Bug 1388604 - move SetReadMode() from MediaResource to BaseMediaResource. r=gerald

It would be less accurate to call SetReadMode(MediaCacheStream::MODE_PLAYBACK)
in ChannelMediaDecoder::MetadataLoaded() instead of DecodeMetadataState::OnMetadataRead()
because MDSM might have started decoding by the time 'metadata loaded' event arrives
in the main thread. However this little inaccuracy should be fine since it only
affects a small amount of data concerning the eviction algorithm.

MozReview-Commit-ID: JoQMGr5Fvge

--HG--
extra : rebase_source : 3663a028522cc8b973964f62e59d7568a5eba10a
extra : source : 359b4454633432d3334a106aedb267a2451afb45

dom/media/BufferMediaResource.h

@@ -43,8 +43,6 @@ private:
     return principal.forget();
   }
   // These methods are called off the main thread.
-  // The mode is initially MODE_PLAYBACK.
-  void SetReadMode(MediaCacheStream::ReadMode aMode) override {}
   nsresult ReadAt(int64_t aOffset, char* aBuffer,
                   uint32_t aCount, uint32_t* aBytes) override
   {

dom/media/ChannelMediaDecoder.cpp

@@ -254,6 +254,9 @@ ChannelMediaDecoder::Load(nsIChannel* aChannel,
   rv = OpenResource(aStreamListener);
   NS_ENSURE_SUCCESS(rv, rv);
 
+  // Set mode to METADATA since we are about to read metadata.
+  mResource->SetReadMode(MediaCacheStream::MODE_METADATA);
+
   SetStateMachine(CreateStateMachine());
   NS_ENSURE_TRUE(GetStateMachine(), NS_ERROR_FAILURE);
 
@@ -501,6 +504,17 @@ ChannelMediaDecoder::Resume()
   }
 }
 
+void
+ChannelMediaDecoder::MetadataLoaded(
+  UniquePtr<MediaInfo> aInfo,
+  UniquePtr<MetadataTags> aTags,
+  MediaDecoderEventVisibility aEventVisibility)
+{
+  MediaDecoder::MetadataLoaded(Move(aInfo), Move(aTags), aEventVisibility);
+  // Set mode to PLAYBACK after reading metadata.
+  mResource->SetReadMode(MediaCacheStream::MODE_PLAYBACK);
+}
+
 } // namespace mozilla
 
 // avoid redefined macro in unified build

dom/media/ChannelMediaDecoder.h

@@ -57,6 +57,10 @@ protected:
   void OnPlaybackEvent(MediaEventType aEvent) override;
   void DurationChanged() override;
   void DownloadProgressed() override;
+  void MetadataLoaded(UniquePtr<MediaInfo> aInfo,
+                      UniquePtr<MetadataTags> aTags,
+                      MediaDecoderEventVisibility aEventVisibility) override;
+
   RefPtr<ResourceCallback> mResourceCallback;
   RefPtr<BaseMediaResource> mResource;
 

dom/media/MediaDecoder.h

@@ -456,6 +456,12 @@ protected:
 
   virtual void OnPlaybackEvent(MediaEventType aEvent);
 
+  // Called when the metadata from the media file has been loaded by the
+  // state machine. Call on the main thread only.
+  virtual void MetadataLoaded(UniquePtr<MediaInfo> aInfo,
+                              UniquePtr<MetadataTags> aTags,
+                              MediaDecoderEventVisibility aEventVisibility);
+
   /******
    * The following members should be accessed with the decoder lock held.
    ******/
@@ -496,12 +502,6 @@ protected:
 private:
   nsCString GetDebugInfo();
 
-  // Called when the metadata from the media file has been loaded by the
-  // state machine. Call on the main thread only.
-  void MetadataLoaded(UniquePtr<MediaInfo> aInfo,
-                      UniquePtr<MetadataTags> aTags,
-                      MediaDecoderEventVisibility aEventVisibility);
-
   // Called when the owner's activity changed.
   void NotifyCompositor();
 

dom/media/MediaDecoderStateMachine.cpp

@@ -341,9 +341,6 @@ public:
     MOZ_ASSERT(!mMetadataRequest.Exists());
     SLOG("Dispatching AsyncReadMetadata");
 
-    // Set mode to METADATA since we are about to read metadata.
-    Resource()->SetReadMode(MediaCacheStream::MODE_METADATA);
-
     // We disconnect mMetadataRequest in Exit() so it is fine to capture
     // a raw pointer here.
     Reader()->ReadMetadata()
@@ -2224,9 +2221,6 @@ DecodeMetadataState::OnMetadataRead(MetadataHolder&& aMetadata)
 {
   mMetadataRequest.Complete();
 
-  // Set mode to PLAYBACK after reading metadata.
-  Resource()->SetReadMode(MediaCacheStream::MODE_PLAYBACK);
-
   mMaster->mInfo.emplace(*aMetadata.mInfo);
   mMaster->mMediaSeekable = Info().mMediaSeekable;
   mMaster->mMediaSeekableOnlyInBufferedRanges =

dom/media/MediaResource.h

@@ -164,8 +164,6 @@ public:
   virtual already_AddRefed<nsIPrincipal> GetCurrentPrincipal() = 0;
 
   // These methods are called off the main thread.
-  // The mode is initially MODE_PLAYBACK.
-  virtual void SetReadMode(MediaCacheStream::ReadMode aMode) = 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,
@@ -325,6 +323,9 @@ public:
   // Resume any downloads that have been suspended.
   virtual void Resume() = 0;
 
+  // The mode is initially MODE_PLAYBACK.
+  virtual void SetReadMode(MediaCacheStream::ReadMode aMode) = 0;
+
   /**
    * Open the stream. This creates a stream listener and returns it in
    * aStreamListener; this listener needs to be notified of incoming data.

dom/media/gtest/MockMediaResource.h

@@ -20,7 +20,6 @@ public:
   {
     return nullptr;
   }
-  void SetReadMode(MediaCacheStream::ReadMode aMode) override {}
   nsresult ReadAt(int64_t aOffset, char* aBuffer, uint32_t aCount,
                   uint32_t* aBytes) override;
   // Data stored in file, caching recommended.

dom/media/hls/HLSResource.h

@@ -48,7 +48,6 @@ public:
   ~HLSResource();
   void Suspend();
   void Resume();
-  void SetReadMode(MediaCacheStream::ReadMode aMode) override { UNIMPLEMENTED(); }
   nsresult ReadAt(int64_t aOffset, char* aBuffer, uint32_t aCount, uint32_t* aBytes) override { UNIMPLEMENTED(); return NS_ERROR_FAILURE; }
   bool ShouldCacheReads() override { UNIMPLEMENTED(); return false; }
   int64_t Tell() override { UNIMPLEMENTED(); return -1; }

dom/media/mediasource/MediaSourceResource.h

@@ -32,7 +32,6 @@ public:
     , mEnded(false)
     {}
 
-  void SetReadMode(MediaCacheStream::ReadMode aMode) override { UNIMPLEMENTED(); }
   nsresult ReadAt(int64_t aOffset, char* aBuffer, uint32_t aCount, uint32_t* aBytes) override { UNIMPLEMENTED(); return NS_ERROR_FAILURE; }
   bool ShouldCacheReads() override { UNIMPLEMENTED(); return false; }
   int64_t Tell() override { UNIMPLEMENTED(); return -1; }

dom/media/mediasource/SourceBufferResource.h

@@ -45,10 +45,6 @@ public:
     UNIMPLEMENTED();
     return nullptr;
   }
-  void SetReadMode(MediaCacheStream::ReadMode aMode) override
-  {
-    UNIMPLEMENTED();
-  }
   nsresult ReadAt(int64_t aOffset,
                   char* aBuffer,
                   uint32_t aCount,