andreapavoni/conn.go

## conn.go
package main

import (
	"code.google.com/p/go.net/websocket"
)

type connection struct {
	// The websocket connection.
	ws *websocket.Conn

	// Buffered channel of outbound messages.
	send chan string
}

func (c *connection) reader() {
	for {
		var message string
		err := websocket.Message.Receive(c.ws, &message)
		if err != nil {
			break
		}
		h.broadcast <- message
	}
	c.ws.Close()
}

func (c *connection) writer() {
	for message := range c.send {
		err := websocket.Message.Send(c.ws, message)
		if err != nil {
			break
		}
	}
	c.ws.Close()
}

func wsHandler(ws *websocket.Conn) {
	c := &connection{send: make(chan string, 256), ws: ws}
	h.register <- c
	defer func() { h.unregister <- c }()
	go c.writer()
	c.reader()
}

## home.html
<html>
<head>
<title>Chat Example</title>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript">
    $(function() {

    var conn;
    var msg = $("#msg");
    var log = $("#log");

    function appendLog(msg) {
        var d = log[0]
        var doScroll = d.scrollTop == d.scrollHeight - d.clientHeight;
        msg.appendTo(log)
        if (doScroll) {
            d.scrollTop = d.scrollHeight - d.clientHeight;
        }
    }

    $("#form").submit(function() {
        if (!conn) {
            return false;
        }
        if (!msg.val()) {
            return false;
        }
        conn.send(msg.val());
        msg.val("");
        return false
    });

    if (window["WebSocket"]) {
        conn = new WebSocket("ws://{{$}}/ws");
        conn.onclose = function(evt) {
            appendLog($("<div><b>Connection closed.</b></div>"))
        }
        conn.onmessage = function(evt) {
            appendLog($("<div/>").text(evt.data))
        }
    } else {
        appendLog($("<div><b>Your browser does not support WebSockets.</b></div>"))
    }
    });
</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"/>
</form>
</body>
</html>

## hub.go
package main

type hub struct {
	// Registered connections.
	connections map[*connection]bool

	// Inbound messages from the connections.
	broadcast chan string

	// Register requests from the connections.
	register chan *connection

	// Unregister requests from connections.
	unregister chan *connection
}

var h = hub{
	broadcast:   make(chan string),
	register:    make(chan *connection),
	unregister:  make(chan *connection),
	connections: make(map[*connection]bool),
}

func (h *hub) run() {
	for {
		select {
		case c := <-h.register:
			h.connections[c] = true
		case c := <-h.unregister:
			delete(h.connections, c)
			close(c.send)
		case m := <-h.broadcast:
			for c := range h.connections {
				select {
				case c.send <- m:
				default:
					delete(h.connections, c)
					close(c.send)
					go c.ws.Close()
				}
			}
		}
	}
}

## main.go
package main

import (
	"code.google.com/p/go.net/websocket"
	"flag"
	"log"
	"net/http"
	"text/template"
)

var addr = flag.String("addr", ":8080", "http service address")
var homeTempl = template.Must(template.ParseFiles("home.html"))

func homeHandler(c http.ResponseWriter, req *http.Request) {
	homeTempl.Execute(c, req.Host)
}

func main() {
	flag.Parse()
	go h.run()
	http.HandleFunc("/", homeHandler)
	http.Handle("/ws", websocket.Handler(wsHandler))
	if err := http.ListenAndServe(*addr, nil); err != nil {
		log.Fatal("ListenAndServe:", err)
	}
}
	package main

	import (
	"code.google.com/p/go.net/websocket"
	)

	type connection struct {
	// The websocket connection.
	ws *websocket.Conn

	// Buffered channel of outbound messages.
	send chan string
	}

	func (c *connection) reader() {
	for {
	var message string
	err := websocket.Message.Receive(c.ws, &message)
	if err != nil {
	break
	}
	h.broadcast <- message
	}
	c.ws.Close()
	}

	func (c *connection) writer() {
	for message := range c.send {
	err := websocket.Message.Send(c.ws, message)
	if err != nil {
	break
	}
	}
	c.ws.Close()
	}

	func wsHandler(ws *websocket.Conn) {
	c := &connection{send: make(chan string, 256), ws: ws}
	h.register <- c
	defer func() { h.unregister <- c }()
	go c.writer()
	c.reader()
	}
	<html>
	<head>
	<title>Chat Example</title>
	<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
	<script type="text/javascript">
	$(function() {

	var conn;
	var msg = $("#msg");
	var log = $("#log");

	function appendLog(msg) {
	var d = log[0]
	var doScroll = d.scrollTop == d.scrollHeight - d.clientHeight;
	msg.appendTo(log)
	if (doScroll) {
	d.scrollTop = d.scrollHeight - d.clientHeight;
	}
	}

	$("#form").submit(function() {
	if (!conn) {
	return false;
	}
	if (!msg.val()) {
	return false;
	}
	conn.send(msg.val());
	msg.val("");
	return false
	});

	if (window["WebSocket"]) {
	conn = new WebSocket("ws://{{$}}/ws");
	conn.onclose = function(evt) {
	appendLog($("<div><b>Connection closed.</b></div>"))
	}
	conn.onmessage = function(evt) {
	appendLog($("<div/>").text(evt.data))
	}
	} else {
	appendLog($("<div><b>Your browser does not support WebSockets.</b></div>"))
	}
	});
	</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"/>
	</form>
	</body>
	</html>
	package main

	type hub struct {
	// Registered connections.
	connections map[*connection]bool

	// Inbound messages from the connections.
	broadcast chan string

	// Register requests from the connections.
	register chan *connection

	// Unregister requests from connections.
	unregister chan *connection
	}

	var h = hub{
	broadcast: make(chan string),
	register: make(chan *connection),
	unregister: make(chan *connection),
	connections: make(map[*connection]bool),
	}

	func (h *hub) run() {
	for {
	select {
	case c := <-h.register:
	h.connections[c] = true
	case c := <-h.unregister:
	delete(h.connections, c)
	close(c.send)
	case m := <-h.broadcast:
	for c := range h.connections {
	select {
	case c.send <- m:
	default:
	delete(h.connections, c)
	close(c.send)
	go c.ws.Close()
	}
	}
	}
	}
	}