WebRTCTransportConfig Breakout, only call session.onClosed once (#283)

* Split out function to create a WebRTCTransportConfig so external projects can replicate sfu.SFU{} functionality easily

* Use interface transportProvider for sfu.Peer{}

* Only call sesson.OnClosed once

pkg/peer.go

@@ -18,11 +18,17 @@ var (
 	ErrOfferIgnored = errors.New("offered ignored")
 )
 
+// TransportProvider provides the peerConnection to the sfu.Peer{}
+// This allows the sfu.SFU{} implementation to be customized / wrapped by another package
+type TransportProvider interface {
+	NewWebRTCTransport(sid string, me MediaEngine) (*WebRTCTransport, error)
+}
+
 // Peer represents a single peer signal session
 type Peer struct {
 	sync.Mutex
-	sfu *SFU
-	pc  *WebRTCTransport
+	provider TransportProvider
+	pc       *WebRTCTransport
 
 	OnIceCandidate func(*webrtc.ICECandidateInit)
 	OnOffer        func(*webrtc.SessionDescription)
@@ -32,9 +38,9 @@ type Peer struct {
 }
 
 // NewPeer creates a new Peer for signaling with the given SFU
-func NewPeer(sfu *SFU) Peer {
+func NewPeer(provider TransportProvider) Peer {
 	return Peer{
-		sfu: sfu,
+		provider: provider,
 	}
 }
 
@@ -53,7 +59,7 @@ func (p *Peer) Join(sid string, sdp webrtc.SessionDescription) (*webrtc.SessionD
 		return nil, fmt.Errorf("error parsing sdp: %v", err)
 	}
 
-	pc, err := p.sfu.NewWebRTCTransport(sid, me)
+	pc, err := p.provider.NewWebRTCTransport(sid, me)
 	if err != nil {
 		return nil, fmt.Errorf("error creating transport: %v", err)
 	}

pkg/session.go

@@ -13,13 +13,15 @@ type Session struct {
 	mu             sync.RWMutex
 	transports     map[string]Transport
 	onCloseHandler func()
+	closed         bool
 }
 
 // NewSession creates a new session
 func NewSession(id string) *Session {
 	return &Session{
 		id:         id,
 		transports: make(map[string]Transport),
+		closed:     false,
 	}
 }
 
@@ -39,8 +41,9 @@ func (s *Session) RemoveTransport(tid string) {
 	delete(s.transports, tid)
 
 	// Close session if no transports
-	if len(s.transports) == 0 && s.onCloseHandler != nil {
+	if len(s.transports) == 0 && s.onCloseHandler != nil && !s.closed {
 		s.onCloseHandler()
+		s.closed = true
 	}
 }
 

pkg/sfu.go

@@ -51,12 +51,8 @@ type SFU struct {
 	sessions map[string]*Session
 }
 
-// NewSFU creates a new sfu instance
-func NewSFU(c Config) *SFU {
-	// Init random seed
-	rand.Seed(time.Now().UnixNano())
-	// Init ballast
-	ballast := make([]byte, c.SFU.Ballast*1024*1024)
+// NewWebRTCTransportConfig parses our settings and returns a usable WebRTCTransportConfig for creating PeerConnections
+func NewWebRTCTransportConfig(c Config) WebRTCTransportConfig {
 	se := webrtc.SettingEngine{}
 
 	// Configure required extensions
@@ -138,6 +134,18 @@ func NewSFU(c Config) *SFU {
 		w.setting.SetNAT1To1IPs(c.WebRTC.Candidates.NAT1To1IPs, webrtc.ICECandidateTypeHost)
 	}
 
+	return w
+}
+
+// NewSFU creates a new sfu instance
+func NewSFU(c Config) *SFU {
+	// Init random seed
+	rand.Seed(time.Now().UnixNano())
+	// Init ballast
+	ballast := make([]byte, c.SFU.Ballast*1024*1024)
+
+	w := NewWebRTCTransportConfig(c)
+
 	s := &SFU{
 		webrtc:   w,
 		sessions: make(map[string]*Session),