main.go
// Copyright 2015 The Gorilla WebSocket Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build ignore
// +build ignore
package main
import (
"flag"
"log"
"net/url"
"os"
"os/signal"
"time"
"github.com/gorilla/websocket"
)
var addr = flag.String("addr", "localhost:8080", "http service address")
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 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 <-done:
return
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")
// Cleanly close the connection by sending a close message and then
// waiting (with timeout) for the server to close the connection.
// 通过发送关闭消息，然后等待（超时）服务器关闭连接，彻底关闭连接。
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):
}
return
}
}
}
hub.go
// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
// Hub maintains the set of active clients and broadcasts messages to the
// clients.
// Hub维护一组活动客户端并向客户端广播消息。
type Hub struct {
// Registered clients. 注册客户端。
clients map[*Client]bool
// Inbound messages from the clients. 来自客户端的入站消息。
broadcast chan []byte
// Register requests from the clients. 注册来自客户端的请求。
register chan *Client
// Unregister requests from clients. 注销客户端的请求。
unregister chan *Client
}
func newHub() *Hub {
return &Hub{
broadcast: make(chan []byte),
register: make(chan *Client),
unregister: make(chan *Client),
clients: make(map[*Client]bool),
}
}
func (h *Hub) run() {
for {
select {
case client := <-h.register:
h.clients[client] = true
case client := <-h.unregister:
if _, ok := h.clients[client]; ok {
delete(h.clients, client)
close(client.send)
}
case message := <-h.broadcast:
for client := range h.clients {
select {
case client.send <- message:
default:
close(client.send)
delete(h.clients, client)
}
}
}
}
}
client.go
// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"bytes"
"log"
"net/http"
"time"
"github.com/gorilla/websocket"
)
const (
// Time allowed to write a message to the peer.
// 允许向对等方写入消息的时间。
writeWait = 10 * time.Second
// Time allowed to read the next pong message from the peer.
// 允许从对等端读取下一条pong消息的时间。
pongWait = 60 * time.Second
// Send pings to peer with this period. Must be less than pongWait.
// 使用此周期向对等方发送ping。必须小于pongWait。
pingPeriod = (pongWait * 9) / 10
// Maximum message size allowed from peer.
// 对等端允许的最大消息大小。
maxMessageSize = 512
)
var (
newline = []byte{'\n'}
space = []byte{' '}
)
var upgrader = websocket.Upgrader{
ReadBufferSize: 1024,
WriteBufferSize: 1024,
}
// Client is a middleman between the websocket connection and the hub.
// 客户端是websocket连接和集线器之间的中间人。
type Client struct {
hub *Hub
// The websocket connection.
// 网络套接字连接。
conn *websocket.Conn
// Buffered channel of outbound messages.
// 出站消息的缓冲通道。
send chan []byte
}
// readPump pumps messages from the websocket connection to the hub.
// readPump将消息从websocket连接到hub。
// The application runs readPump in a per-connection goroutine. The application
// ensures that there is at most one reader on a connection by executing all
// reads from this goroutine.
// 应用程序在每个连接goroutine中运行readPump。应用程序通过执行该goroutine中的所有读取，确保连接上最多有一个读取器。
func (c *Client) readPump() {
defer func() {
c.hub.unregister <- c
c.conn.Close()
}()
c.conn.SetReadLimit(maxMessageSize)
c.conn.SetReadDeadline(time.Now().Add(pongWait))
c.conn.SetPongHandler(func(string) error { c.conn.SetReadDeadline(time.Now().Add(pongWait)); return nil })
for {
_, message, err := c.conn.ReadMessage()e
if err != nil {
if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
log.Printf("error: %v", err)
}
break
}
message = bytes.TrimSpace(bytes.Replace(message, newline, space, -1))
c.hub.broadcast <- message
}
}
// writePump pumps messages from the hub to the websocket connection.
// writePump将消息从hub到websocket连接。
// 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.
// 为每个连接启动一个运行writePump的goroutine。应用程序通过执行来自这个goroutine的所有写入，确保连接最多有一个写入程序。
func (c *Client) 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.
// hub关闭了channel。
c.conn.WriteMessage(websocket.CloseMessage, []byte{})
return
}
w, err := c.conn.NextWriter(websocket.TextMessage)
if err != nil {
return
}
w.Write(message)
// Add queued chat messages to the current websocket message.
// 将排队的聊天消息添加到当前的websocket消息中。
n := len(c.send)
for i := 0; i < n; i++ {
w.Write(newline)
w.Write(<-c.send)
}
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.
// serveW处理来自对等方的websocket请求。
func serveWs(hub *Hub, w http.ResponseWriter, r *http.Request) {
conn, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Println(err)
return
}
client := &Client{hub: hub, 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.
// 允许通过在新goroutines中执行所有工作来收集调用方引用的内存。
go client.writePump()
go client.readPump()
}
home.html
<!DOCTYPE html>
<html lang="en">
<head>
<title>Chat Example</title>
<script type="text/javascript">
window.onload = function () {
var conn;
var msg = document.getElementById("msg");
var log = document.getElementById("log");
function appendLog(item) {
var doScroll = log.scrollTop > log.scrollHeight - log.clientHeight - 1;
log.appendChild(item);
if (doScroll) {
log.scrollTop = log.scrollHeight - log.clientHeight;
}
}
document.getElementById("form").onsubmit = function () {
if (!conn) {
return false;
}
if (!msg.value) {
return false;
}
conn.send(msg.value);
msg.value = "";
return false;
};
if (window["WebSocket"]) {
conn = new WebSocket("ws://" + document.location.host + "/ws");
conn.onclose = function (evt) {
var item = document.createElement("div");
item.innerHTML = "<b>Connection closed.</b>";
appendLog(item);
};
conn.onmessage = function (evt) {
var messages = evt.data.split('\n');
for (var i = 0; i < messages.length; i++) {
var item = document.createElement("div");
item.innerText = messages[i];
appendLog(item);
}
};
} else {
var item = document.createElement("div");
item.innerHTML = "<b>Your browser does not support WebSockets.</b>";
appendLog(item);
}
};
</script>
<style type="text/css">
html {
overflow: hidden;
}
body {
overflow: hidden;
padding: 0;
margin: 0;
width: 100%;
height: 100%;
background: gray;
}
#log {
background: white;
margin: 0;
padding: 0.5em 0.5em 0.5em 0.5em;
position: absolute;
top: 0.5em;
left: 0.5em;
right: 0.5em;
bottom: 3em;
overflow: auto;
}
#form {
padding: 0 0.5em 0 0.5em;
margin: 0;
position: absolute;
bottom: 1em;
left: 0px;
width: 100%;
overflow: hidden;
}
</style>
</head>
<body>
<div id="log"></div>
<form id="form">
<input type="submit" value="Send" />
<input type="text" id="msg" size="64" autofocus />
</form>
</body>
</html>
运行：
go run *.go