Implement current/pending session description methods.

webrtc/api/webrtcsession.h

 /*
  *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 229 matching lines @@
   cricket::IceConfig ParseIceConfig(
       const PeerConnectionInterface::RTCConfiguration& config) const;
 
   void SetIceConfig(const cricket::IceConfig& ice_config);
 
   // Start gathering candidates for any new transports, or transports doing an
   // ICE restart.
   void MaybeStartGathering();
 
   const SessionDescriptionInterface* local_description() const {
-    return local_desc_.get();
+    return pending_local_description_ ? pending_local_description_.get()
+                                      : current_local_description_.get();
   }
   const SessionDescriptionInterface* remote_description() const {
-    return remote_desc_.get();
+    return pending_remote_description_ ? pending_remote_description_.get()
+                                       : current_remote_description_.get();
+  }
+  const SessionDescriptionInterface* current_local_description() const {
+    return current_local_description_.get();
+  }
+  const SessionDescriptionInterface* current_remote_description() const {
+    return current_remote_description_.get();
+  }
+  const SessionDescriptionInterface* pending_local_description() const {
+    return pending_local_description_.get();
+  }
+  const SessionDescriptionInterface* pending_remote_description() const {
+    return pending_remote_description_.get();
   }
 
   // Get the id used as a media stream track's "id" field from ssrc.
   virtual bool GetLocalTrackIdBySsrc(uint32_t ssrc, std::string* track_id);
   virtual bool GetRemoteTrackIdBySsrc(uint32_t ssrc, std::string* track_id);
 
   // Implements DtmfProviderInterface.
   bool CanInsertDtmf(const std::string& track_id) override;
   bool InsertDtmf(const std::string& track_id,
                   int code, int duration) override;
@@ skipping 83 matching lines @@
 
  private:
   // Indicates the type of SessionDescription in a call to SetLocalDescription
   // and SetRemoteDescription.
   enum Action {
     kOffer,
     kPrAnswer,
     kAnswer,
   };
 
+  // Non-const versions of local_description()/remote_description(), for use
+  // internally.
+  SessionDescriptionInterface* mutable_local_description() {
+    return pending_local_description_ ? pending_local_description_.get()
+                                      : current_local_description_.get();
+  }
+  SessionDescriptionInterface* mutable_remote_description() {
+    return pending_remote_description_ ? pending_remote_description_.get()
+                                       : current_remote_description_.get();
+  }
+
   // Log session state.
   void LogState(State old_state, State new_state);
 
   // Updates the state, signaling if necessary.
   virtual void SetState(State state);
 
   // Updates the error state, signaling if necessary.
   // TODO(ronghuawu): remove the SetError method that doesn't take |error_desc|.
   virtual void SetError(Error error, const std::string& error_desc);
 
@@ skipping 145 matching lines @@
 
   const std::unique_ptr<cricket::TransportController> transport_controller_;
   MediaControllerInterface* media_controller_;
   std::unique_ptr<cricket::VoiceChannel> voice_channel_;
   std::unique_ptr<cricket::VideoChannel> video_channel_;
   std::unique_ptr<cricket::DataChannel> data_channel_;
   cricket::ChannelManager* channel_manager_;
   IceObserver* ice_observer_;
   PeerConnectionInterface::IceConnectionState ice_connection_state_;
   bool ice_connection_receiving_;
-  std::unique_ptr<SessionDescriptionInterface> local_desc_;
-  std::unique_ptr<SessionDescriptionInterface> remote_desc_;
+  std::unique_ptr<SessionDescriptionInterface> current_local_description_;
+  std::unique_ptr<SessionDescriptionInterface> pending_local_description_;
+  std::unique_ptr<SessionDescriptionInterface> current_remote_description_;
+  std::unique_ptr<SessionDescriptionInterface> pending_remote_description_;
   // If the remote peer is using a older version of implementation.
   bool older_version_remote_peer_;
   bool dtls_enabled_;
   // Specifies which kind of data channel is allowed. This is controlled
   // by the chrome command-line flag and constraints:
   // 1. If chrome command-line switch 'enable-sctp-data-channels' is enabled,
   // constraint kEnableDtlsSrtp is true, and constaint kEnableRtpDataChannels is
   // not set or false, SCTP is allowed (DCT_SCTP);
   // 2. If constraint kEnableRtpDataChannels is true, RTP is allowed (DCT_RTP);
   // 3. If both 1&2 are false, data channel is not allowed (DCT_NONE).
@@ skipping 21 matching lines @@
 
 #ifdef HAVE_QUIC
   std::unique_ptr<QuicDataTransport> quic_data_transport_;
 #endif  // HAVE_QUIC
 
   RTC_DISALLOW_COPY_AND_ASSIGN(WebRtcSession);
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_WEBRTCSESSION_H_