106 lines
2.5 KiB
Go
106 lines
2.5 KiB
Go
// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import (
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"github.com/gorilla/websocket"
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"log"
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"net/http"
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"time"
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)
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const (
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// Time allowed to write a message to the peer.
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writeWait = 10 * time.Second
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// Time allowed to read the next pong message from the peer.
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pongWait = 60 * time.Second
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// Send pings to peer with this period. Must be less than pongWait.
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pingPeriod = (pongWait * 9) / 10
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// Maximum message size allowed from peer.
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maxMessageSize = 512
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)
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var upgrader = websocket.Upgrader{
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ReadBufferSize: 1024,
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WriteBufferSize: 1024,
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}
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// connection is an middleman between the websocket connection and the hub.
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type connection struct {
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// The websocket connection.
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ws *websocket.Conn
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// Buffered channel of outbound messages.
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send chan []byte
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}
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// readPump pumps messages from the websocket connection to the hub.
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func (c *connection) readPump() {
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defer func() {
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h.unregister <- c
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c.ws.Close()
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}()
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c.ws.SetReadLimit(maxMessageSize)
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c.ws.SetReadDeadline(time.Now().Add(pongWait))
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c.ws.SetPongHandler(func(string) error { c.ws.SetReadDeadline(time.Now().Add(pongWait)); return nil })
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for {
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_, message, err := c.ws.ReadMessage()
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if err != nil {
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if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway) {
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log.Printf("error: %v", err)
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}
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break
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}
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h.broadcast <- message
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}
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}
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// write writes a message with the given message type and payload.
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func (c *connection) write(mt int, payload []byte) error {
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c.ws.SetWriteDeadline(time.Now().Add(writeWait))
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return c.ws.WriteMessage(mt, payload)
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}
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// writePump pumps messages from the hub to the websocket connection.
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func (c *connection) writePump() {
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ticker := time.NewTicker(pingPeriod)
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defer func() {
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ticker.Stop()
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c.ws.Close()
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}()
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for {
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select {
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case message, ok := <-c.send:
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if !ok {
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c.write(websocket.CloseMessage, []byte{})
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return
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}
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if err := c.write(websocket.TextMessage, message); err != nil {
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return
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}
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case <-ticker.C:
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if err := c.write(websocket.PingMessage, []byte{}); err != nil {
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return
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}
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}
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}
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}
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// serveWs handles websocket requests from the peer.
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func serveWs(w http.ResponseWriter, r *http.Request) {
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ws, err := upgrader.Upgrade(w, r, nil)
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if err != nil {
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log.Println(err)
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return
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}
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c := &connection{send: make(chan []byte, 256), ws: ws}
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h.register <- c
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go c.writePump()
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c.readPump()
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}
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