dcping: initial support for redirect; fixes #89

nmdc/conn.go

@@ -176,6 +176,10 @@ func (c *Conn) TextEncoder() *encoding.Encoder {
 	return c.w.Encoder()
 }
 
+func (c *Conn) TextDecoder() *encoding.Decoder {
+	return c.r.Decoder()
+}
+
 func (c *Conn) setEncoding(enc encoding.Encoding, event bool) {
 	if enc != nil {
 		e := enc.NewEncoder()

nmdc/ping.go

@@ -35,6 +35,7 @@ type HubInfo struct {
 	Users    []nmdc.MyINFO
 	Ops      []string
 	Bots     []string
+	Redirect string
 }
 
 func (h *HubInfo) decodeWith(enc encoding.Encoding) error {
@@ -244,6 +245,9 @@ func Ping(ctx context.Context, addr string, conf PingConfig) (_ *HubInfo, gerr e
 			if listStarted || listEnd {
 				return &hub, nil
 			}
+			if hub.Redirect != "" {
+				return &hub, nil
+			}
 			if lastMsg != "" {
 				err = fmt.Errorf("connection closed: %s", lastMsg)
 				if strings.Contains(lastMsg, "registered users only") {
@@ -354,7 +358,13 @@ func Ping(ctx context.Context, addr string, conf PingConfig) (_ *HubInfo, gerr e
 				return &hub, nil
 			}
 		case *nmdc.UserIP:
-			// TODO: some implementations seem to end the list with this message
+		// TODO: some implementations seem to end the list with this message
+		case *nmdc.RawMessage:
+			// TODO: change to ForceMove type, once supported
+			switch msg.Typ {
+			case "ForceMove":
+				hub.Redirect = string(msg.Data)
+			}
 		}
 	}
 }

ping.go

@@ -76,6 +76,7 @@ func Ping(ctx context.Context, addr string, conf *PingConfig) (*HubInfo, error)
 			},
 			Users:    len(hub.Users),
 			UserList: make([]HubUser, 0, len(hub.Users)),
+			Redirect: hub.Redirect,
 		}
 		if info.Desc == "" {
 			info.Desc = hub.Topic
@@ -175,6 +176,7 @@ type HubInfo struct {
 	Users    int       `json:"users" xml:"Users,attr"`
 	Files    uint64    `json:"files,omitempty" xml:"Files,attr,omitempty"`
 	Share    uint64    `json:"share,omitempty" xml:"Shared,attr,omitempty"`
+	Redirect string    `json:"redirect,omitempty" xml:"Redirect,attr,omitempty"`
 	UserList []HubUser `json:"userlist,omitempty" xml:"User,attr,omitempty"`
 }