/
clienthandler.go
90 lines (76 loc) · 2.06 KB
/
clienthandler.go
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package websocket
import (
"log"
"net/http"
"time"
"github.com/gorilla/websocket"
)
const (
// Time allowed to write a message to the peer.
writeWait = 10 * time.Second
// Time allowed to read the next pong message from the peer.
pongWait = 60 * time.Second
// Send pings to peer with this period. Must be less than pongWait.
pingPeriod = (pongWait * 9) / 10
)
var upgrader = websocket.Upgrader{
ReadBufferSize: 1024,
WriteBufferSize: 1024,
}
// ClientHandler is a middleman between the websocket connection and the hub.
type ClientHandler struct {
hub *Hub
// The websocket connection.
conn *websocket.Conn
// Buffered channel of outbound messages.
send chan []byte
}
// writePump pumps messages from the hub to the websocket connection.
//
// A goroutine running writePump is started for each connection. The
// application ensures that there is at most one writer to a connection by
// executing all writes from this goroutine.
func (c *ClientHandler) writePump() {
ticker := time.NewTicker(pingPeriod)
defer func() {
ticker.Stop()
c.conn.Close()
}()
for {
select {
case message, ok := <-c.send:
_ = c.conn.SetWriteDeadline(time.Now().Add(writeWait))
if !ok {
// The hub closed the channel.
_ = c.conn.WriteMessage(websocket.CloseMessage, []byte{})
return
}
w, err := c.conn.NextWriter(websocket.TextMessage)
if err != nil {
return
}
_, _ = w.Write(message)
if err := w.Close(); err != nil {
return
}
case <-ticker.C:
_ = c.conn.SetWriteDeadline(time.Now().Add(writeWait))
if err := c.conn.WriteMessage(websocket.PingMessage, nil); err != nil {
return
}
}
}
}
// ServeWs handles websocket requests from the peer.
func (h *Hub) ServeHTTP(w http.ResponseWriter, r *http.Request) {
conn, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Println(err)
return
}
client := &ClientHandler{hub: h, conn: conn, send: make(chan []byte, 256)}
client.hub.register <- client
// Allow collection of memory referenced by the caller by doing all work in
// new goroutines.
go client.writePump()
}