Add m-esr52 at 52.6.0

1 files changed, 820 insertions, 0 deletions

diff --git a/dom/media/MediaResource.h b/dom/media/MediaResource.h
new file mode 100644
index 0000000000..7d2f153aad
--- /dev/null
+++ b/dom/media/MediaResource.h
@@ -0,0 +1,820 @@
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+#if !defined(MediaResource_h_)
+#define MediaResource_h_
+
+#include "mozilla/Mutex.h"
+#include "nsIChannel.h"
+#include "nsIURI.h"
+#include "nsISeekableStream.h"
+#include "nsIStreamingProtocolController.h"
+#include "nsIStreamListener.h"
+#include "nsIChannelEventSink.h"
+#include "nsIInterfaceRequestor.h"
+#include "Intervals.h"
+#include "MediaCache.h"
+#include "MediaData.h"
+#include "MediaResourceCallback.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/TimeStamp.h"
+#include "nsThreadUtils.h"
+#include <algorithm>
+
+// For HTTP seeking, if number of bytes needing to be
+// seeked forward is less than this value then a read is
+// done rather than a byte range request.
+//
+// If we assume a 100Mbit connection, and assume reissuing an HTTP seek causes
+// a delay of 200ms, then in that 200ms we could have simply read ahead 2MB. So
+// setting SEEK_VS_READ_THRESHOLD to 1MB sounds reasonable.
+static const int64_t SEEK_VS_READ_THRESHOLD = 1 * 1024 * 1024;
+
+static const uint32_t HTTP_REQUESTED_RANGE_NOT_SATISFIABLE_CODE = 416;
+
+// Number of bytes we have accumulated before we assume the connection download
+// rate can be reliably calculated. 57 Segments at IW=3 allows slow start to
+// reach a CWND of 30 (See bug 831998)
+static const int64_t RELIABLE_DATA_THRESHOLD = 57 * 1460;
+
+class nsIHttpChannel;
+class nsIPrincipal;
+
+namespace mozilla {
+
+class MediaChannelStatistics;
+
+/**
+ * This class is useful for estimating rates of data passing through
+ * some channel. The idea is that activity on the channel "starts"
+ * and "stops" over time. At certain times data passes through the
+ * channel (usually while the channel is active; data passing through
+ * an inactive channel is ignored). The GetRate() function computes
+ * an estimate of the "current rate" of the channel, which is some
+ * kind of average of the data passing through over the time the
+ * channel is active.
+ *
+ * All methods take "now" as a parameter so the user of this class can
+ * control the timeline used.
+ */
+class MediaChannelStatistics {
+public:
+  MediaChannelStatistics()
+    : mAccumulatedBytes(0)
+    , mIsStarted(false)
+  {
+    Reset();
+  }
+
+  explicit MediaChannelStatistics(MediaChannelStatistics * aCopyFrom)
+  {
+    MOZ_ASSERT(aCopyFrom);
+    mAccumulatedBytes = aCopyFrom->mAccumulatedBytes;
+    mAccumulatedTime = aCopyFrom->mAccumulatedTime;
+    mLastStartTime = aCopyFrom->mLastStartTime;
+    mIsStarted = aCopyFrom->mIsStarted;
+  }
+
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaChannelStatistics)
+
+  void Reset() {
+    mLastStartTime = TimeStamp();
+    mAccumulatedTime = TimeDuration(0);
+    mAccumulatedBytes = 0;
+    mIsStarted = false;
+  }
+  void Start() {
+    if (mIsStarted)
+      return;
+    mLastStartTime = TimeStamp::Now();
+    mIsStarted = true;
+  }
+  void Stop() {
+    if (!mIsStarted)
+      return;
+    mAccumulatedTime += TimeStamp::Now() - mLastStartTime;
+    mIsStarted = false;
+  }
+  void AddBytes(int64_t aBytes) {
+    if (!mIsStarted) {
+      // ignore this data, it may be related to seeking or some other
+      // operation we don't care about
+      return;
+    }
+    mAccumulatedBytes += aBytes;
+  }
+  double GetRateAtLastStop(bool* aReliable) {
+    double seconds = mAccumulatedTime.ToSeconds();
+    *aReliable = (seconds >= 1.0) ||
+                 (mAccumulatedBytes >= RELIABLE_DATA_THRESHOLD);
+    if (seconds <= 0.0)
+      return 0.0;
+    return static_cast<double>(mAccumulatedBytes)/seconds;
+  }
+  double GetRate(bool* aReliable) {
+    TimeDuration time = mAccumulatedTime;
+    if (mIsStarted) {
+      time += TimeStamp::Now() - mLastStartTime;
+    }
+    double seconds = time.ToSeconds();
+    *aReliable = (seconds >= 3.0) ||
+                 (mAccumulatedBytes >= RELIABLE_DATA_THRESHOLD);
+    if (seconds <= 0.0)
+      return 0.0;
+    return static_cast<double>(mAccumulatedBytes)/seconds;
+  }
+private:
+  ~MediaChannelStatistics() {}
+  int64_t      mAccumulatedBytes;
+  TimeDuration mAccumulatedTime;
+  TimeStamp    mLastStartTime;
+  bool         mIsStarted;
+};
+
+// Represents a section of contiguous media, with a start and end offset.
+// Used to denote ranges of data which are cached.
+
+typedef media::Interval<int64_t> MediaByteRange;
+typedef media::IntervalSet<int64_t> MediaByteRangeSet;
+
+/**
+ * Provides a thread-safe, seek/read interface to resources
+ * loaded from a URI. Uses MediaCache to cache data received over
+ * Necko's async channel API, thus resolving the mismatch between clients
+ * that need efficient random access to the data and protocols that do not
+ * support efficient random access, such as HTTP.
+ *
+ * Instances of this class must be created on the main thread.
+ * Most methods must be called on the main thread only. Read, Seek and
+ * Tell must only be called on non-main threads. In the case of the Ogg
+ * Decoder they are called on the Decode thread for example. You must
+ * ensure that no threads are calling these methods once Close is called.
+ *
+ * Instances of this class are reference counted. Use nsRefPtr for
+ * managing the lifetime of instances of this class.
+ *
+ * The generic implementation of this class is ChannelMediaResource, which can
+ * handle any URI for which Necko supports AsyncOpen.
+ * The 'file:' protocol can be implemented efficiently with direct random
+ * access, so the FileMediaResource implementation class bypasses the cache.
+ * MediaResource::Create automatically chooses the best implementation class.
+ */
+class MediaResource : public nsISupports
+{
+public:
+  // Our refcounting is threadsafe, and when our refcount drops to zero
+  // we dispatch an event to the main thread to delete the MediaResource.
+  // Note that this means it's safe for references to this object to be
+  // released on a non main thread, but the destructor will always run on
+  // the main thread.
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  // The following can be called on the main thread only:
+  // Get the URI
+  virtual nsIURI* URI() const { return nullptr; }
+  // Close the resource, stop any listeners, channels, etc.
+  // Cancels any currently blocking Read request and forces that request to
+  // return an error.
+  virtual nsresult Close() = 0;
+  // Suspend any downloads that are in progress.
+  // If aCloseImmediately is set, resources should be released immediately
+  // since we don't expect to resume again any time soon. Otherwise we
+  // may resume again soon so resources should be held for a little
+  // while.
+  virtual void Suspend(bool aCloseImmediately) = 0;
+  // Resume any downloads that have been suspended.
+  virtual void Resume() = 0;
+  // Get the current principal for the channel
+  virtual already_AddRefed<nsIPrincipal> GetCurrentPrincipal() = 0;
+  // If this returns false, then we shouldn't try to clone this MediaResource
+  // because its underlying resources are not suitable for reuse (e.g.
+  // because the underlying connection has been lost, or this resource
+  // just can't be safely cloned). If this returns true, CloneData could
+  // still fail. If this returns false, CloneData should not be called.
+  virtual bool CanClone() { return false; }
+  // Create a new stream of the same type that refers to the same URI
+  // with a new channel. Any cached data associated with the original
+  // stream should be accessible in the new stream too.
+  virtual already_AddRefed<MediaResource> CloneData(MediaResourceCallback* aCallback) = 0;
+  // Set statistics to be recorded to the object passed in.
+  virtual void RecordStatisticsTo(MediaChannelStatistics *aStatistics) { }
+
+  // These methods are called off the main thread.
+  // The mode is initially MODE_PLAYBACK.
+  virtual void SetReadMode(MediaCacheStream::ReadMode aMode) = 0;
+  // This is the client's estimate of the playback rate assuming
+  // the media plays continuously. The cache can't guess this itself
+  // because it doesn't know when the decoder was paused, buffering, etc.
+  virtual void SetPlaybackRate(uint32_t aBytesPerSecond) = 0;
+  // Read up to aCount bytes from the stream. The read starts at
+  // aOffset in the stream, seeking to that location initially if
+  // it is not the current stream offset. The remaining arguments,
+  // results and requirements are the same as per the Read method.
+  virtual nsresult ReadAt(int64_t aOffset, char* aBuffer,
+                          uint32_t aCount, uint32_t* aBytes) = 0;
+  // This method returns nullptr if anything fails.
+  // Otherwise, it returns an owned buffer.
+  // MediaReadAt may return fewer bytes than requested if end of stream is
+  // encountered. There is no need to call it again to get more data.
+  virtual already_AddRefed<MediaByteBuffer> MediaReadAt(int64_t aOffset, uint32_t aCount)
+  {
+    RefPtr<MediaByteBuffer> bytes = new MediaByteBuffer();
+    bool ok = bytes->SetLength(aCount, fallible);
+    NS_ENSURE_TRUE(ok, nullptr);
+    char* curr = reinterpret_cast<char*>(bytes->Elements());
+    const char* start = curr;
+    while (aCount > 0) {
+      uint32_t bytesRead;
+      nsresult rv = ReadAt(aOffset, curr, aCount, &bytesRead);
+      NS_ENSURE_SUCCESS(rv, nullptr);
+      if (!bytesRead) {
+        break;
+      }
+      aOffset += bytesRead;
+      aCount -= bytesRead;
+      curr += bytesRead;
+    }
+    bytes->SetLength(curr - start);
+    return bytes.forget();
+  }
+
+  // Report the current offset in bytes from the start of the stream.
+  // This is used to approximate where we currently are in the playback of a
+  // media.
+  // A call to ReadAt will update this position.
+  virtual int64_t Tell() = 0;
+  // Moves any existing channel loads into or out of background. Background
+  // loads don't block the load event. This also determines whether or not any
+  // new loads initiated (for example to seek) will be in the background.
+  virtual void SetLoadInBackground(bool aLoadInBackground) {}
+  // Ensures that the value returned by IsSuspendedByCache below is up to date
+  // (i.e. the cache has examined this stream at least once).
+  virtual void EnsureCacheUpToDate() {}
+
+  // These can be called on any thread.
+  // Cached blocks associated with this stream will not be evicted
+  // while the stream is pinned.
+  virtual void Pin() = 0;
+  virtual void Unpin() = 0;
+  // Get the estimated download rate in bytes per second (assuming no
+  // pausing of the channel is requested by Gecko).
+  // *aIsReliable is set to true if we think the estimate is useful.
+  virtual double GetDownloadRate(bool* aIsReliable) = 0;
+  // Get the length of the stream in bytes. Returns -1 if not known.
+  // This can change over time; after a seek operation, a misbehaving
+  // server may give us a resource of a different length to what it had
+  // reported previously --- or it may just lie in its Content-Length
+  // header and give us more or less data than it reported. We will adjust
+  // the result of GetLength to reflect the data that's actually arriving.
+  virtual int64_t GetLength() = 0;
+  // Returns the offset of the first byte of cached data at or after aOffset,
+  // or -1 if there is no such cached data.
+  virtual int64_t GetNextCachedData(int64_t aOffset) = 0;
+  // Returns the end of the bytes starting at the given offset
+  // which are in cache.
+  virtual int64_t GetCachedDataEnd(int64_t aOffset) = 0;
+  // Returns true if all the data from aOffset to the end of the stream
+  // is in cache. If the end of the stream is not known, we return false.
+  virtual bool IsDataCachedToEndOfResource(int64_t aOffset) = 0;
+  // Returns true if we are expecting any more data to arrive
+  // sometime in the not-too-distant future, either from the network or from
+  // an appendBuffer call on a MediaSource element.
+  virtual bool IsExpectingMoreData()
+  {
+    // MediaDecoder::mDecoderPosition is roughly the same as Tell() which
+    // returns a position updated by latest Read() or ReadAt().
+    return !IsDataCachedToEndOfResource(Tell()) && !IsSuspended();
+  }
+  // Returns true if this stream is suspended by the cache because the
+  // cache is full. If true then the decoder should try to start consuming
+  // data, otherwise we may not be able to make progress.
+  // MediaDecoder::NotifySuspendedStatusChanged is called when this
+  // changes.
+  // For resources using the media cache, this returns true only when all
+  // streams for the same resource are all suspended.
+  virtual bool IsSuspendedByCache() = 0;
+  // Returns true if this stream has been suspended.
+  virtual bool IsSuspended() = 0;
+  // Reads only data which is cached in the media cache. If you try to read
+  // any data which overlaps uncached data, or if aCount bytes otherwise can't
+  // be read, this function will return failure. This function be called from
+  // any thread, and it is the only read operation which is safe to call on
+  // the main thread, since it's guaranteed to be non blocking.
+  virtual nsresult ReadFromCache(char* aBuffer,
+                                 int64_t aOffset,
+                                 uint32_t aCount) = 0;
+  // Returns true if the resource can be seeked to unbuffered ranges, i.e.
+  // for an HTTP network stream this returns true if HTTP1.1 Byte Range
+  // requests are supported by the connection/server.
+  virtual bool IsTransportSeekable() = 0;
+
+  /**
+   * Create a resource, reading data from the channel. Call on main thread only.
+   * The caller must follow up by calling resource->Open().
+   */
+  static already_AddRefed<MediaResource> Create(MediaResourceCallback* aCallback, nsIChannel* aChannel);
+
+  /**
+   * Open the stream. This creates a stream listener and returns it in
+   * aStreamListener; this listener needs to be notified of incoming data.
+   */
+  virtual nsresult Open(nsIStreamListener** aStreamListener) = 0;
+
+  /**
+   * Fills aRanges with MediaByteRanges representing the data which is cached
+   * in the media cache. Stream should be pinned during call and while
+   * aRanges is being used.
+   */
+  virtual nsresult GetCachedRanges(MediaByteRangeSet& aRanges) = 0;
+
+  // Ensure that the media cache writes any data held in its partial block.
+  // Called on the main thread only.
+  virtual void FlushCache() { }
+
+  // Notify that the last data byte range was loaded.
+  virtual void NotifyLastByteRange() { }
+
+  // Returns the content type of the resource. This is copied from the
+  // nsIChannel when the MediaResource is created. Safe to call from
+  // any thread.
+  virtual const nsCString& GetContentType() const = 0;
+
+  // Return true if the stream is a live stream
+  virtual bool IsRealTime() {
+    return false;
+  }
+
+  // Returns true if the resource is a live stream.
+  virtual bool IsLiveStream()
+  {
+    return GetLength() == -1;
+  }
+
+  virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+    return 0;
+  }
+
+  virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+  }
+
+  const nsCString& GetContentURL() const { return EmptyCString(); }
+
+protected:
+  virtual ~MediaResource() {};
+
+private:
+  void Destroy();
+};
+
+class BaseMediaResource : public MediaResource {
+public:
+  nsIURI* URI() const override { return mURI; }
+  void SetLoadInBackground(bool aLoadInBackground) override;
+
+  size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const override
+  {
+    // Might be useful to track in the future:
+    // - mChannel
+    // - mURI (possibly owned, looks like just a ref from mChannel)
+    // Not owned:
+    // - mCallback
+    size_t size = MediaResource::SizeOfExcludingThis(aMallocSizeOf);
+    size += mContentType.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
+
+    return size;
+  }
+
+  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override
+  {
+    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+  }
+
+  // Returns the url of the resource. Safe to call from any thread?
+  const nsCString& GetContentURL() const
+  {
+    return mContentURL;
+  }
+
+protected:
+  BaseMediaResource(MediaResourceCallback* aCallback,
+                    nsIChannel* aChannel,
+                    nsIURI* aURI,
+                    const nsACString& aContentType) :
+    mCallback(aCallback),
+    mChannel(aChannel),
+    mURI(aURI),
+    mContentType(aContentType),
+    mLoadInBackground(false)
+  {
+    MOZ_COUNT_CTOR(BaseMediaResource);
+    NS_ASSERTION(!mContentType.IsEmpty(), "Must know content type");
+    mURI->GetSpec(mContentURL);
+  }
+  virtual ~BaseMediaResource()
+  {
+    MOZ_COUNT_DTOR(BaseMediaResource);
+  }
+
+  const nsCString& GetContentType() const override
+  {
+    return mContentType;
+  }
+
+  // Set the request's load flags to aFlags.  If the request is part of a
+  // load group, the request is removed from the group, the flags are set, and
+  // then the request is added back to the load group.
+  void ModifyLoadFlags(nsLoadFlags aFlags);
+
+  // Dispatches an event to call MediaDecoder::NotifyBytesConsumed(aNumBytes, aOffset)
+  // on the main thread. This is called automatically after every read.
+  void DispatchBytesConsumed(int64_t aNumBytes, int64_t aOffset);
+
+  RefPtr<MediaResourceCallback> mCallback;
+
+  // Channel used to download the media data. Must be accessed
+  // from the main thread only.
+  nsCOMPtr<nsIChannel> mChannel;
+
+  // URI in case the stream needs to be re-opened. Access from
+  // main thread only.
+  nsCOMPtr<nsIURI> mURI;
+
+  // Content-Type of the channel. This is copied from the nsIChannel when the
+  // MediaResource is created. This is constant, so accessing from any thread
+  // is safe.
+  const nsCString mContentType;
+
+  // Copy of the url of the channel resource.
+  nsCString mContentURL;
+
+  // True if SetLoadInBackground() has been called with
+  // aLoadInBackground = true, i.e. when the document load event is not
+  // blocked by this resource, and all channel loads will be in the
+  // background.
+  bool mLoadInBackground;
+};
+
+
+/**
+ * This class is responsible for managing the suspend count and report suspend
+ * status of channel.
+ **/
+class ChannelSuspendAgent {
+public:
+  explicit ChannelSuspendAgent(nsIChannel* aChannel)
+  : mChannel(aChannel),
+    mSuspendCount(0),
+    mIsChannelSuspended(false)
+  {}
+
+  // True when the channel has been suspended or needs to be suspended.
+  bool IsSuspended();
+
+  // Return true when the channel is logically suspended, i.e. the suspend
+  // count goes from 0 to 1.
+  bool Suspend();
+
+  // Return true only when the suspend count is equal to zero.
+  bool Resume();
+
+  // Call after opening channel, set channel and check whether the channel
+  // needs to be suspended.
+  void NotifyChannelOpened(nsIChannel* aChannel);
+
+  // Call before closing channel, reset the channel internal status if needed.
+  void NotifyChannelClosing();
+
+  // Check whether we need to suspend the channel.
+  void UpdateSuspendedStatusIfNeeded();
+private:
+  // Only suspends channel but not changes the suspend count.
+  void SuspendInternal();
+
+  nsIChannel* mChannel;
+  Atomic<uint32_t> mSuspendCount;
+  bool mIsChannelSuspended;
+};
+
+/**
+ * This is the MediaResource implementation that wraps Necko channels.
+ * Much of its functionality is actually delegated to MediaCache via
+ * an underlying MediaCacheStream.
+ *
+ * All synchronization is performed by MediaCacheStream; all off-main-
+ * thread operations are delegated directly to that object.
+ */
+class ChannelMediaResource : public BaseMediaResource
+{
+public:
+  ChannelMediaResource(MediaResourceCallback* aDecoder,
+                       nsIChannel* aChannel,
+                       nsIURI* aURI,
+                       const nsACString& aContentType);
+  ~ChannelMediaResource();
+
+  // These are called on the main thread by MediaCache. These must
+  // not block or grab locks, because the media cache is holding its lock.
+  // Notify that data is available from the cache. This can happen even
+  // if this stream didn't read any data, since another stream might have
+  // received data for the same resource.
+  void CacheClientNotifyDataReceived();
+  // Notify that we reached the end of the stream. This can happen even
+  // if this stream didn't read any data, since another stream might have
+  // received data for the same resource.
+  void CacheClientNotifyDataEnded(nsresult aStatus);
+  // Notify that the principal for the cached resource changed.
+  void CacheClientNotifyPrincipalChanged();
+  // Notify the decoder that the cache suspended status changed.
+  void CacheClientNotifySuspendedStatusChanged();
+
+  // These are called on the main thread by MediaCache. These shouldn't block,
+  // but they may grab locks --- the media cache is not holding its lock
+  // when these are called.
+  // Start a new load at the given aOffset. The old load is cancelled
+  // and no more data from the old load will be notified via
+  // MediaCacheStream::NotifyDataReceived/Ended.
+  // This can fail.
+  nsresult CacheClientSeek(int64_t aOffset, bool aResume);
+  // Suspend the current load since data is currently not wanted
+  nsresult CacheClientSuspend();
+  // Resume the current load since data is wanted again
+  nsresult CacheClientResume();
+
+  // Ensure that the media cache writes any data held in its partial block.
+  // Called on the main thread.
+  void FlushCache() override;
+
+  // Notify that the last data byte range was loaded.
+  void NotifyLastByteRange() override;
+
+  // Main thread
+  nsresult Open(nsIStreamListener** aStreamListener) override;
+  nsresult Close() override;
+  void     Suspend(bool aCloseImmediately) override;
+  void     Resume() override;
+  already_AddRefed<nsIPrincipal> GetCurrentPrincipal() override;
+  // Return true if the stream has been closed.
+  bool     IsClosed() const { return mCacheStream.IsClosed(); }
+  bool     CanClone() override;
+  already_AddRefed<MediaResource> CloneData(MediaResourceCallback* aDecoder) override;
+  // Set statistics to be recorded to the object passed in. If not called,
+  // |ChannelMediaResource| will create it's own statistics objects in |Open|.
+  void RecordStatisticsTo(MediaChannelStatistics *aStatistics) override {
+    NS_ASSERTION(aStatistics, "Statistics param cannot be null!");
+    MutexAutoLock lock(mLock);
+    if (!mChannelStatistics) {
+      mChannelStatistics = aStatistics;
+    }
+  }
+  nsresult ReadFromCache(char* aBuffer, int64_t aOffset, uint32_t aCount) override;
+  void     EnsureCacheUpToDate() override;
+
+  // Other thread
+  void     SetReadMode(MediaCacheStream::ReadMode aMode) override;
+  void     SetPlaybackRate(uint32_t aBytesPerSecond) override;
+  nsresult ReadAt(int64_t offset, char* aBuffer,
+                  uint32_t aCount, uint32_t* aBytes) override;
+  already_AddRefed<MediaByteBuffer> MediaReadAt(int64_t aOffset, uint32_t aCount) override;
+  int64_t Tell() override;
+
+  // Any thread
+  void    Pin() override;
+  void    Unpin() override;
+  double  GetDownloadRate(bool* aIsReliable) override;
+  int64_t GetLength() override;
+  int64_t GetNextCachedData(int64_t aOffset) override;
+  int64_t GetCachedDataEnd(int64_t aOffset) override;
+  bool    IsDataCachedToEndOfResource(int64_t aOffset) override;
+  bool    IsSuspendedByCache() override;
+  bool    IsSuspended() override;
+  bool    IsTransportSeekable() override;
+
+  size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const override {
+    // Might be useful to track in the future:
+    //   - mListener (seems minor)
+    //   - mChannelStatistics (seems minor)
+    //     owned if RecordStatisticsTo is not called
+    //   - mDataReceivedEvent (seems minor)
+    size_t size = BaseMediaResource::SizeOfExcludingThis(aMallocSizeOf);
+    size += mCacheStream.SizeOfExcludingThis(aMallocSizeOf);
+
+    return size;
+  }
+
+  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override {
+    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+  }
+
+  class Listener final : public nsIStreamListener,
+                         public nsIInterfaceRequestor,
+                         public nsIChannelEventSink
+  {
+    ~Listener() {}
+  public:
+    explicit Listener(ChannelMediaResource* aResource) : mResource(aResource) {}
+
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIREQUESTOBSERVER
+    NS_DECL_NSISTREAMLISTENER
+    NS_DECL_NSICHANNELEVENTSINK
+    NS_DECL_NSIINTERFACEREQUESTOR
+
+    void Revoke() { mResource = nullptr; }
+
+  private:
+    RefPtr<ChannelMediaResource> mResource;
+  };
+  friend class Listener;
+
+  nsresult GetCachedRanges(MediaByteRangeSet& aRanges) override;
+
+protected:
+  // These are called on the main thread by Listener.
+  nsresult OnStartRequest(nsIRequest* aRequest);
+  nsresult OnStopRequest(nsIRequest* aRequest, nsresult aStatus);
+  nsresult OnDataAvailable(nsIRequest* aRequest,
+                           nsIInputStream* aStream,
+                           uint32_t aCount);
+  nsresult OnChannelRedirect(nsIChannel* aOld, nsIChannel* aNew, uint32_t aFlags);
+
+  // Opens the channel, using an HTTP byte range request to start at mOffset
+  // if possible. Main thread only.
+  nsresult OpenChannel(nsIStreamListener** aStreamListener);
+  nsresult RecreateChannel();
+  // Add headers to HTTP request. Main thread only.
+  nsresult SetupChannelHeaders();
+  // Closes the channel. Main thread only.
+  void CloseChannel();
+
+  // Parses 'Content-Range' header and returns results via parameters.
+  // Returns error if header is not available, values are not parse-able or
+  // values are out of range.
+  nsresult ParseContentRangeHeader(nsIHttpChannel * aHttpChan,
+                                   int64_t& aRangeStart,
+                                   int64_t& aRangeEnd,
+                                   int64_t& aRangeTotal);
+
+  void DoNotifyDataReceived();
+
+  static nsresult CopySegmentToCache(nsIInputStream *aInStream,
+                                     void *aClosure,
+                                     const char *aFromSegment,
+                                     uint32_t aToOffset,
+                                     uint32_t aCount,
+                                     uint32_t *aWriteCount);
+
+  // Main thread access only
+  int64_t            mOffset;
+  RefPtr<Listener> mListener;
+  // A data received event for the decoder that has been dispatched but has
+  // not yet been processed.
+  nsRevocableEventPtr<nsRunnableMethod<ChannelMediaResource, void, false> > mDataReceivedEvent;
+  // When this flag is set, if we get a network error we should silently
+  // reopen the stream.
+  bool               mReopenOnError;
+  // When this flag is set, we should not report the next close of the
+  // channel.
+  bool               mIgnoreClose;
+
+  // Any thread access
+  MediaCacheStream mCacheStream;
+
+  // This lock protects mChannelStatistics
+  Mutex               mLock;
+  RefPtr<MediaChannelStatistics> mChannelStatistics;
+
+  // True if we couldn't suspend the stream and we therefore don't want
+  // to resume later. This is usually due to the channel not being in the
+  // isPending state at the time of the suspend request.
+  bool mIgnoreResume;
+
+  ChannelSuspendAgent mSuspendAgent;
+};
+
+/**
+ * RAII class that handles pinning and unpinning for MediaResource and derived.
+ * This should be used when making calculations that involve potentially-cached
+ * MediaResource data, so that the state of the world can't change out from under
+ * us.
+ */
+template<class T>
+class MOZ_RAII AutoPinned {
+ public:
+  explicit AutoPinned(T* aResource MOZ_GUARD_OBJECT_NOTIFIER_PARAM) : mResource(aResource) {
+    MOZ_GUARD_OBJECT_NOTIFIER_INIT;
+    MOZ_ASSERT(mResource);
+    mResource->Pin();
+  }
+
+  ~AutoPinned() {
+    mResource->Unpin();
+  }
+
+  operator T*() const { return mResource; }
+  T* operator->() const MOZ_NO_ADDREF_RELEASE_ON_RETURN { return mResource; }
+
+private:
+  T* mResource;
+  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
+};
+
+/*
+ * MediaResourceIndex provides a way to access MediaResource objects.
+ * Read, Seek and Tell must only be called on non-main threads.
+ * In the case of the Ogg Decoder they are called on the Decode thread for
+ * example. You must ensure that no threads are calling these methods once
+ * the MediaResource has been Closed.
+ */
+
+class MediaResourceIndex
+{
+public:
+  explicit MediaResourceIndex(MediaResource* aResource)
+    : mResource(aResource)
+    , mOffset(0)
+  {}
+
+  // Read up to aCount bytes from the stream. The buffer must have
+  // enough room for at least aCount bytes. Stores the number of
+  // actual bytes read in aBytes (0 on end of file).
+  // May read less than aCount bytes if the number of
+  // available bytes is less than aCount. Always check *aBytes after
+  // read, and call again if necessary.
+  nsresult Read(char* aBuffer, uint32_t aCount, uint32_t* aBytes);
+  // Seek to the given bytes offset in the stream. aWhence can be
+  // one of:
+  //   NS_SEEK_SET
+  //   NS_SEEK_CUR
+  //   NS_SEEK_END
+  //
+  // In the Http strategy case the cancel will cause the http
+  // channel's listener to close the pipe, forcing an i/o error on any
+  // blocked read. This will allow the decode thread to complete the
+  // event.
+  //
+  // In the case of a seek in progress, the byte range request creates
+  // a new listener. This is done on the main thread via seek
+  // synchronously dispatching an event. This avoids the issue of us
+  // closing the listener but an outstanding byte range request
+  // creating a new one. They run on the same thread so no explicit
+  // synchronisation is required. The byte range request checks for
+  // the cancel flag and does not create a new channel or listener if
+  // we are cancelling.
+  //
+  // The default strategy does not do any seeking - the only issue is
+  // a blocked read which it handles by causing the listener to close
+  // the pipe, as per the http case.
+  //
+  // The file strategy doesn't block for any great length of time so
+  // is fine for a no-op cancel.
+  nsresult Seek(int32_t aWhence, int64_t aOffset);
+  // Report the current offset in bytes from the start of the stream.
+  int64_t Tell() const { return mOffset; }
+
+  // Return the underlying MediaResource.
+  MediaResource* GetResource() const { return mResource; }
+
+  // Read up to aCount bytes from the stream. The read starts at
+  // aOffset in the stream, seeking to that location initially if
+  // it is not the current stream offset.
+  // Unlike MediaResource::ReadAt, ReadAt only returns fewer bytes than
+  // requested if end of stream or an error is encountered. There is no need to
+  // call it again to get more data.
+  // *aBytes will contain the number of bytes copied, even if an error occurred.
+  // ReadAt doesn't have an impact on the offset returned by Tell().
+  nsresult ReadAt(int64_t aOffset, char* aBuffer,
+                  uint32_t aCount, uint32_t* aBytes) const;
+
+  // Convenience methods, directly calling the MediaResource method of the same
+  // name.
+  // Those functions do not update the MediaResource offset as returned
+  // by Tell().
+
+  // This method returns nullptr if anything fails.
+  // Otherwise, it returns an owned buffer.
+  // MediaReadAt may return fewer bytes than requested if end of stream is
+  // encountered. There is no need to call it again to get more data.
+  already_AddRefed<MediaByteBuffer> MediaReadAt(int64_t aOffset, uint32_t aCount) const
+  {
+    return mResource->MediaReadAt(aOffset, aCount);
+  }
+  // Get the length of the stream in bytes. Returns -1 if not known.
+  // This can change over time; after a seek operation, a misbehaving
+  // server may give us a resource of a different length to what it had
+  // reported previously --- or it may just lie in its Content-Length
+  // header and give us more or less data than it reported. We will adjust
+  // the result of GetLength to reflect the data that's actually arriving.
+  int64_t GetLength() const { return mResource->GetLength(); }
+
+private:
+  RefPtr<MediaResource> mResource;
+  int64_t mOffset;
+};
+
+} // namespace mozilla
+
+#endif