track numParticipants in room (#199)

* track numParticipants in room

* only track participant if not a hidden participant

* adjust coding style to use ++

* fix typo

* fix missing nil check

* update roomstore with new numParticipants on participantChanged

* only update roomstore if participant is not hidden

* call StoreRoom directly after StoreParticipant when joining/leaving

pkg/rtc/room.go

@@ -161,6 +161,9 @@ func (r *Room) Join(participant types.Participant, opts *ParticipantOptions, ice
 	if r.FirstJoinedAt() == 0 {
 		r.joinedAt.Store(time.Now().Unix())
 	}
+	if !participant.Hidden() {
+		r.Room.NumParticipants++
+	}
 
 	// it's important to set this before connection, we don't want to miss out on any publishedTracks
 	participant.OnTrackPublished(r.onTrackPublished)
@@ -256,7 +259,11 @@ func (r *Room) RemoveParticipant(identity string) {
 	if ok {
 		delete(r.participants, identity)
 		delete(r.participantOpts, identity)
+		if !p.Hidden() {
+			r.Room.NumParticipants--
+		}
 	}
+
 	r.lock.Unlock()
 	if !ok {
 		return

pkg/service/roommanager.go

@@ -260,12 +260,26 @@ func (r *RoomManager) StartSession(ctx context.Context, roomName string, pi rout
 	if err = r.roomStore.StoreParticipant(ctx, roomName, participant.ToProto()); err != nil {
 		logger.Errorw("could not store participant", err)
 	}
+	// update roomstore with new numParticipants
+	if !participant.Hidden() {
+		err = r.roomStore.StoreRoom(ctx, room.Room)
+		if err != nil {
+			logger.Errorw("could not store room", err)
+		}
+	}
 
 	r.telemetry.ParticipantJoined(ctx, room.Room, participant.ToProto())
 	participant.OnClose(func(p types.Participant) {
 		if err := r.roomStore.DeleteParticipant(ctx, roomName, p.Identity()); err != nil {
 			logger.Errorw("could not delete participant", err)
 		}
+		// update roomstore with new numParticipants
+		if !participant.Hidden() {
+			err = r.roomStore.StoreRoom(ctx, room.Room)
+			if err != nil {
+				logger.Errorw("could not store room", err)
+			}
+		}
 		r.telemetry.ParticipantLeft(ctx, room.Room, p.ToProto())
 	})