var socket = io("ws://103.31.201.154:5555");

function Manager(uri, opts){//返回Manager对象if (!(this instanceof Manager)) return new Manager(uri, opts);if (uri && ('object' == typeof uri)) {opts = uri;uri = undefined;}opts = opts || {};opts.path = opts.path || '/socket.io';this.nsps = {};//所有订阅socket状态的容器this.subs = [];this.opts = opts;//是否重连this.reconnection(opts.reconnection !== false);//最大重连次数this.reconnectionAttempts(opts.reconnectionAttempts || Infinity);//两次重连之间的延迟this.reconnectionDelay(opts.reconnectionDelay || 1000);//两次重连之间的最大延迟this.reconnectionDelayMax(opts.reconnectionDelayMax || 5000);//connection超时时间this.timeout(null == opts.timeout ? 20000 : opts.timeout);//连接状态this.readyState = 'closed';this.uri = uri;//重连数this.connected = 0;//尝试次数this.attempts = 0;//与engine.io数据交互时数据要编码this.encoding = false;// packetBufferthis.packetBuffer = [];this.encoder = new parser.Encoder();this.decoder = new parser.Decoder();//是否自动连接this.autoConnect = opts.autoConnect !== false;//如果自动连接则开始连接if (this.autoConnect) this.open();
}

//清除socket连接超时计时器   this.subs.push({destroy: function(){clearTimeout(timer);}});

Manager.prototype.packet = function(packet){debug('writing packet %j', packet);var self = this;if (!self.encoding) {// encode，encoding标识为trueself.encoding = true;this.encoder.encode(packet, function(encodedPackets) {for (var i = 0; i < encodedPackets.length; i++) {self.engine.write(encodedPackets[i]);}//encode结束，encoding置为falseself.encoding = false;//查询队列执行packet
      self.processPacketQueue();});} else { //如果在encode中，push到Buffer里
    self.packetBuffer.push(packet);}
};

Manager.prototype.open =
Manager.prototype.connect = function(fn){debug('readyState %s', this.readyState);//如果已经打开，直接返回if (~this.readyState.indexOf('open')) return this;debug('opening %s', this.uri);//打开socket连接this.engine = eio(this.uri, this.opts);var socket = this.engine;var self = this;this.readyState = 'opening';// emit `open`var openSub = on(socket, 'open', function() {self.onopen();fn && fn();});// emit `connect_error`var errorSub = on(socket, 'error', function(data){debug('connect_error');self.cleanup();self.readyState = 'closed';self.emitAll('connect_error', data);if (fn) {var err = new Error('Connection error');err.data = data;fn(err);}self.maybeReconnectOnOpen();});if (false !== this._timeout) {var timeout = this._timeout;debug('connect attempt will timeout after %d', timeout);// 设置连接超时var timer = setTimeout(function(){debug('connect attempt timed out after %d', timeout);openSub.destroy();socket.close();socket.emit('error', 'timeout');self.emitAll('connect_timeout', timeout);}, timeout);this.subs.push({destroy: function(){clearTimeout(timer);}});}this.subs.push(openSub);this.subs.push(errorSub);//返回Manager实例（已经打开socket连接的）return this;
};