在php中创建websocket服务器过程讲解
WebSocket服务器是建立在Http服务器之上的长连接服务器，客户端首先会发送一个Http的请求与服务器进行握手。握手成功后会触发onOpen事件，表示连接已就绪，onOpen函数中可以得到$request对象，包含了Http握手的相关信息，如GET参数、Cookie、Http头信息等。
PHP中创建websocket服务器的过程讲解：
SocketService.php:
<?php
class SocketService
{
private $address = '0.0.0.0';
private $port = 8083;
private $_sockets;
public function __construct($address = '', $port='')
{
if(!empty($address)){
$this->address = $address;
}
if(!empty($port)) {
$this->port = $port;
}
}
public function service(){
//获取tcp协议号码。
$tcp = getprotobyname("tcp");
$sock = socket_create(AF_INET, SOCK_STREAM, $tcp);
socket_set_option($sock, SOL_SOCKET, SO_REUSEADDR, 1);
if($sock < 0)
{
throw new Exception("failed to create socket: ".socket_strerror($sock)."\n");
}
socket_bind($sock, $this->address, $this->port);
socket_listen($sock, $this->port);
echo "listen on $this->address $this->port ... \n";
$this->_sockets = $sock;
}
public function run(){
$this->service();
$clients[] = $this->_sockets;
while (true){
$changes = $clients;
$write = NULL;
$except = NULL;
//当select处于等待时,两个客户端中甲先发数据来,则socket_select会在$changes中保留甲的socket并往下运行,另一个客户端的socket就被丢弃了,所以再次循环时,变成只监听甲了,这个可以在新循环中把所有链接的客户端socket再次加进$changes中,则可以避免本程序的这个逻辑错误
/** socket_select是阻塞，有数据请求才处理，否则一直阻塞
* 此处$changes会读取到当前活动的连接
* 比如执行socket_select前的数据如下(描述socket的资源ID)：
* $socket = Resource id #4
* $changes = Array
* (
* [0] => Resource id #5 //客户端1
* [1] => Resource id #4 //server绑定的端口的socket资源
* )
* 调用socket_select之后，此时有两种情况：
* 情况一：如果是新客户端2连接，那么 $changes = array([1] => Resource id #4),此时用于接收新客户端2连接
* 情况二：如果是客户端1(Resource id #5)发送消息，那么$changes = array([1] => Resource id #5)，用户接收客户端1的数据
*
* 通过以上的描述可以看出，socket_select有两个作用，这也是实现了IO复用
* 1、新客户端来了，通过 Resource id #4 介绍新连接，如情况一
* 2、已有连接发送数据，那么实时切换到当前连接，接收数据，如情况二*/
socket_select($changes, $write, $except, NULL);
foreach ($changes as $key => $_sock){
if($this->_sockets == $_sock){ //判断是不是新接入的socket
if(($newClient = socket_accept($_sock)) === false){
die('failed to accept socket: '.socket_strerror($_sock)."\n");
}
$line = trim(socket_read($newClient, 1024));
if($line === false){
socket_shutdown($newClient);
socket_close($newClient);
continue;
}
$this->handshaking($newClient, $line);
//获取client ip
socket_getpeername ($newClient, $ip);
$clients[$ip] = $newClient;
echo "Client ip:{$ip} \n";
echo "Client msg:{$line} \n";
} else {
$byte = socket_recv($_sock, $buffer, 2048, 0);
if($byte < 7) continue;
$msg = $this->message($buffer);
//在这里业务代码
echo "{$key} clinet msg:",$msg,"\n";
fwrite(STDOUT, 'Please input a argument:');
$response = trim(fgets(STDIN));
$this->send($_sock, $response);
echo "{$key} response to Client:".$response,"\n";
}
}
}
}
/**
* 握手处理
* @param $newClient socket
* @return int 接收到的信息
*/
public function handshaking($newClient, $line){
$headers = array();
$lines = preg_split("/\r\n/", $line);
foreach($lines as $line)
{
$line = rtrim($line);
if(preg_match('/^(\S+): (.*)$/', $line, $matches))
{
$headers[$matches[1]] = $matches[2];
}
}
$secKey = $headers['Sec-WebSocket-Key'];
$secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));
$upgrade = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" .
"Upgrade: websocket\r\n" .
"Connection: Upgrade\r\n" .
"WebSocket-Origin: $this->address\r\n" .
"WebSocket-Location: ws://$this->address:$this->port/websocket/websocket\r\n".
"Sec-WebSocket-Accept:$secAccept\r\n\r\n";
return socket_write($newClient, $upgrade, strlen($upgrade));
}
/**
* 解析接收数据
* @param $buffer
* @return null|string
*/
public function message($buffer){
$len = $masks = $data = $decoded = null;
$len = ord($buffer[1]) & 127;
if ($len === 126) {
$masks = substr($buffer, 4, 4);
$data = substr($buffer, 8);
} else if ($len === 127) {
$masks = substr($buffer, 10, 4);
$data = substr($buffer, 14);
} else {
$masks = substr($buffer, 2, 4);
$data = substr($buffer, 6);
}
for ($index = 0; $index < strlen($data); $index++) {
$decoded .= $data[$index] ^ $masks[$index % 4];
}
return $decoded;
}
/**
* 发送数据
* @param $newClinet 新接入的socket
* @param $msg 要发送的数据
* @return int|string
*/
public function send($newClinet, $msg){
$msg = $this->frame($msg);
socket_write($newClinet, $msg, strlen($msg));
}
public function frame($s) {
$a = str_split($s, 125);
if (count($a) == 1) {
return "\x81" . chr(strlen($a[0])) . $a[0];
}
$ns = "";
foreach ($a as $o) {
$ns .= "\x81" . chr(strlen($o)) . $o;
}
return $ns;
}
/**
* 关闭socket
*/
public function close(){
return socket_close($this->_sockets);
}
}
$sock = new SocketService();
$sock->run();client.html:
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width,initial-scale=1, maximum-scale=1, user-scalable=no">
<title>websocket</title>
</head>
<body>
<input id="text" value="">
<input type="submit" value="send" onclick="start()">
<input type="submit" value="close" onclick="close()">
<div id="msg"></div>
<script>
/**
webSocket.readyState
0：未连接
1：连接成功，可通讯
2：正在关闭
3：连接已关闭或无法打开
*/
//创建一个webSocket 实例
var webSocket = new WebSocket("ws://192.168.31.152:8083");
webSocket.onerror = function (event){
onError(event);
};
// 打开websocket
webSocket.onopen = function (event){
onOpen(event);
};
//监听消息
webSocket.onmessage = function (event){
onMessage(event);
};
webSocket.onclose = function (event){ //服务端关闭后 触发
onClose(event);
}
//关闭监听websocket
function onError(event){
document.getElementById("msg").innerHTML = "<p>close</p>";
console.log("error"+event.data);
};
function onOpen(event){
console.log("open:"+sockState());
document.getElementById("msg").innerHTML = "<p>Connect to Service</p>";
};
function onMessage(event){
console.log("onMessage");
document.getElementById("msg").innerHTML += "<p>response:"+event.data+"</p>"
};
function onClose(event){
document.getElementById("msg").innerHTML = "<p>close</p>";
console.log("close:"+sockState());
webSocket.close();
}
function sockState(){
var status = ['未连接','连接成功，可通讯','正在关闭','连接已关闭或无法打开'];
return status[webSocket.readyState];
}
function start(event){
console.log(webSocket);
var msg = document.getElementById('text').value;
document.getElementById('text').value = '';
console.log("send:"+sockState());
console.log("msg="+msg);
webSocket.send("msg="+msg);
document.getElementById("msg").innerHTML += "<p>request"+msg+"</p>"
};
function close(event){
webSocket.close();
}
</script>
</body>
</html>以上便实现了在php中创建websocket服务器的需求。
当然如果要实现更多高级的websocket相关功能，可以试试第三方的websocket服务框架：GoEasy
目前GoEasy提供完整的websocket前后端解决方案，简单的几行代码集成，即可快速搭建您的专属websocket服务。 同时支持各种前端技术框架如小程序、uniapp、vue，支持各种服务端语言如php、java、python等。对websocket有需求的开发者可以来注册试用一下【立即注册】