func main() {
flag.Parse()
log.SetFlags(0)
interrupt := make(chan os.Signal, 1)
signal.Notify(interrupt, os.Interrupt)
u := url.URL{Scheme: "ws", Host: *addr, Path: "/echo"}
log.Printf("connecting to %s", u.String())
c, _, err := websocket.DefaultDialer.Dial(u.String(), nil)
if err != nil {
log.Fatal("dial:", err)
}
defer c.Close()
done := make(chan struct{})
go func() {
defer c.Close()
defer close(done)
for {
_, message, err := c.ReadMessage()
if err != nil {
log.Println("read:", err)
return
}
log.Printf("recv: %s", message)
}
}()
ticker := time.NewTicker(time.Second)
defer ticker.Stop()
for {
select {
case t := <-ticker.C:
err := c.WriteMessage(websocket.TextMessage, []byte(t.String()))
if err != nil {
log.Println("write:", err)
return
}
case <-interrupt:
log.Println("interrupt")
// To cleanly close a connection, a client should send a close
// frame and wait for the server to close the connection.
err := c.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
if err != nil {
log.Println("write close:", err)
return
}
select {
case <-done:
case <-time.After(time.Second):
}
c.Close()
return
}
}
}
// echoCopy echoes messages from the client using io.Copy.
func echoCopy(w http.ResponseWriter, r *http.Request, writerOnly bool) {
conn, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Println("Upgrade:", err)
return
}
defer conn.Close()
for {
mt, r, err := conn.NextReader()
if err != nil {
if err != io.EOF {
log.Println("NextReader:", err)
}
return
}
if mt == websocket.TextMessage {
r = &validator{r: r}
}
w, err := conn.NextWriter(mt)
if err != nil {
log.Println("NextWriter:", err)
return
}
if mt == websocket.TextMessage {
r = &validator{r: r}
}
if writerOnly {
_, err = io.Copy(struct{ io.Writer }{w}, r)
} else {
_, err = io.Copy(w, r)
}
if err != nil {
if err == errInvalidUTF8 {
conn.WriteControl(websocket.CloseMessage,
websocket.FormatCloseMessage(websocket.CloseInvalidFramePayloadData, ""),
time.Time{})
}
log.Println("Copy:", err)
return
}
err = w.Close()
if err != nil {
log.Println("Close:", err)
return
}
}
}
// echoReadAll echoes messages from the client by reading the entire message
// with ioutil.ReadAll.
func echoReadAll(w http.ResponseWriter, r *http.Request, writeMessage bool) {
conn, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Println("Upgrade:", err)
return
}
defer conn.Close()
for {
mt, b, err := conn.ReadMessage()
if err != nil {
if err != io.EOF {
log.Println("NextReader:", err)
}
return
}
if mt == websocket.TextMessage {
if !utf8.Valid(b) {
conn.WriteControl(websocket.CloseMessage,
websocket.FormatCloseMessage(websocket.CloseInvalidFramePayloadData, ""),
time.Time{})
log.Println("ReadAll: invalid utf8")
}
}
if writeMessage {
err = conn.WriteMessage(mt, b)
if err != nil {
log.Println("WriteMessage:", err)
}
} else {
w, err := conn.NextWriter(mt)
if err != nil {
log.Println("NextWriter:", err)
return
}
if _, err := w.Write(b); err != nil {
log.Println("Writer:", err)
return
}
if err := w.Close(); err != nil {
log.Println("Close:", err)
return
}
}
}
}