Implement dynamic tracks addition with renegotiation (#105, #27)

- support adding new endpoints to the already interconnected Members
- implement PeerConnection renegotiation
- add TracksApplied event

CHANGELOG.md

@@ -37,7 +37,8 @@ All user visible changes to this project will be documented in this file. This p
     - Send reason of closing WebSocket connection as [Close](https://tools.ietf.org/html/rfc4566#section-5.14) frame's description ([#58]);
     - Send `Event::RpcSettingsUpdated` when `Member` connects ([#75]);
     - Send relay mode in `Event::PeerCreated` which is used for configuring client's `RtcIceTransportPolicy` ([#79]);
-    - Send `Command::UpdateTracks` on `Event::TracksUpdated` ([#81]).
+    - Emit `TracksApplied` event to create new and update existing tracks ([#105]);
+    - `PeerConnection` renegotiation functionality ([#105]).
 - [Coturn] integration:
     - [Coturn] sessions destroying ([#84]);
     - [Coturn] stats processing ([#94]).
@@ -55,7 +56,8 @@ All user visible changes to this project will be documented in this file. This p
 ### Fixed
 
 - Signalling:
-    - Room crashing when handling commands with non-existent `peer_id` ([#86]).
+    - Room crashing when handling commands with non-existent `peer_id` ([#86]);
+    - Adding new endpoints to the already interconnected `Member`s ([#105]).
 
 [#28]: /../../pull/28
 [#33]: /../../pull/33
@@ -70,6 +72,7 @@ All user visible changes to this project will be documented in this file. This p
 [#94]: /../../pull/94
 [#95]: /../../pull/95
 [#98]: /../../pull/98
+[#105]: /../../pull/105
 
 
 

docs/rfc/0002-webrc-client-api.md → docs/rfc/0002-webrtc-client-api.md

@@ -703,19 +703,6 @@ It's recommended to cache `Peer` ID and `Member` ID relations in `Web Client`'s
 ```
 </details>
 
-#### 10. TracksUpdated
-
-`Media Server` notifies about necessity to update `Track`s in specified `Peer`.
-
-Can be used to update existing `Track` settings (e.g. change to lower video resolution, mute audio).
-
-```rust
-struct TracksUpdated {
-    peer_id: PeerId,
-    tracks_patches: Vec<TrackPatch>,
-}
-```
-
 
 ### Commands
 
@@ -1102,7 +1089,7 @@ Metrics list will be extended as needed.
 
 #### 10. UpdateTracks
 
-`Web Client` asks permission to update `Track`s in specified `Peer`. `Media Server` gives permission by sending `Event::TracksUpdated`.
+`Web Client` asks permission to update `Track`s in specified `Peer`. `Media Server` gives permission by sending `Event::TracksApplied`.
 
 ```rust
 struct UpdateTracks {

jason/CHANGELOG.md

@@ -57,7 +57,9 @@ All user visible changes to this project will be documented in this file. This p
     - Emitting of RPC commands:
         - `AddPeerConnectionMetrics` with `IceConnectionState` and `PeerConnectionState` ([#71], [#87]);
         - `ApplyTracks` for muting/unmuting ([#81]);
-        - `AddPeerConnectionStats` with `RtcStats` ([#90]).
+        - `AddPeerConnectionStats` with `RtcStats` ([#90]);
+    - Handling of RPC events:
+        - `TracksApplied` ([#105]).
 - Error handling:
     - Library API:
         - `JasonError` as library error with trace information and underlying JS error if it is the cause ([#55])
@@ -80,6 +82,7 @@ All user visible changes to this project will be documented in this file. This p
 [#87]: /../../pull/87
 [#90]: /../../pull/90
 [#97]: /../../pull/97
+[#105]: /../../pull/105
 [#106]: /../../pull/106
 
 

jason/src/api/room.rs

@@ -15,8 +15,8 @@ use futures::{
 use js_sys::Promise;
 use medea_client_api_proto::{
     Command, Direction, Event as RpcEvent, EventHandler, IceCandidate,
-    IceConnectionState, IceServer, PeerConnectionState, PeerId, PeerMetrics,
-    Track, TrackId, TrackPatch,
+    IceConnectionState, IceServer, NegotiationRole, PeerConnectionState,
+    PeerId, PeerMetrics, Track, TrackId, TrackPatch, TrackUpdate,
 };
 use tracerr::Traced;
 use wasm_bindgen::{prelude::*, JsValue};
@@ -780,7 +780,7 @@ impl EventHandler for InnerRoom {
     fn on_peer_created(
         &mut self,
         peer_id: PeerId,
-        sdp_offer: Option<String>,
+        negotiation_role: NegotiationRole,
         tracks: Vec<Track>,
         ice_servers: Vec<IceServer>,
         is_force_relayed: bool,
@@ -804,13 +804,16 @@ impl EventHandler for InnerRoom {
 
         self.create_connections_from_tracks(&tracks);
 
+        // TODO(alexlapa): Eliminate code duplication (on_tracks_applied).
+        //                 Doing Room refactoring in another PR, it`ll allow
+        //                 to fix this smoothly.
         let local_stream_constraints = self.local_stream_settings.clone();
         let rpc = Rc::clone(&self.rpc);
         let error_callback = Rc::clone(&self.on_failed_local_stream);
         spawn_local(
             async move {
-                match sdp_offer {
-                    None => {
+                match negotiation_role {
+                    NegotiationRole::Offerer => {
                         let sdp_offer = peer
                             .get_offer(tracks, local_stream_constraints)
                             .await
@@ -826,7 +829,7 @@ impl EventHandler for InnerRoom {
                             mids,
                         });
                     }
-                    Some(offer) => {
+                    NegotiationRole::Answerer(offer) => {
                         let sdp_answer = peer
                             .process_offer(
                                 offer,
@@ -916,16 +919,107 @@ impl EventHandler for InnerRoom {
         });
     }
 
-    /// Updates [`Track`]s of this [`Room`].
-    fn on_tracks_updated(&mut self, peer_id: PeerId, tracks: Vec<TrackPatch>) {
-        if let Some(peer) = self.peers.get(peer_id) {
-            if let Err(err) = peer.update_senders(tracks) {
-                JasonError::from(err).print();
-            }
+    /// Creates new `Track`s, updates existing [`Sender`]s/[`Receiver`]s with
+    /// [`TrackUpdate`]s.
+    ///
+    /// Will start renegotiation process if `Some` [`NegotiationRole`] is
+    /// provided.
+    fn on_tracks_applied(
+        &mut self,
+        peer_id: PeerId,
+        updates: Vec<TrackUpdate>,
+        negotiation_role: Option<NegotiationRole>,
+    ) {
+        let peer = if let Some(peer) = self.peers.get(peer_id) {
+            peer
         } else {
             JasonError::from(tracerr::new!(RoomError::NoSuchPeer(peer_id)))
                 .print();
+            return;
+        };
+
+        let mut new_tracks = Vec::new();
+        let mut patches = Vec::new();
+
+        for update in updates {
+            match update {
+                TrackUpdate::Added(track) => {
+                    new_tracks.push(track);
+                }
+                TrackUpdate::Updated(track_patch) => {
+                    patches.push(track_patch);
+                }
+            }
         }
+        if let Err(err) = peer.update_senders(patches) {
+            JasonError::from(err).print();
+            return;
+        }
+
+        // TODO(alexlapa): Eliminate code duplication (on_peer_created).
+        //                 Doing Room refactoring in another PR, it`ll allow
+        //                 to fix this smoothly.
+        let local_stream_constraints = self.local_stream_settings.clone();
+        let rpc = Rc::clone(&self.rpc);
+        let error_callback = Rc::clone(&self.on_failed_local_stream);
+        spawn_local(
+            async move {
+                match negotiation_role {
+                    None => {
+                        peer.create_tracks(new_tracks)
+                            .await
+                            .map_err(tracerr::map_from_and_wrap!())?;
+                    }
+                    Some(NegotiationRole::Offerer) => {
+                        let sdp_offer = peer
+                            .get_offer(new_tracks, local_stream_constraints)
+                            .await
+                            .map_err(tracerr::map_from_and_wrap!())?;
+                        let mids = peer
+                            .get_mids()
+                            .map_err(tracerr::map_from_and_wrap!())?;
+                        let senders_statuses = peer.get_senders_statuses();
+                        rpc.send_command(Command::MakeSdpOffer {
+                            peer_id,
+                            sdp_offer,
+                            senders_statuses,
+                            mids,
+                        });
+                    }
+                    Some(NegotiationRole::Answerer(offer)) => {
+                        let sdp_answer = peer
+                            .process_offer(
+                                offer,
+                                new_tracks,
+                                local_stream_constraints,
+                            )
+                            .await
+                            .map_err(tracerr::map_from_and_wrap!())?;
+                        let senders_statuses = peer.get_senders_statuses();
+                        rpc.send_command(Command::MakeSdpAnswer {
+                            peer_id,
+                            sdp_answer,
+                            senders_statuses,
+                        });
+                    }
+                };
+                Result::<_, Traced<RoomError>>::Ok(())
+            }
+            .then(|result| async move {
+                if let Err(err) = result {
+                    let (err, trace) = err.into_parts();
+                    match err {
+                        RoomError::InvalidLocalStream(_)
+                        | RoomError::CouldNotGetLocalMedia(_) => {
+                            let e = JasonError::from((err, trace));
+                            e.print();
+                            error_callback.call(e);
+                        }
+                        _ => JasonError::from((err, trace)).print(),
+                    };
+                };
+            }),
+        )
     }
 }
 

jason/src/peer/media/mod.rs

@@ -243,18 +243,14 @@ impl MediaConnections {
         out
     }
 
-    /// Synchronizes local state with provided tracks. Creates new [`Sender`]s
-    /// and [`Receiver`]s for each new [`Track`], and updates [`Track`] if
-    /// its settings has been changed.
+    /// Creates new [`Sender`]s and [`Receiver`]s for each new [`Track`].
     ///
     /// # Errors
     ///
     /// With [`MediaConnectionsError::TransceiverNotFound`] if could not create
     /// new [`Sender`] cause transceiver with specified `mid` does not
     /// exist.
-    // TODO: Doesnt really updates anything, but only generates new senders
-    //       and receivers atm.
-    pub fn update_tracks<I: IntoIterator<Item = Track>>(
+    pub fn create_tracks<I: IntoIterator<Item = Track>>(
         &self,
         tracks: I,
     ) -> Result<()> {

jason/src/peer/mod.rs

@@ -576,7 +576,7 @@ impl PeerConnection {
         local_stream: Option<MediaStreamSettings>,
     ) -> Result<String> {
         self.media_connections
-            .update_tracks(tracks)
+            .create_tracks(tracks)
             .map_err(tracerr::map_from_and_wrap!())?;
 
         self.update_local_stream(local_stream)
@@ -588,10 +588,22 @@ impl PeerConnection {
             .create_and_set_offer()
             .await
             .map_err(tracerr::map_from_and_wrap!())?;
-
         Ok(offer)
     }
 
+    /// Creates new [`Sender`]s and [`Receiver`]s for each new [`Track`].
+    ///
+    /// # Errors
+    ///
+    /// With [`MediaConnectionsError::TransceiverNotFound`] if could not create
+    /// new [`Sender`] because transceiver with specified `mid` doesn't exist.
+    pub async fn create_tracks(&self, tracks: Vec<Track>) -> Result<()> {
+        self.media_connections
+            .create_tracks(tracks)
+            .map_err(tracerr::map_from_and_wrap!())?;
+        Ok(())
+    }
+
     /// Inserts provided [MediaStream][1] into underlying [RTCPeerConnection][2]
     /// if it has all required tracks.
     /// Requests local stream from [`MediaManager`] if no stream was provided.
@@ -775,17 +787,20 @@ impl PeerConnection {
                 Direction::Recv { .. } => true,
             });
 
-        // update receivers
+        // create receivers
         self.media_connections
-            .update_tracks(recv)
+            .create_tracks(recv)
             .map_err(tracerr::map_from_and_wrap!())?;
 
+        // set offer, which will create transceivers and discover remote tracks
+        // in receivers
         self.set_remote_offer(offer)
             .await
             .map_err(tracerr::wrap!())?;
 
+        // create senders
         self.media_connections
-            .update_tracks(send)
+            .create_tracks(send)
             .map_err(tracerr::map_from_and_wrap!())?;
 
         self.update_local_stream(local_constraints)