gateway, voice, & logging improvements

We now store teh sessionID of the gateway connection for later use. We
are now caching the gateway url and will use it until unable to connect
to that gateway.  We're not longer smashing the VoiceConnections map
during reconnects which was causing Voice problems. Slight change to
log output format.

discord.go

@@ -237,5 +237,9 @@ func (s *Session) initialize() {
 // onReady handles the ready event.
 func (s *Session) onReady(se *Session, r *Ready) {
 
+	// Store the SessionID within the Session struct.
+	s.sessionID = r.SessionID
+
+	// Start the heartbeat to keep the connection alive.
 	go s.heartbeat(s.wsConn, s.listening, r.HeartbeatInterval)
 }

logging.go

@@ -57,7 +57,7 @@ func msglog(msgL, caller int, format string, a ...interface{}) {
 
 	msg := fmt.Sprintf(format, a...)
 
-	log.Printf("[DG%d] %s:%d %s %s\n", msgL, file, line, name, msg)
+	log.Printf("[DG%d] %s:%d:%s() %s\n", msgL, file, line, name, msg)
 }
 
 // helper function that wraps msglog for the Session struct

structs.go

@@ -83,6 +83,12 @@ type Session struct {
 
 	// sequence tracks the current gateway api websocket sequence number
 	sequence int
+
+	// stores sessions current Discord Gateway
+	gateway string
+
+	// stores session ID of current Gateway connection
+	sessionID string
 }
 
 type rateLimitMutex struct {

wsapi.go

@@ -50,6 +50,9 @@ type handshakeOp struct {
 
 // Open opens a websocket connection to Discord.
 func (s *Session) Open() (err error) {
+
+	s.log(LogInformational, "called")
+
 	s.Lock()
 	defer func() {
 		if err != nil {
@@ -57,7 +60,10 @@ func (s *Session) Open() (err error) {
 		}
 	}()
 
-	s.VoiceConnections = make(map[string]*VoiceConnection)
+	if s.VoiceConnections == nil {
+		s.log(LogInformational, "creating new VoiceConnections map")
+		s.VoiceConnections = make(map[string]*VoiceConnection)
+	}
 
 	if s.wsConn != nil {
 		err = errors.New("Web socket already opened.")
@@ -65,27 +71,41 @@ func (s *Session) Open() (err error) {
 	}
 
 	// Get the gateway to use for the Websocket connection
-	g, err := s.Gateway()
-	if err != nil {
-		return
-	}
+	if s.gateway == "" {
+		s.gateway, err = s.Gateway()
+		if err != nil {
+			return
+		}
 
-	// Add the version and encoding to the URL
-	g = g + fmt.Sprintf("?v=%v&encoding=json", GATEWAY_VERSION)
+		// Add the version and encoding to the URL
+		s.gateway = fmt.Sprintf("%s?v=%v&encoding=json", s.gateway, GATEWAY_VERSION)
+	}
 
 	header := http.Header{}
 	header.Add("accept-encoding", "zlib")
 
-	// TODO: See if there's a use for the http response.
-	// conn, response, err := websocket.DefaultDialer.Dial(session.Gateway, nil)
-	s.wsConn, _, err = websocket.DefaultDialer.Dial(g, header)
+	s.log(LogInformational, "connecting to gateway %s", s.gateway)
+	s.wsConn, _, err = websocket.DefaultDialer.Dial(s.gateway, header)
 	if err != nil {
+		s.log(LogWarning, "error connecting to gateway %s, %s", s.gateway, err)
+		s.gateway = "" // clear cached gateway
+		// TODO: should we add a retry block here?
 		return
 	}
 
-	err = s.wsConn.WriteJSON(handshakeOp{2, handshakeData{s.Token, handshakeProperties{runtime.GOOS, "Discordgo v" + VERSION, "", "", ""}, 250, s.Compress}})
-	if err != nil {
-		return
+	if s.sessionID != "" && s.sequence > 0 {
+
+		s.log(LogInformational, "sending resume packet to gateway")
+		// TODO: RESUME
+
+	} else {
+
+		s.log(LogInformational, "sending identify packet to gateway")
+		err = s.wsConn.WriteJSON(handshakeOp{2, handshakeData{s.Token, handshakeProperties{runtime.GOOS, "Discordgo v" + VERSION, "", "", ""}, 250, s.Compress}})
+		if err != nil {
+			s.log(LogWarning, "error sending gateway identify packet, %s, %s", s.gateway, err)
+			return
+		}
 	}
 
 	// Create listening outside of listen, as it needs to happen inside the mutex
@@ -292,12 +312,14 @@ func (s *Session) onEvent(messageType int, message []byte) {
 	}
 
 	if s.Debug {
-		s.log(LogDebug, "Op: %d, Seq: %d, Type: %s, Data: %s\n", e.Operation, e.Sequence, e.Type, string(e.RawData))
+		s.log(LogDebug, "Op: %d, Seq: %d, Type: %s, Data: %s", e.Operation, e.Sequence, e.Type, string(e.RawData))
 	}
 
 	// Do not try to Dispatch a non-Dispatch Message
 	if e.Operation != 0 {
 		// But we probably should be doing something with them.
+		// TEMP
+		s.log(LogWarning, "Op: %d, Seq: %d, Type: %s, Data: %s", e.Operation, e.Sequence, e.Type, string(e.RawData))
 		return
 	}