socket.io/lib/client.js

var urlparse = require('url').parse,
		frame = '\ufffdm\ufffd',

Client = module.exports = function(listener, req, res, options, head){
	this.listener = listener;
	this.options({
		timeout: 12000,
		closeTimeout: 0
	}, options);
	this.connections = 0;
	this.connected = false;
	this._heartbeats = 0;
	this.upgradeHead = head;
	this._onConnect(req, res);
};

sys.inherits(Client, require('./utils').options);

Client.prototype.send = function(message){
	if (!this.connected || !(this.connection.readyState === 'open' ||
			this.connection.readyState === 'writeOnly')){
		return this._queue(message);
	}
	this._write(this._encode(message));
	return this;
};

Client.prototype.broadcast = function(message){
	if (!('sessionId' in this)) return this;
	this.listener.broadcast(message, this.sessionId);
	return this;
};

Client.prototype._onMessage = function(data){
	var messages = this._decode(data);
	if (messages === false) return this.listener.options.log('Bad message received from client ' + this.sessionId);
	for (var i = 0, l = messages.length; i < l; i++){
		if (messages[i].substr(0, 3) == '\ufffdh\ufffd'){
			return this._onHeartbeat(data.substr(3));
		}
		this.listener._onClientMessage(messages[i], this);
	}
};

Client.prototype._onConnect = function(req, res){
	var self = this;
	this.request = req;
	this.response = res;
	this.connection = this.request.connection;
	if (this._disconnectTimeout) clearTimeout(this._disconnectTimeout);
};
	
Client.prototype._encode = function(messages){
	var ret = '', message,
			messages = messages instanceof Array ? messages : [];
	for (var i = 0, l = messages.length; i < l; i++){
		message = String(messages[i]);
		ret += message.length + frame + message;
	}
	return frame + ret;
};
	
Client.prototype._decode = function(data){
	if (data.substr(0, 3) !== frame) return false;
	var messages = [];
	do {
		for (var i = 0, n, number = '';; i++){
			var n = data.substr(i, 1);
			if (n === frame){
				number = Number(number);
				break;
			}
			number += n;
		}
		messages.push(data.substr(i, i + number)); // here
		data = data.substr(i + number);
	} while(data !== '');
	return messages;
};
	
Client.prototype._payload = function(){
	var payload = [];
	
	this.connections++;
	this.connected = true;
	
	if (!this.handshaked){
		this._generateSessionId();
		payload.push(this.sessionId);
		this.handshaked = true;
	}
	
	payload = payload.concat(this._writeQueue || []);
	this._writeQueue = [];
	
	if (payload.length) this._write(this._encode(payload));
	if (this.connections === 1) this.listener._onClientConnect(this);
	
	if (this.listener.options.timeout) this._heartbeat();
};
	
Client.prototype._heartbeat = function(){
	var self = this;
	this.send('\ufffdh\ufffd' + ++this._heartbeats);
	this._heartbitTimeout = setTimeout(function(){
		self.close();
	}, this.listener.options.timeout);
};
	
Client.prototype._onHeartbeat = function(h){
	if (h === this._heartbeats) clearTimeout(this._heartbitTimeout);
};

Client.prototype._onClose = function(){
	var self = this;
	clearTimeout(this._heartbeatTimeout);
	this.connected = false;
	this._disconnectTimeout = setTimeout(function(){
		self._onDisconnect();
	}, this.options.closeTimeout);
};

Client.prototype._onDisconnect = function(){
	if (!this.finalized){
		this._writeQueue = [];
		this.connected = false;
		this.finalized = true;
		if (this.handshaked) this.listener._onClientDisconnect(this);
	}
};

Client.prototype._queue = function(message){
	if (!('_writeQueue' in this)){
		this._writeQueue = [];
	}
	this._writeQueue.push(message);
	return this;
};

Client.prototype._generateSessionId = function(){
	if (this.sessionId) return this.listener.options.log('This client already has a session id');
	this.sessionId = Math.random().toString().substr(2);
	return this;
};

Client.prototype._verifyOrigin = function(origin){
	var parts = urlparse(origin), origins = this.listener.options.origins;
	return origins.indexOf('*:*') !== -1 ||
		origins.indexOf(parts.host + ':' + parts.port) !== -1 ||
		origins.indexOf(parts.host + ':*') !== -1 ||
		origins.indexOf('*:' + parts.port) !== -1;
};