1 files changed, 481 insertions, 0 deletions
diff --git a/dom/media/MediaStreamTrack.h b/dom/media/MediaStreamTrack.h
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* 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/. */
+
+#ifndef MEDIASTREAMTRACK_H_
+#define MEDIASTREAMTRACK_H_
+
+#include "mozilla/DOMEventTargetHelper.h"
+#include "nsError.h"
+#include "nsID.h"
+#include "nsIPrincipal.h"
+#include "StreamTracks.h"
+#include "MediaTrackConstraints.h"
+#include "mozilla/CORSMode.h"
+#include "PrincipalChangeObserver.h"
+#include "mozilla/dom/MediaStreamTrackBinding.h"
+#include "mozilla/dom/MediaTrackSettingsBinding.h"
+#include "mozilla/media/MediaUtils.h"
+
+namespace mozilla {
+
+class DOMMediaStream;
+class MediaEnginePhotoCallback;
+class MediaInputPort;
+class MediaStream;
+class MediaStreamGraph;
+class MediaStreamGraphImpl;
+class MediaStreamTrackListener;
+class DirectMediaStreamTrackListener;
+class PeerConnectionImpl;
+class PeerConnectionMedia;
+class PeerIdentity;
+class ProcessedMediaStream;
+class RemoteSourceStreamInfo;
+class SourceStreamInfo;
+
+namespace dom {
+
+class AudioStreamTrack;
+class VideoStreamTrack;
+class MediaStreamError;
+
+/**
+ * Common interface through which a MediaStreamTrack can communicate with its
+ * producer on the main thread.
+ *
+ * Kept alive by a strong ref in all MediaStreamTracks (original and clones)
+ * sharing this source.
+ */
+class MediaStreamTrackSource : public nsISupports
+{
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS(MediaStreamTrackSource)
+
+public:
+  class Sink
+  {
+  public:
+    virtual void PrincipalChanged() = 0;
+  };
+
+  MediaStreamTrackSource(nsIPrincipal* aPrincipal,
+                         const nsString& aLabel)
+    : mPrincipal(aPrincipal),
+      mLabel(aLabel),
+      mStopped(false)
+  {
+    MOZ_COUNT_CTOR(MediaStreamTrackSource);
+  }
+
+  /**
+   * Use to clean up any resources that have to be cleaned before the
+   * destructor is called. It is often too late in the destructor because
+   * of garbage collection having removed the members already.
+   */
+  virtual void Destroy() {}
+
+  /**
+   * Gets the source's MediaSourceEnum for usage by PeerConnections.
+   */
+  virtual MediaSourceEnum GetMediaSource() const = 0;
+
+  /**
+   * Get this TrackSource's principal.
+   */
+  nsIPrincipal* GetPrincipal() const { return mPrincipal; }
+
+  /**
+   * Get the source's current CORSMode. If not applicable CORS_NONE is returned.
+   * The sink will be notified of changes to our CORSMode through
+   * PrincipalChanged().
+   */
+  virtual CORSMode GetCORSMode() const { return CORS_NONE; }
+
+  /**
+   * This is used in WebRTC. A peerIdentity constrained MediaStreamTrack cannot
+   * be sent across the network to anything other than a peer with the provided
+   * identity. If this is set, then GetPrincipal() should return an instance of
+   * nsNullPrincipal.
+   *
+   * A track's PeerIdentity is immutable and will not change during the track's
+   * lifetime.
+   */
+  virtual const PeerIdentity* GetPeerIdentity() const { return nullptr; }
+
+  /**
+   * MediaStreamTrack::GetLabel (see spec) calls through to here.
+   */
+  void GetLabel(nsAString& aLabel) { aLabel.Assign(mLabel); }
+
+  /**
+   * Forwards a photo request to backends that support it. Other backends return
+   * NS_ERROR_NOT_IMPLEMENTED to indicate that a MediaStreamGraph-based fallback
+   * should be used.
+   */
+  virtual nsresult TakePhoto(MediaEnginePhotoCallback*) const { return NS_ERROR_NOT_IMPLEMENTED; }
+
+  typedef media::Pledge<bool, dom::MediaStreamError*> PledgeVoid;
+
+  /**
+   * We provide a fallback solution to ApplyConstraints() here.
+   * Sources that support ApplyConstraints() will have to override it.
+   */
+  virtual already_AddRefed<PledgeVoid>
+  ApplyConstraints(nsPIDOMWindowInner* aWindow,
+                   const dom::MediaTrackConstraints& aConstraints);
+
+  /**
+   * Same for GetSettings (no-op).
+   */
+  virtual void
+  GetSettings(dom::MediaTrackSettings& aResult) {};
+
+  /**
+   * Called by the source interface when all registered sinks have unregistered.
+   */
+  virtual void Stop() = 0;
+
+  /**
+   * Called by each MediaStreamTrack clone on initialization.
+   */
+  void RegisterSink(Sink* aSink)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    if (mStopped) {
+      return;
+    }
+    mSinks.AppendElement(aSink);
+  }
+
+  /**
+   * Called by each MediaStreamTrack clone on Stop() if supported by the
+   * source (us) or destruction.
+   */
+  void UnregisterSink(Sink* aSink)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    if (mSinks.RemoveElement(aSink) && mSinks.IsEmpty()) {
+      MOZ_ASSERT(!mStopped);
+      Stop();
+      mStopped = true;
+    }
+  }
+
+protected:
+  virtual ~MediaStreamTrackSource()
+  {
+    MOZ_COUNT_DTOR(MediaStreamTrackSource);
+  }
+
+  /**
+   * Called by a sub class when the principal has changed.
+   * Notifies all sinks.
+   */
+  void PrincipalChanged()
+  {
+    for (Sink* sink : mSinks) {
+      sink->PrincipalChanged();
+    }
+  }
+
+  // Principal identifying who may access the contents of this source.
+  nsCOMPtr<nsIPrincipal> mPrincipal;
+
+  // Currently registered sinks.
+  nsTArray<Sink*> mSinks;
+
+  // The label of the track we are the source of per the MediaStreamTrack spec.
+  const nsString mLabel;
+
+  // True if all MediaStreamTrack users have unregistered from this source and
+  // Stop() has been called.
+  bool mStopped;
+};
+
+/**
+ * Basic implementation of MediaStreamTrackSource that doesn't forward Stop().
+ */
+class BasicTrackSource : public MediaStreamTrackSource
+{
+public:
+  explicit BasicTrackSource(nsIPrincipal* aPrincipal,
+                            const MediaSourceEnum aMediaSource =
+                            MediaSourceEnum::Other)
+    : MediaStreamTrackSource(aPrincipal, nsString())
+    , mMediaSource(aMediaSource)
+  {}
+
+  MediaSourceEnum GetMediaSource() const override { return mMediaSource; }
+
+  void Stop() override {}
+
+protected:
+  ~BasicTrackSource() {}
+
+  const MediaSourceEnum mMediaSource;
+};
+
+/**
+ * Base class that consumers of a MediaStreamTrack can use to get notifications
+ * about state changes in the track.
+ */
+class MediaStreamTrackConsumer : public nsISupports
+{
+public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS(MediaStreamTrackConsumer)
+
+  /**
+   * Called when the track's readyState transitions to "ended".
+   * Unlike the "ended" event exposed to script this is called for any reason,
+   * including MediaStreamTrack::Stop().
+   */
+  virtual void NotifyEnded(MediaStreamTrack* aTrack) {};
+
+protected:
+  virtual ~MediaStreamTrackConsumer() {}
+};
+
+/**
+ * Class representing a track in a DOMMediaStream.
+ */
+class MediaStreamTrack : public DOMEventTargetHelper,
+                         public MediaStreamTrackSource::Sink
+{
+  // DOMMediaStream owns MediaStreamTrack instances, and requires access to
+  // some internal state, e.g., GetInputStream(), GetOwnedStream().
+  friend class mozilla::DOMMediaStream;
+
+  // PeerConnection and friends need to know our owning DOMStream and track id.
+  friend class mozilla::PeerConnectionImpl;
+  friend class mozilla::PeerConnectionMedia;
+  friend class mozilla::SourceStreamInfo;
+  friend class mozilla::RemoteSourceStreamInfo;
+
+  class PrincipalHandleListener;
+
+public:
+  /**
+   * aTrackID is the MediaStreamGraph track ID for the track in the
+   * MediaStream owned by aStream.
+   */
+  MediaStreamTrack(DOMMediaStream* aStream, TrackID aTrackID,
+      TrackID aInputTrackID,
+      MediaStreamTrackSource* aSource,
+      const MediaTrackConstraints& aConstraints = MediaTrackConstraints());
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(MediaStreamTrack,
+                                           DOMEventTargetHelper)
+
+  nsPIDOMWindowInner* GetParentObject() const;
+  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override = 0;
+
+  virtual AudioStreamTrack* AsAudioStreamTrack() { return nullptr; }
+  virtual VideoStreamTrack* AsVideoStreamTrack() { return nullptr; }
+
+  virtual const AudioStreamTrack* AsAudioStreamTrack() const { return nullptr; }
+  virtual const VideoStreamTrack* AsVideoStreamTrack() const { return nullptr; }
+
+  // WebIDL
+  virtual void GetKind(nsAString& aKind) = 0;
+  void GetId(nsAString& aID) const;
+  void GetLabel(nsAString& aLabel) { GetSource().GetLabel(aLabel); }
+  bool Enabled() { return mEnabled; }
+  void SetEnabled(bool aEnabled);
+  void Stop();
+  void GetConstraints(dom::MediaTrackConstraints& aResult);
+  void GetSettings(dom::MediaTrackSettings& aResult);
+
+  already_AddRefed<Promise>
+  ApplyConstraints(const dom::MediaTrackConstraints& aConstraints, ErrorResult &aRv);
+  already_AddRefed<MediaStreamTrack> Clone();
+  MediaStreamTrackState ReadyState() { return mReadyState; }
+
+  IMPL_EVENT_HANDLER(ended)
+
+  /**
+   * Convenience (and legacy) method for when ready state is "ended".
+   */
+  bool Ended() const { return mReadyState == MediaStreamTrackState::Ended; }
+
+  /**
+   * Forces the ready state to a particular value, for instance when we're
+   * cloning an already ended track.
+   */
+  void SetReadyState(MediaStreamTrackState aState);
+
+  /**
+   * Notified by the MediaStreamGraph, through our owning MediaStream on the
+   * main thread.
+   *
+   * Note that this sets the track to ended and raises the "ended" event
+   * synchronously.
+   */
+  void OverrideEnded();
+
+  /**
+   * Get this track's principal.
+   */
+  nsIPrincipal* GetPrincipal() const { return mPrincipal; }
+
+  /**
+   * Called by the PrincipalHandleListener when this track's PrincipalHandle changes on
+   * the MediaStreamGraph thread. When the PrincipalHandle matches the pending
+   * principal we know that the principal change has propagated to consumers.
+   */
+  void NotifyPrincipalHandleChanged(const PrincipalHandle& aPrincipalHandle);
+
+  /**
+   * Called when this track's readyState transitions to "ended".
+   * Notifies all MediaStreamTrackConsumers that this track ended.
+   */
+  void NotifyEnded();
+
+  /**
+   * Get this track's CORS mode.
+   */
+  CORSMode GetCORSMode() const { return GetSource().GetCORSMode(); }
+
+  /**
+   * Get this track's PeerIdentity.
+   */
+  const PeerIdentity* GetPeerIdentity() const { return GetSource().GetPeerIdentity(); }
+
+  MediaStreamGraph* Graph();
+  MediaStreamGraphImpl* GraphImpl();
+
+  MediaStreamTrackSource& GetSource() const
+  {
+    MOZ_RELEASE_ASSERT(mSource, "The track source is only removed on destruction");
+    return *mSource;
+  }
+
+  // Webrtc allows the remote side to name tracks whatever it wants, and we
+  // need to surface this to content.
+  void AssignId(const nsAString& aID) { mID = aID; }
+
+  // Implementation of MediaStreamTrackSource::Sink
+  void PrincipalChanged() override;
+
+  /**
+   * Add a PrincipalChangeObserver to this track.
+   *
+   * Returns true if it was successfully added.
+   *
+   * Ownership of the PrincipalChangeObserver remains with the caller, and it's
+   * the caller's responsibility to remove the observer before it dies.
+   */
+  bool AddPrincipalChangeObserver(PrincipalChangeObserver<MediaStreamTrack>* aObserver);
+
+  /**
+   * Remove an added PrincipalChangeObserver from this track.
+   *
+   * Returns true if it was successfully removed.
+   */
+  bool RemovePrincipalChangeObserver(PrincipalChangeObserver<MediaStreamTrack>* aObserver);
+
+  /**
+   * Add a MediaStreamTrackConsumer to this track.
+   *
+   * Adding the same consumer multiple times is prohibited.
+   */
+  void AddConsumer(MediaStreamTrackConsumer* aConsumer);
+
+  /**
+   * Remove an added MediaStreamTrackConsumer from this track.
+   */
+  void RemoveConsumer(MediaStreamTrackConsumer* aConsumer);
+
+  /**
+   * Adds a MediaStreamTrackListener to the MediaStreamGraph representation of
+   * this track.
+   */
+  void AddListener(MediaStreamTrackListener* aListener);
+
+  /**
+   * Removes a MediaStreamTrackListener from the MediaStreamGraph representation
+   * of this track.
+   */
+  void RemoveListener(MediaStreamTrackListener* aListener);
+
+  /**
+   * Attempts to add a direct track listener to this track.
+   * Callers must listen to the NotifyInstalled event to know if installing
+   * the listener succeeded (tracks originating from SourceMediaStreams) or
+   * failed (e.g., WebAudio originated tracks).
+   */
+  void AddDirectListener(DirectMediaStreamTrackListener *aListener);
+  void RemoveDirectListener(DirectMediaStreamTrackListener  *aListener);
+
+  /**
+   * Sets up a MediaInputPort from the underlying track that this
+   * MediaStreamTrack represents, to aStream, and returns it.
+   */
+  already_AddRefed<MediaInputPort> ForwardTrackContentsTo(ProcessedMediaStream* aStream,
+                                                          TrackID aDestinationTrackID = TRACK_ANY);
+
+  /**
+   * Returns true if this track is connected to aPort and forwarded to aPort's
+   * output stream.
+   */
+  bool IsForwardedThrough(MediaInputPort* aPort);
+
+  void SetMediaStreamSizeListener(DirectMediaStreamTrackListener* aListener);
+
+protected:
+  virtual ~MediaStreamTrack();
+
+  void Destroy();
+
+  // Returns the original DOMMediaStream's underlying input stream.
+  MediaStream* GetInputStream();
+
+  // Returns the owning DOMMediaStream's underlying owned stream.
+  ProcessedMediaStream* GetOwnedStream();
+
+  // Returns the original DOMMediaStream. If this track is a clone,
+  // the original track's owning DOMMediaStream is returned.
+  DOMMediaStream* GetInputDOMStream();
+
+  /**
+   * Sets the principal and notifies PrincipalChangeObservers if it changes.
+   */
+  void SetPrincipal(nsIPrincipal* aPrincipal);
+
+  /**
+   * Creates a new MediaStreamTrack with the same type, input track ID and
+   * source as this MediaStreamTrack.
+   * aTrackID is the TrackID the new track will have in its owned stream.
+   */
+  virtual already_AddRefed<MediaStreamTrack> CloneInternal(DOMMediaStream* aOwningStream,
+                                                           TrackID aTrackID) = 0;
+
+  nsTArray<PrincipalChangeObserver<MediaStreamTrack>*> mPrincipalChangeObservers;
+
+  nsTArray<RefPtr<MediaStreamTrackConsumer>> mConsumers;
+
+  RefPtr<DOMMediaStream> mOwningStream;
+  TrackID mTrackID;
+  TrackID mInputTrackID;
+  RefPtr<MediaStreamTrackSource> mSource;
+  RefPtr<MediaStreamTrack> mOriginalTrack;
+  nsCOMPtr<nsIPrincipal> mPrincipal;
+  nsCOMPtr<nsIPrincipal> mPendingPrincipal;
+  RefPtr<PrincipalHandleListener> mPrincipalHandleListener;
+  // Keep tracking MediaStreamTrackListener and DirectMediaStreamTrackListener,
+  // so we can remove them in |Destory|.
+  nsTArray<RefPtr<MediaStreamTrackListener>> mTrackListeners;
+  nsTArray<RefPtr<DirectMediaStreamTrackListener>> mDirectTrackListeners;
+  nsString mID;
+  MediaStreamTrackState mReadyState;
+  bool mEnabled;
+  dom::MediaTrackConstraints mConstraints;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif /* MEDIASTREAMTRACK_H_ */