Revert of Moving MediaStreamSignaling logic into PeerConnection.

talk/app/webrtc/mediastreamsignaling.h

Index: talk/app/webrtc/mediastreamsignaling.h
diff --git a/talk/app/webrtc/mediastreamsignaling.h b/talk/app/webrtc/mediastreamsignaling.h
index e8c5c110d007f5e1e0cb3a09bfd71bf36bd8c749..b858b5b5a0c4a92b3d64153dc26fb70ea318e710 100644
--- a/talk/app/webrtc/mediastreamsignaling.h
+++ b/talk/app/webrtc/mediastreamsignaling.h
@@ -25,4 +25,379 @@
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// TODO(deadbeef): Remove this file once Chrome build files don't reference it.
+#ifndef TALK_APP_WEBRTC_MEDIASTREAMSIGNALING_H_
+#define TALK_APP_WEBRTC_MEDIASTREAMSIGNALING_H_
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "talk/app/webrtc/datachannel.h"
+#include "talk/app/webrtc/mediastream.h"
+#include "talk/app/webrtc/peerconnectioninterface.h"
+#include "talk/app/webrtc/streamcollection.h"
+#include "talk/session/media/mediasession.h"
+#include "webrtc/base/scoped_ref_ptr.h"
+#include "webrtc/base/sigslot.h"
+
+namespace rtc {
+class Thread;
+}  // namespace rtc
+
+namespace webrtc {
+
+class RemoteMediaStreamFactory;
+
+// A MediaStreamSignalingObserver is notified when events happen to
+// MediaStreams, MediaStreamTracks or DataChannels associated with the observed
+// MediaStreamSignaling object. The notifications identify the stream, track or
+// channel.
+class MediaStreamSignalingObserver {
+ public:
+  // Triggered when the remote SessionDescription has a new stream.
+  virtual void OnAddRemoteStream(MediaStreamInterface* stream) = 0;
+
+  // Triggered when the remote SessionDescription removes a stream.
+  virtual void OnRemoveRemoteStream(MediaStreamInterface* stream) = 0;
+
+  // Triggered when the remote SessionDescription has a new data channel.
+  virtual void OnAddDataChannel(DataChannelInterface* data_channel) = 0;
+
+  // Triggered when the remote SessionDescription has a new audio track.
+  virtual void OnAddRemoteAudioTrack(MediaStreamInterface* stream,
+                                     AudioTrackInterface* audio_track,
+                                     uint32_t ssrc) = 0;
+
+  // Triggered when the remote SessionDescription has a new video track.
+  virtual void OnAddRemoteVideoTrack(MediaStreamInterface* stream,
+                                     VideoTrackInterface* video_track,
+                                     uint32_t ssrc) = 0;
+
+  // Triggered when the remote SessionDescription has removed an audio track.
+  virtual void OnRemoveRemoteAudioTrack(MediaStreamInterface* stream,
+                                        AudioTrackInterface* audio_track)  = 0;
+
+  // Triggered when the remote SessionDescription has removed a video track.
+  virtual void OnRemoveRemoteVideoTrack(MediaStreamInterface* stream,
+                                        VideoTrackInterface* video_track) = 0;
+
+  // Triggered when the local SessionDescription has a new audio track.
+  virtual void OnAddLocalAudioTrack(MediaStreamInterface* stream,
+                                    AudioTrackInterface* audio_track,
+                                    uint32_t ssrc) = 0;
+
+  // Triggered when the local SessionDescription has a new video track.
+  virtual void OnAddLocalVideoTrack(MediaStreamInterface* stream,
+                                    VideoTrackInterface* video_track,
+                                    uint32_t ssrc) = 0;
+
+  // Triggered when the local SessionDescription has removed an audio track.
+  virtual void OnRemoveLocalAudioTrack(MediaStreamInterface* stream,
+                                       AudioTrackInterface* audio_track,
+                                       uint32_t ssrc) = 0;
+
+  // Triggered when the local SessionDescription has removed a video track.
+  virtual void OnRemoveLocalVideoTrack(MediaStreamInterface* stream,
+                                       VideoTrackInterface* video_track) = 0;
+
+  // Triggered when RemoveLocalStream is called. |stream| is no longer used
+  // when negotiating and all tracks in |stream| should stop providing data to
+  // this PeerConnection. This doesn't mean that the local session description
+  // has changed and OnRemoveLocalAudioTrack and OnRemoveLocalVideoTrack is not
+  // called for each individual track.
+  virtual void OnRemoveLocalStream(MediaStreamInterface* stream) = 0;
+
+ protected:
+  ~MediaStreamSignalingObserver() {}
+};
+
+// MediaStreamSignaling works as a glue between MediaStreams and a cricket
+// classes for SessionDescriptions.
+// It is used for creating cricket::MediaSessionOptions given the local
+// MediaStreams and data channels.
+//
+// It is responsible for creating remote MediaStreams given a remote
+// SessionDescription and creating cricket::MediaSessionOptions given
+// local MediaStreams.
+//
+// To signal that a DataChannel should be established:
+// 1. Call AddDataChannel with the new DataChannel. Next time
+//    GetMediaSessionOptions will include the description of the DataChannel.
+// 2. When a local session description is set, call UpdateLocalStreams with the
+//    session description. This will set the SSRC used for sending data on
+//    this DataChannel.
+// 3. When remote session description is set, call UpdateRemoteStream with the
+//    session description. If the DataChannel label and a SSRC is included in
+//    the description, the DataChannel is updated with SSRC that will be used
+//    for receiving data.
+// 4. When both the local and remote SSRC of a DataChannel is set the state of
+//    the DataChannel change to kOpen.
+//
+// To setup a DataChannel initialized by the remote end.
+// 1. When remote session description is set, call UpdateRemoteStream with the
+//    session description. If a label and a SSRC of a new DataChannel is found
+//    MediaStreamSignalingObserver::OnAddDataChannel with the label and SSRC is
+//    triggered.
+// 2. Create a DataChannel instance with the label and set the remote SSRC.
+// 3. Call AddDataChannel with this new DataChannel.  GetMediaSessionOptions
+//    will include the description of the DataChannel.
+// 4. Create a local session description and call UpdateLocalStreams. This will
+//    set the local SSRC used by the DataChannel.
+// 5. When both the local and remote SSRC of a DataChannel is set the state of
+//    the DataChannel change to kOpen.
+//
+// To close a DataChannel:
+// 1. Call DataChannel::Close. This will change the state of the DataChannel to
+//    kClosing. GetMediaSessionOptions will not
+//    include the description of the DataChannel.
+// 2. When a local session description is set, call UpdateLocalStreams with the
+//    session description. The description will no longer contain the
+//    DataChannel label or SSRC.
+// 3. When remote session description is set, call UpdateRemoteStream with the
+//    session description. The description will no longer contain the
+//    DataChannel label or SSRC. The DataChannel SSRC is updated with SSRC=0.
+//    The DataChannel change state to kClosed.
+
+class MediaStreamSignaling : public sigslot::has_slots<> {
+ public:
+  typedef std::map<std::string, rtc::scoped_refptr<DataChannel> >
+      RtpDataChannels;
+  typedef std::vector<rtc::scoped_refptr<DataChannel>> SctpDataChannels;
+
+  MediaStreamSignaling(rtc::Thread* signaling_thread,
+                       MediaStreamSignalingObserver* stream_observer,
+                       cricket::ChannelManager* channel_manager);
+  virtual ~MediaStreamSignaling();
+
+  // Notify all referenced objects that MediaStreamSignaling will be teared
+  // down. This method must be called prior to the dtor.
+  void TearDown();
+
+  // Set a factory for creating data channels that are initiated by the remote
+  // peer.
+  void SetDataChannelFactory(DataChannelFactory* data_channel_factory) {
+    data_channel_factory_ = data_channel_factory;
+  }
+
+  // Checks if |id| is available to be assigned to a new SCTP data channel.
+  bool IsSctpSidAvailable(int sid) const;
+
+  // Gets the first available SCTP id that is not assigned to any existing
+  // data channels.
+  bool AllocateSctpSid(rtc::SSLRole role, int* sid);
+
+  // Adds |local_stream| to the collection of known MediaStreams that will be
+  // offered in a SessionDescription.
+  bool AddLocalStream(MediaStreamInterface* local_stream);
+
+  // Removes |local_stream| from the collection of known MediaStreams that will
+  // be offered in a SessionDescription.
+  void RemoveLocalStream(MediaStreamInterface* local_stream);
+
+  // Checks if any data channel has been added.
+  bool HasDataChannels() const;
+  // Adds |data_channel| to the collection of DataChannels that will be
+  // be offered in a SessionDescription.
+  bool AddDataChannel(DataChannel* data_channel);
+  // After we receive an OPEN message, create a data channel and add it.
+  bool AddDataChannelFromOpenMessage(const cricket::ReceiveDataParams& params,
+                                     const rtc::Buffer& payload);
+  void RemoveSctpDataChannel(int sid);
+
+  // Returns a MediaSessionOptions struct with options decided by |options|,
+  // the local MediaStreams and DataChannels.
+  virtual bool GetOptionsForOffer(
+      const PeerConnectionInterface::RTCOfferAnswerOptions& rtc_options,
+      cricket::MediaSessionOptions* session_options);
+
+  // Returns a MediaSessionOptions struct with options decided by
+  // |constraints|, the local MediaStreams and DataChannels.
+  virtual bool GetOptionsForAnswer(
+      const MediaConstraintsInterface* constraints,
+      cricket::MediaSessionOptions* options);
+
+  // Called when the remote session description has changed. The purpose is to
+  // update remote MediaStreams and DataChannels with the current
+  // session state.
+  // If the remote SessionDescription contain information about a new remote
+  // MediaStreams a new remote MediaStream is created and
+  // MediaStreamSignalingObserver::OnAddStream is called.
+  // If a remote MediaStream is missing from
+  // the remote SessionDescription MediaStreamSignalingObserver::OnRemoveStream
+  // is called.
+  // If the SessionDescription contains information about a new DataChannel,
+  // MediaStreamSignalingObserver::OnAddDataChannel is called with the
+  // DataChannel.
+  void OnRemoteDescriptionChanged(const SessionDescriptionInterface* desc);
+
+  // Called when the local session description has changed. The purpose is to
+  // update local and remote MediaStreams and DataChannels with the current
+  // session state.
+  // If |desc| indicates that the media type should be rejected, the method
+  // ends the remote MediaStreamTracks.
+  // It also updates local DataChannels with information about its local SSRC.
+  void OnLocalDescriptionChanged(const SessionDescriptionInterface* desc);
+
+  // Called when the audio channel closes.
+  void OnAudioChannelClose();
+  // Called when the video channel closes.
+  void OnVideoChannelClose();
+  // Called when the data channel closes.
+  void OnDataChannelClose();
+
+  // Returns all current known local MediaStreams.
+  StreamCollectionInterface* local_streams() const { return local_streams_;}
+
+  // Returns all current remote MediaStreams.
+  StreamCollectionInterface* remote_streams() const {
+    return remote_streams_.get();
+  }
+  void OnDataTransportCreatedForSctp();
+  void OnDtlsRoleReadyForSctp(rtc::SSLRole role);
+  void OnRemoteSctpDataChannelClosed(uint32_t sid);
+
+  const SctpDataChannels& sctp_data_channels() const {
+    return sctp_data_channels_;
+  }
+
+ private:
+  struct RemotePeerInfo {
+    RemotePeerInfo()
+        : msid_supported(false),
+          default_audio_track_needed(false),
+          default_video_track_needed(false) {
+    }
+    // True if it has been discovered that the remote peer support MSID.
+    bool msid_supported;
+    // The remote peer indicates in the session description that audio will be
+    // sent but no MSID is given.
+    bool default_audio_track_needed;
+    // The remote peer indicates in the session description that video will be
+    // sent but no MSID is given.
+    bool default_video_track_needed;
+
+    bool IsDefaultMediaStreamNeeded() {
+      return !msid_supported && (default_audio_track_needed ||
+          default_video_track_needed);
+    }
+  };
+
+  struct TrackInfo {
+    TrackInfo() : ssrc(0) {}
+    TrackInfo(const std::string& stream_label,
+              const std::string track_id,
+              uint32_t ssrc)
+        : stream_label(stream_label), track_id(track_id), ssrc(ssrc) {}
+    std::string stream_label;
+    std::string track_id;
+    uint32_t ssrc;
+  };
+  typedef std::vector<TrackInfo> TrackInfos;
+
+  // Makes sure a MediaStream Track is created for each StreamParam in
+  // |streams|. |media_type| is the type of the |streams| and can be either
+  // audio or video.
+  // If a new MediaStream is created it is added to |new_streams|.
+  void UpdateRemoteStreamsList(
+      const std::vector<cricket::StreamParams>& streams,
+      cricket::MediaType media_type,
+      StreamCollection* new_streams);
+
+  // Triggered when a remote track has been seen for the first time in a remote
+  // session description. It creates a remote MediaStreamTrackInterface
+  // implementation and triggers MediaStreamSignaling::OnAddRemoteAudioTrack or
+  // MediaStreamSignaling::OnAddRemoteVideoTrack.
+  void OnRemoteTrackSeen(const std::string& stream_label,
+                         const std::string& track_id,
+                         uint32_t ssrc,
+                         cricket::MediaType media_type);
+
+  // Triggered when a remote track has been removed from a remote session
+  // description. It removes the remote track with id |track_id| from a remote
+  // MediaStream and triggers MediaStreamSignaling::OnRemoveRemoteAudioTrack or
+  // MediaStreamSignaling::OnRemoveRemoteVideoTrack.
+  void OnRemoteTrackRemoved(const std::string& stream_label,
+                            const std::string& track_id,
+                            cricket::MediaType media_type);
+
+  // Set the MediaStreamTrackInterface::TrackState to |kEnded| on all remote
+  // tracks of type |media_type|.
+  void RejectRemoteTracks(cricket::MediaType media_type);
+
+  // Finds remote MediaStreams without any tracks and removes them from
+  // |remote_streams_| and notifies the observer that the MediaStream no longer
+  // exist.
+  void UpdateEndedRemoteMediaStreams();
+  void MaybeCreateDefaultStream();
+  TrackInfos* GetRemoteTracks(cricket::MediaType type);
+
+  // Returns a map of currently negotiated LocalTrackInfo of type |type|.
+  TrackInfos* GetLocalTracks(cricket::MediaType type);
+  bool FindLocalTrack(const std::string& track_id, cricket::MediaType type);
+
+  // Loops through the vector of |streams| and finds added and removed
+  // StreamParams since last time this method was called.
+  // For each new or removed StreamParam NotifyLocalTrackAdded or
+  // NotifyLocalTrackRemoved in invoked.
+  void UpdateLocalTracks(const std::vector<cricket::StreamParams>& streams,
+                         cricket::MediaType media_type);
+
+  // Triggered when a local track has been seen for the first time in a local
+  // session description.
+  // This method triggers MediaStreamSignaling::OnAddLocalAudioTrack or
+  // MediaStreamSignaling::OnAddLocalVideoTrack if the rtp streams in the local
+  // SessionDescription can be mapped to a MediaStreamTrack in a MediaStream in
+  // |local_streams_|
+  void OnLocalTrackSeen(const std::string& stream_label,
+                        const std::string& track_id,
+                        uint32_t ssrc,
+                        cricket::MediaType media_type);
+
+  // Triggered when a local track has been removed from a local session
+  // description.
+  // This method triggers MediaStreamSignaling::OnRemoveLocalAudioTrack or
+  // MediaStreamSignaling::OnRemoveLocalVideoTrack if a stream has been removed
+  // from the local SessionDescription and the stream can be mapped to a
+  // MediaStreamTrack in a MediaStream in |local_streams_|.
+  void OnLocalTrackRemoved(const std::string& stream_label,
+                           const std::string& track_id,
+                           uint32_t ssrc,
+                           cricket::MediaType media_type);
+
+  void UpdateLocalRtpDataChannels(const cricket::StreamParamsVec& streams);
+  void UpdateRemoteRtpDataChannels(const cricket::StreamParamsVec& streams);
+  void UpdateClosingDataChannels(
+      const std::vector<std::string>& active_channels, bool is_local_update);
+  void CreateRemoteDataChannel(const std::string& label, uint32_t remote_ssrc);
+
+  const TrackInfo* FindTrackInfo(const TrackInfos& infos,
+                                 const std::string& stream_label,
+                                 const std::string track_id) const;
+
+  // Returns the index of the specified SCTP DataChannel in sctp_data_channels_,
+  // or -1 if not found.
+  int FindDataChannelBySid(int sid) const;
+
+  RemotePeerInfo remote_info_;
+  rtc::Thread* signaling_thread_;
+  DataChannelFactory* data_channel_factory_;
+  MediaStreamSignalingObserver* stream_observer_;
+  rtc::scoped_refptr<StreamCollection> local_streams_;
+  rtc::scoped_refptr<StreamCollection> remote_streams_;
+  rtc::scoped_ptr<RemoteMediaStreamFactory> remote_stream_factory_;
+
+  TrackInfos remote_audio_tracks_;
+  TrackInfos remote_video_tracks_;
+  TrackInfos local_audio_tracks_;
+  TrackInfos local_video_tracks_;
+
+  int last_allocated_sctp_even_sid_;
+  int last_allocated_sctp_odd_sid_;
+
+  RtpDataChannels rtp_data_channels_;
+  SctpDataChannels sctp_data_channels_;
+};
+
+}  // namespace webrtc
+
+#endif  // TALK_APP_WEBRTC_MEDIASTREAMSIGNALING_H_