gecko-dev/dom/media/webaudio/MediaStreamAudioDestinationNode.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */

#include "MediaStreamAudioDestinationNode.h"
#include "nsIDocument.h"
#include "mozilla/dom/MediaStreamAudioDestinationNodeBinding.h"
#include "AudioNodeEngine.h"
#include "AudioNodeStream.h"
#include "DOMMediaStream.h"
#include "MediaStreamTrack.h"
#include "TrackUnionStream.h"

namespace mozilla {
namespace dom {

class AudioDestinationTrackSource final :
  public MediaStreamTrackSource
{
public:
  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(AudioDestinationTrackSource,
                                           MediaStreamTrackSource)

  AudioDestinationTrackSource(MediaStreamAudioDestinationNode* aNode,
                              nsIPrincipal* aPrincipal)
    : MediaStreamTrackSource(aPrincipal, nsString())
    , mNode(aNode)
  {
  }

  void Destroy() override
  {
    if (mNode) {
      mNode->DestroyMediaStream();
      mNode = nullptr;
    }
  }

  MediaSourceEnum GetMediaSource() const override
  {
    return MediaSourceEnum::AudioCapture;
  }

  void Stop() override
  {
    Destroy();
  }

  void Disable() override
  {
  }

  void Enable() override
  {
  }

private:
  ~AudioDestinationTrackSource() = default;

  RefPtr<MediaStreamAudioDestinationNode> mNode;
};

NS_IMPL_ADDREF_INHERITED(AudioDestinationTrackSource,
                         MediaStreamTrackSource)
NS_IMPL_RELEASE_INHERITED(AudioDestinationTrackSource,
                          MediaStreamTrackSource)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(AudioDestinationTrackSource)
NS_INTERFACE_MAP_END_INHERITING(MediaStreamTrackSource)
NS_IMPL_CYCLE_COLLECTION_INHERITED(AudioDestinationTrackSource,
                                   MediaStreamTrackSource,
                                   mNode)

NS_IMPL_CYCLE_COLLECTION_INHERITED(MediaStreamAudioDestinationNode, AudioNode, mDOMStream)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaStreamAudioDestinationNode)
NS_INTERFACE_MAP_END_INHERITING(AudioNode)

NS_IMPL_ADDREF_INHERITED(MediaStreamAudioDestinationNode, AudioNode)
NS_IMPL_RELEASE_INHERITED(MediaStreamAudioDestinationNode, AudioNode)

MediaStreamAudioDestinationNode::MediaStreamAudioDestinationNode(AudioContext* aContext)
  : AudioNode(aContext,
              2,
              ChannelCountMode::Explicit,
              ChannelInterpretation::Speakers)
  , mDOMStream(
      DOMAudioNodeMediaStream::CreateTrackUnionStreamAsInput(GetOwner(),
                                                             this,
                                                             aContext->Graph()))
{
  // Ensure an audio track with the correct ID is exposed to JS
  nsIDocument* doc = aContext->GetParentObject()->GetExtantDoc();
  RefPtr<MediaStreamTrackSource> source =
    new AudioDestinationTrackSource(this, doc->NodePrincipal());
  RefPtr<MediaStreamTrack> track =
    mDOMStream->CreateDOMTrack(AudioNodeStream::AUDIO_TRACK,
                               MediaSegment::AUDIO, source,
                               MediaTrackConstraints());
  mDOMStream->AddTrackInternal(track);

  ProcessedMediaStream* outputStream = mDOMStream->GetInputStream()->AsProcessedStream();
  MOZ_ASSERT(!!outputStream);
  AudioNodeEngine* engine = new AudioNodeEngine(this);
  mStream = AudioNodeStream::Create(aContext, engine,
                                    AudioNodeStream::EXTERNAL_OUTPUT,
                                    aContext->Graph());
  mPort = outputStream->AllocateInputPort(mStream, AudioNodeStream::AUDIO_TRACK);
}

/* static */ already_AddRefed<MediaStreamAudioDestinationNode>
MediaStreamAudioDestinationNode::Create(AudioContext& aAudioContext,
                                        const AudioNodeOptions& aOptions,
                                        ErrorResult& aRv)
{
  if (aAudioContext.IsOffline()) {
    aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
    return nullptr;
  }

  if (aAudioContext.CheckClosed(aRv)) {
    return nullptr;
  }

  RefPtr<MediaStreamAudioDestinationNode> audioNode =
    new MediaStreamAudioDestinationNode(&aAudioContext);

  audioNode->Initialize(aOptions, aRv);
  if (NS_WARN_IF(aRv.Failed())) {
    return nullptr;
  }

  return audioNode.forget();
}

size_t
MediaStreamAudioDestinationNode::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
{
  // Future:
  // - mDOMStream
  size_t amount = AudioNode::SizeOfExcludingThis(aMallocSizeOf);
  amount += mPort->SizeOfIncludingThis(aMallocSizeOf);
  return amount;
}

size_t
MediaStreamAudioDestinationNode::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
{
  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
}

void
MediaStreamAudioDestinationNode::DestroyMediaStream()
{
  AudioNode::DestroyMediaStream();
  if (mPort) {
    mPort->Destroy();
    mPort = nullptr;
  }
}

JSObject*
MediaStreamAudioDestinationNode::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
  return MediaStreamAudioDestinationNodeBinding::Wrap(aCx, this, aGivenProto);
}

} // namespace dom
} // namespace mozilla