third_party/WebKit/Source/platform/mediastream/MediaStreamComponent.h

/*
 * Copyright (C) 2011 Ericsson AB. All rights reserved.
 * Copyright (C) 2013 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer
 *    in the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of Ericsson nor the names of its contributors
 *    may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef MediaStreamComponent_h
#define MediaStreamComponent_h

#include "platform/audio/AudioSourceProvider.h"
#include "platform/heap/Handle.h"
#include "public/platform/WebMediaStreamTrack.h"
#include "wtf/Forward.h"
#include "wtf/ThreadingPrimitives.h"
#include "wtf/text/WTFString.h"
#include <memory>

namespace blink {

class MediaStreamSource;
class WebAudioSourceProvider;

// A MediaStreamComponent is a MediaStreamTrack.
// TODO(hta): Consider merging the two classes.

class PLATFORM_EXPORT MediaStreamComponent final
    : public GarbageCollectedFinalized<MediaStreamComponent> {
  USING_PRE_FINALIZER(MediaStreamComponent, dispose);

 public:
  // This class represents whatever data the Web layer uses to represent
  // a track. It needs to be able to answer the getSettings question.
  class TrackData {
    USING_FAST_MALLOC(TrackData);

   public:
    virtual void getSettings(WebMediaStreamTrack::Settings&) = 0;
    virtual ~TrackData() {}
  };

  static MediaStreamComponent* create(MediaStreamSource*);
  static MediaStreamComponent* create(const String& id, MediaStreamSource*);

  // |m_trackData| may hold pointers to GC objects indirectly, and it may touch
  // eagerly finalized objects in destruction.
  // So this class runs pre-finalizer to finalize |m_trackData| promptly.
  void dispose();

  MediaStreamSource* source() const { return m_source.get(); }

  String id() const { return m_id; }
  bool enabled() const { return m_enabled; }
  void setEnabled(bool enabled) { m_enabled = enabled; }
  bool muted() const { return m_muted; }
  void setMuted(bool muted) { m_muted = muted; }
  AudioSourceProvider* getAudioSourceProvider() { return &m_sourceProvider; }
  void setSourceProvider(WebAudioSourceProvider* provider) {
    m_sourceProvider.wrap(provider);
  }

  TrackData* getTrackData() const { return m_trackData.get(); }
  void setTrackData(std::unique_ptr<TrackData> trackData) {
    m_trackData = std::move(trackData);
  }
  void getSettings(WebMediaStreamTrack::Settings&);

  DECLARE_TRACE();

 private:
  MediaStreamComponent(const String& id, MediaStreamSource*);

  // AudioSourceProviderImpl wraps a WebAudioSourceProvider::provideInput()
  // calls into chromium to get a rendered audio stream.

  class PLATFORM_EXPORT AudioSourceProviderImpl final
      : public AudioSourceProvider {
   public:
    AudioSourceProviderImpl() : m_webAudioSourceProvider(0) {}

    ~AudioSourceProviderImpl() override {}

    // Wraps the given blink::WebAudioSourceProvider to
    // blink::AudioSourceProvider.
    void wrap(WebAudioSourceProvider*);

    // blink::AudioSourceProvider
    void provideInput(AudioBus*, size_t framesToProcess) override;

   private:
    WebAudioSourceProvider* m_webAudioSourceProvider;
    Mutex m_provideInputLock;
  };

  AudioSourceProviderImpl m_sourceProvider;
  Member<MediaStreamSource> m_source;
  String m_id;
  bool m_enabled;
  bool m_muted;
  std::unique_ptr<TrackData> m_trackData;
};

typedef HeapVector<Member<MediaStreamComponent>> MediaStreamComponentVector;

}  // namespace blink

#endif  // MediaStreamComponent_h