Simplify TURN data retrieval API.

Receivers no longer must implement the rather large "Sender" interface and
a complete "Session" object also is no longer required to get TURN data.

go/channelling/api/handle_self.go

@@ -44,7 +44,7 @@ func (api *channellingAPI) HandleSelf(sender channelling.Sender, session *channe
 		Token:      token,
 		Version:    api.config.Version,
 		ApiVersion: apiVersion,
-		Turn:       api.TurnDataCreator.CreateTurnData(sender, session),
+		Turn:       api.TurnDataCreator.CreateTurnData(session.Id, sender),
 		Stun:       api.config.StunURIs,
 	}
 	api.BusManager.Trigger(channelling.BusManagerSession, session.Id, session.Userid(), nil, nil)

go/channelling/client.go

@@ -28,7 +28,8 @@ import (
 )
 
 type Sender interface {
-	Index() uint64
+	TurnDataReceiver
+
 	Send(buffercache.Buffer)
 	Outgoing(interface{})
 }
@@ -106,3 +107,10 @@ func (client *Client) ReplaceAndClose(oldClient *Client) {
 		oldClient.Close()
 	}()
 }
+
+func (client *Client) TurnDataAvailable(turn *DataTurn) {
+	client.Outgoing(&DataTurnUpdate{
+		Type: "TurnUpdate",
+		Turn: turn,
+	})
+}

go/channelling/hub.go

@@ -91,13 +91,13 @@ func (h *hub) ClientInfo(details bool) (clientCount int, sessions map[string]*Da
 	return
 }
 
-func (h *hub) CreateTurnData(sender Sender, session *Session) *DataTurn {
+func (h *hub) CreateTurnData(sessionId string, receiver TurnDataReceiver) *DataTurn {
 	if len(h.turnSecret) > 0 {
 		// Create turn data credentials for shared secret auth with TURN
 		// server. See http://tools.ietf.org/html/draft-uberti-behave-turn-rest-00
 		// and https://code.google.com/p/rfc5766-turn-server/ REST API auth
 		// and set shared secret in TURN server with static-auth-secret.
-		id := session.Id
+		id := sessionId
 		bar := sha256.New()
 		bar.Write([]byte(id))
 		id = base64.StdEncoding.EncodeToString(bar.Sum(nil))

go/channelling/pipeline.go

@@ -270,3 +270,10 @@ func (pipeline *Pipeline) attach(sink Sink) error {
 	pipeline.sink = sink
 	return nil
 }
+
+func (pipeline *Pipeline) TurnDataAvailable(turn *DataTurn) {
+	pipeline.Outgoing(&DataTurnUpdate{
+		Type: "TurnUpdate",
+		Turn: turn,
+	})
+}

go/channelling/turndata.go

@@ -21,6 +21,18 @@
 
 package channelling
 
+type TurnDataReceiver interface {
+	Index() uint64
+
+	TurnDataAvailable(*DataTurn)
+}
+
 type TurnDataCreator interface {
-	CreateTurnData(Sender, *Session) *DataTurn
+	/*
+		First parameter is the id of the session that requests the TURN data.
+		Second parameter will be notified when TURN data become available if none
+		were ready at the time the method was called (can be nil if no notification
+		is required).
+	*/
+	CreateTurnData(string, TurnDataReceiver) *DataTurn
 }

go/channelling/turnservice_manager.go

@@ -35,7 +35,7 @@ type TURNServiceManager interface {
 
 type turnServiceManager struct {
 	sync.Mutex
-	pleaders map[uint64]Sender // Mapping of clients waiting to receive TURN data.
+	pleaders map[uint64]TurnDataReceiver // Mapping of clients waiting to receive TURN data.
 
 	uri         string
 	accessToken string
@@ -51,7 +51,7 @@ func NewTURNServiceManager(uri string, accessToken string, clientID string) TURN
 		clientID:    clientID,
 
 		turnService: turnService,
-		pleaders:    make(map[uint64]Sender),
+		pleaders:    make(map[uint64]TurnDataReceiver),
 	}
 
 	turnService.Open(accessToken, clientID, "")
@@ -71,14 +71,16 @@ func NewTURNServiceManager(uri string, accessToken string, clientID string) TURN
 	return mgr
 }
 
-func (mgr *turnServiceManager) CreateTurnData(sender Sender, session *Session) *DataTurn {
+func (mgr *turnServiceManager) CreateTurnData(sessionId string, receiver TurnDataReceiver) *DataTurn {
 	credentials := mgr.turnService.Credentials(false)
 	turn, err := mgr.turnData(credentials)
 	if err != nil || turn.Ttl == 0 {
 		// When no data was return from service, refresh quickly.
-		mgr.Lock()
-		mgr.pleaders[sender.Index()] = sender
-		mgr.Unlock()
+		if receiver != nil {
+			mgr.Lock()
+			mgr.pleaders[receiver.Index()] = receiver
+			mgr.Unlock()
+		}
 
 		// Have client come back early.
 		turn.Ttl = 300
@@ -129,12 +131,9 @@ func (mgr *turnServiceManager) onCredentials(credentials *turnservicecli.CachedC
 	mgr.Lock()
 	for _, sender := range mgr.pleaders {
 		if turn, err := mgr.turnData(credentials); err == nil {
-			sender.Outgoing(&DataTurnUpdate{
-				Type: "TurnUpdate",
-				Turn: turn,
-			})
+			sender.TurnDataAvailable(turn)
 		}
 	}
-	mgr.pleaders = make(map[uint64]Sender) // Clear.
+	mgr.pleaders = make(map[uint64]TurnDataReceiver) // Clear.
 	mgr.Unlock()
 }