1 files changed, 473 insertions, 0 deletions
diff --git a/xpcom/base/nsConsoleService.cpp b/xpcom/base/nsConsoleService.cpp
new file mode 100644
index 000000000..3862a02c4
--- /dev/null
+++ b/xpcom/base/nsConsoleService.cpp
@@ -0,0 +1,473 @@
+/* -*- 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/. */
+
+/*
+ * Maintains a circular buffer of recent messages, and notifies
+ * listeners when new messages are logged.
+ */
+
+/* Threadsafe. */
+
+#include "nsMemory.h"
+#include "nsCOMArray.h"
+#include "nsThreadUtils.h"
+
+#include "nsConsoleService.h"
+#include "nsConsoleMessage.h"
+#include "nsIClassInfoImpl.h"
+#include "nsIConsoleListener.h"
+#include "nsPrintfCString.h"
+#include "nsProxyRelease.h"
+#include "nsIScriptError.h"
+#include "nsISupportsPrimitives.h"
+
+#include "mozilla/Preferences.h"
+
+#if defined(ANDROID)
+#include <android/log.h>
+#include "mozilla/dom/ContentChild.h"
+#endif
+#ifdef XP_WIN
+#include <windows.h>
+#endif
+
+#ifdef MOZ_TASK_TRACER
+#include "GeckoTaskTracer.h"
+using namespace mozilla::tasktracer;
+#endif
+
+using namespace mozilla;
+
+NS_IMPL_ADDREF(nsConsoleService)
+NS_IMPL_RELEASE(nsConsoleService)
+NS_IMPL_CLASSINFO(nsConsoleService, nullptr,
+                  nsIClassInfo::THREADSAFE | nsIClassInfo::SINGLETON,
+                  NS_CONSOLESERVICE_CID)
+NS_IMPL_QUERY_INTERFACE_CI(nsConsoleService, nsIConsoleService, nsIObserver)
+NS_IMPL_CI_INTERFACE_GETTER(nsConsoleService, nsIConsoleService, nsIObserver)
+
+static bool sLoggingEnabled = true;
+static bool sLoggingBuffered = true;
+#if defined(ANDROID)
+static bool sLoggingLogcat = true;
+#endif // defined(ANDROID)
+
+nsConsoleService::MessageElement::~MessageElement()
+{
+}
+
+nsConsoleService::nsConsoleService()
+  : mCurrentSize(0)
+  , mDeliveringMessage(false)
+  , mLock("nsConsoleService.mLock")
+{
+  // XXX grab this from a pref!
+  // hm, but worry about circularity, bc we want to be able to report
+  // prefs errs...
+  mMaximumSize = 250;
+}
+
+
+void
+nsConsoleService::ClearMessagesForWindowID(const uint64_t innerID)
+{
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+  MutexAutoLock lock(mLock);
+
+  for (MessageElement* e = mMessages.getFirst(); e != nullptr; ) {
+    // Only messages implementing nsIScriptError interface expose the
+    // inner window ID.
+    nsCOMPtr<nsIScriptError> scriptError = do_QueryInterface(e->Get());
+    if (!scriptError) {
+      e = e->getNext();
+      continue;
+    }
+    uint64_t innerWindowID;
+    nsresult rv = scriptError->GetInnerWindowID(&innerWindowID);
+    if (NS_FAILED(rv) || innerWindowID != innerID) {
+      e = e->getNext();
+      continue;
+    }
+
+    MessageElement* next = e->getNext();
+    e->remove();
+    delete e;
+    mCurrentSize--;
+    MOZ_ASSERT(mCurrentSize < mMaximumSize);
+
+    e = next;
+  }
+}
+
+void
+nsConsoleService::ClearMessages()
+{
+  // NB: A lock is not required here as it's only called from |Reset| which
+  //     locks for us and from the dtor.
+  while (!mMessages.isEmpty()) {
+    MessageElement* e = mMessages.popFirst();
+    delete e;
+  }
+  mCurrentSize = 0;
+}
+
+nsConsoleService::~nsConsoleService()
+{
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+
+  ClearMessages();
+}
+
+class AddConsolePrefWatchers : public Runnable
+{
+public:
+  explicit AddConsolePrefWatchers(nsConsoleService* aConsole) : mConsole(aConsole)
+  {
+  }
+
+  NS_IMETHOD Run() override
+  {
+    Preferences::AddBoolVarCache(&sLoggingEnabled, "consoleservice.enabled", true);
+    Preferences::AddBoolVarCache(&sLoggingBuffered, "consoleservice.buffered", true);
+#if defined(ANDROID)
+    Preferences::AddBoolVarCache(&sLoggingLogcat, "consoleservice.logcat", true);
+#endif // defined(ANDROID)
+
+    nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+    MOZ_ASSERT(obs);
+    obs->AddObserver(mConsole, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
+    obs->AddObserver(mConsole, "inner-window-destroyed", false);
+
+    if (!sLoggingBuffered) {
+      mConsole->Reset();
+    }
+    return NS_OK;
+  }
+
+private:
+  RefPtr<nsConsoleService> mConsole;
+};
+
+nsresult
+nsConsoleService::Init()
+{
+  NS_DispatchToMainThread(new AddConsolePrefWatchers(this));
+
+  return NS_OK;
+}
+
+namespace {
+
+class LogMessageRunnable : public Runnable
+{
+public:
+  LogMessageRunnable(nsIConsoleMessage* aMessage, nsConsoleService* aService)
+    : mMessage(aMessage)
+    , mService(aService)
+  { }
+
+  NS_DECL_NSIRUNNABLE
+
+private:
+  nsCOMPtr<nsIConsoleMessage> mMessage;
+  RefPtr<nsConsoleService> mService;
+};
+
+NS_IMETHODIMP
+LogMessageRunnable::Run()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // Snapshot of listeners so that we don't reenter this hash during
+  // enumeration.
+  nsCOMArray<nsIConsoleListener> listeners;
+  mService->CollectCurrentListeners(listeners);
+
+  mService->SetIsDelivering();
+
+  for (int32_t i = 0; i < listeners.Count(); ++i) {
+    listeners[i]->Observe(mMessage);
+  }
+
+  mService->SetDoneDelivering();
+
+  return NS_OK;
+}
+
+} // namespace
+
+// nsIConsoleService methods
+NS_IMETHODIMP
+nsConsoleService::LogMessage(nsIConsoleMessage* aMessage)
+{
+  return LogMessageWithMode(aMessage, OutputToLog);
+}
+
+// This can be called off the main thread.
+nsresult
+nsConsoleService::LogMessageWithMode(nsIConsoleMessage* aMessage,
+                                     nsConsoleService::OutputMode aOutputMode)
+{
+  if (!aMessage) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  if (!sLoggingEnabled) {
+    return NS_OK;
+  }
+
+  if (NS_IsMainThread() && mDeliveringMessage) {
+    nsCString msg;
+    aMessage->ToString(msg);
+    NS_WARNING(nsPrintfCString("Reentrancy error: some client attempted "
+      "to display a message to the console while in a console listener. "
+      "The following message was discarded: \"%s\"", msg.get()).get());
+    return NS_ERROR_FAILURE;
+  }
+
+  RefPtr<LogMessageRunnable> r;
+  nsCOMPtr<nsIConsoleMessage> retiredMessage;
+
+  /*
+   * Lock while updating buffer, and while taking snapshot of
+   * listeners array.
+   */
+  {
+    MutexAutoLock lock(mLock);
+
+#if defined(ANDROID)
+    if (sLoggingLogcat && aOutputMode == OutputToLog) {
+      nsCString msg;
+      aMessage->ToString(msg);
+
+      /** Attempt to use the process name as the log tag. */
+      mozilla::dom::ContentChild* child =
+          mozilla::dom::ContentChild::GetSingleton();
+      nsCString appName;
+      if (child) {
+        child->GetProcessName(appName);
+      } else {
+        appName = "GeckoConsole";
+      }
+
+      uint32_t logLevel = 0;
+      aMessage->GetLogLevel(&logLevel);
+
+      android_LogPriority logPriority = ANDROID_LOG_INFO;
+      switch (logLevel) {
+        case nsIConsoleMessage::debug:
+          logPriority = ANDROID_LOG_DEBUG;
+          break;
+        case nsIConsoleMessage::info:
+          logPriority = ANDROID_LOG_INFO;
+          break;
+        case nsIConsoleMessage::warn:
+          logPriority = ANDROID_LOG_WARN;
+          break;
+        case nsIConsoleMessage::error:
+          logPriority = ANDROID_LOG_ERROR;
+          break;
+      }
+
+      __android_log_print(logPriority, appName.get(), "%s", msg.get());
+    }
+#endif
+#ifdef XP_WIN
+    if (IsDebuggerPresent()) {
+      nsString msg;
+      aMessage->GetMessageMoz(getter_Copies(msg));
+      msg.Append('\n');
+      OutputDebugStringW(msg.get());
+    }
+#endif
+#ifdef MOZ_TASK_TRACER
+    {
+      nsCString msg;
+      aMessage->ToString(msg);
+      int prefixPos = msg.Find(GetJSLabelPrefix());
+      if (prefixPos >= 0) {
+        nsDependentCSubstring submsg(msg, prefixPos);
+        AddLabel("%s", submsg.BeginReading());
+      }
+    }
+#endif
+
+    if (sLoggingBuffered) {
+      MessageElement* e = new MessageElement(aMessage);
+      mMessages.insertBack(e);
+      if (mCurrentSize != mMaximumSize) {
+        mCurrentSize++;
+      } else {
+        MessageElement* p = mMessages.popFirst();
+        MOZ_ASSERT(p);
+        p->swapMessage(retiredMessage);
+        delete p;
+      }
+    }
+
+    if (mListeners.Count() > 0) {
+      r = new LogMessageRunnable(aMessage, this);
+    }
+  }
+
+  if (retiredMessage) {
+    // Release |retiredMessage| on the main thread in case it is an instance of
+    // a mainthread-only class like nsScriptErrorWithStack and we're off the
+    // main thread.
+    NS_ReleaseOnMainThread(retiredMessage.forget());
+  }
+
+  if (r) {
+    // avoid failing in XPCShell tests
+    nsCOMPtr<nsIThread> mainThread = do_GetMainThread();
+    if (mainThread) {
+      NS_DispatchToMainThread(r.forget());
+    }
+  }
+
+  return NS_OK;
+}
+
+void
+nsConsoleService::CollectCurrentListeners(
+  nsCOMArray<nsIConsoleListener>& aListeners)
+{
+  MutexAutoLock lock(mLock);
+  for (auto iter = mListeners.Iter(); !iter.Done(); iter.Next()) {
+    nsIConsoleListener* value = iter.UserData();
+    aListeners.AppendObject(value);
+  }
+}
+
+NS_IMETHODIMP
+nsConsoleService::LogStringMessage(const char16_t* aMessage)
+{
+  if (!sLoggingEnabled) {
+    return NS_OK;
+  }
+
+  RefPtr<nsConsoleMessage> msg(new nsConsoleMessage(aMessage));
+  return this->LogMessage(msg);
+}
+
+NS_IMETHODIMP
+nsConsoleService::GetMessageArray(uint32_t* aCount,
+                                  nsIConsoleMessage*** aMessages)
+{
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+
+  MutexAutoLock lock(mLock);
+
+  if (mMessages.isEmpty()) {
+    /*
+     * Make a 1-length output array so that nobody gets confused,
+     * and return a count of 0.  This should result in a 0-length
+     * array object when called from script.
+     */
+    nsIConsoleMessage** messageArray = (nsIConsoleMessage**)
+      moz_xmalloc(sizeof(nsIConsoleMessage*));
+    *messageArray = nullptr;
+    *aMessages = messageArray;
+    *aCount = 0;
+
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(mCurrentSize <= mMaximumSize);
+  nsIConsoleMessage** messageArray =
+    static_cast<nsIConsoleMessage**>(moz_xmalloc(sizeof(nsIConsoleMessage*)
+                                                 * mCurrentSize));
+
+  uint32_t i = 0;
+  for (MessageElement* e = mMessages.getFirst(); e != nullptr; e = e->getNext()) {
+    nsCOMPtr<nsIConsoleMessage> m = e->Get();
+    m.forget(&messageArray[i]);
+    i++;
+  }
+
+  MOZ_ASSERT(i == mCurrentSize);
+
+  *aCount = i;
+  *aMessages = messageArray;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsConsoleService::RegisterListener(nsIConsoleListener* aListener)
+{
+  if (!NS_IsMainThread()) {
+    NS_ERROR("nsConsoleService::RegisterListener is main thread only.");
+    return NS_ERROR_NOT_SAME_THREAD;
+  }
+
+  nsCOMPtr<nsISupports> canonical = do_QueryInterface(aListener);
+
+  MutexAutoLock lock(mLock);
+  if (mListeners.GetWeak(canonical)) {
+    // Reregistering a listener isn't good
+    return NS_ERROR_FAILURE;
+  }
+  mListeners.Put(canonical, aListener);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsConsoleService::UnregisterListener(nsIConsoleListener* aListener)
+{
+  if (!NS_IsMainThread()) {
+    NS_ERROR("nsConsoleService::UnregisterListener is main thread only.");
+    return NS_ERROR_NOT_SAME_THREAD;
+  }
+
+  nsCOMPtr<nsISupports> canonical = do_QueryInterface(aListener);
+
+  MutexAutoLock lock(mLock);
+
+  if (!mListeners.GetWeak(canonical)) {
+    // Unregistering a listener that was never registered?
+    return NS_ERROR_FAILURE;
+  }
+  mListeners.Remove(canonical);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsConsoleService::Reset()
+{
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+
+  /*
+   * Make sure nobody trips into the buffer while it's being reset
+   */
+  MutexAutoLock lock(mLock);
+
+  ClearMessages();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsConsoleService::Observe(nsISupports* aSubject, const char* aTopic,
+                          const char16_t* aData)
+{
+  if (!strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
+    // Dump all our messages, in case any are cycle collected.
+    Reset();
+    // We could remove ourselves from the observer service, but it is about to
+    // drop all observers anyways, so why bother.
+  } else if (!strcmp(aTopic, "inner-window-destroyed")) {
+    nsCOMPtr<nsISupportsPRUint64> supportsInt = do_QueryInterface(aSubject);
+    MOZ_ASSERT(supportsInt);
+
+    uint64_t windowId;
+    MOZ_ALWAYS_SUCCEEDS(supportsInt->GetData(&windowId));
+
+    ClearMessagesForWindowID(windowId);
+  } else {
+    MOZ_CRASH();
+  }
+  return NS_OK;
+}