max(0.01F, std::min(1440.0F, mozilla::Preferences::GetFloat(
+      "browser.cache.frecency_half_life_hours", kDefaultHalfLifeHours)));
+    break;
+  }
+
+  mozilla::Preferences::AddBoolVarCache(
+    &sSanitizeOnShutdown, "privacy.sanitize.sanitizeOnShutdown", kDefaultSanitizeOnShutdown);
+  mozilla::Preferences::AddBoolVarCache(
+    &sClearCacheOnShutdown, "privacy.clearOnShutdown.cache", kDefaultClearCacheOnShutdown);
+
+  mozilla::Preferences::AddAtomicUintVarCache(
+    &sMaxShutdownIOLag, "browser.cache.max_shutdown_io_lag", kDefaultMaxShutdownIOLag);
+}
+
+// static
+uint32_t CacheObserver::MemoryCacheCapacity()
+{
+  if (sMemoryCacheCapacity >= 0)
+    return sMemoryCacheCapacity << 10;
+
+  if (sAutoMemoryCacheCapacity != -1)
+    return sAutoMemoryCacheCapacity;
+
+  static uint64_t bytes = PR_GetPhysicalMemorySize();
+  // If getting the physical memory failed, arbitrarily assume
+  // 32 MB of RAM. We use a low default to have a reasonable
+  // size on all the devices we support.
+  if (bytes == 0)
+    bytes = 32 * 1024 * 1024;
+
+  // Conversion from unsigned int64_t to double doesn't work on all platforms.
+  // We need to truncate the value at INT64_MAX to make sure we don't
+  // overflow.
+  if (bytes > INT64_MAX)
+    bytes = INT64_MAX;
+
+  uint64_t kbytes = bytes >> 10;
+  double kBytesD = double(kbytes);
+  double x = log(kBytesD)/log(2.0) - 14;
+
+  int32_t capacity = 0;
+  if (x > 0) {
+    capacity = (int32_t)(x * x / 3.0 + x + 2.0 / 3 + 0.1); // 0.1 for rounding
+    if (capacity > 32)
+      capacity = 32;
+    capacity <<= 20;
+  }
+
+  // Result is in bytes.
+  return sAutoMemoryCacheCapacity = capacity;
+}
+
+// static
+bool CacheObserver::UseNewCache()
+{
+  uint32_t useNewCache = sUseNewCache;
+
+  if (sUseNewCacheTemp)
+    useNewCache = 1;
+
+  switch (useNewCache) {
+    case 0: // use the old cache backend
+      return false;
+
+    case 1: // use the new cache backend
+      return true;
+  }
+
+  return true;
+}
+
+// static
+void
+CacheObserver::SetDiskCacheCapacity(uint32_t aCapacity)
+{
+  sDiskCacheCapacity = aCapacity >> 10;
+
+  if (!sSelf) {
+    return;
+  }
+
+  if (NS_IsMainThread()) {
+    sSelf->StoreDiskCacheCapacity();
+  } else {
+    nsCOMPtr<nsIRunnable> event =
+      NewRunnableMethod(sSelf, &CacheObserver::StoreDiskCacheCapacity);
+    NS_DispatchToMainThread(event);
+  }
+}
+
+void
+CacheObserver::StoreDiskCacheCapacity()
+{
+  mozilla::Preferences::SetInt("browser.cache.disk.capacity",
+                               sDiskCacheCapacity);
+}
+
+// static
+void
+CacheObserver::SetCacheFSReported()
+{
+  sCacheFSReported = true;
+
+  if (!sSelf) {
+    return;
+  }
+
+  if (NS_IsMainThread()) {
+    sSelf->StoreCacheFSReported();
+  } else {
+    nsCOMPtr<nsIRunnable> event =
+      NewRunnableMethod(sSelf, &CacheObserver::StoreCacheFSReported);
+    NS_DispatchToMainThread(event);
+  }
+}
+
+void
+CacheObserver::StoreCacheFSReported()
+{
+  mozilla::Preferences::SetInt("browser.cache.disk.filesystem_reported",
+                               sCacheFSReported);
+}
+
+// static
+void
+CacheObserver::SetHashStatsReported()
+{
+  sHashStatsReported = true;
+
+  if (!sSelf) {
+    return;
+  }
+
+  if (NS_IsMainThread()) {
+    sSelf->StoreHashStatsReported();
+  } else {
+    nsCOMPtr<nsIRunnable> event =
+      NewRunnableMethod(sSelf, &CacheObserver::StoreHashStatsReported);
+    NS_DispatchToMainThread(event);
+  }
+}
+
+void
+CacheObserver::StoreHashStatsReported()
+{
+  mozilla::Preferences::SetInt("browser.cache.disk.hashstats_reported",
+                               sHashStatsReported);
+}
+
+// static
+void CacheObserver::ParentDirOverride(nsIFile** aDir)
+{
+  if (NS_WARN_IF(!aDir))
+    return;
+
+  *aDir = nullptr;
+
+  if (!sSelf)
+    return;
+  if (!sSelf->mCacheParentDirectoryOverride)
+    return;
+
+  sSelf->mCacheParentDirectoryOverride->Clone(aDir);
+}
+
+namespace {
+namespace CacheStorageEvictHelper {
+
+nsresult ClearStorage(bool const aPrivate,
+                      bool const aAnonymous,
+                      NeckoOriginAttributes &aOa)
+{
+  nsresult rv;
+
+  aOa.SyncAttributesWithPrivateBrowsing(aPrivate);
+  RefPtr<LoadContextInfo> info = GetLoadContextInfo(aAnonymous, aOa);
+
+  nsCOMPtr<nsICacheStorage> storage;
+  RefPtr<CacheStorageService> service = CacheStorageService::Self();
+  NS_ENSURE_TRUE(service, NS_ERROR_FAILURE);
+
+  // Clear disk storage
+  rv = service->DiskCacheStorage(info, false, getter_AddRefs(storage));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = storage->AsyncEvictStorage(nullptr);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Clear memory storage
+  rv = service->MemoryCacheStorage(info, getter_AddRefs(storage));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = storage->AsyncEvictStorage(nullptr);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult Run(NeckoOriginAttributes &aOa)
+{
+  nsresult rv;
+
+  // Clear all [private X anonymous] combinations
+  rv = ClearStorage(false, false, aOa);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = ClearStorage(false, true, aOa);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = ClearStorage(true, false, aOa);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = ClearStorage(true, true, aOa);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+} // CacheStorageEvictHelper
+} // anon
+
+// static
+bool CacheObserver::EntryIsTooBig(int64_t aSize, bool aUsingDisk)
+{
+  // If custom limit is set, check it.
+  int64_t preferredLimit = aUsingDisk ? sMaxDiskEntrySize : sMaxMemoryEntrySize;
+
+  // do not convert to bytes when the limit is -1, which means no limit
+  if (preferredLimit > 0) {
+    preferredLimit <<= 10;
+  }
+
+  if (preferredLimit != -1 && aSize > preferredLimit)
+    return true;
+
+  // Otherwise (or when in the custom limit), check limit based on the global
+  // limit.  It's 1/8 (>> 3) of the respective capacity.
+  int64_t derivedLimit = aUsingDisk
+    ? (static_cast<int64_t>(DiskCacheCapacity() >> 3))
+    : (static_cast<int64_t>(MemoryCacheCapacity() >> 3));
+
+  if (aSize > derivedLimit)
+    return true;
+
+  return false;
+}
+
+// static
+bool CacheObserver::IsPastShutdownIOLag()
+{
+#ifdef DEBUG
+  return false;
+#endif
+
+  if (sShutdownDemandedTime == PR_INTERVAL_NO_TIMEOUT ||
+      sMaxShutdownIOLag == UINT32_MAX) {
+    return false;
+  }
+
+  static const PRIntervalTime kMaxShutdownIOLag =
+    PR_SecondsToInterval(sMaxShutdownIOLag);
+
+  if ((PR_IntervalNow() - sShutdownDemandedTime) > kMaxShutdownIOLag) {
+    return true;
+  }
+
+  return false;
+}
+
+NS_IMETHODIMP
+CacheObserver::Observe(nsISupports* aSubject,
+                       const char* aTopic,
+                       const char16_t* aData)
+{
+  if (!strcmp(aTopic, "prefservice:after-app-defaults")) {
+    CacheFileIOManager::Init();
+    return NS_OK;
+  }
+
+  if (!strcmp(aTopic, "profile-do-change")) {
+    AttachToPreferences();
+    CacheFileIOManager::Init();
+    CacheFileIOManager::OnProfile();
+    return NS_OK;
+  }
+
+  if (!strcmp(aTopic, "browser-delayed-startup-finished")) {
+    uint32_t activeVersion = UseNewCache() ? 1 : 0;
+    CacheStorageService::CleaupCacheDirectories(sAutoDeleteCacheVersion, activeVersion);
+    return NS_OK;
+  }
+
+  if (!strcmp(aTopic, "profile-change-net-teardown") ||
+      !strcmp(aTopic, "profile-before-change") ||
+      !strcmp(aTopic, "xpcom-shutdown")) {
+    if (sShutdownDemandedTime == PR_INTERVAL_NO_TIMEOUT) {
+      sShutdownDemandedTime = PR_IntervalNow();
+    }
+
+    RefPtr<CacheStorageService> service = CacheStorageService::Self();
+    if (service) {
+      service->Shutdown();
+    }
+
+    CacheFileIOManager::Shutdown();
+    return NS_OK;
+  }
+
+  if (!strcmp(aTopic, "last-pb-context-exited")) {
+    RefPtr<CacheStorageService> service = CacheStorageService::Self();
+    if (service) {
+      service->DropPrivateBrowsingEntries();
+    }
+
+    return NS_OK;
+  }
+
+  if (!strcmp(aTopic, "clear-origin-attributes-data")) {
+    NeckoOriginAttributes oa;
+    if (!oa.Init(nsDependentString(aData))) {
+      NS_ERROR("Could not parse NeckoOriginAttributes JSON in clear-origin-attributes-data notification");
+      return NS_OK;
+    }
+
+    nsresult rv = CacheStorageEvictHelper::Run(oa);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return NS_OK;
+  }
+
+  if (!strcmp(aTopic, "memory-pressure")) {
+    RefPtr<CacheStorageService> service = CacheStorageService::Self();
+    if (service)
+      service->PurgeFromMemory(nsICacheStorageService::PURGE_EVERYTHING);
+
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(false, "Missing observer handler");
+  return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheObserver.h b/netwerk/cache2/CacheObserver.h
new file mode 100644
index 0000000000..62e5bbc6ec
--- /dev/null
+++ b/netwerk/cache2/CacheObserver.h
@@ -0,0 +1,121 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheObserver__h__
+#define CacheObserver__h__
+
+#include "nsIObserver.h"
+#include "nsIFile.h"
+#include "nsCOMPtr.h"
+#include "nsWeakReference.h"
+#include <algorithm>
+
+namespace mozilla {
+namespace net {
+
+class CacheObserver : public nsIObserver
+                    , public nsSupportsWeakReference
+{
+  virtual ~CacheObserver() {}
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+  static nsresult Init();
+  static nsresult Shutdown();
+  static CacheObserver* Self() { return sSelf; }
+
+  // Access to preferences
+  static bool UseNewCache();
+  static bool UseDiskCache()
+    { return sUseDiskCache; }
+  static bool UseMemoryCache()
+    { return sUseMemoryCache; }
+  static uint32_t MetadataMemoryLimit() // result in bytes.
+    { return sMetadataMemoryLimit << 10; }
+  static uint32_t MemoryCacheCapacity(); // result in bytes.
+  static uint32_t DiskCacheCapacity() // result in bytes.
+    { return sDiskCacheCapacity << 10; }
+  static void SetDiskCacheCapacity(uint32_t); // parameter in bytes.
+  static uint32_t DiskFreeSpaceSoftLimit() // result in bytes.
+    { return sDiskFreeSpaceSoftLimit << 10; }
+  static uint32_t DiskFreeSpaceHardLimit() // result in bytes.
+    { return sDiskFreeSpaceHardLimit << 10; }
+  static bool SmartCacheSizeEnabled()
+    { return sSmartCacheSizeEnabled; }
+  static uint32_t PreloadChunkCount()
+    { return sPreloadChunkCount; }
+  static uint32_t MaxMemoryEntrySize() // result in bytes.
+    { return sMaxMemoryEntrySize << 10; }
+  static uint32_t MaxDiskEntrySize() // result in bytes.
+    { return sMaxDiskEntrySize << 10; }
+  static uint32_t MaxDiskChunksMemoryUsage(bool aPriority) // result in bytes.
+    { return aPriority ? sMaxDiskPriorityChunksMemoryUsage << 10
+                       : sMaxDiskChunksMemoryUsage << 10; }
+  static uint32_t CompressionLevel()
+    { return sCompressionLevel; }
+  static uint32_t HalfLifeSeconds()
+    { return sHalfLifeHours * 60.0F * 60.0F; }
+  static int32_t HalfLifeExperiment()
+    { return sHalfLifeExperiment; }
+  static bool ClearCacheOnShutdown()
+    { return sSanitizeOnShutdown && sClearCacheOnShutdown; }
+  static bool CacheFSReported()
+    { return sCacheFSReported; }
+  static void SetCacheFSReported();
+  static bool HashStatsReported()
+    { return sHashStatsReported; }
+  static void SetHashStatsReported();
+  static void ParentDirOverride(nsIFile ** aDir);
+
+  static bool EntryIsTooBig(int64_t aSize, bool aUsingDisk);
+
+  static uint32_t MaxShutdownIOLag()
+    { return sMaxShutdownIOLag; }
+  static bool IsPastShutdownIOLag();
+
+  static bool ShuttingDown()
+    { return sShutdownDemandedTime != PR_INTERVAL_NO_TIMEOUT; }
+
+private:
+  static CacheObserver* sSelf;
+
+  void StoreDiskCacheCapacity();
+  void StoreCacheFSReported();
+  void StoreHashStatsReported();
+  void AttachToPreferences();
+
+  static uint32_t sUseNewCache;
+  static bool sUseMemoryCache;
+  static bool sUseDiskCache;
+  static uint32_t sMetadataMemoryLimit;
+  static int32_t sMemoryCacheCapacity;
+  static int32_t sAutoMemoryCacheCapacity;
+  static Atomic<uint32_t, Relaxed> sDiskCacheCapacity;
+  static uint32_t sDiskFreeSpaceSoftLimit;
+  static uint32_t sDiskFreeSpaceHardLimit;
+  static bool sSmartCacheSizeEnabled;
+  static uint32_t sPreloadChunkCount;
+  static int32_t sMaxMemoryEntrySize;
+  static int32_t sMaxDiskEntrySize;
+  static uint32_t sMaxDiskChunksMemoryUsage;
+  static uint32_t sMaxDiskPriorityChunksMemoryUsage;
+  static uint32_t sCompressionLevel;
+  static float sHalfLifeHours;
+  static int32_t sHalfLifeExperiment;
+  static bool sSanitizeOnShutdown;
+  static bool sClearCacheOnShutdown;
+  static bool sCacheFSReported;
+  static bool sHashStatsReported;
+  static Atomic<uint32_t, Relaxed> sMaxShutdownIOLag;
+  static Atomic<PRIntervalTime> sShutdownDemandedTime;
+
+  // Non static properties, accessible via sSelf
+  nsCOMPtr<nsIFile> mCacheParentDirectoryOverride;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheStorage.cpp b/netwerk/cache2/CacheStorage.cpp
new file mode 100644
index 0000000000..1d84195a40
--- /dev/null
+++ b/netwerk/cache2/CacheStorage.cpp
@@ -0,0 +1,245 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheStorage.h"
+#include "CacheStorageService.h"
+#include "CacheEntry.h"
+#include "CacheObserver.h"
+
+#include "OldWrappers.h"
+
+#include "nsICacheEntryDoomCallback.h"
+
+#include "nsIApplicationCache.h"
+#include "nsIApplicationCacheService.h"
+#include "nsIURI.h"
+#include "nsNetCID.h"
+#include "nsServiceManagerUtils.h"
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(CacheStorage, nsICacheStorage)
+
+CacheStorage::CacheStorage(nsILoadContextInfo* aInfo,
+                           bool aAllowDisk,
+                           bool aLookupAppCache,
+                           bool aSkipSizeCheck,
+                           bool aPinning)
+: mLoadContextInfo(GetLoadContextInfo(aInfo))
+, mWriteToDisk(aAllowDisk)
+, mLookupAppCache(aLookupAppCache)
+, mSkipSizeCheck(aSkipSizeCheck)
+, mPinning(aPinning)
+{
+}
+
+CacheStorage::~CacheStorage()
+{
+}
+
+NS_IMETHODIMP CacheStorage::AsyncOpenURI(nsIURI *aURI,
+                                         const nsACString & aIdExtension,
+                                         uint32_t aFlags,
+                                         nsICacheEntryOpenCallback *aCallback)
+{
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  if (MOZ_UNLIKELY(!CacheObserver::UseDiskCache()) && mWriteToDisk &&
+                   !(aFlags & OPEN_INTERCEPTED)) {
+    aCallback->OnCacheEntryAvailable(nullptr, false, nullptr, NS_ERROR_NOT_AVAILABLE);
+    return NS_OK;
+  }
+
+  if (MOZ_UNLIKELY(!CacheObserver::UseMemoryCache()) && !mWriteToDisk &&
+                   !(aFlags & OPEN_INTERCEPTED)) {
+    aCallback->OnCacheEntryAvailable(nullptr, false, nullptr, NS_ERROR_NOT_AVAILABLE);
+    return NS_OK;
+  }
+
+  NS_ENSURE_ARG(aURI);
+  NS_ENSURE_ARG(aCallback);
+
+  nsresult rv;
+
+  bool truncate = aFlags & nsICacheStorage::OPEN_TRUNCATE;
+
+  nsCOMPtr<nsIURI> noRefURI;
+  rv = aURI->CloneIgnoringRef(getter_AddRefs(noRefURI));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString asciiSpec;
+  rv = noRefURI->GetAsciiSpec(asciiSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIApplicationCache> appCache;
+  if (LookupAppCache()) {
+    rv = ChooseApplicationCache(noRefURI, getter_AddRefs(appCache));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (appCache) {
+      // From a chosen appcache open only as readonly
+      aFlags &= ~nsICacheStorage::OPEN_TRUNCATE;
+    }
+  }
+
+  if (appCache) {
+    nsAutoCString scheme;
+    rv = noRefURI->GetScheme(scheme);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    RefPtr<_OldCacheLoad> appCacheLoad =
+      new _OldCacheLoad(scheme, asciiSpec, aCallback, appCache,
+                        LoadInfo(), WriteToDisk(), aFlags);
+    rv = appCacheLoad->Start();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    LOG(("CacheStorage::AsyncOpenURI loading from appcache"));
+    return NS_OK;
+  }
+
+  RefPtr<CacheEntryHandle> entry;
+  rv = CacheStorageService::Self()->AddStorageEntry(
+    this, asciiSpec, aIdExtension,
+    truncate, // replace any existing one?
+    getter_AddRefs(entry));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // May invoke the callback synchronously
+  entry->Entry()->AsyncOpen(aCallback, aFlags);
+
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP CacheStorage::OpenTruncate(nsIURI *aURI, const nsACString & aIdExtension,
+                                         nsICacheEntry **aCacheEntry)
+{
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  nsresult rv;
+
+  nsCOMPtr<nsIURI> noRefURI;
+  rv = aURI->CloneIgnoringRef(getter_AddRefs(noRefURI));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString asciiSpec;
+  rv = noRefURI->GetAsciiSpec(asciiSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<CacheEntryHandle> handle;
+  rv = CacheStorageService::Self()->AddStorageEntry(
+    this, asciiSpec, aIdExtension,
+    true, // replace any existing one
+    getter_AddRefs(handle));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Just open w/o callback, similar to nsICacheEntry.recreate().
+  handle->Entry()->AsyncOpen(nullptr, OPEN_TRUNCATE);
+
+  // Return a write handler, consumer is supposed to fill in the entry.
+  RefPtr<CacheEntryHandle> writeHandle = handle->Entry()->NewWriteHandle();
+  writeHandle.forget(aCacheEntry);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorage::Exists(nsIURI *aURI, const nsACString & aIdExtension,
+                                   bool *aResult)
+{
+  NS_ENSURE_ARG(aURI);
+  NS_ENSURE_ARG(aResult);
+
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  nsresult rv;
+
+  nsCOMPtr<nsIURI> noRefURI;
+  rv = aURI->CloneIgnoringRef(getter_AddRefs(noRefURI));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString asciiSpec;
+  rv = noRefURI->GetAsciiSpec(asciiSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return CacheStorageService::Self()->CheckStorageEntry(
+    this, asciiSpec, aIdExtension, aResult);
+}
+
+NS_IMETHODIMP CacheStorage::AsyncDoomURI(nsIURI *aURI, const nsACString & aIdExtension,
+                                         nsICacheEntryDoomCallback* aCallback)
+{
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  nsresult rv;
+
+  nsCOMPtr<nsIURI> noRefURI;
+  rv = aURI->CloneIgnoringRef(getter_AddRefs(noRefURI));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString asciiSpec;
+  rv = noRefURI->GetAsciiSpec(asciiSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = CacheStorageService::Self()->DoomStorageEntry(
+    this, asciiSpec, aIdExtension, aCallback);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorage::AsyncEvictStorage(nsICacheEntryDoomCallback* aCallback)
+{
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  nsresult rv = CacheStorageService::Self()->DoomStorageEntries(
+    this, aCallback);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorage::AsyncVisitStorage(nsICacheStorageVisitor* aVisitor,
+                                              bool aVisitEntries)
+{
+  LOG(("CacheStorage::AsyncVisitStorage [this=%p, cb=%p, disk=%d]", this, aVisitor, (bool)mWriteToDisk));
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  nsresult rv = CacheStorageService::Self()->WalkStorageEntries(
+    this, aVisitEntries, aVisitor);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+// Internal
+
+nsresult CacheStorage::ChooseApplicationCache(nsIURI* aURI,
+                                              nsIApplicationCache** aCache)
+{
+  nsresult rv;
+
+  nsCOMPtr<nsIApplicationCacheService> appCacheService =
+    do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString cacheKey;
+  rv = aURI->GetAsciiSpec(cacheKey);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = appCacheService->ChooseApplicationCache(cacheKey, LoadInfo(), aCache);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheStorage.h b/netwerk/cache2/CacheStorage.h
new file mode 100644
index 0000000000..85c5bccdbb
--- /dev/null
+++ b/netwerk/cache2/CacheStorage.h
@@ -0,0 +1,81 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheStorage__h__
+#define CacheStorage__h__
+
+#include "nsICacheStorage.h"
+#include "CacheEntry.h"
+#include "LoadContextInfo.h"
+
+#include "nsRefPtrHashtable.h"
+#include "nsThreadUtils.h"
+#include "nsCOMPtr.h"
+#include "nsILoadContextInfo.h"
+#include "nsIApplicationCache.h"
+#include "nsICacheEntryDoomCallback.h"
+
+class nsIURI;
+class nsIApplicationCache;
+
+namespace mozilla {
+namespace net {
+
+// This dance is needed to make CacheEntryTable declarable-only in headers
+// w/o exporting CacheEntry.h file to make nsNetModule.cpp compilable.
+typedef nsRefPtrHashtable<nsCStringHashKey, CacheEntry> TCacheEntryTable;
+class CacheEntryTable : public TCacheEntryTable
+{
+public:
+  enum EType
+  {
+    MEMORY_ONLY,
+    ALL_ENTRIES
+  };
+
+  explicit CacheEntryTable(EType aType) : mType(aType) { }
+  EType Type() const
+  {
+    return mType;
+  }
+private:
+  EType const mType;
+  CacheEntryTable() = delete;
+};
+
+class CacheStorage : public nsICacheStorage
+{
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSICACHESTORAGE
+
+public:
+  CacheStorage(nsILoadContextInfo* aInfo,
+               bool aAllowDisk,
+               bool aLookupAppCache,
+               bool aSkipSizeCheck,
+               bool aPinning);
+
+protected:
+  virtual ~CacheStorage();
+
+  nsresult ChooseApplicationCache(nsIURI* aURI, nsIApplicationCache** aCache);
+
+  RefPtr<LoadContextInfo> mLoadContextInfo;
+  bool mWriteToDisk : 1;
+  bool mLookupAppCache : 1;
+  bool mSkipSizeCheck: 1;
+  bool mPinning : 1;
+
+public:
+  nsILoadContextInfo* LoadInfo() const { return mLoadContextInfo; }
+  bool WriteToDisk() const { return mWriteToDisk && !mLoadContextInfo->IsPrivate(); }
+  bool LookupAppCache() const { return mLookupAppCache; }
+  bool SkipSizeCheck() const { return mSkipSizeCheck; }
+  bool Pinning() const { return mPinning; }
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/CacheStorageService.cpp b/netwerk/cache2/CacheStorageService.cpp
new file mode 100644
index 0000000000..67ef4c5267
--- /dev/null
+++ b/netwerk/cache2/CacheStorageService.cpp
@@ -0,0 +1,2290 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheLog.h"
+#include "CacheStorageService.h"
+#include "CacheFileIOManager.h"
+#include "CacheObserver.h"
+#include "CacheIndex.h"
+#include "CacheIndexIterator.h"
+#include "CacheStorage.h"
+#include "AppCacheStorage.h"
+#include "CacheEntry.h"
+#include "CacheFileUtils.h"
+
+#include "OldWrappers.h"
+#include "nsCacheService.h"
+#include "nsDeleteDir.h"
+
+#include "nsICacheStorageVisitor.h"
+#include "nsIObserverService.h"
+#include "nsIFile.h"
+#include "nsIURI.h"
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsServiceManagerUtils.h"
+#include "nsWeakReference.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Services.h"
+
+namespace mozilla {
+namespace net {
+
+namespace {
+
+void AppendMemoryStorageID(nsAutoCString &key)
+{
+  key.Append('/');
+  key.Append('M');
+}
+
+} // namespace
+
+// Not defining as static or class member of CacheStorageService since
+// it would otherwise need to include CacheEntry.h and that then would
+// need to be exported to make nsNetModule.cpp compilable.
+typedef nsClassHashtable<nsCStringHashKey, CacheEntryTable>
+        GlobalEntryTables;
+
+/**
+ * Keeps tables of entries.  There is one entries table for each distinct load
+ * context type.  The distinction is based on following load context info states:
+ * <isPrivate|isAnon|appId|inIsolatedMozBrowser> which builds a mapping key.
+ *
+ * Thread-safe to access, protected by the service mutex.
+ */
+static GlobalEntryTables* sGlobalEntryTables;
+
+CacheMemoryConsumer::CacheMemoryConsumer(uint32_t aFlags)
+: mReportedMemoryConsumption(0)
+, mFlags(aFlags)
+{
+}
+
+void
+CacheMemoryConsumer::DoMemoryReport(uint32_t aCurrentSize)
+{
+  if (!(mFlags & DONT_REPORT) && CacheStorageService::Self()) {
+    CacheStorageService::Self()->OnMemoryConsumptionChange(this, aCurrentSize);
+  }
+}
+
+CacheStorageService::MemoryPool::MemoryPool(EType aType)
+: mType(aType)
+, mMemorySize(0)
+{
+}
+
+CacheStorageService::MemoryPool::~MemoryPool()
+{
+  if (mMemorySize != 0) {
+    NS_ERROR("Network cache reported memory consumption is not at 0, probably leaking?");
+  }
+}
+
+uint32_t
+CacheStorageService::MemoryPool::Limit() const
+{
+  switch (mType) {
+  case DISK:
+    return CacheObserver::MetadataMemoryLimit();
+  case MEMORY:
+    return CacheObserver::MemoryCacheCapacity();
+  }
+
+  MOZ_CRASH("Bad pool type");
+  return 0;
+}
+
+NS_IMPL_ISUPPORTS(CacheStorageService,
+                  nsICacheStorageService,
+                  nsIMemoryReporter,
+                  nsITimerCallback,
+                  nsICacheTesting)
+
+CacheStorageService* CacheStorageService::sSelf = nullptr;
+
+CacheStorageService::CacheStorageService()
+: mLock("CacheStorageService.mLock")
+, mForcedValidEntriesLock("CacheStorageService.mForcedValidEntriesLock")
+, mShutdown(false)
+, mDiskPool(MemoryPool::DISK)
+, mMemoryPool(MemoryPool::MEMORY)
+{
+  CacheFileIOManager::Init();
+
+  MOZ_ASSERT(!sSelf);
+
+  sSelf = this;
+  sGlobalEntryTables = new GlobalEntryTables();
+
+  RegisterStrongMemoryReporter(this);
+}
+
+CacheStorageService::~CacheStorageService()
+{
+  LOG(("CacheStorageService::~CacheStorageService"));
+  sSelf = nullptr;
+}
+
+void CacheStorageService::Shutdown()
+{
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (mShutdown)
+    return;
+
+  LOG(("CacheStorageService::Shutdown - start"));
+
+  mShutdown = true;
+
+  nsCOMPtr<nsIRunnable> event =
+    NewRunnableMethod(this, &CacheStorageService::ShutdownBackground);
+  Dispatch(event);
+
+#ifdef NS_FREE_PERMANENT_DATA
+  sGlobalEntryTables->Clear();
+  delete sGlobalEntryTables;
+#endif
+  sGlobalEntryTables = nullptr;
+
+  LOG(("CacheStorageService::Shutdown - done"));
+}
+
+void CacheStorageService::ShutdownBackground()
+{
+  LOG(("CacheStorageService::ShutdownBackground - start"));
+
+  MOZ_ASSERT(IsOnManagementThread());
+
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    // Cancel purge timer to avoid leaking.
+    if (mPurgeTimer) {
+      LOG(("  freeing the timer"));
+      mPurgeTimer->Cancel();
+    }
+  }
+
+#ifdef NS_FREE_PERMANENT_DATA
+  Pool(false).mFrecencyArray.Clear();
+  Pool(false).mExpirationArray.Clear();
+  Pool(true).mFrecencyArray.Clear();
+  Pool(true).mExpirationArray.Clear();
+#endif
+
+  LOG(("CacheStorageService::ShutdownBackground - done"));
+}
+
+// Internal management methods
+
+namespace {
+
+// WalkCacheRunnable
+// Base class for particular storage entries visiting
+class WalkCacheRunnable : public Runnable
+                        , public CacheStorageService::EntryInfoCallback
+{
+protected:
+  WalkCacheRunnable(nsICacheStorageVisitor* aVisitor,
+                    bool aVisitEntries)
+    : mService(CacheStorageService::Self())
+    , mCallback(aVisitor)
+    , mSize(0)
+    , mNotifyStorage(true)
+    , mVisitEntries(aVisitEntries)
+    , mCancel(false)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+  }
+
+  virtual ~WalkCacheRunnable()
+  {
+    if (mCallback) {
+      ProxyReleaseMainThread(mCallback);
+    }
+  }
+
+  RefPtr<CacheStorageService> mService;
+  nsCOMPtr<nsICacheStorageVisitor> mCallback;
+
+  uint64_t mSize;
+
+  bool mNotifyStorage : 1;
+  bool mVisitEntries : 1;
+
+  Atomic<bool> mCancel;
+};
+
+// WalkMemoryCacheRunnable
+// Responsible to visit memory storage and walk
+// all entries on it asynchronously.
+class WalkMemoryCacheRunnable : public WalkCacheRunnable
+{
+public:
+  WalkMemoryCacheRunnable(nsILoadContextInfo *aLoadInfo,
+                          bool aVisitEntries,
+                          nsICacheStorageVisitor* aVisitor)
+    : WalkCacheRunnable(aVisitor, aVisitEntries)
+  {
+    CacheFileUtils::AppendKeyPrefix(aLoadInfo, mContextKey);
+    MOZ_ASSERT(NS_IsMainThread());
+  }
+
+  nsresult Walk()
+  {
+    return mService->Dispatch(this);
+  }
+
+private:
+  NS_IMETHOD Run() override
+  {
+    if (CacheStorageService::IsOnManagementThread()) {
+      LOG(("WalkMemoryCacheRunnable::Run - collecting [this=%p]", this));
+      // First, walk, count and grab all entries from the storage
+
+      mozilla::MutexAutoLock lock(CacheStorageService::Self()->Lock());
+
+      if (!CacheStorageService::IsRunning())
+        return NS_ERROR_NOT_INITIALIZED;
+
+      CacheEntryTable* entries;
+      if (sGlobalEntryTables->Get(mContextKey, &entries)) {
+        for (auto iter = entries->Iter(); !iter.Done(); iter.Next()) {
+          CacheEntry* entry = iter.UserData();
+
+          // Ignore disk entries
+          if (entry->IsUsingDisk()) {
+            continue;
+          }
+
+          mSize += entry->GetMetadataMemoryConsumption();
+
+          int64_t size;
+          if (NS_SUCCEEDED(entry->GetDataSize(&size))) {
+            mSize += size;
+          }
+          mEntryArray.AppendElement(entry);
+        }
+      }
+
+      // Next, we dispatch to the main thread
+    } else if (NS_IsMainThread()) {
+      LOG(("WalkMemoryCacheRunnable::Run - notifying [this=%p]", this));
+
+      if (mNotifyStorage) {
+        LOG(("  storage"));
+
+        // Second, notify overall storage info
+        mCallback->OnCacheStorageInfo(mEntryArray.Length(), mSize,
+                                      CacheObserver::MemoryCacheCapacity(), nullptr);
+        if (!mVisitEntries)
+          return NS_OK; // done
+
+        mNotifyStorage = false;
+
+      } else {
+        LOG(("  entry [left=%d, canceled=%d]", mEntryArray.Length(), (bool)mCancel));
+
+        // Third, notify each entry until depleted or canceled
+        if (!mEntryArray.Length() || mCancel) {
+          mCallback->OnCacheEntryVisitCompleted();
+          return NS_OK; // done
+        }
+
+        // Grab the next entry
+        RefPtr<CacheEntry> entry = mEntryArray[0];
+        mEntryArray.RemoveElementAt(0);
+
+        // Invokes this->OnEntryInfo, that calls the callback with all
+        // information of the entry.
+        CacheStorageService::GetCacheEntryInfo(entry, this);
+      }
+    } else {
+      MOZ_CRASH("Bad thread");
+      return NS_ERROR_FAILURE;
+    }
+
+    NS_DispatchToMainThread(this);
+    return NS_OK;
+  }
+
+  virtual ~WalkMemoryCacheRunnable()
+  {
+    if (mCallback)
+      ProxyReleaseMainThread(mCallback);
+  }
+
+  virtual void OnEntryInfo(const nsACString & aURISpec, const nsACString & aIdEnhance,
+                           int64_t aDataSize, int32_t aFetchCount,
+                           uint32_t aLastModifiedTime, uint32_t aExpirationTime,
+                           bool aPinned) override
+  {
+    nsresult rv;
+
+    nsCOMPtr<nsIURI> uri;
+    rv = NS_NewURI(getter_AddRefs(uri), aURISpec);
+    if (NS_FAILED(rv)) {
+      return;
+    }
+
+    rv = mCallback->OnCacheEntryInfo(uri, aIdEnhance, aDataSize, aFetchCount,
+                                     aLastModifiedTime, aExpirationTime, aPinned);
+    if (NS_FAILED(rv)) {
+      LOG(("  callback failed, canceling the walk"));
+      mCancel = true;
+    }
+  }
+
+private:
+  nsCString mContextKey;
+  nsTArray<RefPtr<CacheEntry> > mEntryArray;
+};
+
+// WalkDiskCacheRunnable
+// Using the cache index information to get the list of files per context.
+class WalkDiskCacheRunnable : public WalkCacheRunnable
+{
+public:
+  WalkDiskCacheRunnable(nsILoadContextInfo *aLoadInfo,
+                        bool aVisitEntries,
+                        nsICacheStorageVisitor* aVisitor)
+    : WalkCacheRunnable(aVisitor, aVisitEntries)
+    , mLoadInfo(aLoadInfo)
+    , mPass(COLLECT_STATS)
+  {
+  }
+
+  nsresult Walk()
+  {
+    // TODO, bug 998693
+    // Initial index build should be forced here so that about:cache soon
+    // after startup gives some meaningfull results.
+
+    // Dispatch to the INDEX level in hope that very recent cache entries
+    // information gets to the index list before we grab the index iterator
+    // for the first time.  This tries to avoid miss of entries that has
+    // been created right before the visit is required.
+    RefPtr<CacheIOThread> thread = CacheFileIOManager::IOThread();
+    NS_ENSURE_TRUE(thread, NS_ERROR_NOT_INITIALIZED);
+
+    return thread->Dispatch(this, CacheIOThread::INDEX);
+  }
+
+private:
+  // Invokes OnCacheEntryInfo callback for each single found entry.
+  // There is one instance of this class per one entry.
+  class OnCacheEntryInfoRunnable : public Runnable
+  {
+  public:
+    explicit OnCacheEntryInfoRunnable(WalkDiskCacheRunnable* aWalker)
+      : mWalker(aWalker)
+    {
+    }
+
+    NS_IMETHOD Run() override
+    {
+      MOZ_ASSERT(NS_IsMainThread());
+
+      nsresult rv;
+
+      nsCOMPtr<nsIURI> uri;
+      rv = NS_NewURI(getter_AddRefs(uri), mURISpec);
+      if (NS_FAILED(rv)) {
+        return NS_OK;
+      }
+
+      rv = mWalker->mCallback->OnCacheEntryInfo(
+        uri, mIdEnhance, mDataSize, mFetchCount,
+        mLastModifiedTime, mExpirationTime, mPinned);
+      if (NS_FAILED(rv)) {
+        mWalker->mCancel = true;
+      }
+
+      return NS_OK;
+    }
+
+    RefPtr<WalkDiskCacheRunnable> mWalker;
+
+    nsCString mURISpec;
+    nsCString mIdEnhance;
+    int64_t mDataSize;
+    int32_t mFetchCount;
+    uint32_t mLastModifiedTime;
+    uint32_t mExpirationTime;
+    bool mPinned;
+  };
+
+  NS_IMETHOD Run() override
+  {
+    // The main loop
+    nsresult rv;
+
+    if (CacheStorageService::IsOnManagementThread()) {
+      switch (mPass) {
+      case COLLECT_STATS:
+        // Get quickly the cache stats.
+        uint32_t size;
+        rv = CacheIndex::GetCacheStats(mLoadInfo, &size, &mCount);
+        if (NS_FAILED(rv)) {
+          if (mVisitEntries) {
+            // both onStorageInfo and onCompleted are expected
+            NS_DispatchToMainThread(this);
+          }
+          return NS_DispatchToMainThread(this);
+        }
+
+        mSize = size << 10;
+
+        // Invoke onCacheStorageInfo with valid information.
+        NS_DispatchToMainThread(this);
+
+        if (!mVisitEntries) {
+          return NS_OK; // done
+        }
+
+        mPass = ITERATE_METADATA;
+        MOZ_FALLTHROUGH;
+
+      case ITERATE_METADATA:
+        // Now grab the context iterator.
+        if (!mIter) {
+          rv = CacheIndex::GetIterator(mLoadInfo, true, getter_AddRefs(mIter));
+          if (NS_FAILED(rv)) {
+            // Invoke onCacheEntryVisitCompleted now
+            return NS_DispatchToMainThread(this);
+          }
+        }
+
+        while (!mCancel && !CacheObserver::ShuttingDown()) {
+          if (CacheIOThread::YieldAndRerun())
+            return NS_OK;
+
+          SHA1Sum::Hash hash;
+          rv = mIter->GetNextHash(&hash);
+          if (NS_FAILED(rv))
+            break; // done (or error?)
+
+          // This synchronously invokes OnEntryInfo on this class where we
+          // redispatch to the main thread for the consumer callback.
+          CacheFileIOManager::GetEntryInfo(&hash, this);
+        }
+
+        // Invoke onCacheEntryVisitCompleted on the main thread
+        NS_DispatchToMainThread(this);
+      }
+    } else if (NS_IsMainThread()) {
+      if (mNotifyStorage) {
+        nsCOMPtr<nsIFile> dir;
+        CacheFileIOManager::GetCacheDirectory(getter_AddRefs(dir));
+        mCallback->OnCacheStorageInfo(mCount, mSize, CacheObserver::DiskCacheCapacity(), dir);
+        mNotifyStorage = false;
+      } else {
+        mCallback->OnCacheEntryVisitCompleted();
+      }
+    } else {
+      MOZ_CRASH("Bad thread");
+      return NS_ERROR_FAILURE;
+    }
+
+    return NS_OK;
+  }
+
+  virtual void OnEntryInfo(const nsACString & aURISpec, const nsACString & aIdEnhance,
+                           int64_t aDataSize, int32_t aFetchCount,
+                           uint32_t aLastModifiedTime, uint32_t aExpirationTime,
+                           bool aPinned) override
+  {
+    // Called directly from CacheFileIOManager::GetEntryInfo.
+
+    // Invoke onCacheEntryInfo on the main thread for this entry.
+    RefPtr<OnCacheEntryInfoRunnable> info = new OnCacheEntryInfoRunnable(this);
+    info->mURISpec = aURISpec;
+    info->mIdEnhance = aIdEnhance;
+    info->mDataSize = aDataSize;
+    info->mFetchCount = aFetchCount;
+    info->mLastModifiedTime = aLastModifiedTime;
+    info->mExpirationTime = aExpirationTime;
+    info->mPinned = aPinned;
+
+    NS_DispatchToMainThread(info);
+  }
+
+  RefPtr<nsILoadContextInfo> mLoadInfo;
+  enum {
+    // First, we collect stats for the load context.
+    COLLECT_STATS,
+
+    // Second, if demanded, we iterate over the entries gethered
+    // from the iterator and call CacheFileIOManager::GetEntryInfo
+    // for each found entry.
+    ITERATE_METADATA,
+  } mPass;
+
+  RefPtr<CacheIndexIterator> mIter;
+  uint32_t mCount;
+};
+
+} // namespace
+
+void CacheStorageService::DropPrivateBrowsingEntries()
+{
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (mShutdown)
+    return;
+
+  nsTArray<nsCString> keys;
+  for (auto iter = sGlobalEntryTables->Iter(); !iter.Done(); iter.Next()) {
+    const nsACString& key = iter.Key();
+    nsCOMPtr<nsILoadContextInfo> info = CacheFileUtils::ParseKey(key);
+    if (info && info->IsPrivate()) {
+      keys.AppendElement(key);
+    }
+  }
+
+  for (uint32_t i = 0; i < keys.Length(); ++i) {
+    DoomStorageEntries(keys[i], nullptr, true, false, nullptr);
+  }
+}
+
+namespace {
+
+class CleaupCacheDirectoriesRunnable : public Runnable
+{
+public:
+  NS_DECL_NSIRUNNABLE
+  static bool Post(uint32_t aVersion, uint32_t aActive);
+
+private:
+  CleaupCacheDirectoriesRunnable(uint32_t aVersion, uint32_t aActive)
+    : mVersion(aVersion), mActive(aActive)
+  {
+    nsCacheService::GetDiskCacheDirectory(getter_AddRefs(mCache1Dir));
+    CacheFileIOManager::GetCacheDirectory(getter_AddRefs(mCache2Dir));
+#if defined(MOZ_WIDGET_ANDROID)
+    CacheFileIOManager::GetProfilelessCacheDirectory(getter_AddRefs(mCache2Profileless));
+#endif
+  }
+
+  virtual ~CleaupCacheDirectoriesRunnable() {}
+  uint32_t mVersion, mActive;
+  nsCOMPtr<nsIFile> mCache1Dir, mCache2Dir;
+#if defined(MOZ_WIDGET_ANDROID)
+  nsCOMPtr<nsIFile> mCache2Profileless;
+#endif
+};
+
+// static
+bool CleaupCacheDirectoriesRunnable::Post(uint32_t aVersion, uint32_t aActive)
+{
+  // CleaupCacheDirectories is called regardless what cache version is set up to use.
+  // To obtain the cache1 directory we must unfortunatelly instantiate the old cache
+  // service despite it may not be used at all...  This also initialize nsDeleteDir.
+  nsCOMPtr<nsICacheService> service = do_GetService(NS_CACHESERVICE_CONTRACTID);
+  if (!service)
+    return false;
+
+  nsCOMPtr<nsIEventTarget> thread;
+  service->GetCacheIOTarget(getter_AddRefs(thread));
+  if (!thread)
+    return false;
+
+  RefPtr<CleaupCacheDirectoriesRunnable> r =
+    new CleaupCacheDirectoriesRunnable(aVersion, aActive);
+  thread->Dispatch(r, NS_DISPATCH_NORMAL);
+  return true;
+}
+
+NS_IMETHODIMP CleaupCacheDirectoriesRunnable::Run()
+{
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  if (mCache1Dir) {
+    nsDeleteDir::RemoveOldTrashes(mCache1Dir);
+  }
+  if (mCache2Dir) {
+    nsDeleteDir::RemoveOldTrashes(mCache2Dir);
+  }
+#if defined(MOZ_WIDGET_ANDROID)
+  if (mCache2Profileless) {
+    nsDeleteDir::RemoveOldTrashes(mCache2Profileless);
+    // Always delete the profileless cache on Android
+    nsDeleteDir::DeleteDir(mCache2Profileless, true, 30000);
+  }
+#endif
+
+  // Delete the non-active version cache data right now
+  if (mVersion == mActive) {
+    return NS_OK;
+  }
+
+  switch (mVersion) {
+  case 0:
+    if (mCache1Dir) {
+      nsDeleteDir::DeleteDir(mCache1Dir, true, 30000);
+    }
+    break;
+  case 1:
+    if (mCache2Dir) {
+      nsDeleteDir::DeleteDir(mCache2Dir, true, 30000);
+    }
+    break;
+  }
+
+  return NS_OK;
+}
+
+} // namespace
+
+// static
+void CacheStorageService::CleaupCacheDirectories(uint32_t aVersion, uint32_t aActive)
+{
+  // Make sure we schedule just once in case CleaupCacheDirectories gets called
+  // multiple times from some reason.
+  static bool runOnce = CleaupCacheDirectoriesRunnable::Post(aVersion, aActive);
+  if (!runOnce) {
+    NS_WARNING("Could not start cache trashes cleanup");
+  }
+}
+
+// Helper methods
+
+// static
+bool CacheStorageService::IsOnManagementThread()
+{
+  RefPtr<CacheStorageService> service = Self();
+  if (!service)
+    return false;
+
+  nsCOMPtr<nsIEventTarget> target = service->Thread();
+  if (!target)
+    return false;
+
+  bool currentThread;
+  nsresult rv = target->IsOnCurrentThread(&currentThread);
+  return NS_SUCCEEDED(rv) && currentThread;
+}
+
+already_AddRefed<nsIEventTarget> CacheStorageService::Thread() const
+{
+  return CacheFileIOManager::IOTarget();
+}
+
+nsresult CacheStorageService::Dispatch(nsIRunnable* aEvent)
+{
+  RefPtr<CacheIOThread> cacheIOThread = CacheFileIOManager::IOThread();
+  if (!cacheIOThread)
+    return NS_ERROR_NOT_AVAILABLE;
+
+  return cacheIOThread->Dispatch(aEvent, CacheIOThread::MANAGEMENT);
+}
+
+// nsICacheStorageService
+
+NS_IMETHODIMP CacheStorageService::MemoryCacheStorage(nsILoadContextInfo *aLoadContextInfo,
+                                                      nsICacheStorage * *_retval)
+{
+  NS_ENSURE_ARG(aLoadContextInfo);
+  NS_ENSURE_ARG(_retval);
+
+  nsCOMPtr<nsICacheStorage> storage;
+  if (CacheObserver::UseNewCache()) {
+    storage = new CacheStorage(aLoadContextInfo, false, false, false, false);
+  }
+  else {
+    storage = new _OldStorage(aLoadContextInfo, false, false, false, nullptr);
+  }
+
+  storage.forget(_retval);
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorageService::DiskCacheStorage(nsILoadContextInfo *aLoadContextInfo,
+                                                    bool aLookupAppCache,
+                                                    nsICacheStorage * *_retval)
+{
+  NS_ENSURE_ARG(aLoadContextInfo);
+  NS_ENSURE_ARG(_retval);
+
+  // TODO save some heap granularity - cache commonly used storages.
+
+  // When disk cache is disabled, still provide a storage, but just keep stuff
+  // in memory.
+  bool useDisk = CacheObserver::UseDiskCache();
+
+  nsCOMPtr<nsICacheStorage> storage;
+  if (CacheObserver::UseNewCache()) {
+    storage = new CacheStorage(aLoadContextInfo, useDisk, aLookupAppCache, false /* size limit */, false /* don't pin */);
+  }
+  else {
+    storage = new _OldStorage(aLoadContextInfo, useDisk, aLookupAppCache, false, nullptr);
+  }
+
+  storage.forget(_retval);
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorageService::PinningCacheStorage(nsILoadContextInfo *aLoadContextInfo,
+                                                       nsICacheStorage * *_retval)
+{
+  NS_ENSURE_ARG(aLoadContextInfo);
+  NS_ENSURE_ARG(_retval);
+
+  if (!CacheObserver::UseNewCache()) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  // When disk cache is disabled don't pretend we cache.
+  if (!CacheObserver::UseDiskCache()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsCOMPtr<nsICacheStorage> storage = new CacheStorage(
+    aLoadContextInfo, true /* use disk */, false /* no appcache */, true /* ignore size checks */, true /* pin */);
+  storage.forget(_retval);
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorageService::AppCacheStorage(nsILoadContextInfo *aLoadContextInfo,
+                                                   nsIApplicationCache *aApplicationCache,
+                                                   nsICacheStorage * *_retval)
+{
+  NS_ENSURE_ARG(aLoadContextInfo);
+  NS_ENSURE_ARG(_retval);
+
+  nsCOMPtr<nsICacheStorage> storage;
+  if (CacheObserver::UseNewCache()) {
+    // Using classification since cl believes we want to instantiate this method
+    // having the same name as the desired class...
+    storage = new mozilla::net::AppCacheStorage(aLoadContextInfo, aApplicationCache);
+  }
+  else {
+    storage = new _OldStorage(aLoadContextInfo, true, false, true, aApplicationCache);
+  }
+
+  storage.forget(_retval);
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorageService::SynthesizedCacheStorage(nsILoadContextInfo *aLoadContextInfo,
+                                                           nsICacheStorage * *_retval)
+{
+  NS_ENSURE_ARG(aLoadContextInfo);
+  NS_ENSURE_ARG(_retval);
+
+  nsCOMPtr<nsICacheStorage> storage;
+  if (CacheObserver::UseNewCache()) {
+    storage = new CacheStorage(aLoadContextInfo, false, false, true /* skip size checks for synthesized cache */, false /* no pinning */);
+  }
+  else {
+    storage = new _OldStorage(aLoadContextInfo, false, false, false, nullptr);
+  }
+
+  storage.forget(_retval);
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorageService::Clear()
+{
+  nsresult rv;
+
+  if (CacheObserver::UseNewCache()) {
+    // Tell the index to block notification to AsyncGetDiskConsumption.
+    // Will be allowed again from CacheFileContextEvictor::EvictEntries()
+    // when all the context have been removed from disk.
+    CacheIndex::OnAsyncEviction(true);
+
+    {
+      mozilla::MutexAutoLock lock(mLock);
+
+      {
+        mozilla::MutexAutoLock forcedValidEntriesLock(mForcedValidEntriesLock);
+        mForcedValidEntries.Clear();
+      }
+
+      NS_ENSURE_TRUE(!mShutdown, NS_ERROR_NOT_INITIALIZED);
+
+      nsTArray<nsCString> keys;
+      for (auto iter = sGlobalEntryTables->Iter(); !iter.Done(); iter.Next()) {
+        keys.AppendElement(iter.Key());
+      }
+
+      for (uint32_t i = 0; i < keys.Length(); ++i) {
+        DoomStorageEntries(keys[i], nullptr, true, false, nullptr);
+      }
+
+      // Passing null as a load info means to evict all contexts.
+      // EvictByContext() respects the entry pinning.  EvictAll() does not.
+      rv = CacheFileIOManager::EvictByContext(nullptr, false);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  } else {
+    nsCOMPtr<nsICacheService> serv =
+        do_GetService(NS_CACHESERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = serv->EvictEntries(nsICache::STORE_ANYWHERE);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorageService::PurgeFromMemory(uint32_t aWhat)
+{
+  uint32_t what;
+
+  switch (aWhat) {
+  case PURGE_DISK_DATA_ONLY:
+    what = CacheEntry::PURGE_DATA_ONLY_DISK_BACKED;
+    break;
+
+  case PURGE_DISK_ALL:
+    what = CacheEntry::PURGE_WHOLE_ONLY_DISK_BACKED;
+    break;
+
+  case PURGE_EVERYTHING:
+    what = CacheEntry::PURGE_WHOLE;
+    break;
+
+  default:
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsCOMPtr<nsIRunnable> event =
+    new PurgeFromMemoryRunnable(this, what);
+
+  return Dispatch(event);
+}
+
+NS_IMETHODIMP CacheStorageService::PurgeFromMemoryRunnable::Run()
+{
+  if (NS_IsMainThread()) {
+    nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+    if (observerService) {
+      observerService->NotifyObservers(nullptr, "cacheservice:purge-memory-pools", nullptr);
+    }
+
+    return NS_OK;
+  }
+
+  if (mService) {
+    // TODO not all flags apply to both pools
+    mService->Pool(true).PurgeAll(mWhat);
+    mService->Pool(false).PurgeAll(mWhat);
+    mService = nullptr;
+  }
+
+  NS_DispatchToMainThread(this);
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorageService::AsyncGetDiskConsumption(
+  nsICacheStorageConsumptionObserver* aObserver)
+{
+  NS_ENSURE_ARG(aObserver);
+
+  nsresult rv;
+
+  if (CacheObserver::UseNewCache()) {
+    rv = CacheIndex::AsyncGetDiskConsumption(aObserver);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    rv = _OldGetDiskConsumption::Get(aObserver);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheStorageService::GetIoTarget(nsIEventTarget** aEventTarget)
+{
+  NS_ENSURE_ARG(aEventTarget);
+
+  if (CacheObserver::UseNewCache()) {
+    nsCOMPtr<nsIEventTarget> ioTarget = CacheFileIOManager::IOTarget();
+    ioTarget.forget(aEventTarget);
+  }
+  else {
+    nsresult rv;
+
+    nsCOMPtr<nsICacheService> serv =
+        do_GetService(NS_CACHESERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = serv->GetCacheIOTarget(aEventTarget);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+// Methods used by CacheEntry for management of in-memory structures.
+
+namespace {
+
+class FrecencyComparator
+{
+public:
+  bool Equals(CacheEntry* a, CacheEntry* b) const {
+    return a->GetFrecency() == b->GetFrecency();
+  }
+  bool LessThan(CacheEntry* a, CacheEntry* b) const {
+    return a->GetFrecency() < b->GetFrecency();
+  }
+};
+
+class ExpirationComparator
+{
+public:
+  bool Equals(CacheEntry* a, CacheEntry* b) const {
+    return a->GetExpirationTime() == b->GetExpirationTime();
+  }
+  bool LessThan(CacheEntry* a, CacheEntry* b) const {
+    return a->GetExpirationTime() < b->GetExpirationTime();
+  }
+};
+
+} // namespace
+
+void
+CacheStorageService::RegisterEntry(CacheEntry* aEntry)
+{
+  MOZ_ASSERT(IsOnManagementThread());
+
+  if (mShutdown || !aEntry->CanRegister())
+    return;
+
+  TelemetryRecordEntryCreation(aEntry);
+
+  LOG(("CacheStorageService::RegisterEntry [entry=%p]", aEntry));
+
+  MemoryPool& pool = Pool(aEntry->IsUsingDisk());
+  pool.mFrecencyArray.AppendElement(aEntry);
+  pool.mExpirationArray.AppendElement(aEntry);
+
+  aEntry->SetRegistered(true);
+}
+
+void
+CacheStorageService::UnregisterEntry(CacheEntry* aEntry)
+{
+  MOZ_ASSERT(IsOnManagementThread());
+
+  if (!aEntry->IsRegistered())
+    return;
+
+  TelemetryRecordEntryRemoval(aEntry);
+
+  LOG(("CacheStorageService::UnregisterEntry [entry=%p]", aEntry));
+
+  MemoryPool& pool = Pool(aEntry->IsUsingDisk());
+  mozilla::DebugOnly<bool> removedFrecency = pool.mFrecencyArray.RemoveElement(aEntry);
+  mozilla::DebugOnly<bool> removedExpiration = pool.mExpirationArray.RemoveElement(aEntry);
+
+  MOZ_ASSERT(mShutdown || (removedFrecency && removedExpiration));
+
+  // Note: aEntry->CanRegister() since now returns false
+  aEntry->SetRegistered(false);
+}
+
+static bool
+AddExactEntry(CacheEntryTable* aEntries,
+              nsACString const& aKey,
+              CacheEntry* aEntry,
+              bool aOverwrite)
+{
+  RefPtr<CacheEntry> existingEntry;
+  if (!aOverwrite && aEntries->Get(aKey, getter_AddRefs(existingEntry))) {
+    bool equals = existingEntry == aEntry;
+    LOG(("AddExactEntry [entry=%p equals=%d]", aEntry, equals));
+    return equals; // Already there...
+  }
+
+  LOG(("AddExactEntry [entry=%p put]", aEntry));
+  aEntries->Put(aKey, aEntry);
+  return true;
+}
+
+static bool
+RemoveExactEntry(CacheEntryTable* aEntries,
+                 nsACString const& aKey,
+                 CacheEntry* aEntry,
+                 bool aOverwrite)
+{
+  RefPtr<CacheEntry> existingEntry;
+  if (!aEntries->Get(aKey, getter_AddRefs(existingEntry))) {
+    LOG(("RemoveExactEntry [entry=%p already gone]", aEntry));
+    return false; // Already removed...
+  }
+
+  if (!aOverwrite && existingEntry != aEntry) {
+    LOG(("RemoveExactEntry [entry=%p already replaced]", aEntry));
+    return false; // Already replaced...
+  }
+
+  LOG(("RemoveExactEntry [entry=%p removed]", aEntry));
+  aEntries->Remove(aKey);
+  return true;
+}
+
+bool
+CacheStorageService::RemoveEntry(CacheEntry* aEntry, bool aOnlyUnreferenced)
+{
+  LOG(("CacheStorageService::RemoveEntry [entry=%p]", aEntry));
+
+  nsAutoCString entryKey;
+  nsresult rv = aEntry->HashingKey(entryKey);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("aEntry->HashingKey() failed?");
+    return false;
+  }
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (mShutdown) {
+    LOG(("  after shutdown"));
+    return false;
+  }
+
+  if (aOnlyUnreferenced) {
+    if (aEntry->IsReferenced()) {
+      LOG(("  still referenced, not removing"));
+      return false;
+    }
+
+    if (!aEntry->IsUsingDisk() && IsForcedValidEntry(aEntry->GetStorageID(), entryKey)) {
+      LOG(("  forced valid, not removing"));
+      return false;
+    }
+  }
+
+  CacheEntryTable* entries;
+  if (sGlobalEntryTables->Get(aEntry->GetStorageID(), &entries))
+    RemoveExactEntry(entries, entryKey, aEntry, false /* don't overwrite */);
+
+  nsAutoCString memoryStorageID(aEntry->GetStorageID());
+  AppendMemoryStorageID(memoryStorageID);
+
+  if (sGlobalEntryTables->Get(memoryStorageID, &entries))
+    RemoveExactEntry(entries, entryKey, aEntry, false /* don't overwrite */);
+
+  return true;
+}
+
+void
+CacheStorageService::RecordMemoryOnlyEntry(CacheEntry* aEntry,
+                                           bool aOnlyInMemory,
+                                           bool aOverwrite)
+{
+  LOG(("CacheStorageService::RecordMemoryOnlyEntry [entry=%p, memory=%d, overwrite=%d]",
+    aEntry, aOnlyInMemory, aOverwrite));
+  // This method is responsible to put this entry to a special record hashtable
+  // that contains only entries that are stored in memory.
+  // Keep in mind that every entry, regardless of whether is in-memory-only or not
+  // is always recorded in the storage master hash table, the one identified by
+  // CacheEntry.StorageID().
+
+  mLock.AssertCurrentThreadOwns();
+
+  if (mShutdown) {
+    LOG(("  after shutdown"));
+    return;
+  }
+
+  nsresult rv;
+
+  nsAutoCString entryKey;
+  rv = aEntry->HashingKey(entryKey);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("aEntry->HashingKey() failed?");
+    return;
+  }
+
+  CacheEntryTable* entries = nullptr;
+  nsAutoCString memoryStorageID(aEntry->GetStorageID());
+  AppendMemoryStorageID(memoryStorageID);
+
+  if (!sGlobalEntryTables->Get(memoryStorageID, &entries)) {
+    if (!aOnlyInMemory) {
+      LOG(("  not recorded as memory only"));
+      return;
+    }
+
+    entries = new CacheEntryTable(CacheEntryTable::MEMORY_ONLY);
+    sGlobalEntryTables->Put(memoryStorageID, entries);
+    LOG(("  new memory-only storage table for %s", memoryStorageID.get()));
+  }
+
+  if (aOnlyInMemory) {
+    AddExactEntry(entries, entryKey, aEntry, aOverwrite);
+  }
+  else {
+    RemoveExactEntry(entries, entryKey, aEntry, aOverwrite);
+  }
+}
+
+// Checks if a cache entry is forced valid (will be loaded directly from cache
+// without further validation) - see nsICacheEntry.idl for further details
+bool CacheStorageService::IsForcedValidEntry(nsACString const &aContextKey,
+                                             nsACString const &aEntryKey)
+{
+  return IsForcedValidEntry(aContextKey + aEntryKey);
+}
+
+bool CacheStorageService::IsForcedValidEntry(nsACString const &aContextEntryKey)
+{
+  mozilla::MutexAutoLock lock(mForcedValidEntriesLock);
+
+  TimeStamp validUntil;
+
+  if (!mForcedValidEntries.Get(aContextEntryKey, &validUntil)) {
+    return false;
+  }
+
+  if (validUntil.IsNull()) {
+    return false;
+  }
+
+  // Entry timeout not reached yet
+  if (TimeStamp::NowLoRes() <= validUntil) {
+    return true;
+  }
+
+  // Entry timeout has been reached
+  mForcedValidEntries.Remove(aContextEntryKey);
+  return false;
+}
+
+// Allows a cache entry to be loaded directly from cache without further
+// validation - see nsICacheEntry.idl for further details
+void CacheStorageService::ForceEntryValidFor(nsACString const &aContextKey,
+                                             nsACString const &aEntryKey,
+                                             uint32_t aSecondsToTheFuture)
+{
+  mozilla::MutexAutoLock lock(mForcedValidEntriesLock);
+
+  TimeStamp now = TimeStamp::NowLoRes();
+  ForcedValidEntriesPrune(now);
+
+  // This will be the timeout
+  TimeStamp validUntil = now + TimeDuration::FromSeconds(aSecondsToTheFuture);
+
+  mForcedValidEntries.Put(aContextKey + aEntryKey, validUntil);
+}
+
+void CacheStorageService::RemoveEntryForceValid(nsACString const &aContextKey,
+                                                nsACString const &aEntryKey)
+{
+  mozilla::MutexAutoLock lock(mForcedValidEntriesLock);
+
+  LOG(("CacheStorageService::RemoveEntryForceValid context='%s' entryKey=%s",
+       aContextKey.BeginReading(), aEntryKey.BeginReading()));
+  mForcedValidEntries.Remove(aContextKey + aEntryKey);
+}
+
+// Cleans out the old entries in mForcedValidEntries
+void CacheStorageService::ForcedValidEntriesPrune(TimeStamp &now)
+{
+  static TimeDuration const oneMinute = TimeDuration::FromSeconds(60);
+  static TimeStamp dontPruneUntil = now + oneMinute;
+  if (now < dontPruneUntil)
+    return;
+
+  for (auto iter = mForcedValidEntries.Iter(); !iter.Done(); iter.Next()) {
+    if (iter.Data() < now) {
+      iter.Remove();
+    }
+  }
+  dontPruneUntil = now + oneMinute;
+}
+
+void
+CacheStorageService::OnMemoryConsumptionChange(CacheMemoryConsumer* aConsumer,
+                                               uint32_t aCurrentMemoryConsumption)
+{
+  LOG(("CacheStorageService::OnMemoryConsumptionChange [consumer=%p, size=%u]",
+    aConsumer, aCurrentMemoryConsumption));
+
+  uint32_t savedMemorySize = aConsumer->mReportedMemoryConsumption;
+  if (savedMemorySize == aCurrentMemoryConsumption)
+    return;
+
+  // Exchange saved size with current one.
+  aConsumer->mReportedMemoryConsumption = aCurrentMemoryConsumption;
+
+  bool usingDisk = !(aConsumer->mFlags & CacheMemoryConsumer::MEMORY_ONLY);
+  bool overLimit = Pool(usingDisk).OnMemoryConsumptionChange(
+    savedMemorySize, aCurrentMemoryConsumption);
+
+  if (!overLimit)
+    return;
+
+  // It's likely the timer has already been set when we get here,
+  // check outside the lock to save resources.
+  if (mPurgeTimer)
+    return;
+
+  // We don't know if this is called under the service lock or not,
+  // hence rather dispatch.
+  RefPtr<nsIEventTarget> cacheIOTarget = Thread();
+  if (!cacheIOTarget)
+    return;
+
+  // Dispatch as a priority task, we want to set the purge timer
+  // ASAP to prevent vain redispatch of this event.
+  nsCOMPtr<nsIRunnable> event =
+    NewRunnableMethod(this, &CacheStorageService::SchedulePurgeOverMemoryLimit);
+  cacheIOTarget->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+}
+
+bool
+CacheStorageService::MemoryPool::OnMemoryConsumptionChange(uint32_t aSavedMemorySize,
+                                                           uint32_t aCurrentMemoryConsumption)
+{
+  mMemorySize -= aSavedMemorySize;
+  mMemorySize += aCurrentMemoryConsumption;
+
+  LOG(("  mMemorySize=%u (+%u,-%u)", uint32_t(mMemorySize), aCurrentMemoryConsumption, aSavedMemorySize));
+
+  // Bypass purging when memory has not grew up significantly
+  if (aCurrentMemoryConsumption <= aSavedMemorySize)
+    return false;
+
+  return mMemorySize > Limit();
+}
+
+void
+CacheStorageService::SchedulePurgeOverMemoryLimit()
+{
+  LOG(("CacheStorageService::SchedulePurgeOverMemoryLimit"));
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (mShutdown) {
+    LOG(("  past shutdown"));
+    return;
+  }
+
+  if (mPurgeTimer) {
+    LOG(("  timer already up"));
+    return;
+  }
+
+  mPurgeTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
+  if (mPurgeTimer) {
+    nsresult rv;
+    rv = mPurgeTimer->InitWithCallback(this, 1000, nsITimer::TYPE_ONE_SHOT);
+    LOG(("  timer init rv=0x%08x", rv));
+  }
+}
+
+NS_IMETHODIMP
+CacheStorageService::Notify(nsITimer* aTimer)
+{
+  LOG(("CacheStorageService::Notify"));
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (aTimer == mPurgeTimer) {
+    mPurgeTimer = nullptr;
+
+    nsCOMPtr<nsIRunnable> event =
+      NewRunnableMethod(this, &CacheStorageService::PurgeOverMemoryLimit);
+    Dispatch(event);
+  }
+
+  return NS_OK;
+}
+
+void
+CacheStorageService::PurgeOverMemoryLimit()
+{
+  MOZ_ASSERT(IsOnManagementThread());
+
+  LOG(("CacheStorageService::PurgeOverMemoryLimit"));
+
+  static TimeDuration const kFourSeconds = TimeDuration::FromSeconds(4);
+  TimeStamp now = TimeStamp::NowLoRes();
+
+  if (!mLastPurgeTime.IsNull() && now - mLastPurgeTime < kFourSeconds) {
+    LOG(("  bypassed, too soon"));
+    return;
+  }
+
+  mLastPurgeTime = now;
+
+  Pool(true).PurgeOverMemoryLimit();
+  Pool(false).PurgeOverMemoryLimit();
+}
+
+void
+CacheStorageService::MemoryPool::PurgeOverMemoryLimit()
+{
+  TimeStamp start(TimeStamp::Now());
+
+  uint32_t const memoryLimit = Limit();
+  if (mMemorySize > memoryLimit) {
+    LOG(("  memory data consumption over the limit, abandon expired entries"));
+    PurgeExpired();
+  }
+
+  bool frecencyNeedsSort = true;
+
+  // No longer makes sense since:
+  // Memory entries are never purged partially, only as a whole when the memory
+  // cache limit is overreached.
+  // Disk entries throw the data away ASAP so that only metadata are kept.
+  // TODO when this concept of two separate pools is found working, the code should
+  // clean up.
+#if 0
+  if (mMemorySize > memoryLimit) {
+    LOG(("  memory data consumption over the limit, abandon disk backed data"));
+    PurgeByFrecency(frecencyNeedsSort, CacheEntry::PURGE_DATA_ONLY_DISK_BACKED);
+  }
+
+  if (mMemorySize > memoryLimit) {
+    LOG(("  metadata consumtion over the limit, abandon disk backed entries"));
+    PurgeByFrecency(frecencyNeedsSort, CacheEntry::PURGE_WHOLE_ONLY_DISK_BACKED);
+  }
+#endif
+
+  if (mMemorySize > memoryLimit) {
+    LOG(("  memory data consumption over the limit, abandon any entry"));
+    PurgeByFrecency(frecencyNeedsSort, CacheEntry::PURGE_WHOLE);
+  }
+
+  LOG(("  purging took %1.2fms", (TimeStamp::Now() - start).ToMilliseconds()));
+}
+
+void
+CacheStorageService::MemoryPool::PurgeExpired()
+{
+  MOZ_ASSERT(IsOnManagementThread());
+
+  mExpirationArray.Sort(ExpirationComparator());
+  uint32_t now = NowInSeconds();
+
+  uint32_t const memoryLimit = Limit();
+
+  for (uint32_t i = 0; mMemorySize > memoryLimit && i < mExpirationArray.Length();) {
+    if (CacheIOThread::YieldAndRerun())
+      return;
+
+    RefPtr<CacheEntry> entry = mExpirationArray[i];
+
+    uint32_t expirationTime = entry->GetExpirationTime();
+    if (expirationTime > 0 && expirationTime <= now &&
+        entry->Purge(CacheEntry::PURGE_WHOLE)) {
+      LOG(("  purged expired, entry=%p, exptime=%u (now=%u)",
+        entry.get(), entry->GetExpirationTime(), now));
+      continue;
+    }
+
+    // not purged, move to the next one
+    ++i;
+  }
+}
+
+void
+CacheStorageService::MemoryPool::PurgeByFrecency(bool &aFrecencyNeedsSort, uint32_t aWhat)
+{
+  MOZ_ASSERT(IsOnManagementThread());
+
+  if (aFrecencyNeedsSort) {
+    mFrecencyArray.Sort(FrecencyComparator());
+    aFrecencyNeedsSort = false;
+  }
+
+  uint32_t const memoryLimit = Limit();
+
+  for (uint32_t i = 0; mMemorySize > memoryLimit && i < mFrecencyArray.Length();) {
+    if (CacheIOThread::YieldAndRerun())
+      return;
+
+    RefPtr<CacheEntry> entry = mFrecencyArray[i];
+
+    if (entry->Purge(aWhat)) {
+      LOG(("  abandoned (%d), entry=%p, frecency=%1.10f",
+        aWhat, entry.get(), entry->GetFrecency()));
+      continue;
+    }
+
+    // not purged, move to the next one
+    ++i;
+  }
+}
+
+void
+CacheStorageService::MemoryPool::PurgeAll(uint32_t aWhat)
+{
+  LOG(("CacheStorageService::MemoryPool::PurgeAll aWhat=%d", aWhat));
+  MOZ_ASSERT(IsOnManagementThread());
+
+  for (uint32_t i = 0; i < mFrecencyArray.Length();) {
+    if (CacheIOThread::YieldAndRerun())
+      return;
+
+    RefPtr<CacheEntry> entry = mFrecencyArray[i];
+
+    if (entry->Purge(aWhat)) {
+      LOG(("  abandoned entry=%p", entry.get()));
+      continue;
+    }
+
+    // not purged, move to the next one
+    ++i;
+  }
+}
+
+// Methods exposed to and used by CacheStorage.
+
+nsresult
+CacheStorageService::AddStorageEntry(CacheStorage const* aStorage,
+                                     const nsACString & aURI,
+                                     const nsACString & aIdExtension,
+                                     bool aReplace,
+                                     CacheEntryHandle** aResult)
+{
+  NS_ENSURE_FALSE(mShutdown, NS_ERROR_NOT_INITIALIZED);
+
+  NS_ENSURE_ARG(aStorage);
+
+  nsAutoCString contextKey;
+  CacheFileUtils::AppendKeyPrefix(aStorage->LoadInfo(), contextKey);
+
+  return AddStorageEntry(contextKey, aURI, aIdExtension,
+                         aStorage->WriteToDisk(),
+                         aStorage->SkipSizeCheck(),
+                         aStorage->Pinning(),
+                         aReplace,
+                         aResult);
+}
+
+nsresult
+CacheStorageService::AddStorageEntry(nsCSubstring const& aContextKey,
+                                     const nsACString & aURI,
+                                     const nsACString & aIdExtension,
+                                     bool aWriteToDisk,
+                                     bool aSkipSizeCheck,
+                                     bool aPin,
+                                     bool aReplace,
+                                     CacheEntryHandle** aResult)
+{
+  nsresult rv;
+
+  nsAutoCString entryKey;
+  rv = CacheEntry::HashingKey(EmptyCString(), aIdExtension, aURI, entryKey);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  LOG(("CacheStorageService::AddStorageEntry [entryKey=%s, contextKey=%s]",
+    entryKey.get(), aContextKey.BeginReading()));
+
+  RefPtr<CacheEntry> entry;
+  RefPtr<CacheEntryHandle> handle;
+
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    NS_ENSURE_FALSE(mShutdown, NS_ERROR_NOT_INITIALIZED);
+
+    // Ensure storage table
+    CacheEntryTable* entries;
+    if (!sGlobalEntryTables->Get(aContextKey, &entries)) {
+      entries = new CacheEntryTable(CacheEntryTable::ALL_ENTRIES);
+      sGlobalEntryTables->Put(aContextKey, entries);
+      LOG(("  new storage entries table for context '%s'", aContextKey.BeginReading()));
+    }
+
+    bool entryExists = entries->Get(entryKey, getter_AddRefs(entry));
+
+    if (entryExists && !aReplace) {
+      // check whether we want to turn this entry to a memory-only.
+      if (MOZ_UNLIKELY(!aWriteToDisk) && MOZ_LIKELY(entry->IsUsingDisk())) {
+        LOG(("  entry is persistent but we want mem-only, replacing it"));
+        aReplace = true;
+      }
+    }
+
+    // If truncate is demanded, delete and doom the current entry
+    if (entryExists && aReplace) {
+      entries->Remove(entryKey);
+
+      LOG(("  dooming entry %p for %s because of OPEN_TRUNCATE", entry.get(), entryKey.get()));
+      // On purpose called under the lock to prevent races of doom and open on I/O thread
+      // No need to remove from both memory-only and all-entries tables.  The new entry
+      // will overwrite the shadow entry in its ctor.
+      entry->DoomAlreadyRemoved();
+
+      entry = nullptr;
+      entryExists = false;
+
+      // Would only lead to deleting force-valid timestamp again.  We don't need the
+      // replace information anymore after this point anyway.
+      aReplace = false;
+    }
+
+    // Ensure entry for the particular URL
+    if (!entryExists) {
+      // When replacing with a new entry, always remove the current force-valid timestamp,
+      // this is the only place to do it.
+      if (aReplace) {
+        RemoveEntryForceValid(aContextKey, entryKey);
+      }
+
+      // Entry is not in the hashtable or has just been truncated...
+      entry = new CacheEntry(aContextKey, aURI, aIdExtension, aWriteToDisk, aSkipSizeCheck, aPin);
+      entries->Put(entryKey, entry);
+      LOG(("  new entry %p for %s", entry.get(), entryKey.get()));
+    }
+
+    if (entry) {
+      // Here, if this entry was not for a long time referenced by any consumer,
+      // gets again first 'handles count' reference.
+      handle = entry->NewHandle();
+    }
+  }
+
+  handle.forget(aResult);
+  return NS_OK;
+}
+
+nsresult
+CacheStorageService::CheckStorageEntry(CacheStorage const* aStorage,
+                                       const nsACString & aURI,
+                                       const nsACString & aIdExtension,
+                                       bool* aResult)
+{
+  nsresult rv;
+
+  nsAutoCString contextKey;
+  CacheFileUtils::AppendKeyPrefix(aStorage->LoadInfo(), contextKey);
+
+  if (!aStorage->WriteToDisk()) {
+    AppendMemoryStorageID(contextKey);
+  }
+
+  LOG(("CacheStorageService::CheckStorageEntry [uri=%s, eid=%s, contextKey=%s]",
+    aURI.BeginReading(), aIdExtension.BeginReading(), contextKey.get()));
+
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    NS_ENSURE_FALSE(mShutdown, NS_ERROR_NOT_INITIALIZED);
+
+    nsAutoCString entryKey;
+    rv = CacheEntry::HashingKey(EmptyCString(), aIdExtension, aURI, entryKey);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    CacheEntryTable* entries;
+    if ((*aResult = sGlobalEntryTables->Get(contextKey, &entries)) &&
+        entries->GetWeak(entryKey, aResult)) {
+      LOG(("  found in hash tables"));
+      return NS_OK;
+    }
+  }
+
+  if (!aStorage->WriteToDisk()) {
+    // Memory entry, nothing more to do.
+    LOG(("  not found in hash tables"));
+    return NS_OK;
+  }
+
+  // Disk entry, not found in the hashtable, check the index.
+  nsAutoCString fileKey;
+  rv = CacheEntry::HashingKey(contextKey, aIdExtension, aURI, fileKey);
+
+  CacheIndex::EntryStatus status;
+  rv = CacheIndex::HasEntry(fileKey, &status);
+  if (NS_FAILED(rv) || status == CacheIndex::DO_NOT_KNOW) {
+    LOG(("  index doesn't know, rv=0x%08x", rv));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  *aResult = status == CacheIndex::EXISTS;
+  LOG(("  %sfound in index", *aResult ? "" : "not "));
+  return NS_OK;
+}
+
+namespace {
+
+class CacheEntryDoomByKeyCallback : public CacheFileIOListener
+                                  , public nsIRunnable
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIRUNNABLE
+
+  explicit CacheEntryDoomByKeyCallback(nsICacheEntryDoomCallback* aCallback)
+    : mCallback(aCallback) { }
+
+private:
+  virtual ~CacheEntryDoomByKeyCallback();
+
+  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) override { return NS_OK; }
+  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf, nsresult aResult) override { return NS_OK; }
+  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult) override { return NS_OK; }
+  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) override { return NS_OK; }
+  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) override { return NS_OK; }
+
+  nsCOMPtr<nsICacheEntryDoomCallback> mCallback;
+  nsresult mResult;
+};
+
+CacheEntryDoomByKeyCallback::~CacheEntryDoomByKeyCallback()
+{
+  if (mCallback)
+    ProxyReleaseMainThread(mCallback);
+}
+
+NS_IMETHODIMP CacheEntryDoomByKeyCallback::OnFileDoomed(CacheFileHandle *aHandle,
+                                                        nsresult aResult)
+{
+  if (!mCallback)
+    return NS_OK;
+
+  mResult = aResult;
+  if (NS_IsMainThread()) {
+    Run();
+  } else {
+    NS_DispatchToMainThread(this);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP CacheEntryDoomByKeyCallback::Run()
+{
+  mCallback->OnCacheEntryDoomed(mResult);
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(CacheEntryDoomByKeyCallback, CacheFileIOListener, nsIRunnable);
+
+} // namespace
+
+nsresult
+CacheStorageService::DoomStorageEntry(CacheStorage const* aStorage,
+                                      const nsACString & aURI,
+                                      const nsACString & aIdExtension,
+                                      nsICacheEntryDoomCallback* aCallback)
+{
+  LOG(("CacheStorageService::DoomStorageEntry"));
+
+  NS_ENSURE_ARG(aStorage);
+
+  nsAutoCString contextKey;
+  CacheFileUtils::AppendKeyPrefix(aStorage->LoadInfo(), contextKey);
+
+  nsAutoCString entryKey;
+  nsresult rv = CacheEntry::HashingKey(EmptyCString(), aIdExtension, aURI, entryKey);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<CacheEntry> entry;
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    NS_ENSURE_FALSE(mShutdown, NS_ERROR_NOT_INITIALIZED);
+
+    CacheEntryTable* entries;
+    if (sGlobalEntryTables->Get(contextKey, &entries)) {
+      if (entries->Get(entryKey, getter_AddRefs(entry))) {
+        if (aStorage->WriteToDisk() || !entry->IsUsingDisk()) {
+          // When evicting from disk storage, purge
+          // When evicting from memory storage and the entry is memory-only, purge
+          LOG(("  purging entry %p for %s [storage use disk=%d, entry use disk=%d]",
+            entry.get(), entryKey.get(), aStorage->WriteToDisk(), entry->IsUsingDisk()));
+          entries->Remove(entryKey);
+        }
+        else {
+          // Otherwise, leave it
+          LOG(("  leaving entry %p for %s [storage use disk=%d, entry use disk=%d]",
+            entry.get(), entryKey.get(), aStorage->WriteToDisk(), entry->IsUsingDisk()));
+          entry = nullptr;
+        }
+      }
+    }
+
+    if (!entry) {
+      RemoveEntryForceValid(contextKey, entryKey);
+    }
+  }
+
+  if (entry) {
+    LOG(("  dooming entry %p for %s", entry.get(), entryKey.get()));
+    return entry->AsyncDoom(aCallback);
+  }
+
+  LOG(("  no entry loaded for %s", entryKey.get()));
+
+  if (aStorage->WriteToDisk()) {
+    nsAutoCString contextKey;
+    CacheFileUtils::AppendKeyPrefix(aStorage->LoadInfo(), contextKey);
+
+    rv = CacheEntry::HashingKey(contextKey, aIdExtension, aURI, entryKey);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    LOG(("  dooming file only for %s", entryKey.get()));
+
+    RefPtr<CacheEntryDoomByKeyCallback> callback(
+      new CacheEntryDoomByKeyCallback(aCallback));
+    rv = CacheFileIOManager::DoomFileByKey(entryKey, callback);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return NS_OK;
+  }
+
+  class Callback : public Runnable
+  {
+  public:
+    explicit Callback(nsICacheEntryDoomCallback* aCallback) : mCallback(aCallback) { }
+    NS_IMETHOD Run() override
+    {
+      mCallback->OnCacheEntryDoomed(NS_ERROR_NOT_AVAILABLE);
+      return NS_OK;
+    }
+    nsCOMPtr<nsICacheEntryDoomCallback> mCallback;
+  };
+
+  if (aCallback) {
+    RefPtr<Runnable> callback = new Callback(aCallback);
+    return NS_DispatchToMainThread(callback);
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheStorageService::DoomStorageEntries(CacheStorage const* aStorage,
+                                        nsICacheEntryDoomCallback* aCallback)
+{
+  LOG(("CacheStorageService::DoomStorageEntries"));
+
+  NS_ENSURE_FALSE(mShutdown, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_ARG(aStorage);
+
+  nsAutoCString contextKey;
+  CacheFileUtils::AppendKeyPrefix(aStorage->LoadInfo(), contextKey);
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  return DoomStorageEntries(contextKey, aStorage->LoadInfo(),
+                            aStorage->WriteToDisk(), aStorage->Pinning(),
+                            aCallback);
+}
+
+nsresult
+CacheStorageService::DoomStorageEntries(nsCSubstring const& aContextKey,
+                                        nsILoadContextInfo* aContext,
+                                        bool aDiskStorage,
+                                        bool aPinned,
+                                        nsICacheEntryDoomCallback* aCallback)
+{
+  LOG(("CacheStorageService::DoomStorageEntries [context=%s]", aContextKey.BeginReading()));
+
+  mLock.AssertCurrentThreadOwns();
+
+  NS_ENSURE_TRUE(!mShutdown, NS_ERROR_NOT_INITIALIZED);
+
+  nsAutoCString memoryStorageID(aContextKey);
+  AppendMemoryStorageID(memoryStorageID);
+
+  if (aDiskStorage) {
+    LOG(("  dooming disk+memory storage of %s", aContextKey.BeginReading()));
+
+    // Walk one by one and remove entries according their pin status
+    CacheEntryTable *diskEntries, *memoryEntries;
+    if (sGlobalEntryTables->Get(aContextKey, &diskEntries)) {
+      sGlobalEntryTables->Get(memoryStorageID, &memoryEntries);
+
+      for (auto iter = diskEntries->Iter(); !iter.Done(); iter.Next()) {
+        auto entry = iter.Data();
+        if (entry->DeferOrBypassRemovalOnPinStatus(aPinned)) {
+          continue;
+        }
+
+        if (memoryEntries) {
+          RemoveExactEntry(memoryEntries, iter.Key(), entry, false);
+        }
+        iter.Remove();
+      }
+    }
+
+    if (aContext && !aContext->IsPrivate()) {
+      LOG(("  dooming disk entries"));
+      CacheFileIOManager::EvictByContext(aContext, aPinned);
+    }
+  } else {
+    LOG(("  dooming memory-only storage of %s", aContextKey.BeginReading()));
+
+    // Remove the memory entries table from the global tables.
+    // Since we store memory entries also in the disk entries table
+    // we need to remove the memory entries from the disk table one
+    // by one manually.
+    nsAutoPtr<CacheEntryTable> memoryEntries;
+    sGlobalEntryTables->RemoveAndForget(memoryStorageID, memoryEntries);
+
+    CacheEntryTable* diskEntries;
+    if (memoryEntries && sGlobalEntryTables->Get(aContextKey, &diskEntries)) {
+      for (auto iter = memoryEntries->Iter(); !iter.Done(); iter.Next()) {
+        auto entry = iter.Data();
+        RemoveExactEntry(diskEntries, iter.Key(), entry, false);
+      }
+    }
+  }
+
+  {
+    mozilla::MutexAutoLock lock(mForcedValidEntriesLock);
+
+    if (aContext) {
+      for (auto iter = mForcedValidEntries.Iter(); !iter.Done(); iter.Next()) {
+        bool matches;
+        DebugOnly<nsresult> rv = CacheFileUtils::KeyMatchesLoadContextInfo(
+          iter.Key(), aContext, &matches);
+        MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+        if (matches) {
+          iter.Remove();
+        }
+      }
+    } else {
+      mForcedValidEntries.Clear();
+    }
+  }
+
+  // An artificial callback.  This is a candidate for removal tho.  In the new
+  // cache any 'doom' or 'evict' function ensures that the entry or entries
+  // being doomed is/are not accessible after the function returns.  So there is
+  // probably no need for a callback - has no meaning.  But for compatibility
+  // with the old cache that is still in the tree we keep the API similar to be
+  // able to make tests as well as other consumers work for now.
+  class Callback : public Runnable
+  {
+  public:
+    explicit Callback(nsICacheEntryDoomCallback* aCallback) : mCallback(aCallback) { }
+    NS_IMETHOD Run() override
+    {
+      mCallback->OnCacheEntryDoomed(NS_OK);
+      return NS_OK;
+    }
+    nsCOMPtr<nsICacheEntryDoomCallback> mCallback;
+  };
+
+  if (aCallback) {
+    RefPtr<Runnable> callback = new Callback(aCallback);
+    return NS_DispatchToMainThread(callback);
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheStorageService::WalkStorageEntries(CacheStorage const* aStorage,
+                                        bool aVisitEntries,
+                                        nsICacheStorageVisitor* aVisitor)
+{
+  LOG(("CacheStorageService::WalkStorageEntries [cb=%p, visitentries=%d]", aVisitor, aVisitEntries));
+  NS_ENSURE_FALSE(mShutdown, NS_ERROR_NOT_INITIALIZED);
+
+  NS_ENSURE_ARG(aStorage);
+
+  if (aStorage->WriteToDisk()) {
+    RefPtr<WalkDiskCacheRunnable> event =
+      new WalkDiskCacheRunnable(aStorage->LoadInfo(), aVisitEntries, aVisitor);
+    return event->Walk();
+  }
+
+  RefPtr<WalkMemoryCacheRunnable> event =
+    new WalkMemoryCacheRunnable(aStorage->LoadInfo(), aVisitEntries, aVisitor);
+  return event->Walk();
+}
+
+void
+CacheStorageService::CacheFileDoomed(nsILoadContextInfo* aLoadContextInfo,
+                                     const nsACString & aIdExtension,
+                                     const nsACString & aURISpec)
+{
+  nsAutoCString contextKey;
+  CacheFileUtils::AppendKeyPrefix(aLoadContextInfo, contextKey);
+
+  nsAutoCString entryKey;
+  CacheEntry::HashingKey(EmptyCString(), aIdExtension, aURISpec, entryKey);
+
+  mozilla::MutexAutoLock lock(mLock);
+
+  if (mShutdown) {
+    return;
+  }
+
+  CacheEntryTable* entries;
+  RefPtr<CacheEntry> entry;
+
+  if (sGlobalEntryTables->Get(contextKey, &entries) &&
+      entries->Get(entryKey, getter_AddRefs(entry))) {
+    if (entry->IsFileDoomed()) {
+      // Need to remove under the lock to avoid possible race leading
+      // to duplication of the entry per its key.
+      RemoveExactEntry(entries, entryKey, entry, false);
+      entry->DoomAlreadyRemoved();
+    }
+
+    // Entry found, but it's not the entry that has been found doomed
+    // by the lower eviction layer.  Just leave everything unchanged.
+    return;
+  }
+
+  RemoveEntryForceValid(contextKey, entryKey);
+}
+
+bool
+CacheStorageService::GetCacheEntryInfo(nsILoadContextInfo* aLoadContextInfo,
+                                       const nsACString & aIdExtension,
+                                       const nsACString & aURISpec,
+                                       EntryInfoCallback *aCallback)
+{
+  nsAutoCString contextKey;
+  CacheFileUtils::AppendKeyPrefix(aLoadContextInfo, contextKey);
+
+  nsAutoCString entryKey;
+  CacheEntry::HashingKey(EmptyCString(), aIdExtension, aURISpec, entryKey);
+
+  RefPtr<CacheEntry> entry;
+  {
+    mozilla::MutexAutoLock lock(mLock);
+
+    if (mShutdown) {
+      return false;
+    }
+
+    CacheEntryTable* entries;
+    if (!sGlobalEntryTables->Get(contextKey, &entries)) {
+      return false;
+    }
+
+    if (!entries->Get(entryKey, getter_AddRefs(entry))) {
+      return false;
+    }
+  }
+
+  GetCacheEntryInfo(entry, aCallback);
+  return true;
+}
+
+// static
+void
+CacheStorageService::GetCacheEntryInfo(CacheEntry* aEntry,
+                                       EntryInfoCallback *aCallback)
+{
+  nsCString const uriSpec = aEntry->GetURI();
+  nsCString const enhanceId = aEntry->GetEnhanceID();
+
+  uint32_t dataSize;
+  if (NS_FAILED(aEntry->GetStorageDataSize(&dataSize))) {
+    dataSize = 0;
+  }
+  int32_t fetchCount;
+  if (NS_FAILED(aEntry->GetFetchCount(&fetchCount))) {
+    fetchCount = 0;
+  }
+  uint32_t lastModified;
+  if (NS_FAILED(aEntry->GetLastModified(&lastModified))) {
+    lastModified = 0;
+  }
+  uint32_t expirationTime;
+  if (NS_FAILED(aEntry->GetExpirationTime(&expirationTime))) {
+    expirationTime = 0;
+  }
+
+  aCallback->OnEntryInfo(uriSpec, enhanceId, dataSize,
+                         fetchCount, lastModified, expirationTime,
+                         aEntry->IsPinned());
+}
+
+// static
+uint32_t CacheStorageService::CacheQueueSize(bool highPriority)
+{
+  RefPtr<CacheIOThread> thread = CacheFileIOManager::IOThread();
+  MOZ_ASSERT(thread);
+  return thread->QueueSize(highPriority);
+}
+
+// Telementry collection
+
+namespace {
+
+bool TelemetryEntryKey(CacheEntry const* entry, nsAutoCString& key)
+{
+  nsAutoCString entryKey;
+  nsresult rv = entry->HashingKey(entryKey);
+  if (NS_FAILED(rv))
+    return false;
+
+  if (entry->GetStorageID().IsEmpty()) {
+    // Hopefully this will be const-copied, saves some memory
+    key = entryKey;
+  } else {
+    key.Assign(entry->GetStorageID());
+    key.Append(':');
+    key.Append(entryKey);
+  }
+
+  return true;
+}
+
+} // namespace
+
+void
+CacheStorageService::TelemetryPrune(TimeStamp &now)
+{
+  static TimeDuration const oneMinute = TimeDuration::FromSeconds(60);
+  static TimeStamp dontPruneUntil = now + oneMinute;
+  if (now < dontPruneUntil)
+    return;
+
+  static TimeDuration const fifteenMinutes = TimeDuration::FromSeconds(900);
+  for (auto iter = mPurgeTimeStamps.Iter(); !iter.Done(); iter.Next()) {
+    if (now - iter.Data() > fifteenMinutes) {
+      // We are not interested in resurrection of entries after 15 minutes
+      // of time.  This is also the limit for the telemetry.
+      iter.Remove();
+    }
+  }
+  dontPruneUntil = now + oneMinute;
+}
+
+void
+CacheStorageService::TelemetryRecordEntryCreation(CacheEntry const* entry)
+{
+  MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+
+  nsAutoCString key;
+  if (!TelemetryEntryKey(entry, key))
+    return;
+
+  TimeStamp now = TimeStamp::NowLoRes();
+  TelemetryPrune(now);
+
+  // When an entry is craeted (registered actually) we check if there is
+  // a timestamp marked when this very same cache entry has been removed
+  // (deregistered) because of over-memory-limit purging.  If there is such
+  // a timestamp found accumulate telemetry on how long the entry was away.
+  TimeStamp timeStamp;
+  if (!mPurgeTimeStamps.Get(key, &timeStamp))
+    return;
+
+  mPurgeTimeStamps.Remove(key);
+
+  Telemetry::AccumulateTimeDelta(Telemetry::HTTP_CACHE_ENTRY_RELOAD_TIME,
+                                 timeStamp, TimeStamp::NowLoRes());
+}
+
+void
+CacheStorageService::TelemetryRecordEntryRemoval(CacheEntry const* entry)
+{
+  MOZ_ASSERT(CacheStorageService::IsOnManagementThread());
+
+  // Doomed entries must not be considered, we are only interested in purged
+  // entries.  Note that the mIsDoomed flag is always set before deregistration
+  // happens.
+  if (entry->IsDoomed())
+    return;
+
+  nsAutoCString key;
+  if (!TelemetryEntryKey(entry, key))
+    return;
+
+  // When an entry is removed (deregistered actually) we put a timestamp for this
+  // entry to the hashtable so that when the entry is created (registered) again
+  // we know how long it was away.  Also accumulate number of AsyncOpen calls on
+  // the entry, this tells us how efficiently the pool actually works.
+
+  TimeStamp now = TimeStamp::NowLoRes();
+  TelemetryPrune(now);
+  mPurgeTimeStamps.Put(key, now);
+
+  Telemetry::Accumulate(Telemetry::HTTP_CACHE_ENTRY_REUSE_COUNT, entry->UseCount());
+  Telemetry::AccumulateTimeDelta(Telemetry::HTTP_CACHE_ENTRY_ALIVE_TIME,
+                                 entry->LoadStart(), TimeStamp::NowLoRes());
+}
+
+// nsIMemoryReporter
+
+size_t
+CacheStorageService::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  CacheStorageService::Self()->Lock().AssertCurrentThreadOwns();
+
+  size_t n = 0;
+  // The elemets are referenced by sGlobalEntryTables and are reported from there
+  n += Pool(true).mFrecencyArray.ShallowSizeOfExcludingThis(mallocSizeOf);
+  n += Pool(true).mExpirationArray.ShallowSizeOfExcludingThis(mallocSizeOf);
+  n += Pool(false).mFrecencyArray.ShallowSizeOfExcludingThis(mallocSizeOf);
+  n += Pool(false).mExpirationArray.ShallowSizeOfExcludingThis(mallocSizeOf);
+  // Entries reported manually in CacheStorageService::CollectReports callback
+  if (sGlobalEntryTables) {
+    n += sGlobalEntryTables->ShallowSizeOfIncludingThis(mallocSizeOf);
+  }
+
+  return n;
+}
+
+size_t
+CacheStorageService::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+NS_IMETHODIMP
+CacheStorageService::CollectReports(nsIHandleReportCallback* aHandleReport,
+                                    nsISupports* aData, bool aAnonymize)
+{
+  MOZ_COLLECT_REPORT(
+    "explicit/network/cache2/io", KIND_HEAP, UNITS_BYTES,
+    CacheFileIOManager::SizeOfIncludingThis(MallocSizeOf),
+    "Memory used by the cache IO manager.");
+
+  MOZ_COLLECT_REPORT(
+    "explicit/network/cache2/index", KIND_HEAP, UNITS_BYTES,
+    CacheIndex::SizeOfIncludingThis(MallocSizeOf),
+    "Memory used by the cache index.");
+
+  MutexAutoLock lock(mLock);
+
+  // Report the service instance, this doesn't report entries, done lower
+  MOZ_COLLECT_REPORT(
+    "explicit/network/cache2/service", KIND_HEAP, UNITS_BYTES,
+    SizeOfIncludingThis(MallocSizeOf),
+    "Memory used by the cache storage service.");
+
+  // Report all entries, each storage separately (by the context key)
+  //
+  // References are:
+  // sGlobalEntryTables to N CacheEntryTable
+  // CacheEntryTable to N CacheEntry
+  // CacheEntry to 1 CacheFile
+  // CacheFile to
+  //   N CacheFileChunk (keeping the actual data)
+  //   1 CacheFileMetadata (keeping http headers etc.)
+  //   1 CacheFileOutputStream
+  //   N CacheFileInputStream
+  if (sGlobalEntryTables) {
+    for (auto iter1 = sGlobalEntryTables->Iter(); !iter1.Done(); iter1.Next()) {
+      CacheStorageService::Self()->Lock().AssertCurrentThreadOwns();
+
+      CacheEntryTable* table = iter1.UserData();
+
+      size_t size = 0;
+      mozilla::MallocSizeOf mallocSizeOf = CacheStorageService::MallocSizeOf;
+
+      size += table->ShallowSizeOfIncludingThis(mallocSizeOf);
+      for (auto iter2 = table->Iter(); !iter2.Done(); iter2.Next()) {
+        size += iter2.Key().SizeOfExcludingThisIfUnshared(mallocSizeOf);
+
+        // Bypass memory-only entries, those will be reported when iterating the
+        // memory only table. Memory-only entries are stored in both ALL_ENTRIES
+        // and MEMORY_ONLY hashtables.
+        RefPtr<mozilla::net::CacheEntry> const& entry = iter2.Data();
+        if (table->Type() == CacheEntryTable::MEMORY_ONLY ||
+            entry->IsUsingDisk()) {
+          size += entry->SizeOfIncludingThis(mallocSizeOf);
+        }
+      }
+
+      // These key names are not privacy-sensitive.
+      aHandleReport->Callback(
+        EmptyCString(),
+        nsPrintfCString("explicit/network/cache2/%s-storage(%s)",
+          table->Type() == CacheEntryTable::MEMORY_ONLY ? "memory" : "disk",
+          iter1.Key().BeginReading()),
+        nsIMemoryReporter::KIND_HEAP, nsIMemoryReporter::UNITS_BYTES, size,
+        NS_LITERAL_CSTRING("Memory used by the cache storage."),
+        aData);
+    }
+  }
+
+  return NS_OK;
+}
+
+// nsICacheTesting
+
+NS_IMETHODIMP
+CacheStorageService::IOThreadSuspender::Run()
+{
+  MonitorAutoLock mon(mMon);
+  while (!mSignaled) {
+    mon.Wait();
+  }
+  return NS_OK;
+}
+
+void
+CacheStorageService::IOThreadSuspender::Notify()
+{
+  MonitorAutoLock mon(mMon);
+  mSignaled = true;
+  mon.Notify();
+}
+
+NS_IMETHODIMP
+CacheStorageService::SuspendCacheIOThread(uint32_t aLevel)
+{
+  RefPtr<CacheIOThread> thread = CacheFileIOManager::IOThread();
+  if (!thread) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  MOZ_ASSERT(!mActiveIOSuspender);
+  mActiveIOSuspender = new IOThreadSuspender();
+  return thread->Dispatch(mActiveIOSuspender, aLevel);
+}
+
+NS_IMETHODIMP
+CacheStorageService::ResumeCacheIOThread()
+{
+  MOZ_ASSERT(mActiveIOSuspender);
+
+  RefPtr<IOThreadSuspender> suspender;
+  suspender.swap(mActiveIOSuspender);
+  suspender->Notify();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheStorageService::Flush(nsIObserver* aObserver)
+{
+  RefPtr<CacheIOThread> thread = CacheFileIOManager::IOThread();
+  if (!thread) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsCOMPtr<nsIObserverService> observerService =
+    mozilla::services::GetObserverService();
+  if (!observerService) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Adding as weak, the consumer is responsible to keep the reference
+  // until notified.
+  observerService->AddObserver(aObserver, "cacheservice:purge-memory-pools", false);
+
+  // This runnable will do the purging and when done, notifies the above observer.
+  // We dispatch it to the CLOSE level, so all data writes scheduled up to this time
+  // will be done before this purging happens.
+  RefPtr<CacheStorageService::PurgeFromMemoryRunnable> r =
+    new CacheStorageService::PurgeFromMemoryRunnable(this, CacheEntry::PURGE_WHOLE);
+
+  return thread->Dispatch(r, CacheIOThread::WRITE);
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/CacheStorageService.h b/netwerk/cache2/CacheStorageService.h
new file mode 100644
index 0000000000..f40459d842
--- /dev/null
+++ b/netwerk/cache2/CacheStorageService.h
@@ -0,0 +1,422 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CacheStorageService__h__
+#define CacheStorageService__h__
+
+#include "nsICacheStorageService.h"
+#include "nsIMemoryReporter.h"
+#include "nsITimer.h"
+#include "nsICacheTesting.h"
+
+#include "nsClassHashtable.h"
+#include "nsDataHashtable.h"
+#include "nsString.h"
+#include "nsThreadUtils.h"
+#include "nsProxyRelease.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/TimeStamp.h"
+#include "nsTArray.h"
+
+class nsIURI;
+class nsICacheEntryDoomCallback;
+class nsICacheStorageVisitor;
+class nsIRunnable;
+class nsIThread;
+class nsIEventTarget;
+
+namespace mozilla {
+namespace net {
+
+class CacheStorageService;
+class CacheStorage;
+class CacheEntry;
+class CacheEntryHandle;
+
+class CacheMemoryConsumer
+{
+private:
+  friend class CacheStorageService;
+  uint32_t mReportedMemoryConsumption : 30;
+  uint32_t mFlags : 2;
+
+private:
+  CacheMemoryConsumer() = delete;
+
+protected:
+  enum {
+    // No special treatment, reports always to the disk-entries pool.
+    NORMAL = 0,
+    // This consumer is belonging to a memory-only cache entry, used to decide
+    // which of the two disk and memory pools count this consumption at.
+    MEMORY_ONLY = 1 << 0,
+    // Prevent reports of this consumer at all, used for disk data chunks since
+    // we throw them away as soon as the entry is not used by any consumer and
+    // don't want to make them wipe the whole pool out during their short life.
+    DONT_REPORT = 1 << 1
+  };
+
+  explicit CacheMemoryConsumer(uint32_t aFlags);
+  ~CacheMemoryConsumer() { DoMemoryReport(0); }
+  void DoMemoryReport(uint32_t aCurrentSize);
+};
+
+class CacheStorageService final : public nsICacheStorageService
+                                , public nsIMemoryReporter
+                                , public nsITimerCallback
+                                , public nsICacheTesting
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSICACHESTORAGESERVICE
+  NS_DECL_NSIMEMORYREPORTER
+  NS_DECL_NSITIMERCALLBACK
+  NS_DECL_NSICACHETESTING
+
+  CacheStorageService();
+
+  void Shutdown();
+  void DropPrivateBrowsingEntries();
+
+  // Takes care of deleting any pending trashes for both cache1 and cache2
+  // as well as the cache directory of an inactive cache version when requested.
+  static void CleaupCacheDirectories(uint32_t aVersion, uint32_t aActive);
+
+  static CacheStorageService* Self() { return sSelf; }
+  static nsISupports* SelfISupports() { return static_cast<nsICacheStorageService*>(Self()); }
+  nsresult Dispatch(nsIRunnable* aEvent);
+  static bool IsRunning() { return sSelf && !sSelf->mShutdown; }
+  static bool IsOnManagementThread();
+  already_AddRefed<nsIEventTarget> Thread() const;
+  mozilla::Mutex& Lock() { return mLock; }
+
+  // Tracks entries that may be forced valid in a pruned hashtable.
+  nsDataHashtable<nsCStringHashKey, TimeStamp> mForcedValidEntries;
+  void ForcedValidEntriesPrune(TimeStamp &now);
+
+  // Helper thread-safe interface to pass entry info, only difference from
+  // nsICacheStorageVisitor is that instead of nsIURI only the uri spec is
+  // passed.
+  class EntryInfoCallback {
+  public:
+    virtual void OnEntryInfo(const nsACString & aURISpec, const nsACString & aIdEnhance,
+                             int64_t aDataSize, int32_t aFetchCount,
+                             uint32_t aLastModifiedTime, uint32_t aExpirationTime,
+                             bool aPinned) = 0;
+  };
+
+  // Invokes OnEntryInfo for the given aEntry, synchronously.
+  static void GetCacheEntryInfo(CacheEntry* aEntry, EntryInfoCallback *aVisitor);
+
+  static uint32_t CacheQueueSize(bool highPriority);
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf)
+
+private:
+  virtual ~CacheStorageService();
+  void ShutdownBackground();
+
+private:
+  // The following methods may only be called on the management
+  // thread.
+  friend class CacheEntry;
+
+  /**
+   * Registers the entry in management ordered arrays, a mechanism
+   * helping with weighted purge of entries.
+   * Management arrays keep hard reference to the entry.  Entry is
+   * responsible to remove it self or the service is responsible to
+   * remove the entry when it's no longer needed.
+   */
+  void RegisterEntry(CacheEntry* aEntry);
+
+  /**
+   * Deregisters the entry from management arrays.  References are
+   * then released.
+   */
+  void UnregisterEntry(CacheEntry* aEntry);
+
+  /**
+   * Removes the entry from the related entry hash table, if still present.
+   */
+  bool RemoveEntry(CacheEntry* aEntry, bool aOnlyUnreferenced = false);
+
+  /**
+   * Tells the storage service whether this entry is only to be stored in
+   * memory.
+   */
+  void RecordMemoryOnlyEntry(CacheEntry* aEntry,
+                             bool aOnlyInMemory,
+                             bool aOverwrite);
+
+  /**
+   * Sets a cache entry valid (overrides the default loading behavior by loading
+   * directly from cache) for the given number of seconds
+   * See nsICacheEntry.idl for more details
+   */
+  void ForceEntryValidFor(nsACString const &aContextKey,
+                          nsACString const &aEntryKey,
+                          uint32_t aSecondsToTheFuture);
+
+  /**
+   * Remove the validity info
+   */
+  void RemoveEntryForceValid(nsACString const &aContextKey,
+                             nsACString const &aEntryKey);
+
+  /**
+   * Retrieves the status of the cache entry to see if it has been forced valid
+   * (so it will loaded directly from cache without further validation)
+   */
+  bool IsForcedValidEntry(nsACString const &aContextKey,
+                          nsACString const &aEntryKey);
+
+private:
+  friend class CacheIndex;
+
+  /**
+   * CacheIndex uses this to prevent a cache entry from being prememptively
+   * thrown away when forced valid
+   * See nsICacheEntry.idl for more details
+   */
+  bool IsForcedValidEntry(nsACString const &aEntryKeyWithContext);
+
+private:
+  // These are helpers for telemetry monitoring of the memory pools.
+  void TelemetryPrune(TimeStamp &now);
+  void TelemetryRecordEntryCreation(CacheEntry const* entry);
+  void TelemetryRecordEntryRemoval(CacheEntry const* entry);
+
+private:
+  // Following methods are thread safe to call.
+  friend class CacheStorage;
+
+  /**
+   * Get, or create when not existing and demanded, an entry for the storage
+   * and uri+id extension.
+   */
+  nsresult AddStorageEntry(CacheStorage const* aStorage,
+                           const nsACString & aURI,
+                           const nsACString & aIdExtension,
+                           bool aReplace,
+                           CacheEntryHandle** aResult);
+
+  /**
+   * Check existance of an entry.  This may throw NS_ERROR_NOT_AVAILABLE
+   * when the information cannot be obtained synchronously w/o blocking.
+   */
+  nsresult CheckStorageEntry(CacheStorage const* aStorage,
+                             const nsACString & aURI,
+                             const nsACString & aIdExtension,
+                             bool* aResult);
+
+  /**
+   * Removes the entry from the related entry hash table, if still present
+   * and returns it.
+   */
+  nsresult DoomStorageEntry(CacheStorage const* aStorage,
+                            const nsACString & aURI,
+                            const nsACString & aIdExtension,
+                            nsICacheEntryDoomCallback* aCallback);
+
+  /**
+   * Removes and returns entry table for the storage.
+   */
+  nsresult DoomStorageEntries(CacheStorage const* aStorage,
+                              nsICacheEntryDoomCallback* aCallback);
+
+  /**
+   * Walk all entiries beloging to the storage.
+   */
+  nsresult WalkStorageEntries(CacheStorage const* aStorage,
+                              bool aVisitEntries,
+                              nsICacheStorageVisitor* aVisitor);
+
+private:
+  friend class CacheFileIOManager;
+
+  /**
+   * CacheFileIOManager uses this method to notify CacheStorageService that
+   * an active entry was removed. This method is called even if the entry
+   * removal was originated by CacheStorageService.
+   */
+  void CacheFileDoomed(nsILoadContextInfo* aLoadContextInfo,
+                       const nsACString & aIdExtension,
+                       const nsACString & aURISpec);
+
+  /**
+   * Tries to find an existing entry in the hashtables and synchronously call
+   * OnCacheEntryInfo of the aVisitor callback when found.
+   * @retuns
+   *   true, when the entry has been found that also implies the callbacks has
+   *        beem invoked
+   *   false, when an entry has not been found
+   */
+  bool GetCacheEntryInfo(nsILoadContextInfo* aLoadContextInfo,
+                         const nsACString & aIdExtension,
+                         const nsACString & aURISpec,
+                         EntryInfoCallback *aCallback);
+
+private:
+  friend class CacheMemoryConsumer;
+
+  /**
+   * When memory consumption of this entry radically changes, this method
+   * is called to reflect the size of allocated memory.  This call may purge
+   * unspecified number of entries from memory (but not from disk).
+   */
+  void OnMemoryConsumptionChange(CacheMemoryConsumer* aConsumer,
+                                 uint32_t aCurrentMemoryConsumption);
+
+  /**
+   * If not already pending, it schedules mPurgeTimer that fires after 1 second
+   * and dispatches PurgeOverMemoryLimit().
+   */
+  void SchedulePurgeOverMemoryLimit();
+
+  /**
+   * Called on the management thread, removes all expired and then least used
+   * entries from the memory, first from the disk pool and then from the memory
+   * pool.
+   */
+  void PurgeOverMemoryLimit();
+
+private:
+  nsresult DoomStorageEntries(nsCSubstring const& aContextKey,
+                              nsILoadContextInfo* aContext,
+                              bool aDiskStorage,
+                              bool aPin,
+                              nsICacheEntryDoomCallback* aCallback);
+  nsresult AddStorageEntry(nsCSubstring const& aContextKey,
+                           const nsACString & aURI,
+                           const nsACString & aIdExtension,
+                           bool aWriteToDisk,
+                           bool aSkipSizeCheck,
+                           bool aPin,
+                           bool aReplace,
+                           CacheEntryHandle** aResult);
+
+  static CacheStorageService* sSelf;
+
+  mozilla::Mutex mLock;
+  mozilla::Mutex mForcedValidEntriesLock;
+
+  bool mShutdown;
+
+  // Accessible only on the service thread
+  class MemoryPool
+  {
+  public:
+    enum EType
+    {
+      DISK,
+      MEMORY,
+    } mType;
+
+    explicit MemoryPool(EType aType);
+    ~MemoryPool();
+
+    nsTArray<RefPtr<CacheEntry> > mFrecencyArray;
+    nsTArray<RefPtr<CacheEntry> > mExpirationArray;
+    Atomic<uint32_t, Relaxed> mMemorySize;
+
+    bool OnMemoryConsumptionChange(uint32_t aSavedMemorySize,
+                                   uint32_t aCurrentMemoryConsumption);
+    /**
+     * Purges entries from memory based on the frecency ordered array.
+     */
+    void PurgeOverMemoryLimit();
+    void PurgeExpired();
+    void PurgeByFrecency(bool &aFrecencyNeedsSort, uint32_t aWhat);
+    void PurgeAll(uint32_t aWhat);
+
+  private:
+    uint32_t Limit() const;
+    MemoryPool() = delete;
+  };
+
+  MemoryPool mDiskPool;
+  MemoryPool mMemoryPool;
+  TimeStamp mLastPurgeTime;
+  MemoryPool& Pool(bool aUsingDisk)
+  {
+    return aUsingDisk ? mDiskPool : mMemoryPool;
+  }
+  MemoryPool const& Pool(bool aUsingDisk) const
+  {
+    return aUsingDisk ? mDiskPool : mMemoryPool;
+  }
+
+  nsCOMPtr<nsITimer> mPurgeTimer;
+
+  class PurgeFromMemoryRunnable : public Runnable
+  {
+  public:
+    PurgeFromMemoryRunnable(CacheStorageService* aService, uint32_t aWhat)
+      : mService(aService), mWhat(aWhat) { }
+
+  private:
+    virtual ~PurgeFromMemoryRunnable() { }
+
+    NS_IMETHOD Run() override;
+
+    RefPtr<CacheStorageService> mService;
+    uint32_t mWhat;
+  };
+
+  // Used just for telemetry purposes, accessed only on the management thread.
+  // Note: not included in the memory reporter, this is not expected to be huge
+  // and also would be complicated to report since reporting happens on the main
+  // thread but this table is manipulated on the management thread.
+  nsDataHashtable<nsCStringHashKey, mozilla::TimeStamp> mPurgeTimeStamps;
+
+  // nsICacheTesting
+  class IOThreadSuspender : public Runnable
+  {
+  public:
+    IOThreadSuspender() : mMon("IOThreadSuspender"), mSignaled(false) { }
+    void Notify();
+  private:
+    virtual ~IOThreadSuspender() { }
+    NS_IMETHOD Run() override;
+
+    Monitor mMon;
+    bool mSignaled;
+  };
+
+  RefPtr<IOThreadSuspender> mActiveIOSuspender;
+};
+
+template<class T>
+void ProxyRelease(nsCOMPtr<T> &object, nsIThread* thread)
+{
+  NS_ProxyRelease(thread, object.forget());
+}
+
+template<class T>
+void ProxyReleaseMainThread(nsCOMPtr<T> &object)
+{
+  nsCOMPtr<nsIThread> mainThread = do_GetMainThread();
+  ProxyRelease(object, mainThread);
+}
+
+} // namespace net
+} // namespace mozilla
+
+#define NS_CACHE_STORAGE_SERVICE_CID \
+  { 0xea70b098, 0x5014, 0x4e21, \
+  { 0xae, 0xe1, 0x75, 0xe6, 0xb2, 0xc4, 0xb8, 0xe0 } } \
+
+#define NS_CACHE_STORAGE_SERVICE_CONTRACTID \
+  "@mozilla.org/netwerk/cache-storage-service;1"
+
+#define NS_CACHE_STORAGE_SERVICE_CONTRACTID2 \
+  "@mozilla.org/network/cache-storage-service;1"
+
+#endif
diff --git a/netwerk/cache2/OldWrappers.cpp b/netwerk/cache2/OldWrappers.cpp
new file mode 100644
index 0000000000..81df88df0e
--- /dev/null
+++ b/netwerk/cache2/OldWrappers.cpp
@@ -0,0 +1,1155 @@
+// Stuff to link the old imp to the new api - will go away!
+
+#include "CacheLog.h"
+#include "OldWrappers.h"
+#include "CacheStorage.h"
+#include "CacheStorageService.h"
+#include "LoadContextInfo.h"
+#include "nsCacheService.h"
+
+#include "nsIURI.h"
+#include "nsICacheSession.h"
+#include "nsIApplicationCache.h"
+#include "nsIApplicationCacheService.h"
+#include "nsIStreamTransportService.h"
+#include "nsIFile.h"
+#include "nsICacheEntryDoomCallback.h"
+#include "nsICacheListener.h"
+#include "nsICacheStorageVisitor.h"
+
+#include "nsServiceManagerUtils.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsProxyRelease.h"
+#include "mozilla/Telemetry.h"
+
+static NS_DEFINE_CID(kStreamTransportServiceCID,
+                     NS_STREAMTRANSPORTSERVICE_CID);
+
+static uint32_t const CHECK_MULTITHREADED = nsICacheStorage::CHECK_MULTITHREADED;
+
+namespace mozilla {
+namespace net {
+
+namespace {
+
+// Fires the doom callback back on the main thread
+// after the cache I/O thread is looped.
+
+class DoomCallbackSynchronizer : public Runnable
+{
+public:
+  explicit DoomCallbackSynchronizer(nsICacheEntryDoomCallback* cb) : mCB(cb)
+  {
+    MOZ_COUNT_CTOR(DoomCallbackSynchronizer);
+  }
+  nsresult Dispatch();
+
+private:
+  virtual ~DoomCallbackSynchronizer()
+  {
+    MOZ_COUNT_DTOR(DoomCallbackSynchronizer);
+  }
+
+  NS_DECL_NSIRUNNABLE
+  nsCOMPtr<nsICacheEntryDoomCallback> mCB;
+};
+
+nsresult DoomCallbackSynchronizer::Dispatch()
+{
+  nsresult rv;
+
+  nsCOMPtr<nsICacheService> serv =
+      do_GetService(NS_CACHESERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIEventTarget> eventTarget;
+  rv = serv->GetCacheIOTarget(getter_AddRefs(eventTarget));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = eventTarget->Dispatch(this, NS_DISPATCH_NORMAL);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP DoomCallbackSynchronizer::Run()
+{
+  if (!NS_IsMainThread()) {
+    NS_DispatchToMainThread(this);
+  }
+  else {
+    if (mCB)
+      mCB->OnCacheEntryDoomed(NS_OK);
+  }
+  return NS_OK;
+}
+
+// Receives doom callback from the old API and forwards to the new API
+
+class DoomCallbackWrapper : public nsICacheListener
+{
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSICACHELISTENER
+
+  explicit DoomCallbackWrapper(nsICacheEntryDoomCallback* cb) : mCB(cb)
+  {
+    MOZ_COUNT_CTOR(DoomCallbackWrapper);
+  }
+
+private:
+  virtual ~DoomCallbackWrapper()
+  {
+    MOZ_COUNT_DTOR(DoomCallbackWrapper);
+  }
+
+  nsCOMPtr<nsICacheEntryDoomCallback> mCB;
+};
+
+NS_IMPL_ISUPPORTS(DoomCallbackWrapper, nsICacheListener);
+
+NS_IMETHODIMP DoomCallbackWrapper::OnCacheEntryAvailable(nsICacheEntryDescriptor *descriptor,
+                                                         nsCacheAccessMode accessGranted,
+                                                         nsresult status)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP DoomCallbackWrapper::OnCacheEntryDoomed(nsresult status)
+{
+  if (!mCB)
+    return NS_ERROR_NULL_POINTER;
+
+  mCB->OnCacheEntryDoomed(status);
+  mCB = nullptr;
+  return NS_OK;
+}
+
+} // namespace
+
+// _OldVisitCallbackWrapper
+// Receives visit callbacks from the old API and forwards it to the new API
+
+NS_IMPL_ISUPPORTS(_OldVisitCallbackWrapper, nsICacheVisitor)
+
+_OldVisitCallbackWrapper::~_OldVisitCallbackWrapper()
+{
+  if (!mHit) {
+    // The device has not been found, to not break the chain, simulate
+    // storage info callback.
+    mCB->OnCacheStorageInfo(0, 0, 0, nullptr);
+  }
+
+  if (mVisitEntries) {
+    mCB->OnCacheEntryVisitCompleted();
+  }
+
+  MOZ_COUNT_DTOR(_OldVisitCallbackWrapper);
+}
+
+NS_IMETHODIMP _OldVisitCallbackWrapper::VisitDevice(const char * deviceID,
+                                                    nsICacheDeviceInfo *deviceInfo,
+                                                    bool *_retval)
+{
+  if (!mCB)
+    return NS_ERROR_NULL_POINTER;
+
+  *_retval = false;
+  if (strcmp(deviceID, mDeviceID)) {
+    // Not the device we want to visit
+    return NS_OK;
+  }
+
+  mHit = true;
+
+  nsresult rv;
+
+  uint32_t capacity;
+  rv = deviceInfo->GetMaximumSize(&capacity);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIFile> dir;
+  if (!strcmp(mDeviceID, "disk")) {
+    nsCacheService::GetDiskCacheDirectory(getter_AddRefs(dir));
+  } else if (!strcmp(mDeviceID, "offline")) {
+    nsCacheService::GetAppCacheDirectory(getter_AddRefs(dir));
+  }
+
+  if (mLoadInfo->IsAnonymous()) {
+    // Anonymous visiting reports 0, 0 since we cannot count that
+    // early the number of anon entries.
+    mCB->OnCacheStorageInfo(0, 0, capacity, dir);
+  } else {
+    // Non-anon visitor counts all non-anon + ALL ANON entries,
+    // there is no way to determine the number of entries when
+    // using the old cache APIs - there is no concept of anonymous
+    // storage.
+    uint32_t entryCount;
+    rv = deviceInfo->GetEntryCount(&entryCount);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    uint32_t totalSize;
+    rv = deviceInfo->GetTotalSize(&totalSize);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mCB->OnCacheStorageInfo(entryCount, totalSize, capacity, dir);
+  }
+
+  *_retval = mVisitEntries;
+  return NS_OK;
+}
+
+NS_IMETHODIMP _OldVisitCallbackWrapper::VisitEntry(const char * deviceID,
+                                                   nsICacheEntryInfo *entryInfo,
+                                                   bool *_retval)
+{
+  MOZ_ASSERT(!strcmp(deviceID, mDeviceID));
+
+  nsresult rv;
+
+  *_retval = true;
+
+  // Read all informative properties from the entry.
+  nsXPIDLCString clientId;
+  rv = entryInfo->GetClientID(getter_Copies(clientId));
+  if (NS_FAILED(rv))
+    return NS_OK;
+
+  if (mLoadInfo->IsPrivate() !=
+      StringBeginsWith(clientId, NS_LITERAL_CSTRING("HTTP-memory-only-PB"))) {
+    return NS_OK;
+  }
+
+  nsAutoCString cacheKey, enhanceId;
+  rv = entryInfo->GetKey(cacheKey);
+  if (NS_FAILED(rv))
+    return NS_OK;
+
+  if (StringBeginsWith(cacheKey, NS_LITERAL_CSTRING("anon&"))) {
+    if (!mLoadInfo->IsAnonymous())
+      return NS_OK;
+
+    cacheKey = Substring(cacheKey, 5, cacheKey.Length());
+  } else if (mLoadInfo->IsAnonymous()) {
+    return NS_OK;
+  }
+
+  if (StringBeginsWith(cacheKey, NS_LITERAL_CSTRING("id="))) {
+    int32_t uriSpecEnd = cacheKey.Find("&uri=");
+    if (uriSpecEnd == kNotFound) // Corrupted, ignore
+      return NS_OK;
+
+    enhanceId = Substring(cacheKey, 3, uriSpecEnd - 3);
+    cacheKey = Substring(cacheKey, uriSpecEnd + 1, cacheKey.Length());
+  }
+
+  if (StringBeginsWith(cacheKey, NS_LITERAL_CSTRING("uri="))) {
+    cacheKey = Substring(cacheKey, 4, cacheKey.Length());
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  // cacheKey is strip of any prefixes
+  rv = NS_NewURI(getter_AddRefs(uri), cacheKey);
+  if (NS_FAILED(rv))
+    return NS_OK;
+
+  uint32_t dataSize;
+  if (NS_FAILED(entryInfo->GetDataSize(&dataSize)))
+    dataSize = 0;
+  int32_t fetchCount;
+  if (NS_FAILED(entryInfo->GetFetchCount(&fetchCount)))
+    fetchCount = 0;
+  uint32_t expirationTime;
+  if (NS_FAILED(entryInfo->GetExpirationTime(&expirationTime)))
+    expirationTime = 0;
+  uint32_t lastModified;
+  if (NS_FAILED(entryInfo->GetLastModified(&lastModified)))
+    lastModified = 0;
+
+  // Send them to the consumer.
+  rv = mCB->OnCacheEntryInfo(
+    uri, enhanceId, (int64_t)dataSize, fetchCount, lastModified, expirationTime, false);
+
+  *_retval = NS_SUCCEEDED(rv);
+  return NS_OK;
+}
+
+// _OldGetDiskConsumption
+
+//static
+nsresult _OldGetDiskConsumption::Get(nsICacheStorageConsumptionObserver* aCallback)
+{
+  nsresult rv;
+
+  nsCOMPtr<nsICacheService> serv =
+      do_GetService(NS_CACHESERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<_OldGetDiskConsumption> cb = new _OldGetDiskConsumption(aCallback);
+
+  // _OldGetDiskConsumption stores the found size value, but until dispatched
+  // to the main thread it doesn't call on the consupmtion observer. See bellow.
+  rv = serv->VisitEntries(cb);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // We are called from CacheStorageService::AsyncGetDiskConsumption whose IDL
+  // documentation claims the callback is always delievered asynchronously
+  // back to the main thread.  Despite we know the result synchronosusly when
+  // querying the old cache, we need to stand the word and dispatch the result
+  // to the main thread asynchronously.  Hence the dispatch here.
+  return NS_DispatchToMainThread(cb);
+}
+
+NS_IMPL_ISUPPORTS_INHERITED(_OldGetDiskConsumption,
+                            Runnable,
+                            nsICacheVisitor)
+
+_OldGetDiskConsumption::_OldGetDiskConsumption(
+  nsICacheStorageConsumptionObserver* aCallback)
+  : mCallback(aCallback)
+  , mSize(0)
+{
+}
+
+NS_IMETHODIMP
+_OldGetDiskConsumption::Run()
+{
+  mCallback->OnNetworkCacheDiskConsumption(mSize);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+_OldGetDiskConsumption::VisitDevice(const char * deviceID,
+                                    nsICacheDeviceInfo *deviceInfo,
+                                    bool *_retval)
+{
+  if (!strcmp(deviceID, "disk")) {
+    uint32_t size;
+    nsresult rv = deviceInfo->GetTotalSize(&size);
+    if (NS_SUCCEEDED(rv))
+      mSize = (int64_t)size;
+  }
+
+  *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+_OldGetDiskConsumption::VisitEntry(const char * deviceID,
+                                   nsICacheEntryInfo *entryInfo,
+                                   bool *_retval)
+{
+  MOZ_CRASH("Unexpected");
+  return NS_OK;
+}
+
+
+// _OldCacheEntryWrapper
+
+_OldCacheEntryWrapper::_OldCacheEntryWrapper(nsICacheEntryDescriptor* desc)
+: mOldDesc(desc), mOldInfo(desc)
+{
+  MOZ_COUNT_CTOR(_OldCacheEntryWrapper);
+  LOG(("Creating _OldCacheEntryWrapper %p for descriptor %p", this, desc));
+}
+
+_OldCacheEntryWrapper::_OldCacheEntryWrapper(nsICacheEntryInfo* info)
+: mOldDesc(nullptr), mOldInfo(info)
+{
+  MOZ_COUNT_CTOR(_OldCacheEntryWrapper);
+  LOG(("Creating _OldCacheEntryWrapper %p for info %p", this, info));
+}
+
+_OldCacheEntryWrapper::~_OldCacheEntryWrapper()
+{
+  MOZ_COUNT_DTOR(_OldCacheEntryWrapper);
+  LOG(("Destroying _OldCacheEntryWrapper %p for descriptor %p", this, mOldInfo.get()));
+}
+
+NS_IMETHODIMP _OldCacheEntryWrapper::GetIsForcedValid(bool *aIsForcedValid)
+{
+  // Unused stub
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP _OldCacheEntryWrapper::ForceValidFor(uint32_t aSecondsToTheFuture)
+{
+  // Unused stub
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMPL_ISUPPORTS(_OldCacheEntryWrapper, nsICacheEntry)
+
+NS_IMETHODIMP _OldCacheEntryWrapper::AsyncDoom(nsICacheEntryDoomCallback* listener)
+{
+  RefPtr<DoomCallbackWrapper> cb = listener
+    ? new DoomCallbackWrapper(listener)
+    : nullptr;
+  return AsyncDoom(cb);
+}
+
+NS_IMETHODIMP _OldCacheEntryWrapper::GetDataSize(int64_t *aSize)
+{
+  uint32_t size;
+  nsresult rv = GetDataSize(&size);
+  if (NS_FAILED(rv))
+    return rv;
+
+  *aSize = size;
+  return NS_OK;
+}
+
+NS_IMETHODIMP _OldCacheEntryWrapper::GetAltDataSize(int64_t *aSize)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP _OldCacheEntryWrapper::GetPersistent(bool *aPersistToDisk)
+{
+  if (!mOldDesc) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  nsresult rv;
+
+  nsCacheStoragePolicy policy;
+  rv = mOldDesc->GetStoragePolicy(&policy);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *aPersistToDisk = policy != nsICache::STORE_IN_MEMORY;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP _OldCacheEntryWrapper::Recreate(bool aMemoryOnly,
+                                              nsICacheEntry** aResult)
+{
+  NS_ENSURE_TRUE(mOldDesc, NS_ERROR_NOT_AVAILABLE);
+
+  nsCacheAccessMode mode;
+  nsresult rv = mOldDesc->GetAccessGranted(&mode);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!(mode & nsICache::ACCESS_WRITE))
+    return NS_ERROR_NOT_AVAILABLE;
+
+  LOG(("_OldCacheEntryWrapper::Recreate [this=%p]", this));
+
+  if (aMemoryOnly)
+    mOldDesc->SetStoragePolicy(nsICache::STORE_IN_MEMORY);
+
+  nsCOMPtr<nsICacheEntry> self(this);
+  self.forget(aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP _OldCacheEntryWrapper::OpenInputStream(int64_t offset,
+                                                     nsIInputStream * *_retval)
+{
+  if (offset > PR_UINT32_MAX)
+    return NS_ERROR_INVALID_ARG;
+
+  return OpenInputStream(uint32_t(offset), _retval);
+}
+NS_IMETHODIMP _OldCacheEntryWrapper::OpenOutputStream(int64_t offset,
+                                                      nsIOutputStream * *_retval)
+{
+  if (offset > PR_UINT32_MAX)
+    return NS_ERROR_INVALID_ARG;
+
+  return OpenOutputStream(uint32_t(offset), _retval);
+}
+
+NS_IMETHODIMP _OldCacheEntryWrapper::MaybeMarkValid()
+{
+  LOG(("_OldCacheEntryWrapper::MaybeMarkValid [this=%p]", this));
+
+  NS_ENSURE_TRUE(mOldDesc, NS_ERROR_NULL_POINTER);
+
+  nsCacheAccessMode mode;
+  nsresult rv = mOldDesc->GetAccessGranted(&mode);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (mode & nsICache::ACCESS_WRITE) {
+    LOG(("Marking cache entry valid [entry=%p, descr=%p]", this, mOldDesc));
+    return mOldDesc->MarkValid();
+  }
+
+  LOG(("Not marking read-only cache entry valid [entry=%p, descr=%p]", this, mOldDesc));
+  return NS_OK;
+}
+
+NS_IMETHODIMP _OldCacheEntryWrapper::HasWriteAccess(bool aWriteAllowed_unused, bool *aWriteAccess)
+{
+  NS_ENSURE_TRUE(mOldDesc, NS_ERROR_NULL_POINTER);
+  NS_ENSURE_ARG(aWriteAccess);
+
+  nsCacheAccessMode mode;
+  nsresult rv = mOldDesc->GetAccessGranted(&mode);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *aWriteAccess = !!(mode & nsICache::ACCESS_WRITE);
+
+  LOG(("_OldCacheEntryWrapper::HasWriteAccess [this=%p, write-access=%d]", this, *aWriteAccess));
+
+  return NS_OK;
+}
+
+namespace {
+
+class MetaDataVisitorWrapper : public nsICacheMetaDataVisitor
+{
+  virtual ~MetaDataVisitorWrapper() {}
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSICACHEMETADATAVISITOR
+  explicit MetaDataVisitorWrapper(nsICacheEntryMetaDataVisitor* cb) : mCB(cb) {}
+  nsCOMPtr<nsICacheEntryMetaDataVisitor> mCB;
+};
+
+NS_IMPL_ISUPPORTS(MetaDataVisitorWrapper, nsICacheMetaDataVisitor)
+
+NS_IMETHODIMP
+MetaDataVisitorWrapper::VisitMetaDataElement(char const * key,
+                                             char const * value,
+                                             bool *goon)
+{
+  *goon = true;
+  return mCB->OnMetaDataElement(key, value);
+}
+
+} // namespace
+
+NS_IMETHODIMP _OldCacheEntryWrapper::VisitMetaData(nsICacheEntryMetaDataVisitor* cb)
+{
+  RefPtr<MetaDataVisitorWrapper> w = new MetaDataVisitorWrapper(cb);
+  return mOldDesc->VisitMetaData(w);
+}
+
+namespace {
+
+nsresult
+GetCacheSessionNameForStoragePolicy(
+        nsCSubstring const &scheme,
+        nsCacheStoragePolicy storagePolicy,
+        bool isPrivate,
+        NeckoOriginAttributes const *originAttribs,
+        nsACString& sessionName)
+{
+  MOZ_ASSERT(!isPrivate || storagePolicy == nsICache::STORE_IN_MEMORY);
+
+  // HTTP
+  if (scheme.EqualsLiteral("http") ||
+      scheme.EqualsLiteral("https")) {
+    switch (storagePolicy) {
+    case nsICache::STORE_IN_MEMORY:
+      if (isPrivate)
+        sessionName.AssignLiteral("HTTP-memory-only-PB");
+      else
+        sessionName.AssignLiteral("HTTP-memory-only");
+      break;
+    case nsICache::STORE_OFFLINE:
+      // XXX This is actually never used, only added to prevent
+      // any compatibility damage.
+      sessionName.AssignLiteral("HTTP-offline");
+      break;
+    default:
+      sessionName.AssignLiteral("HTTP");
+      break;
+    }
+  }
+  // WYCIWYG
+  else if (scheme.EqualsLiteral("wyciwyg")) {
+    if (isPrivate)
+      sessionName.AssignLiteral("wyciwyg-private");
+    else
+      sessionName.AssignLiteral("wyciwyg");
+  }
+  // FTP
+  else if (scheme.EqualsLiteral("ftp")) {
+    if (isPrivate)
+      sessionName.AssignLiteral("FTP-private");
+    else
+      sessionName.AssignLiteral("FTP");
+  }
+  // all remaining URL scheme
+  else {
+    // Since with the new API a consumer cannot specify its own session name
+    // and partitioning of the cache is handled stricly only by the cache
+    // back-end internally, we will use a separate session name to pretend
+    // functionality of the new API wrapping the Darin's cache for all other
+    // URL schemes.
+    // Deliberately omitting |anonymous| since other session types don't
+    // recognize it too.
+    sessionName.AssignLiteral("other");
+    if (isPrivate)
+      sessionName.AppendLiteral("-private");
+  }
+
+  nsAutoCString suffix;
+  originAttribs->CreateSuffix(suffix);
+  sessionName.Append(suffix);
+
+  return NS_OK;
+}
+
+nsresult
+GetCacheSession(nsCSubstring const &aScheme,
+                bool aWriteToDisk,
+                nsILoadContextInfo* aLoadInfo,
+                nsIApplicationCache* aAppCache,
+                nsICacheSession** _result)
+{
+  nsresult rv;
+
+  nsCacheStoragePolicy storagePolicy;
+  if (aAppCache)
+    storagePolicy = nsICache::STORE_OFFLINE;
+  else if (!aWriteToDisk || aLoadInfo->IsPrivate())
+    storagePolicy = nsICache::STORE_IN_MEMORY;
+  else
+    storagePolicy = nsICache::STORE_ANYWHERE;
+
+  nsAutoCString clientId;
+  if (aAppCache) {
+    aAppCache->GetClientID(clientId);
+  }
+  else {
+    rv = GetCacheSessionNameForStoragePolicy(
+      aScheme,
+      storagePolicy,
+      aLoadInfo->IsPrivate(),
+      aLoadInfo->OriginAttributesPtr(),
+      clientId);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  LOG(("  GetCacheSession for client=%s, policy=%d", clientId.get(), storagePolicy));
+
+  nsCOMPtr<nsICacheService> serv =
+      do_GetService(NS_CACHESERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsICacheSession> session;
+  rv = nsCacheService::GlobalInstance()->CreateSessionInternal(clientId.get(),
+                                                               storagePolicy,
+                                                               nsICache::STREAM_BASED,
+                                                               getter_AddRefs(session));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = session->SetIsPrivate(aLoadInfo->IsPrivate());
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = session->SetDoomEntriesIfExpired(false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (aAppCache) {
+    nsCOMPtr<nsIFile> profileDirectory;
+    aAppCache->GetProfileDirectory(getter_AddRefs(profileDirectory));
+    if (profileDirectory)
+      rv = session->SetProfileDirectory(profileDirectory);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  session.forget(_result);
+  return NS_OK;
+}
+
+} // namespace
+
+
+NS_IMPL_ISUPPORTS_INHERITED(_OldCacheLoad, Runnable, nsICacheListener)
+
+_OldCacheLoad::_OldCacheLoad(nsCSubstring const& aScheme,
+                             nsCSubstring const& aCacheKey,
+                             nsICacheEntryOpenCallback* aCallback,
+                             nsIApplicationCache* aAppCache,
+                             nsILoadContextInfo* aLoadInfo,
+                             bool aWriteToDisk,
+                             uint32_t aFlags)
+  : mScheme(aScheme)
+  , mCacheKey(aCacheKey)
+  , mCallback(aCallback)
+  , mLoadInfo(GetLoadContextInfo(aLoadInfo))
+  , mFlags(aFlags)
+  , mWriteToDisk(aWriteToDisk)
+  , mNew(true)
+  , mOpening(true)
+  , mSync(false)
+  , mStatus(NS_ERROR_UNEXPECTED)
+  , mRunCount(0)
+  , mAppCache(aAppCache)
+{
+  MOZ_COUNT_CTOR(_OldCacheLoad);
+}
+
+_OldCacheLoad::~_OldCacheLoad()
+{
+  ProxyReleaseMainThread(mAppCache);
+  MOZ_COUNT_DTOR(_OldCacheLoad);
+}
+
+nsresult _OldCacheLoad::Start()
+{
+  LOG(("_OldCacheLoad::Start [this=%p, key=%s]", this, mCacheKey.get()));
+
+  mLoadStart = mozilla::TimeStamp::Now();
+
+  nsresult rv;
+
+  // Consumers that can invoke this code as first and off the main thread
+  // are responsible for initiating these two services on the main thread.
+  // Currently this is only nsWyciwygChannel.
+
+  // XXX: Start the cache service; otherwise DispatchToCacheIOThread will
+  // fail.
+  nsCOMPtr<nsICacheService> service =
+    do_GetService(NS_CACHESERVICE_CONTRACTID, &rv);
+
+  // Ensure the stream transport service gets initialized on the main thread
+  if (NS_SUCCEEDED(rv) && NS_IsMainThread()) {
+    nsCOMPtr<nsIStreamTransportService> sts =
+      do_GetService(kStreamTransportServiceCID, &rv);
+  }
+
+  if (NS_SUCCEEDED(rv)) {
+    rv = service->GetCacheIOTarget(getter_AddRefs(mCacheThread));
+  }
+
+  if (NS_SUCCEEDED(rv)) {
+    bool onCacheTarget;
+    rv = mCacheThread->IsOnCurrentThread(&onCacheTarget);
+    if (NS_SUCCEEDED(rv) && onCacheTarget) {
+      mSync = true;
+    }
+  }
+
+  if (NS_SUCCEEDED(rv)) {
+    if (mSync) {
+      rv = Run();
+    }
+    else {
+      rv = mCacheThread->Dispatch(this, NS_DISPATCH_NORMAL);
+    }
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+_OldCacheLoad::Run()
+{
+  LOG(("_OldCacheLoad::Run [this=%p, key=%s, cb=%p]", this, mCacheKey.get(), mCallback.get()));
+
+  nsresult rv;
+
+  if (mOpening) {
+    mOpening = false;
+    nsCOMPtr<nsICacheSession> session;
+    rv = GetCacheSession(mScheme, mWriteToDisk, mLoadInfo, mAppCache,
+                         getter_AddRefs(session));
+    if (NS_SUCCEEDED(rv)) {
+      // AsyncOpenCacheEntry isn't really async when its called on the
+      // cache service thread.
+
+      nsCacheAccessMode cacheAccess;
+      if (mFlags & nsICacheStorage::OPEN_TRUNCATE)
+        cacheAccess = nsICache::ACCESS_WRITE;
+      else if ((mFlags & nsICacheStorage::OPEN_READONLY) || mAppCache)
+        cacheAccess = nsICache::ACCESS_READ;
+      else
+        cacheAccess = nsICache::ACCESS_READ_WRITE;
+
+      LOG(("  session->AsyncOpenCacheEntry with access=%d", cacheAccess));
+
+      bool bypassBusy = mFlags & nsICacheStorage::OPEN_BYPASS_IF_BUSY;
+
+      if (mSync && cacheAccess == nsICache::ACCESS_WRITE) {
+        nsCOMPtr<nsICacheEntryDescriptor> entry;
+        rv = session->OpenCacheEntry(mCacheKey, cacheAccess, bypassBusy,
+          getter_AddRefs(entry));
+
+        nsCacheAccessMode grantedAccess = 0;
+        if (NS_SUCCEEDED(rv)) {
+          entry->GetAccessGranted(&grantedAccess);
+        }
+
+        return OnCacheEntryAvailable(entry, grantedAccess, rv);
+      }
+
+      rv = session->AsyncOpenCacheEntry(mCacheKey, cacheAccess, this, bypassBusy);
+      if (NS_SUCCEEDED(rv))
+        return NS_OK;
+    }
+
+    // Opening failed, propagate the error to the consumer
+    LOG(("  Opening cache entry failed with rv=0x%08x", rv));
+    mStatus = rv;
+    mNew = false;
+    NS_DispatchToMainThread(this);
+  } else {
+    if (!mCallback) {
+      LOG(("  duplicate call, bypassed"));
+      return NS_OK;
+    }
+
+    if (NS_SUCCEEDED(mStatus)) {
+      if (mFlags & nsICacheStorage::OPEN_TRUNCATE) {
+        mozilla::Telemetry::AccumulateTimeDelta(
+          mozilla::Telemetry::NETWORK_CACHE_V1_TRUNCATE_TIME_MS,
+          mLoadStart);
+      }
+      else if (mNew) {
+        mozilla::Telemetry::AccumulateTimeDelta(
+          mozilla::Telemetry::NETWORK_CACHE_V1_MISS_TIME_MS,
+          mLoadStart);
+      }
+      else {
+        mozilla::Telemetry::AccumulateTimeDelta(
+          mozilla::Telemetry::NETWORK_CACHE_V1_HIT_TIME_MS,
+          mLoadStart);
+      }
+    }
+
+    if (!(mFlags & CHECK_MULTITHREADED))
+      Check();
+
+    // break cycles
+    nsCOMPtr<nsICacheEntryOpenCallback> cb = mCallback.forget();
+    mCacheThread = nullptr;
+    nsCOMPtr<nsICacheEntry> entry = mCacheEntry.forget();
+
+    rv = cb->OnCacheEntryAvailable(entry, mNew, mAppCache, mStatus);
+
+    if (NS_FAILED(rv) && entry) {
+      LOG(("  cb->OnCacheEntryAvailable failed with rv=0x%08x", rv));
+      if (mNew)
+        entry->AsyncDoom(nullptr);
+      else
+        entry->Close();
+    }
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+_OldCacheLoad::OnCacheEntryAvailable(nsICacheEntryDescriptor *entry,
+                                     nsCacheAccessMode access,
+                                     nsresult status)
+{
+  LOG(("_OldCacheLoad::OnCacheEntryAvailable [this=%p, ent=%p, cb=%p, appcache=%p, access=%x]",
+    this, entry, mCallback.get(), mAppCache.get(), access));
+
+  // XXX Bug 759805: Sometimes we will call this method directly from
+  // HttpCacheQuery::Run when AsyncOpenCacheEntry fails, but
+  // AsyncOpenCacheEntry will also call this method. As a workaround, we just
+  // ensure we only execute this code once.
+  NS_ENSURE_TRUE(mRunCount == 0, NS_ERROR_UNEXPECTED);
+  ++mRunCount;
+
+  mCacheEntry = entry ? new _OldCacheEntryWrapper(entry) : nullptr;
+  mStatus = status;
+  mNew = access == nsICache::ACCESS_WRITE;
+
+  if (mFlags & CHECK_MULTITHREADED)
+    Check();
+
+  if (mSync)
+    return Run();
+
+  return NS_DispatchToMainThread(this);
+}
+
+void
+_OldCacheLoad::Check()
+{
+  if (!mCacheEntry)
+    return;
+
+  if (mNew)
+    return;
+
+  uint32_t result;
+  nsresult rv = mCallback->OnCacheEntryCheck(mCacheEntry, mAppCache, &result);
+  LOG(("  OnCacheEntryCheck result ent=%p, cb=%p, appcache=%p, rv=0x%08x, result=%d",
+    mCacheEntry.get(), mCallback.get(), mAppCache.get(), rv, result));
+
+  if (NS_FAILED(rv)) {
+    NS_WARNING("cache check failed");
+  }
+
+  if (NS_FAILED(rv) || result == nsICacheEntryOpenCallback::ENTRY_NOT_WANTED) {
+    mCacheEntry->Close();
+    mCacheEntry = nullptr;
+    mStatus = NS_ERROR_CACHE_KEY_NOT_FOUND;
+  }
+}
+
+NS_IMETHODIMP
+_OldCacheLoad::OnCacheEntryDoomed(nsresult)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+// nsICacheStorage old cache wrapper
+
+NS_IMPL_ISUPPORTS(_OldStorage, nsICacheStorage)
+
+_OldStorage::_OldStorage(nsILoadContextInfo* aInfo,
+                         bool aAllowDisk,
+                         bool aLookupAppCache,
+                         bool aOfflineStorage,
+                         nsIApplicationCache* aAppCache)
+: mLoadInfo(GetLoadContextInfo(aInfo))
+, mAppCache(aAppCache)
+, mWriteToDisk(aAllowDisk)
+, mLookupAppCache(aLookupAppCache)
+, mOfflineStorage(aOfflineStorage)
+{
+  MOZ_COUNT_CTOR(_OldStorage);
+}
+
+_OldStorage::~_OldStorage()
+{
+  MOZ_COUNT_DTOR(_OldStorage);
+}
+
+NS_IMETHODIMP _OldStorage::AsyncOpenURI(nsIURI *aURI,
+                                        const nsACString & aIdExtension,
+                                        uint32_t aFlags,
+                                        nsICacheEntryOpenCallback *aCallback)
+{
+  NS_ENSURE_ARG(aURI);
+  NS_ENSURE_ARG(aCallback);
+
+#ifdef MOZ_LOGGING
+  nsAutoCString uriSpec;
+  aURI->GetAsciiSpec(uriSpec);
+  LOG(("_OldStorage::AsyncOpenURI [this=%p, uri=%s, ide=%s, flags=%x]",
+    this, uriSpec.get(), aIdExtension.BeginReading(), aFlags));
+#endif
+
+  nsresult rv;
+
+  nsAutoCString cacheKey, scheme;
+  rv = AssembleCacheKey(aURI, aIdExtension, cacheKey, scheme);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!mAppCache && (mLookupAppCache || mOfflineStorage)) {
+    rv = ChooseApplicationCache(cacheKey, getter_AddRefs(mAppCache));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (mAppCache) {
+      // From a chosen appcache open only as readonly
+      aFlags &= ~nsICacheStorage::OPEN_TRUNCATE;
+    }
+  }
+
+  RefPtr<_OldCacheLoad> cacheLoad =
+    new _OldCacheLoad(scheme, cacheKey, aCallback, mAppCache,
+                      mLoadInfo, mWriteToDisk, aFlags);
+
+  rv = cacheLoad->Start();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP _OldStorage::OpenTruncate(nsIURI *aURI, const nsACString & aIdExtension,
+                                        nsICacheEntry **aCacheEntry)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP _OldStorage::Exists(nsIURI *aURI, const nsACString & aIdExtension,
+                                   bool *aResult)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP _OldStorage::AsyncDoomURI(nsIURI *aURI, const nsACString & aIdExtension,
+                                        nsICacheEntryDoomCallback* aCallback)
+{
+  LOG(("_OldStorage::AsyncDoomURI"));
+
+  nsresult rv;
+
+  nsAutoCString cacheKey, scheme;
+  rv = AssembleCacheKey(aURI, aIdExtension, cacheKey, scheme);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsICacheSession> session;
+  rv = GetCacheSession(scheme, mWriteToDisk, mLoadInfo, mAppCache,
+                       getter_AddRefs(session));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<DoomCallbackWrapper> cb = aCallback
+    ? new DoomCallbackWrapper(aCallback)
+    : nullptr;
+  rv = session->DoomEntry(cacheKey, cb);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP _OldStorage::AsyncEvictStorage(nsICacheEntryDoomCallback* aCallback)
+{
+  LOG(("_OldStorage::AsyncEvictStorage"));
+
+  nsresult rv;
+
+  if (!mAppCache && mOfflineStorage) {
+    nsCOMPtr<nsIApplicationCacheService> appCacheService =
+      do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = appCacheService->Evict(mLoadInfo);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else if (mAppCache) {
+    nsCOMPtr<nsICacheSession> session;
+    rv = GetCacheSession(EmptyCString(),
+                          mWriteToDisk, mLoadInfo, mAppCache,
+                          getter_AddRefs(session));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = session->EvictEntries();
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    // Oh, I'll be so happy when session names are gone...
+    nsCOMPtr<nsICacheSession> session;
+    rv = GetCacheSession(NS_LITERAL_CSTRING("http"),
+                          mWriteToDisk, mLoadInfo, mAppCache,
+                          getter_AddRefs(session));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = session->EvictEntries();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = GetCacheSession(NS_LITERAL_CSTRING("wyciwyg"),
+                          mWriteToDisk, mLoadInfo, mAppCache,
+                          getter_AddRefs(session));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = session->EvictEntries();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // This clears any data from scheme other then http, wyciwyg or ftp
+    rv = GetCacheSession(EmptyCString(),
+                          mWriteToDisk, mLoadInfo, mAppCache,
+                          getter_AddRefs(session));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = session->EvictEntries();
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (aCallback) {
+    RefPtr<DoomCallbackSynchronizer> sync =
+      new DoomCallbackSynchronizer(aCallback);
+    rv = sync->Dispatch();
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP _OldStorage::AsyncVisitStorage(nsICacheStorageVisitor* aVisitor,
+                                             bool aVisitEntries)
+{
+  LOG(("_OldStorage::AsyncVisitStorage"));
+
+  NS_ENSURE_ARG(aVisitor);
+
+  nsresult rv;
+
+  nsCOMPtr<nsICacheService> serv =
+    do_GetService(NS_CACHESERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  char* deviceID;
+  if (mAppCache || mOfflineStorage) {
+    deviceID = const_cast<char*>("offline");
+  } else if (!mWriteToDisk || mLoadInfo->IsPrivate()) {
+    deviceID = const_cast<char*>("memory");
+  } else {
+    deviceID = const_cast<char*>("disk");
+  }
+
+  RefPtr<_OldVisitCallbackWrapper> cb = new _OldVisitCallbackWrapper(
+    deviceID, aVisitor, aVisitEntries, mLoadInfo);
+  rv = nsCacheService::GlobalInstance()->VisitEntriesInternal(cb);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+// Internal
+
+nsresult _OldStorage::AssembleCacheKey(nsIURI *aURI,
+                                       nsACString const & aIdExtension,
+                                       nsACString & aCacheKey,
+                                       nsACString & aScheme)
+{
+  // Copied from nsHttpChannel::AssembleCacheKey
+
+  aCacheKey.Truncate();
+
+  nsresult rv;
+
+  rv = aURI->GetScheme(aScheme);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString uriSpec;
+  if (aScheme.EqualsLiteral("http") ||
+      aScheme.EqualsLiteral("https")) {
+    if (mLoadInfo->IsAnonymous()) {
+      aCacheKey.AssignLiteral("anon&");
+    }
+
+    if (!aIdExtension.IsEmpty()) {
+      aCacheKey.AppendPrintf("id=%s&", aIdExtension.BeginReading());
+    }
+
+    nsCOMPtr<nsIURI> noRefURI;
+    rv = aURI->CloneIgnoringRef(getter_AddRefs(noRefURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = noRefURI->GetAsciiSpec(uriSpec);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!aCacheKey.IsEmpty()) {
+      aCacheKey.AppendLiteral("uri=");
+    }
+  }
+  else if (aScheme.EqualsLiteral("wyciwyg")) {
+    rv = aURI->GetSpec(uriSpec);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  else {
+    rv = aURI->GetAsciiSpec(uriSpec);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  aCacheKey.Append(uriSpec);
+
+  return NS_OK;
+}
+
+nsresult _OldStorage::ChooseApplicationCache(nsCSubstring const &cacheKey,
+                                             nsIApplicationCache** aCache)
+{
+  nsresult rv;
+
+  nsCOMPtr<nsIApplicationCacheService> appCacheService =
+    do_GetService(NS_APPLICATIONCACHESERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = appCacheService->ChooseApplicationCache(cacheKey, mLoadInfo, aCache);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/cache2/OldWrappers.h b/netwerk/cache2/OldWrappers.h
new file mode 100644
index 0000000000..f85b0741ac
--- /dev/null
+++ b/netwerk/cache2/OldWrappers.h
@@ -0,0 +1,284 @@
+// Stuff to link the old imp to the new api - will go away!
+
+#ifndef OLDWRAPPERS__H__
+#define OLDWRAPPERS__H__
+
+#include "nsICacheEntry.h"
+#include "nsICacheListener.h"
+#include "nsICacheStorage.h"
+
+#include "nsCOMPtr.h"
+#include "nsICacheEntryOpenCallback.h"
+#include "nsICacheEntryDescriptor.h"
+#include "nsICacheStorageVisitor.h"
+#include "nsThreadUtils.h"
+#include "mozilla/TimeStamp.h"
+
+class nsIURI;
+class nsICacheEntryOpenCallback;
+class nsICacheStorageConsumptionObserver;
+class nsIApplicationCache;
+class nsILoadContextInfo;
+
+namespace mozilla { namespace net {
+
+class CacheStorage;
+
+class _OldCacheEntryWrapper : public nsICacheEntry
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  // nsICacheEntryDescriptor
+  NS_IMETHOD SetExpirationTime(uint32_t expirationTime) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->SetExpirationTime(expirationTime);
+  }
+  nsresult OpenInputStream(uint32_t offset, nsIInputStream * *_retval)
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->OpenInputStream(offset, _retval);
+  }
+  nsresult OpenOutputStream(uint32_t offset, nsIOutputStream * *_retval)
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->OpenOutputStream(offset, _retval);
+  }
+  NS_IMETHOD OpenAlternativeOutputStream(const nsACString & type, nsIOutputStream * *_retval) override
+  {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+  NS_IMETHOD OpenAlternativeInputStream(const nsACString & type, nsIInputStream * *_retval) override
+  {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  NS_IMETHOD GetPredictedDataSize(int64_t *aPredictedDataSize) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->GetPredictedDataSize(aPredictedDataSize);
+  }
+  NS_IMETHOD SetPredictedDataSize(int64_t aPredictedDataSize) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->SetPredictedDataSize(aPredictedDataSize);
+  }
+  NS_IMETHOD GetSecurityInfo(nsISupports * *aSecurityInfo) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->GetSecurityInfo(aSecurityInfo);
+  }
+  NS_IMETHOD SetSecurityInfo(nsISupports *aSecurityInfo) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->SetSecurityInfo(aSecurityInfo);
+  }
+  NS_IMETHOD GetStorageDataSize(uint32_t *aStorageDataSize) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->GetStorageDataSize(aStorageDataSize);
+  }
+  nsresult AsyncDoom(nsICacheListener *listener)
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->AsyncDoom(listener);
+  }
+  NS_IMETHOD MarkValid(void) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->MarkValid();
+  }
+  NS_IMETHOD Close(void) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->Close();
+  }
+  NS_IMETHOD GetMetaDataElement(const char * key, char * *_retval) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->GetMetaDataElement(key, _retval);
+  }
+  NS_IMETHOD SetMetaDataElement(const char * key, const char * value) override
+  {
+    return !mOldDesc ? NS_ERROR_NULL_POINTER :
+                       mOldDesc->SetMetaDataElement(key, value);
+  }
+
+  NS_IMETHOD GetDiskStorageSizeInKB(uint32_t *aDiskStorageSize) override
+  {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  // nsICacheEntryInfo
+  NS_IMETHOD GetKey(nsACString & aKey) override
+  {
+    return mOldInfo->GetKey(aKey);
+  }
+  NS_IMETHOD GetFetchCount(int32_t *aFetchCount) override
+  {
+    return mOldInfo->GetFetchCount(aFetchCount);
+  }
+  NS_IMETHOD GetLastFetched(uint32_t *aLastFetched) override
+  {
+    return mOldInfo->GetLastFetched(aLastFetched);
+  }
+  NS_IMETHOD GetLastModified(uint32_t *aLastModified) override
+  {
+    return mOldInfo->GetLastModified(aLastModified);
+  }
+  NS_IMETHOD GetExpirationTime(uint32_t *aExpirationTime) override
+  {
+    return mOldInfo->GetExpirationTime(aExpirationTime);
+  }
+  nsresult GetDataSize(uint32_t *aDataSize)
+  {
+    return mOldInfo->GetDataSize(aDataSize);
+  }
+
+  NS_IMETHOD AsyncDoom(nsICacheEntryDoomCallback* listener) override;
+  NS_IMETHOD GetPersistent(bool *aPersistToDisk) override;
+  NS_IMETHOD GetIsForcedValid(bool *aIsForcedValid) override;
+  NS_IMETHOD ForceValidFor(uint32_t aSecondsToTheFuture) override;
+  NS_IMETHOD SetValid() override { return NS_OK; }
+  NS_IMETHOD MetaDataReady() override { return NS_OK; }
+  NS_IMETHOD Recreate(bool, nsICacheEntry**) override;
+  NS_IMETHOD GetDataSize(int64_t *size) override;
+  NS_IMETHOD GetAltDataSize(int64_t *size) override;
+  NS_IMETHOD OpenInputStream(int64_t offset, nsIInputStream * *_retval) override;
+  NS_IMETHOD OpenOutputStream(int64_t offset, nsIOutputStream * *_retval) override;
+  NS_IMETHOD MaybeMarkValid() override;
+  NS_IMETHOD HasWriteAccess(bool aWriteOnly, bool *aWriteAccess) override;
+  NS_IMETHOD VisitMetaData(nsICacheEntryMetaDataVisitor*) override;
+
+  explicit _OldCacheEntryWrapper(nsICacheEntryDescriptor* desc);
+  explicit _OldCacheEntryWrapper(nsICacheEntryInfo* info);
+
+private:
+  virtual ~_OldCacheEntryWrapper();
+
+  _OldCacheEntryWrapper() = delete;
+  nsICacheEntryDescriptor* mOldDesc; // ref holded in mOldInfo
+  nsCOMPtr<nsICacheEntryInfo> mOldInfo;
+};
+
+
+class _OldCacheLoad : public Runnable
+                    , public nsICacheListener
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIRUNNABLE
+  NS_DECL_NSICACHELISTENER
+
+  _OldCacheLoad(nsCSubstring const& aScheme,
+                nsCSubstring const& aCacheKey,
+                nsICacheEntryOpenCallback* aCallback,
+                nsIApplicationCache* aAppCache,
+                nsILoadContextInfo* aLoadInfo,
+                bool aWriteToDisk,
+                uint32_t aFlags);
+
+  nsresult Start();
+
+protected:
+  virtual ~_OldCacheLoad();
+
+private:
+  void Check();
+
+  nsCOMPtr<nsIEventTarget> mCacheThread;
+
+  nsCString const mScheme;
+  nsCString const mCacheKey;
+  nsCOMPtr<nsICacheEntryOpenCallback> mCallback;
+  nsCOMPtr<nsILoadContextInfo> mLoadInfo;
+  uint32_t const mFlags;
+
+  bool const mWriteToDisk : 1;
+  bool mNew : 1;
+  bool mOpening : 1;
+  bool mSync : 1;
+
+  nsCOMPtr<nsICacheEntry> mCacheEntry;
+  nsresult mStatus;
+  uint32_t mRunCount;
+  nsCOMPtr<nsIApplicationCache> mAppCache;
+
+  mozilla::TimeStamp mLoadStart;
+};
+
+
+class _OldStorage : public nsICacheStorage
+{
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSICACHESTORAGE
+
+public:
+  _OldStorage(nsILoadContextInfo* aInfo,
+              bool aAllowDisk,
+              bool aLookupAppCache,
+              bool aOfflineStorage,
+              nsIApplicationCache* aAppCache);
+
+private:
+  virtual ~_OldStorage();
+  nsresult AssembleCacheKey(nsIURI *aURI, nsACString const & aIdExtension,
+                            nsACString & aCacheKey, nsACString & aScheme);
+  nsresult ChooseApplicationCache(nsCSubstring const &cacheKey, nsIApplicationCache** aCache);
+
+  nsCOMPtr<nsILoadContextInfo> mLoadInfo;
+  nsCOMPtr<nsIApplicationCache> mAppCache;
+  bool const mWriteToDisk : 1;
+  bool const mLookupAppCache : 1;
+  bool const mOfflineStorage : 1;
+};
+
+class _OldVisitCallbackWrapper : public nsICacheVisitor
+{
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSICACHEVISITOR
+
+  _OldVisitCallbackWrapper(char const * deviceID,
+                           nsICacheStorageVisitor * cb,
+                           bool visitEntries,
+                           nsILoadContextInfo * aInfo)
+  : mCB(cb)
+  , mVisitEntries(visitEntries)
+  , mDeviceID(deviceID)
+  , mLoadInfo(aInfo)
+  , mHit(false)
+  {
+    MOZ_COUNT_CTOR(_OldVisitCallbackWrapper);
+  }
+
+private:
+  virtual ~_OldVisitCallbackWrapper();
+  nsCOMPtr<nsICacheStorageVisitor> mCB;
+  bool mVisitEntries;
+  char const * mDeviceID;
+  nsCOMPtr<nsILoadContextInfo> mLoadInfo;
+  bool mHit; // set to true when the device was found
+};
+
+class _OldGetDiskConsumption : public Runnable,
+                               public nsICacheVisitor
+{
+public:
+  static nsresult Get(nsICacheStorageConsumptionObserver* aCallback);
+
+private:
+  explicit _OldGetDiskConsumption(nsICacheStorageConsumptionObserver* aCallback);
+  virtual ~_OldGetDiskConsumption() {}
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSICACHEVISITOR
+  NS_DECL_NSIRUNNABLE
+
+  nsCOMPtr<nsICacheStorageConsumptionObserver> mCallback;
+  int64_t mSize;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif
diff --git a/netwerk/cache2/moz.build b/netwerk/cache2/moz.build
new file mode 100644
index 0000000000..4fc6db59de
--- /dev/null
+++ b/netwerk/cache2/moz.build
@@ -0,0 +1,59 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPIDL_SOURCES += [
+    'nsICacheEntry.idl',
+    'nsICacheEntryDoomCallback.idl',
+    'nsICacheEntryOpenCallback.idl',
+    'nsICacheStorage.idl',
+    'nsICacheStorageService.idl',
+    'nsICacheStorageVisitor.idl',
+    'nsICacheTesting.idl',
+]
+
+XPIDL_MODULE = 'necko_cache2'
+
+EXPORTS += [
+    'CacheObserver.h',
+    'CacheStorageService.h',
+]
+
+UNIFIED_SOURCES += [
+    'CacheEntry.cpp',
+    'CacheFile.cpp',
+    'CacheFileChunk.cpp',
+    'CacheFileContextEvictor.cpp',
+    'CacheFileInputStream.cpp',
+    'CacheFileIOManager.cpp',
+    'CacheFileMetadata.cpp',
+    'CacheFileOutputStream.cpp',
+    'CacheFileUtils.cpp',
+    'CacheHashUtils.cpp',
+    'CacheIndex.cpp',
+    'CacheIndexContextIterator.cpp',
+    'CacheIndexIterator.cpp',
+    'CacheIOThread.cpp',
+    'CacheLog.cpp',
+    'CacheObserver.cpp',
+    'CacheStorage.cpp',
+    'CacheStorageService.cpp',
+    'OldWrappers.cpp',
+]
+
+# AppCacheStorage.cpp cannot be built in unified mode because it uses plarena.h.
+SOURCES += [
+    'AppCacheStorage.cpp',
+]
+
+LOCAL_INCLUDES += [
+    '/netwerk/base',
+    '/netwerk/cache',
+]
+
+FINAL_LIBRARY = 'xul'
+
+if CONFIG['GNU_CXX']:
+    CXXFLAGS += ['-Wno-error=shadow']
diff --git a/netwerk/cache2/nsICacheEntry.idl b/netwerk/cache2/nsICacheEntry.idl
new file mode 100644
index 0000000000..1885b9423c
--- /dev/null
+++ b/netwerk/cache2/nsICacheEntry.idl
@@ -0,0 +1,292 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+#include "nsICache.idl"
+
+interface nsIInputStream;
+interface nsIOutputStream;
+interface nsICacheEntryDoomCallback;
+
+interface nsICacheListener;
+interface nsIFile;
+interface nsICacheEntryMetaDataVisitor;
+
+[scriptable, uuid(607c2a2c-0a48-40b9-a956-8cf2bb9857cf)]
+interface nsICacheEntry : nsISupports
+{
+  /**
+   * Placeholder for the initial value of expiration time.
+   */
+  const unsigned long NO_EXPIRATION_TIME = 0xFFFFFFFF;
+
+  /**
+   * Get the key identifying the cache entry.
+   */
+  readonly attribute ACString key;
+
+  /**
+   * Whether the entry is memory/only or persisted to disk.
+   * Note: private browsing entries are reported as persistent for consistency
+   * while are not actually persisted to disk.
+   */
+  readonly attribute boolean persistent;
+
+  /**
+   * Get the number of times the cache entry has been opened.
+   */
+  readonly attribute long  fetchCount;
+
+  /**
+   * Get the last time the cache entry was opened (in seconds since the Epoch).
+   */
+  readonly attribute uint32_t  lastFetched;
+
+  /**
+   * Get the last time the cache entry was modified (in seconds since the Epoch).
+   */
+  readonly attribute uint32_t  lastModified;
+
+  /**
+   * Get the expiration time of the cache entry (in seconds since the Epoch).
+   */
+  readonly attribute uint32_t  expirationTime;
+
+  /**
+   * Set the time at which the cache entry should be considered invalid (in
+   * seconds since the Epoch).
+   */
+  void setExpirationTime(in uint32_t expirationTime);
+
+  /**
+   * This method is intended to override the per-spec cache validation
+   * decisions for a duration specified in seconds. The current state can
+   * be examined with isForcedValid (see below). This value is not persisted,
+   * so it will not survive session restart. Cache entries that are forced valid
+   * will not be evicted from the cache for the duration of forced validity.
+   * This means that there is a potential problem if the number of forced valid
+   * entries grows to take up more space than the cache size allows.
+   *
+   * NOTE: entries that have been forced valid will STILL be ignored by HTTP
+   * channels if they have expired AND the resource in question requires
+   * validation after expiring. This is to avoid using known-stale content.
+   *
+   * @param aSecondsToTheFuture
+   *        the number of seconds the default cache validation behavior will be
+   *        overridden before it returns to normal
+   */
+  void forceValidFor(in unsigned long aSecondsToTheFuture);
+
+  /**
+   * The state variable for whether this entry is currently forced valid.
+   * Defaults to false for normal cache validation behavior, and will return
+   * true if the number of seconds set by forceValidFor() has yet to be reached.
+   */
+  readonly attribute boolean isForcedValid;
+
+  /**
+   * Open blocking input stream to cache data.  Use the stream transport
+   * service to asynchronously read this stream on a background thread.
+   * The returned stream MAY implement nsISeekableStream.
+   *
+   * @param offset
+   *        read starting from this offset into the cached data.  an offset
+   *        beyond the end of the stream has undefined consequences.
+   *
+   * @return non-blocking, buffered input stream.
+   */
+  nsIInputStream openInputStream(in long long offset);
+
+  /**
+   * Open non-blocking output stream to cache data.  The returned stream
+   * MAY implement nsISeekableStream.
+   *
+   * If opening an output stream to existing cached data, the data will be
+   * truncated to the specified offset.
+   *
+   * @param offset
+   *        write starting from this offset into the cached data.  an offset
+   *        beyond the end of the stream has undefined consequences.
+   *
+   * @return blocking, buffered output stream.
+   */
+  nsIOutputStream openOutputStream(in long long offset);
+
+  /**
+    * Stores the Content-Length specified in the HTTP header for this
+    * entry. Checked before we write to the cache entry, to prevent ever
+    * taking up space in the cache for an entry that we know up front
+    * is going to have to be evicted anyway. See bug 588507.
+    */
+  attribute int64_t predictedDataSize;
+
+  /**
+   * Get/set security info on the cache entry for this descriptor.
+   */
+  attribute nsISupports securityInfo;
+
+  /**
+   * Get the size of the cache entry data, as stored. This may differ
+   * from the entry's dataSize, if the entry is compressed.
+   */
+  readonly attribute unsigned long storageDataSize;
+
+  /**
+   * Asynchronously doom an entry. Listener will be notified about the status
+   * of the operation. Null may be passed if caller doesn't care about the
+   * result.
+   */
+  void asyncDoom(in nsICacheEntryDoomCallback listener);
+
+  /**
+   * Methods for accessing meta data.  Meta data is a table of key/value
+   * string pairs.  The strings do not have to conform to any particular
+   * charset, but they must be null terminated.
+   */
+  string getMetaDataElement(in string key);
+  void   setMetaDataElement(in string key, in string value);
+
+  /**
+   * Obtain the list of metadata keys this entry keeps.
+   *
+   * NOTE: The callback is invoked under the CacheFile's lock.  It means
+   * there should not be made any calls to the entry from the visitor and
+   * if the values need to be processed somehow, it's better to cache them
+   * and process outside the callback.
+   */
+  void visitMetaData(in nsICacheEntryMetaDataVisitor visitor);
+
+  /**
+   * Claims that all metadata on this entry are up-to-date and this entry
+   * now can be delivered to other waiting consumers.
+   *
+   * We need such method since metadata must be delivered synchronously.
+   */
+  void metaDataReady();
+
+  /**
+   * Called by consumer upon 304/206 response from the server.  This marks
+   * the entry content as positively revalidated.
+   * Consumer uses this method after the consumer has returned ENTRY_NEEDS_REVALIDATION
+   * result from onCacheEntryCheck and after successfull revalidation with the server.
+   */
+  void setValid();
+
+  /**
+   * Returns the size in kilobytes used to store the cache entry on disk.
+   */
+   readonly attribute uint32_t diskStorageSizeInKB;
+
+  /**
+   * Doom this entry and open a new, empty, entry for write.  Consumer has
+   * to exchange the entry this method is called on for the newly created.
+   * Used on 200 responses to conditional requests.
+   *
+   * @param aMemoryOnly
+   *    - whether the entry is to be created as memory/only regardless how
+   *      the entry being recreated persistence is set
+   * @returns
+   *    - an entry that can be used to write to
+   * @throws
+   *    - NS_ERROR_NOT_AVAILABLE when the entry cannot be from some reason
+   *      recreated for write
+   */
+  nsICacheEntry recreate([optional] in boolean aMemoryOnly);
+
+  /**
+   * Returns the length of data this entry holds.
+   * @throws
+   *    NS_ERROR_IN_PROGRESS when the write is still in progress.
+   */
+  readonly attribute long long dataSize;
+
+  /**
+  * Returns the length of data this entry holds.
+  * @throws
+  *    - NS_ERROR_IN_PROGRESS when a write is still in progress (either real
+                              content or alt data).
+  *    - NS_ERROR_NOT_AVAILABLE if alt data does not exist.
+  */
+  readonly attribute long long altDataSize;
+
+  /**
+   * Opens and returns an output stream that a consumer may use to save an
+   * alternate representation of the data.
+   * @throws
+   *    - NS_ERROR_NOT_AVAILABLE if the real data hasn't been written.
+   *    - NS_ERROR_IN_PROGRESS when the writing regular content or alt-data to
+   *      the cache entry is still in progress.
+   *
+   * If there is alt-data already saved, it will be overwritten.
+   */
+  nsIOutputStream openAlternativeOutputStream(in ACString type);
+
+  /**
+   * Opens and returns an input stream that can be used to read the alternative
+   * representation previously saved in the cache.
+   * If this call is made while writing alt-data is still in progress, it is
+   * still possible to read content from the input stream as it's being written.
+   * @throws
+   *    - NS_ERROR_NOT_AVAILABLE if the alt-data representation doesn't exist at
+   *      all or if alt-data of the given type doesn't exist.
+   */
+  nsIInputStream openAlternativeInputStream(in ACString type);
+
+  /****************************************************************************
+   * The following methods might be added to some nsICacheEntryInternal
+   * interface since we want to remove them as soon as the old cache backend is
+   * completely removed.
+   */
+
+  /**
+   * @deprecated
+   * FOR BACKWARD COMPATIBILITY ONLY
+   * When the old cache backend is eventually removed, this method
+   * can be removed too.
+   *
+   * In the new backend: this method is no-op
+   * In the old backend: this method delegates to nsICacheEntryDescriptor.close()
+   */
+  void close();
+
+  /**
+   * @deprecated
+   * FOR BACKWARD COMPATIBILITY ONLY
+   * Marks the entry as valid so that others can use it and get only readonly
+   * access when the entry is held by the 1st writer.
+   */
+  void markValid();
+
+  /**
+   * @deprecated
+   * FOR BACKWARD COMPATIBILITY ONLY
+   * Marks the entry as valid when write access is acquired.
+   */
+  void maybeMarkValid();
+
+  /**
+   * @deprecated
+   * FOR BACKWARD COMPATIBILITY ONLY / KINDA HACK
+   * @param aWriteAllowed
+   *    Consumer indicates whether write to the entry is allowed for it.
+   *    Depends on implementation how the flag is handled.
+   * @returns
+   *    true when write access is acquired for this entry,
+   *    false otherwise
+   */
+  boolean hasWriteAccess(in boolean aWriteAllowed);
+};
+
+/**
+ * Argument for nsICacheEntry.visitMetaData, provides access to all metadata
+ * keys and values stored on the entry.
+ */
+[scriptable, uuid(fea3e276-6ba5-4ceb-a581-807d1f43f6d0)]
+interface nsICacheEntryMetaDataVisitor : nsISupports
+{
+  /**
+   * Called over each key / value pair.
+   */
+  void onMetaDataElement(in string key, in string value);
+};
diff --git a/netwerk/cache2/nsICacheEntryDoomCallback.idl b/netwerk/cache2/nsICacheEntryDoomCallback.idl
new file mode 100644
index 0000000000..a16a738292
--- /dev/null
+++ b/netwerk/cache2/nsICacheEntryDoomCallback.idl
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(2f8896be-232f-4140-afb3-1faffb56f3c6)]
+interface nsICacheEntryDoomCallback : nsISupports
+{
+  /**
+   * Callback invoked after an entry or entries has/have been
+   * doomed from the cache.
+   */
+  void onCacheEntryDoomed(in nsresult aResult);
+};
diff --git a/netwerk/cache2/nsICacheEntryOpenCallback.idl b/netwerk/cache2/nsICacheEntryOpenCallback.idl
new file mode 100644
index 0000000000..68409bb7eb
--- /dev/null
+++ b/netwerk/cache2/nsICacheEntryOpenCallback.idl
@@ -0,0 +1,91 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsICacheEntry;
+interface nsIApplicationCache;
+
+[scriptable, uuid(1fc9fe11-c6ac-4748-94bd-8555a5a12b94)]
+interface nsICacheEntryOpenCallback : nsISupports
+{
+  /**
+   * State of the entry determined by onCacheEntryCheck.
+   *
+   * ENTRY_WANTED - the consumer is interested in the entry, we will pass it.
+   * RECHECK_AFTER_WRITE_FINISHED - the consumer cannot use the entry while data is
+   *    still being written and wants to check it again after the current write is
+   *    finished. This actually prevents concurrent read/write and is used with
+   *    non-resumable HTTP responses.
+   * ENTRY_NEEDS_REVALIDATION - entry needs to be revalidated first with origin server,
+   *    this means the loading channel will decide whether to use the entry content
+   *    as is after it gets a positive response from the server about validity of the
+   *    content ; when a new content needs to be loaded from the server, the loading
+   *    channel opens a new entry with OPEN_TRUNCATE flag which dooms the one
+   *    this check has been made for.
+   * ENTRY_NOT_WANTED - the consumer is not interested in the entry, we will not pass it.
+   */
+  const unsigned long ENTRY_WANTED = 0;
+  const unsigned long RECHECK_AFTER_WRITE_FINISHED = 1;
+  const unsigned long ENTRY_NEEDS_REVALIDATION = 2;
+  const unsigned long ENTRY_NOT_WANTED = 3;
+
+  /**
+   * Callback to perform any validity checks before the entry should be used.
+   * Called before onCacheEntryAvailable callback, depending on the result it
+   * may be called more then one time.
+   *
+   * This callback is ensured to be called on the same thread on which asyncOpenURI
+   * has been called, unless nsICacheStorage.CHECK_MULTITHREADED flag has been specified.
+   * In that case this callback can be invoked on any thread, usually it is the cache I/O
+   * or cache management thread.
+   *
+   * IMPORTANT NOTE: 
+   * This callback may be invoked sooner then respective asyncOpenURI call exits.
+   *
+   * @param aEntry
+   *    An entry to examine.  Consumer has a chance to decide whether the
+   *    entry is valid or not.
+   * @param aApplicationCache
+   *    Optional, application cache the entry has been found in, if any.
+   * @return
+   *    State of the entry, see the constants just above.
+   */
+  unsigned long onCacheEntryCheck(in nsICacheEntry aEntry,
+                                  in nsIApplicationCache aApplicationCache);
+
+  /**
+   * Callback giving actual result of asyncOpenURI.  It may give consumer the cache 
+   * entry or a failure result when it's not possible to open it from some reason.
+   * This callback is ensured to be called on the same thread on which asyncOpenURI
+   * has been called.
+   *
+   * IMPORTANT NOTE: 
+   * This callback may be invoked sooner then respective asyncOpenURI call exits.
+   *
+   * @param aEntry
+   *    The entry bound to the originally requested URI.  May be null when
+   *    loading from a particular application cache and the URI has not
+   *    been found in that application cache.
+   * @param aNew
+   *    Whether no data so far has been stored for this entry, i.e. reading
+   *    it will just fail.  When aNew is true, a server request should be
+   *    made and data stored to this new entry.
+   * @param aApplicationCache
+   *    When an entry had been found in an application cache, this is the
+   *    given application cache.  It should be associated with the loading
+   *    channel.
+   * @param aResult
+   *    Result of the request.  This may be a failure only when one of these
+   *    issues occur:
+   *    - the cache storage service could not be started due to some unexpected
+   *      faulure
+   *    - there is not enough disk space to create new entries
+   *    - cache entry was not found in a given application cache
+   */
+  void onCacheEntryAvailable(in nsICacheEntry aEntry,
+                             in boolean aNew,
+                             in nsIApplicationCache aApplicationCache,
+                             in nsresult aResult);
+};
diff --git a/netwerk/cache2/nsICacheStorage.idl b/netwerk/cache2/nsICacheStorage.idl
new file mode 100644
index 0000000000..f500a300b9
--- /dev/null
+++ b/netwerk/cache2/nsICacheStorage.idl
@@ -0,0 +1,134 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+interface nsICacheEntry;
+interface nsICacheEntryOpenCallback;
+interface nsICacheEntryDoomCallback;
+interface nsICacheStorageVisitor;
+
+/**
+ * Representation of a cache storage. There can be just-in-mem,
+ * in-mem+on-disk, in-mem+on-disk+app-cache or just a specific
+ * app-cache storage.
+ */
+[scriptable, uuid(35d104a6-d252-4fd4-8a56-3c14657cad3b)]
+interface nsICacheStorage : nsISupports
+{
+  /**
+   * Placeholder for specifying "no special flags" during open.
+   */
+  const uint32_t OPEN_NORMALLY = 0;
+
+  /**
+   * Rewrite any existing data when opening a URL.
+   */
+  const uint32_t OPEN_TRUNCATE = 1 << 0;
+
+  /**
+   * Only open an existing entry.  Don't create a new one.
+   */
+  const uint32_t OPEN_READONLY = 1 << 1;
+
+  /**
+   * Use for first-paint blocking loads.
+   */
+  const uint32_t OPEN_PRIORITY = 1 << 2;
+
+  /**
+   * Bypass the cache load when write is still in progress.
+   */
+  const uint32_t OPEN_BYPASS_IF_BUSY = 1 << 3;
+
+  /**
+   * Perform the cache entry check (onCacheEntryCheck invocation) on any thread 
+   * for optimal perfomance optimization.  If this flag is not specified it is
+   * ensured that onCacheEntryCheck is called on the same thread as respective 
+   * asyncOpen has been called.
+   */
+  const uint32_t CHECK_MULTITHREADED = 1 << 4;
+
+  /**
+   * Don't automatically update any 'last used' metadata of the entry.
+   */
+  const uint32_t OPEN_SECRETLY = 1 << 5;
+
+  /**
+   * Entry is being opened as part of a service worker interception.  Do not
+   * allow the cache to be disabled in this case.
+   */
+  const uint32_t OPEN_INTERCEPTED = 1 << 6;
+
+  /**
+   * Asynchronously opens a cache entry for the specified URI.
+   * Result is fetched asynchronously via the callback.
+   *
+   * @param aURI
+   *    The URI to search in cache or to open for writting.
+   * @param aIdExtension
+   *    Any string that will extend (distinguish) the entry.  Two entries
+   *    with the same aURI but different aIdExtension will be comletely
+   *    different entries.  If you don't know what aIdExtension should be
+   *    leave it empty.
+   * @param aFlags
+   *    OPEN_NORMALLY - open cache entry normally for read and write
+   *    OPEN_TRUNCATE - delete any existing entry before opening it
+   *    OPEN_READONLY - don't create an entry if there is none
+   *    OPEN_PRIORITY - give this request a priority over others
+   *    OPEN_BYPASS_IF_BUSY - backward compatibility only, LOAD_BYPASS_LOCAL_CACHE_IF_BUSY
+   *    CHECK_MULTITHREADED - onCacheEntryCheck may be called on any thread, consumer 
+   *                          implementation is thread-safe
+   * @param aCallback
+   *    The consumer that receives the result.
+   *    IMPORTANT: The callback may be called sooner the method returns.
+   */
+  void asyncOpenURI(in nsIURI aURI, in ACString aIdExtension,
+                    in uint32_t aFlags,
+                    in nsICacheEntryOpenCallback aCallback);
+
+  /**
+   * Immediately opens a new and empty cache entry in the storage, any existing
+   * entries are immediately doomed.  This is similar to the recreate() method
+   * on nsICacheEntry.
+   *
+   * Storage may not implement this method and throw NS_ERROR_NOT_IMPLEMENTED.
+   * In that case consumer must use asyncOpen with OPEN_TRUNCATE flag and get
+   * the new entry via a callback.
+   *
+   * @param aURI @see asyncOpenURI
+   * @param aIdExtension @see asyncOpenURI
+   */
+  nsICacheEntry openTruncate(in nsIURI aURI,
+                             in ACString aIdExtension);
+
+  /**
+   * Synchronously check on existance of an entry.  In case of disk entries
+   * this uses information from the cache index.  When the index data are not
+   * up to date or index is still building, NS_ERROR_NOT_AVAILABLE is thrown.
+   * The same error may throw any storage implementation that cannot determine
+   * entry state without blocking the caller.
+   */
+  boolean exists(in nsIURI aURI, in ACString aIdExtension);
+
+  /**
+   * Asynchronously removes an entry belonging to the URI from the cache.
+   */
+  void asyncDoomURI(in nsIURI aURI, in ACString aIdExtension,
+                    in nsICacheEntryDoomCallback aCallback);
+
+  /**
+   * Asynchronously removes all cached entries under this storage.
+   * NOTE: Disk storage also evicts memory storage.
+   */
+  void asyncEvictStorage(in nsICacheEntryDoomCallback aCallback);
+
+  /**
+   * Visits the storage and its entries.
+   * NOTE: Disk storage also visits memory storage.
+   */
+  void asyncVisitStorage(in nsICacheStorageVisitor aVisitor,
+                         in boolean aVisitEntries);
+};
diff --git a/netwerk/cache2/nsICacheStorageService.idl b/netwerk/cache2/nsICacheStorageService.idl
new file mode 100644
index 0000000000..2be9b1bab0
--- /dev/null
+++ b/netwerk/cache2/nsICacheStorageService.idl
@@ -0,0 +1,126 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsICacheStorage;
+interface nsILoadContextInfo;
+interface nsIApplicationCache;
+interface nsIEventTarget;
+interface nsICacheStorageConsumptionObserver;
+
+/**
+ * Provides access to particual cache storages of the network URI cache.
+ */
+[scriptable, uuid(ae29c44b-fbc3-4552-afaf-0a157ce771e7)]
+interface nsICacheStorageService : nsISupports
+{
+  /**
+   * Get storage where entries will only remain in memory, never written
+   * to the disk.
+   *
+   * NOTE: Any existing disk entry for [URL|id-extension] will be doomed
+   * prior opening an entry using this memory-only storage.  Result of
+   * AsyncOpenURI will be a new and empty memory-only entry.  Using
+   * OPEN_READONLY open flag has no effect on this behavior.
+   *
+   * @param aLoadContextInfo
+   *    Information about the loading context, this focuses the storage JAR and
+   *    respects separate storage for private browsing.
+   */
+  nsICacheStorage memoryCacheStorage(in nsILoadContextInfo aLoadContextInfo);
+
+  /**
+   * Get storage where entries will be written to disk when not forbidden by
+   * response headers.
+   *
+   * @param aLookupAppCache
+   *    When set true (for top level document loading channels) app cache will
+   *    be first to check on to find entries in.
+   */
+  nsICacheStorage diskCacheStorage(in nsILoadContextInfo aLoadContextInfo,
+                                   in bool aLookupAppCache);
+
+  /**
+   * Get storage where entries will be written to disk and marked as pinned.
+   * These pinned entries are immune to over limit eviction and call of clear()
+   * on this service.
+   */
+  nsICacheStorage pinningCacheStorage(in nsILoadContextInfo aLoadContextInfo);
+
+  /**
+   * Get storage for a specified application cache obtained using some different
+   * mechanism.
+   *
+   * @param aLoadContextInfo
+   *    Mandatory reference to a load context information.
+   * @param aApplicationCache
+   *    Optional reference to an existing appcache.  When left null, this will
+   *    work with offline cache as a whole.
+   */
+  nsICacheStorage appCacheStorage(in nsILoadContextInfo aLoadContextInfo,
+                                  in nsIApplicationCache aApplicationCache);
+
+  /**
+   * Get storage for synthesized cache entries that we currently use for ServiceWorker interception in non-e10s mode.
+   *
+   * This cache storage has no limits on file size to allow the ServiceWorker to intercept large files.
+   */
+  nsICacheStorage synthesizedCacheStorage(in nsILoadContextInfo aLoadContextInfo);
+
+  /**
+   * Evict the whole cache.
+   */
+  void clear();
+
+  /**
+   * Purge only data of disk backed entries.  Metadata are left for
+   * performance purposes.
+   */
+  const uint32_t PURGE_DISK_DATA_ONLY = 1;
+  /**
+   * Purge whole disk backed entries from memory.  Disk files will
+   * be left unattended.
+   */
+  const uint32_t PURGE_DISK_ALL = 2;
+  /**
+   * Purge all entries we keep in memory, including memory-storage
+   * entries.  This may be dangerous to use.
+   */
+  const uint32_t PURGE_EVERYTHING = 3;
+  /**
+   * Purges data we keep warmed in memory.  Use for tests and for
+   * saving memory.
+   */
+  void purgeFromMemory(in uint32_t aWhat);
+
+  /**
+   * I/O thread target to use for any operations on disk
+   */
+  readonly attribute nsIEventTarget ioTarget;
+
+  /**
+   * Asynchronously determine how many bytes of the disk space the cache takes.
+   * @see nsICacheStorageConsumptionObserver
+   * @param aObserver
+   *    A mandatory (weak referred) observer.  Documented at
+   *    nsICacheStorageConsumptionObserver.
+   *    NOTE: the observer MUST implement nsISupportsWeakReference.
+   */
+  void asyncGetDiskConsumption(in nsICacheStorageConsumptionObserver aObserver);
+};
+
+[scriptable, uuid(7728ab5b-4c01-4483-a606-32bf5b8136cb)]
+interface nsICacheStorageConsumptionObserver : nsISupports
+{
+  /**
+   * Callback invoked to answer asyncGetDiskConsumption call. Always triggered
+   * on the main thread.
+   * NOTE: implementers must also implement nsISupportsWeakReference.
+   *
+   * @param aDiskSize
+   *    The disk consumption in bytes.
+   */
+  void onNetworkCacheDiskConsumption(in int64_t aDiskSize);
+};
diff --git a/netwerk/cache2/nsICacheStorageVisitor.idl b/netwerk/cache2/nsICacheStorageVisitor.idl
new file mode 100644
index 0000000000..d6720acce7
--- /dev/null
+++ b/netwerk/cache2/nsICacheStorageVisitor.idl
@@ -0,0 +1,33 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+interface nsIFile;
+
+[scriptable, uuid(6cc7c253-93b6-482b-8e9d-1e04d8e9d655)]
+interface nsICacheStorageVisitor : nsISupports
+{
+  /**
+   */
+  void onCacheStorageInfo(in uint32_t aEntryCount,
+                          in uint64_t aConsumption,
+                          in uint64_t aCapacity,
+                          in nsIFile aDiskDirectory);
+
+  /**
+   */
+  void onCacheEntryInfo(in nsIURI aURI,
+                        in ACString aIdEnhance,
+                        in int64_t aDataSize,
+                        in long aFetchCount,
+                        in uint32_t aLastModifiedTime,
+                        in uint32_t aExpirationTime,
+                        in boolean aPinned);
+
+  /**
+   */
+  void onCacheEntryVisitCompleted();
+};
diff --git a/netwerk/cache2/nsICacheTesting.idl b/netwerk/cache2/nsICacheTesting.idl
new file mode 100644
index 0000000000..15704f7caa
--- /dev/null
+++ b/netwerk/cache2/nsICacheTesting.idl
@@ -0,0 +1,20 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIObserver;
+
+/**
+ * This is an internal interface used only for testing purposes.
+ *
+ * THIS IS NOT AN API TO BE USED BY EXTENSIONS! ONLY USED BY MOZILLA TESTS.
+ */
+[scriptable, builtinclass, uuid(4e8ba935-92e1-4a74-944b-b1a2f02a7480)]
+interface nsICacheTesting : nsISupports
+{
+  void suspendCacheIOThread(in uint32_t aLevel);
+  void resumeCacheIOThread();
+  void flush(in nsIObserver aObserver);
+};