libnmdc: support hub-redirects

.hgtags

@@ -4,3 +4,4 @@
 d8b64d5527c2a5e4d76872e5bc3d69f7646135c6 libnmdc-r3
 fca41372e400853775b02e951f9db91d87f41adb nmdc-log-service-1.0.1
 050b424a7c5d5a27c9323c8810f3afbead1f5b96 libnmdc-r4
+da9f123633f9c28be6435ed7898139665d4c39d9 nmdc-log-service-1.0.2

src/libnmdc/libnmdc.go

@@ -15,6 +15,7 @@ import (
 const (
 	DEFAULT_CLIENT_TAG   string        = "libnmdc.go"
 	DEFAULT_HUB_NAME     string        = "(unknown)"
+	SEND_KEEPALIVE_EVERY time.Duration = 29 * time.Second
 )
 
 type ConnectionState int
@@ -314,15 +315,13 @@ func (this *HubConnection) processProtocolMessage(message string) {
 			this.State = CONNECTIONSTATE_CONNECTED
 		}
 
-	case "$UserCommand":
-		// $UserCommand 1 1 Group chat\New group chat$<%[mynick]> !groupchat_new&#124;|
-		// TODO
-
 	case "$ForceMove":
-		// TODO
+		this.Hco.Address = HubAddress(commandParts[1])
+		this.conn.Close() // we'll reconnect onto the new address
 
 	// IGNORABLE COMMANDS
 	case "$Supports":
+	case "$UserCommand": // TODO $UserCommand 1 1 Group chat\New group chat$<%[mynick]> !groupchat_new&#124;|
 	case "$UserList":
 	case "$OpList":
 	case "$HubTopic":
@@ -370,7 +369,17 @@ func (this *HubConnection) worker() {
 		// Read from socket into our local buffer (blocking)
 		if this.connValid {
 			readBuff := make([]byte, 1024)
+			this.conn.SetReadDeadline(time.Now().Add(SEND_KEEPALIVE_EVERY))
 			nbytes, err = this.conn.Read(readBuff)
+
+			if err != nil && err.(net.Error).Timeout() {
+				// No data before read deadline
+				err = nil
+
+				// Send KA packet
+				_, err = this.conn.Write([]byte("|"))
+			}
+
 			if nbytes > 0 {
 				fullBuffer += string(readBuff[0:nbytes])
 			}