我有一个示例代码用于进行实验，试图在一个简单的聊天示例中思考“如何“同步”nodejs 和 php。
这是我的 NodeJS 服务器：
var redis = require('redis'),
subscriber = redis.createClient(),
publisher = redis.createClient();
//var sckio = require('socket.io').listen(8888);
var http = require('http');
var querystring = require('querystring');
var WebSocketServer = require('ws').Server
var ENCODING = 'utf8';
var tCounter = 0;
/* #################################### */
// Event on "subscribe" to any channel
subscriber.on("subscribe", function (channel, count) {
// Publish to redis server Test Message
publisher.publish("chat", "NODEJS MESSAGE");
});
// Suscrib to redis server
subscriber.on('message', function (channel, json) {
console.log('SUB: ' + channel + ' | ' + json);
console.log('PHP PUSH TO REDIS, AND NODE CAPTURE REDIS PUSH: ' + (getMicrotime(true) - tCounter));
});
subscriber.subscribe('chat'); // Subs to "mysql" channel
/*
var clients = [];
sckio.sockets.on('connection', function (socket) {
clients.push(socket);
publisher.publish("chat", "User connected");
socket.on('message', function (from, msg) {
publisher.publish("chat", msg);
clients.forEach(function (client) {
if (client === socket) return;
client.send(msg);
});
});
socket.on('disconnect', function () {
clients.splice(clients.indexOf(socket), 1);
publisher.publish("chat", "User disconnected");
});
});
*/
var wss = new WebSocketServer({port: 8888, timeout : 500});
var wsClients = [];
wss.on('connection', function(ws) {
ws.AUTH_ID = Math.random();
wsClients.push(ws);
publisher.publish("chat", "User enter");
ws.on('message', function(message) {
wsClients.forEach(function (client) {
client.send(ws.AUTH_ID + ' ' + message);
});
tCounter = getMicrotime(true);
console.log('CALL TO PHP: ' + tCounter);
PostCode('CODE TO PHP FROM NODE', function() {
wsClients.forEach(function (client) {
client.send('PHP SAVE DATA');
});
});
});
ws.on('close', function(message) {
wsClients.splice(wsClients.indexOf(ws), 1);
publisher.publish("chat", "User left");
});
ws.send('HELLO USER!');
});
function getMicrotime(get_as_float) {
var now = new Date().getTime() / 1000;
var s = parseInt(now, 10);
return (get_as_float) ? now : (Math.round((now - s) * 1000) / 1000) + ' ' + s;
}
function PostCode(codestring, callback) {
// Build the post string from an object
var post_data = querystring.stringify({
'output_format': 'json',
'js_code' : codestring
});
// An object of options to indicate where to post to
var post_options = {
host: '127.0.0.1',
port: '80',
path: '/NodeJS/chat_system/php_system.php',
method: 'POST',
headers: {
'Content-Type': 'application/x-www-form-urlencoded',
'Content-Length': post_data.length
}
};
// Set up the request
var post_req = http.request(post_options, function(res) {
res.setEncoding(ENCODING);
res.on('data', function (chunk) {
console.log('Response FROM PHP: ' + chunk);
if (typeof callback == 'function') {
callback(chunk);
}
});
});
// post the data
post_req.write(post_data);
post_req.end();
}
这是我的 PHP 服务器
require 'Predis/Autoloader.php';
Predis\Autoloader::register();
function pushToRedis($data) {
try {
$redis = new Predis\Client(array(
'scheme' => 'tcp',
'host' => '127.0.0.1',
'port' => 6379,
));
} catch (Exception $e) {
echo "Couldn't connected to Redis";
echo $e->getMessage();
return false;
}
$json = json_encode($data);
$redis->publish("chat", $json);
return true;
}
pushToRedis('PHP PUSH TO REDIS!');
header('Content-Type: application/json');
echo json_encode(array('response' => print_r(array($_REQUEST, $_SERVER), true)));
我的客户：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>WebSockets - Simple chat</title>
<style>
.chat { width: 400px; height: 250px; overflow-y: scroll; }
</style>
</head>
<body>
<script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>
<script>
var connection = new WebSocket('ws://127.0.0.1:8888');
$(document).ready(function() {
/*
var socket = io.connect('http://127.0.0.1:8888');
socket.on('message', function (data) {
alert(data);
});
socket.send('HELLO!');
*/
connection.onopen = function () {
console.log('connected!');
};
connection.onerror = function (error) {
};
connection.onmessage = function (message) {
$('.chat').append(message.data + '<br>');
$('.chat').scrollTop($('.chat')[0].scrollHeight);
};
$('input[name="text"]').on('keydown', function(e) {
if (e.keyCode === 13) {
var msg = $(this).val();
connection.send(msg);
$(this).val('').focus();
}
});
});
</script>
<div class="chat">
</div>
<input type="text" name="text">
</body>
</html>
问题是当网络繁忙时，PHP 通过 Redis 返回响应给 NodeJS 的顺序。
例如：我从de javascript客户端发送更多消息，然后，NodeJS每条消息都调用PHP，PHP将数据保存在MYSQL中，并调用Redis，NodeJS检测Redis推送并更新客户端。但是，在某些情况下，如果我从 Javascript 客户端循环发送一些消息（for(0-10000)），我不会以相同的顺序回复其他客户端，以防客户端中的数字为 200,201,300,202,320,203。
我认为这是因为 PHP 延迟响应。
我的问题是如何管理响应以正确顺序更新客户？因为这个问题可能会导致客户端以错误的顺序接收聊天消息。