WebRtcMediaStreamTrackAdapter, maps 1 webrtc and 1 blink track

content/renderer/media/webrtc/webrtc_media_stream_track_adapter.h

+// Copyright (c) 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_MEDIA_STREAM_TRACK_ADAPTER_H_
+#define CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_MEDIA_STREAM_TRACK_ADAPTER_H_
+
+#include <memory>
+
+#include "base/memory/ref_counted.h"
+#include "content/common/content_export.h"
+#include "content/renderer/media/remote_media_stream_track_adapter.h"
+#include "content/renderer/media/webrtc/media_stream_video_webrtc_sink.h"
+#include "content/renderer/media/webrtc/webrtc_audio_sink.h"
+#include "content/renderer/media/webrtc/webrtc_media_stream_track_adapter.h"
+#include "third_party/WebKit/public/platform/WebMediaStream.h"
+#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
+#include "third_party/webrtc/api/mediastreaminterface.h"
+
+namespace content {
+
+class PeerConnectionDependencyFactory;
+
+// This is a mapping between a webrtc and blink media stream track. It takes
+// care of creation, initialization and disposing of tracks independently of
+// media streams.
+// There are different sinks/adapters used whether the track is local or remote
+// and whether it is an audio or video track; this adapter hides that fact and
+// lets you use a single class for any type of track.
+class CONTENT_EXPORT WebRtcMediaStreamTrackAdapter
+    : public base::RefCountedThreadSafe<WebRtcMediaStreamTrackAdapter> {
+ public:
+  // Invoke on the main thread. The returned adapter is fully initialized, see
+  // |is_initialized|.
+  static scoped_refptr<WebRtcMediaStreamTrackAdapter> CreateLocalTrackAdapter(
+      PeerConnectionDependencyFactory* factory,
+      const scoped_refptr<base::SingleThreadTaskRunner>& main_thread,
+      const blink::WebMediaStreamTrack& web_track);
+  // Invoke on the webrtc signaling thread. Initialization finishes on the main
+  // thread in a post, meaning returned adapters are ensured to be initialized
+  // in posts to the main thread, see |is_initialized|.
+  static scoped_refptr<WebRtcMediaStreamTrackAdapter> CreateRemoteTrackAdapter(
+      PeerConnectionDependencyFactory* factory,
+      const scoped_refptr<base::SingleThreadTaskRunner>& main_thread,
+      webrtc::MediaStreamTrackInterface* webrtc_track);
+  // Must be called before all external references are released (i.e. before
+  // destruction). Invoke on the main thread. Disposing may finish
+  // asynchronously using the webrtc signaling thread and the main thread. After
+  // calling this method it is safe to release all external references to the
+  // adapter.
+  void Dispose();
+
+  // The adapter must be initialized in order to use |web_track| and
+  // |webrtc_track|.
+  bool is_initialized() const;
+  const blink::WebMediaStreamTrack& web_track() const;
+  webrtc::MediaStreamTrackInterface* webrtc_track() const;
+  bool IsEqual(const blink::WebMediaStreamTrack& web_track) const;
+
+  // For testing.
+  WebRtcAudioSink* GetLocalTrackAudioSinkForTesting() {
+    return local_track_audio_sink_.get();
+  }
+  MediaStreamVideoWebRtcSink* GetLocalTrackVideoSinkForTesting() {
+    return local_track_video_sink_.get();
+  }
+  RemoteAudioTrackAdapter* GetRemoteAudioTrackAdapterForTesting() {
+    return remote_audio_track_adapter_.get();
+  }
+  RemoteVideoTrackAdapter* GetRemoteVideoTrackAdapterForTesting() {
+    return remote_video_track_adapter_.get();
+  }
+
+ protected:
+  friend class base::RefCountedThreadSafe<WebRtcMediaStreamTrackAdapter>;
+
+  WebRtcMediaStreamTrackAdapter(
+      PeerConnectionDependencyFactory* factory,
+      const scoped_refptr<base::SingleThreadTaskRunner>& main_thread);
+  virtual ~WebRtcMediaStreamTrackAdapter();
+
+ private:
+  // Initialization of local tracks occurs on the main thread.
+  void InitializeLocalAudioTrack(const blink::WebMediaStreamTrack& web_track);
+  void InitializeLocalVideoTrack(const blink::WebMediaStreamTrack& web_track);
+  // Initialization of remote tracks starts on the webrtc signaling thread and
+  // finishes on the main thread.
+  void InitializeRemoteAudioTrack(
+      webrtc::AudioTrackInterface* webrtc_audio_track);
+  void InitializeRemoteVideoTrack(
+      webrtc::VideoTrackInterface* webrtc_video_track);
+  void FinalizeRemoteTrackInitializationOnMainThread();
+
+  // Disposing starts and finishes on the main thread. Local tracks and remote
+  // video tracks are disposed synchronously. Remote audio tracks are disposed
+  // asynchronously with a jump to the webrtc signaling thread and back.
+  void DisposeLocalAudioTrack();
+  void DisposeLocalVideoTrack();
+  void DisposeRemoteAudioTrack();
+  void DisposeRemoteVideoTrack();
+  void UnregisterRemoteAudioTrackAdapterOnSignalingThread();
+  void FinalizeRemoteTrackDisposingOnMainThread();
+
+  // Pointer to a |PeerConnectionDependencyFactory| owned by the |RenderThread|.
+  // It's valid for the lifetime of |RenderThread|.
+  PeerConnectionDependencyFactory* const factory_;
+  scoped_refptr<base::SingleThreadTaskRunner> main_thread_;
+
+  // This class is immutable between being initialized (triggered by
+  // |Create...|) and being disposed (by calling |Dispose|). As such, no locks
+  // are required in the implementation for only inherently racey actions could
+  // cause problems (such as disposing while still in use).
+  bool is_initialized_;
+  blink::WebMediaStreamTrack web_track_;
+  scoped_refptr<webrtc::MediaStreamTrackInterface> webrtc_track_;
+  // If the track is local, a sink is added to the local webrtc track that is
+  // owned by us.
+  std::unique_ptr<WebRtcAudioSink> local_track_audio_sink_;
+  std::unique_ptr<MediaStreamVideoWebRtcSink> local_track_video_sink_;
+  // If the track is remote, an adapter is used that listens to notifications on
+  // the remote webrtc track and notifies Blink.
+  scoped_refptr<RemoteAudioTrackAdapter> remote_audio_track_adapter_;
+  scoped_refptr<RemoteVideoTrackAdapter> remote_video_track_adapter_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebRtcMediaStreamTrackAdapter);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_MEDIA_STREAM_TRACK_ADAPTER_H_