'use strict';
/*!
* ws: a node.js websocket client
* Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
* MIT Licensed
*/
var url = require('url')
, util = require('util')
, http = require('http')
, https = require('https')
, crypto = require('crypto')
, stream = require('stream')
, Ultron = require('ultron')
, Options = require('options')
, Sender = require('./Sender')
, Receiver = require('./Receiver')
, SenderHixie = require('./Sender.hixie')
, ReceiverHixie = require('./Receiver.hixie')
, Extensions = require('./Extensions')
, PerMessageDeflate = require('./PerMessageDeflate')
, EventEmitter = require('events').EventEmitter;
/**
* Constants
*/
// Default protocol version
var protocolVersion = 13;
// Close timeout
var closeTimeout = 30 * 1000; // Allow 30 seconds to terminate the connection cleanly
/**
* WebSocket implementation
*
* @constructor
* @param {String} address Connection address.
* @param {String|Array} protocols WebSocket protocols.
* @param {Object} options Additional connection options.
* @api public
*/
function WebSocket(address, protocols, options) {
if (this instanceof WebSocket === false) {
return new WebSocket(address, protocols, options);
}
EventEmitter.call(this);
if (protocols && !Array.isArray(protocols) && 'object' === typeof protocols) {
// accept the "options" Object as the 2nd argument
options = protocols;
protocols = null;
}
if ('string' === typeof protocols) {
protocols = [ protocols ];
}
if (!Array.isArray(protocols)) {
protocols = [];
}
this._socket = null;
this._ultron = null;
this._closeReceived = false;
this.bytesReceived = 0;
this.readyState = null;
this.supports = {};
this.extensions = {};
this._binaryType = 'nodebuffer';
if (Array.isArray(address)) {
initAsServerClient.apply(this, address.concat(options));
} else {
initAsClient.apply(this, [address, protocols, options]);
}
}
/**
* Inherits from EventEmitter.
*/
util.inherits(WebSocket, EventEmitter);
/**
* Ready States
*/
["CONNECTING", "OPEN", "CLOSING", "CLOSED"].forEach(function each(state, index) {
WebSocket.prototype[state] = WebSocket[state] = index;
});
/**
* Gracefully closes the connection, after sending a description message to the server
*
* @param {Object} data to be sent to the server
* @api public
*/
WebSocket.prototype.close = function close(code, data) {
if (this.readyState === WebSocket.CLOSED) return;
if (this.readyState === WebSocket.CONNECTING) {
this.readyState = WebSocket.CLOSED;
return;
}
if (this.readyState === WebSocket.CLOSING) {
if (this._closeReceived && this._isServer) {
this.terminate();
}
return;
}
var self = this;
try {
this.readyState = WebSocket.CLOSING;
this._closeCode = code;
this._closeMessage = data;
var mask = !this._isServer;
this._sender.close(code, data, mask, function(err) {
if (err) self.emit('error', err);
if (self._closeReceived && self._isServer) {
self.terminate();
} else {
// ensure that the connection is cleaned up even when no response of closing handshake.
clearTimeout(self._closeTimer);
self._closeTimer = setTimeout(cleanupWebsocketResources.bind(self, true), closeTimeout);
}
});
} catch (e) {
this.emit('error', e);
}
};
/**
* Pause the client stream
*
* @api public
*/
WebSocket.prototype.pause = function pauser() {
if (this.readyState !== WebSocket.OPEN) throw new Error('not opened');
return this._socket.pause();
};
/**
* Sends a ping
*
* @param {Object} data to be sent to the server
* @param {Object} Members - mask: boolean, binary: boolean
* @param {boolean} dontFailWhenClosed indicates whether or not to throw if the connection isnt open
* @api public
*/
WebSocket.prototype.ping = function ping(data, options, dontFailWhenClosed) {
if (this.readyState !== WebSocket.OPEN) {
if (dontFailWhenClosed === true) return;
throw new Error('not opened');
}
options = options || {};
if (typeof options.mask === 'undefined') options.mask = !this._isServer;
this._sender.ping(data, options);
};
/**
* Sends a pong
*
* @param {Object} data to be sent to the server
* @param {Object} Members - mask: boolean, binary: boolean
* @param {boolean} dontFailWhenClosed indicates whether or not to throw if the connection isnt open
* @api public
*/
WebSocket.prototype.pong = function(data, options, dontFailWhenClosed) {
if (this.readyState !== WebSocket.OPEN) {
if (dontFailWhenClosed === true) return;
throw new Error('not opened');
}
options = options || {};
if (typeof options.mask === 'undefined') options.mask = !this._isServer;
this._sender.pong(data, options);
};
/**
* Resume the client stream
*
* @api public
*/
WebSocket.prototype.resume = function resume() {
if (this.readyState !== WebSocket.OPEN) throw new Error('not opened');
return this._socket.resume();
};
/**
* Sends a piece of data
*
* @param {Object} data to be sent to the server
* @param {Object} Members - mask: boolean, binary: boolean, compress: boolean
* @param {function} Optional callback which is executed after the send completes
* @api public
*/
WebSocket.prototype.send = function send(data, options, cb) {
if (typeof options === 'function') {
cb = options;
options = {};
}
if (this.readyState !== WebSocket.OPEN) {
if (typeof cb === 'function') cb(new Error('not opened'));
else throw new Error('not opened');
return;
}
if (!data) data = '';
if (this._queue) {
var self = this;
this._queue.push(function() { self.send(data, options, cb); });
return;
}
options = options || {};
options.fin = true;
if (typeof options.binary === 'undefined') {
options.binary = (data instanceof ArrayBuffer || data instanceof Buffer ||
data instanceof Uint8Array ||
data instanceof Uint16Array ||
data instanceof Uint32Array ||
data instanceof Int8Array ||
data instanceof Int16Array ||
data instanceof Int32Array ||
data instanceof Float32Array ||
data instanceof Float64Array);
}
if (typeof options.mask === 'undefined') options.mask = !this._isServer;
if (typeof options.compress === 'undefined') options.compress = true;
if (!this.extensions[PerMessageDeflate.extensionName]) {
options.compress = false;
}
var readable = typeof stream.Readable === 'function'
? stream.Readable
: stream.Stream;
if (data instanceof readable) {
startQueue(this);
var self = this;
sendStream(this, data, options, function send(error) {
process.nextTick(function tock() {
executeQueueSends(self);
});
if (typeof cb === 'function') cb(error);
});
} else {
this._sender.send(data, options, cb);
}
};
/**
* Streams data through calls to a user supplied function
*
* @param {Object} Members - mask: boolean, binary: boolean, compress: boolean
* @param {function} 'function (error, send)' which is executed on successive ticks of which send is 'function (data, final)'.
* @api public
*/
WebSocket.prototype.stream = function stream(options, cb) {
if (typeof options === 'function') {
cb = options;
options = {};
}
var self = this;
if (typeof cb !== 'function') throw new Error('callback must be provided');
if (this.readyState !== WebSocket.OPEN) {
if (typeof cb === 'function') cb(new Error('not opened'));
else throw new Error('not opened');
return;
}
if (this._queue) {
this._queue.push(function () { self.stream(options, cb); });
return;
}
options = options || {};
if (typeof options.mask === 'undefined') options.mask = !this._isServer;
if (typeof options.compress === 'undefined') options.compress = true;
if (!this.extensions[PerMessageDeflate.extensionName]) {
options.compress = false;
}
startQueue(this);
function send(data, final) {
try {
if (self.readyState !== WebSocket.OPEN) throw new Error('not opened');
options.fin = final === true;
self._sender.send(data, options);
if (!final) process.nextTick(cb.bind(null, null, send));
else executeQueueSends(self);
} catch (e) {
if (typeof cb === 'function') cb(e);
else {
delete self._queue;
self.emit('error', e);
}
}
}
process.nextTick(cb.bind(null, null, send));
};
/**
* Immediately shuts down the connection
*
* @api public
*/
WebSocket.prototype.terminate = function terminate() {
if (this.readyState === WebSocket.CLOSED) return;
if (this._socket) {
this.readyState = WebSocket.CLOSING;
// End the connection
try { this._socket.end(); }
catch (e) {
// Socket error during end() call, so just destroy it right now
cleanupWebsocketResources.call(this, true);
return;
}
// Add a timeout to ensure that the connection is completely
// cleaned up within 30 seconds, even if the clean close procedure
// fails for whatever reason
// First cleanup any pre-existing timeout from an earlier "terminate" call,
// if one exists. Otherwise terminate calls in quick succession will leak timeouts
// and hold the program open for `closeTimout` time.
if (this._closeTimer) { clearTimeout(this._closeTimer); }
this._closeTimer = setTimeout(cleanupWebsocketResources.bind(this, true), closeTimeout);
} else if (this.readyState === WebSocket.CONNECTING) {
cleanupWebsocketResources.call(this, true);
}
};
/**
* Expose bufferedAmount
*
* @api public
*/
Object.defineProperty(WebSocket.prototype, 'bufferedAmount', {
get: function get() {
var amount = 0;
if (this._socket) {
amount = this._socket.bufferSize || 0;
}
return amount;
}
});
/**
* Expose binaryType
*
* This deviates from the W3C interface since ws doesn't support the required
* default "blob" type (instead we define a custom "nodebuffer" type).
*
* @see http://dev.w3.org/html5/websockets/#the-websocket-interface
* @api public
*/
Object.defineProperty(WebSocket.prototype, 'binaryType', {
get: function get() {
return this._binaryType;
},
set: function set(type) {
if (type === 'arraybuffer' || type === 'nodebuffer')
this._binaryType = type;
else
throw new SyntaxError('unsupported binaryType: must be either "nodebuffer" or "arraybuffer"');
}
});
/**
* Emulates the W3C Browser based WebSocket interface using function members.
*
* @see http://dev.w3.org/html5/websockets/#the-websocket-interface
* @api public
*/
['open', 'error', 'close', 'message'].forEach(function(method) {
Object.defineProperty(WebSocket.prototype, 'on' + method, {
/**
* Returns the current listener
*
* @returns {Mixed} the set function or undefined
* @api public
*/
get: function get() {
var listener = this.listeners(method)[0];
return listener ? (listener._listener ? listener._listener : listener) : undefined;
},
/**
* Start listening for events
*
* @param {Function} listener the listener
* @returns {Mixed} the set function or undefined
* @api public
*/
set: function set(listener) {
this.removeAllListeners(method);
this.addEventListener(method, listener);
}
});
});
/**
* Emulates the W3C Browser based WebSocket interface using addEventListener.
*
* @see https://developer.mozilla.org/en/DOM/element.addEventListener
* @see http://dev.w3.org/html5/websockets/#the-websocket-interface
* @api public
*/
WebSocket.prototype.addEventListener = function(method, listener) {
var target = this;
function onMessage (data, flags) {
if (flags.binary && this.binaryType === 'arraybuffer')
data = new Uint8Array(data).buffer;
listener.call(target, new MessageEvent(data, !!flags.binary, target));
}
function onClose (code, message) {
listener.call(target, new CloseEvent(code, message, target));
}
function onError (event) {
event.type = 'error';
event.target = target;
listener.call(target, event);
}
function onOpen () {
listener.call(target, new OpenEvent(target));
}
if (typeof listener === 'function') {
if (method === 'message') {
// store a reference so we can return the original function from the
// addEventListener hook
onMessage._listener = listener;
this.on(method, onMessage);
} else if (method === 'close') {
// store a reference so we can return the original function from the
// addEventListener hook
onClose._listener = listener;
this.on(method, onClose);
} else if (method === 'error') {
// store a reference so we can return the original function from the
// addEventListener hook
onError._listener = listener;
this.on(method, onError);
} else if (method === 'open') {
// store a reference so we can return the original function from the
// addEventListener hook
onOpen._listener = listener;
this.on(method, onOpen);
} else {
this.on(method, listener);
}
}
};
module.exports = WebSocket;
module.exports.buildHostHeader = buildHostHeader
/**
* W3C MessageEvent
*
* @see http://www.w3.org/TR/html5/comms.html
* @constructor
* @api private
*/
function MessageEvent(dataArg, isBinary, target) {
this.type = 'message';
this.data = dataArg;
this.target = target;
this.binary = isBinary; // non-standard.
}
/**
* W3C CloseEvent
*
* @see http://www.w3.org/TR/html5/comms.html
* @constructor
* @api private
*/
function CloseEvent(code, reason, target) {
this.type = 'close';
this.wasClean = (typeof code === 'undefined' || code === 1000);
this.code = code;
this.reason = reason;
this.target = target;
}
/**
* W3C OpenEvent
*
* @see http://www.w3.org/TR/html5/comms.html
* @constructor
* @api private
*/
function OpenEvent(target) {
this.type = 'open';
this.target = target;
}
// Append port number to Host header, only if specified in the url
// and non-default
function buildHostHeader(isSecure, hostname, port) {
var headerHost = hostname;
if (hostname) {
if ((isSecure && (port != 443)) || (!isSecure && (port != 80))){
headerHost = headerHost + ':' + port;
}
}
return headerHost;
}
/**
* Entirely private apis,
* which may or may not be bound to a sepcific WebSocket instance.
*/
function initAsServerClient(req, socket, upgradeHead, options) {
options = new Options({
protocolVersion: protocolVersion,
protocol: null,
extensions: {},
maxPayload: 0
}).merge(options);
// expose state properties
this.protocol = options.value.protocol;
this.protocolVersion = options.value.protocolVersion;
this.extensions = options.value.extensions;
this.supports.binary = (this.protocolVersion !== 'hixie-76');
this.upgradeReq = req;
this.readyState = WebSocket.CONNECTING;
this._isServer = true;
this.maxPayload = options.value.maxPayload;
// establish connection
if (options.value.protocolVersion === 'hixie-76') {
establishConnection.call(this, ReceiverHixie, SenderHixie, socket, upgradeHead);
} else {
establishConnection.call(this, Receiver, Sender, socket, upgradeHead);
}
}
function initAsClient(address, protocols, options) {
options = new Options({
origin: null,
protocolVersion: protocolVersion,
host: null,
headers: null,
protocol: protocols.join(','),
agent: null,
// ssl-related options
pfx: null,
key: null,
passphrase: null,
cert: null,
ca: null,
ciphers: null,
rejectUnauthorized: null,
perMessageDeflate: true,
localAddress: null
}).merge(options);
if (options.value.protocolVersion !== 8 && options.value.protocolVersion !== 13) {
throw new Error('unsupported protocol version');
}
// verify URL and establish http class
var serverUrl = url.parse(address);
var isUnixSocket = serverUrl.protocol === 'ws+unix:';
if (!serverUrl.host && !isUnixSocket) throw new Error('invalid url');
var isSecure = serverUrl.protocol === 'wss:' || serverUrl.protocol === 'https:';
var httpObj = isSecure ? https : http;
var port = serverUrl.port || (isSecure ? 443 : 80);
var auth = serverUrl.auth;
// prepare extensions
var extensionsOffer = {};
var perMessageDeflate;
if (options.value.perMessageDeflate) {
perMessageDeflate = new PerMessageDeflate(typeof options.value.perMessageDeflate !== true ? options.value.perMessageDeflate : {}, false);
extensionsOffer[PerMessageDeflate.extensionName] = perMessageDeflate.offer();
}
// expose state properties
this._isServer = false;
this.url = address;
this.protocolVersion = options.value.protocolVersion;
this.supports.binary = (this.protocolVersion !== 'hixie-76');
// begin handshake
var key = new Buffer(options.value.protocolVersion + '-' + Date.now()).toString('base64');
var shasum = crypto.createHash('sha1');
shasum.update(key + '258EAFA5-E914-47DA-95CA-C5AB0DC85B11');
var expectedServerKey = shasum.digest('base64');
var agent = options.value.agent;
var headerHost = buildHostHeader(isSecure, serverUrl.hostname, port)
var requestOptions = {
port: port,
host: serverUrl.hostname,
headers: {
'Connection': 'Upgrade',
'Upgrade': 'websocket',
'Host': headerHost,
'Sec-WebSocket-Version': options.value.protocolVersion,
'Sec-WebSocket-Key': key
}
};
// If we have basic auth.
if (auth) {
requestOptions.headers.Authorization = 'Basic ' + new Buffer(auth).toString('base64');
}
if (options.value.protocol) {
requestOptions.headers['Sec-WebSocket-Protocol'] = options.value.protocol;
}
if (options.value.host) {
requestOptions.headers.Host = options.value.host;
}
if (options.value.headers) {
for (var header in options.value.headers) {
if (options.value.headers.hasOwnProperty(header)) {
requestOptions.headers[header] = options.value.headers[header];
}
}
}
if (Object.keys(extensionsOffer).length) {
requestOptions.headers['Sec-WebSocket-Extensions'] = Extensions.format(extensionsOffer);
}
if (options.isDefinedAndNonNull('pfx')
|| options.isDefinedAndNonNull('key')
|| options.isDefinedAndNonNull('passphrase')
|| options.isDefinedAndNonNull('cert')
|| options.isDefinedAndNonNull('ca')
|| options.isDefinedAndNonNull('ciphers')
|| options.isDefinedAndNonNull('rejectUnauthorized')) {
if (options.isDefinedAndNonNull('pfx')) requestOptions.pfx = options.value.pfx;
if (options.isDefinedAndNonNull('key')) requestOptions.key = options.value.key;
if (options.isDefinedAndNonNull('passphrase')) requestOptions.passphrase = options.value.passphrase;
if (options.isDefinedAndNonNull('cert')) requestOptions.cert = options.value.cert;
if (options.isDefinedAndNonNull('ca')) requestOptions.ca = options.value.ca;
if (options.isDefinedAndNonNull('ciphers')) requestOptions.ciphers = options.value.ciphers;
if (options.isDefinedAndNonNull('rejectUnauthorized')) requestOptions.rejectUnauthorized = options.value.rejectUnauthorized;
if (!agent) {
// global agent ignores client side certificates
agent = new httpObj.Agent(requestOptions);
}
}
requestOptions.path = serverUrl.path || '/';
if (agent) {
requestOptions.agent = agent;
}
if (isUnixSocket) {
requestOptions.socketPath = serverUrl.pathname;
}
if (options.value.localAddress) {
requestOptions.localAddress = options.value.localAddress;
}
if (options.value.origin) {
if (options.value.protocolVersion < 13) requestOptions.headers['Sec-WebSocket-Origin'] = options.value.origin;
else requestOptions.headers.Origin = options.value.origin;
}
var self = this;
var req = httpObj.request(requestOptions);
req.on('error', function onerror(error) {
self.emit('error', error);
cleanupWebsocketResources.call(self, error);
});
req.once('response', function response(res) {
var error;
if (!self.emit('unexpected-response', req, res)) {
error = new Error('unexpected server response (' + res.statusCode + ')');
req.abort();
self.emit('error', error);
}
cleanupWebsocketResources.call(self, error);
});
req.once('upgrade', function upgrade(res, socket, upgradeHead) {
if (self.readyState === WebSocket.CLOSED) {
// client closed before server accepted connection
self.emit('close');
self.removeAllListeners();
socket.end();
return;
}
var serverKey = res.headers['sec-websocket-accept'];
if (typeof serverKey === 'undefined' || serverKey !== expectedServerKey) {
self.emit('error', 'invalid server key');
self.removeAllListeners();
socket.end();
return;
}
var serverProt = res.headers['sec-websocket-protocol'];
var protList = (options.value.protocol || "").split(/, */);
var protError = null;
if (!options.value.protocol && serverProt) {
protError = 'server sent a subprotocol even though none requested';
} else if (options.value.protocol && !serverProt) {
protError = 'server sent no subprotocol even though requested';
} else if (serverProt && protList.indexOf(serverProt) === -1) {
protError = 'server responded with an invalid protocol';
}
if (protError) {
self.emit('error', protError);
self.removeAllListeners();
socket.end();
return;
} else if (serverProt) {
self.protocol = serverProt;
}
var serverExtensions = Extensions.parse(res.headers['sec-websocket-extensions']);
if (perMessageDeflate && serverExtensions[PerMessageDeflate.extensionName]) {
try {
perMessageDeflate.accept(serverExtensions[PerMessageDeflate.extensionName]);
} catch (err) {
self.emit('error', 'invalid extension parameter');
self.removeAllListeners();
socket.end();
return;
}
self.extensions[PerMessageDeflate.extensionName] = perMessageDeflate;
}
establishConnection.call(self, Receiver, Sender, socket, upgradeHead);
// perform cleanup on http resources
req.removeAllListeners();
req = null;
agent = null;
});
req.end();
this.readyState = WebSocket.CONNECTING;
}
function establishConnection(ReceiverClass, SenderClass, socket, upgradeHead) {
var ultron = this._ultron = new Ultron(socket)
, called = false
, self = this;
socket.setTimeout(0);
socket.setNoDelay(true);
this._receiver = new ReceiverClass(this.extensions,this.maxPayload);
this._socket = socket;
// socket cleanup handlers
ultron.on('end', cleanupWebsocketResources.bind(this));
ultron.on('close', cleanupWebsocketResources.bind(this));
ultron.on('error', cleanupWebsocketResources.bind(this));
// ensure that the upgradeHead is added to the receiver
function firstHandler(data) {
if (called || self.readyState === WebSocket.CLOSED) return;
called = true;
socket.removeListener('data', firstHandler);
ultron.on('data', realHandler);
if (upgradeHead && upgradeHead.length > 0) {
realHandler(upgradeHead);
upgradeHead = null;
}
if (data) realHandler(data);
}
// subsequent packets are pushed straight to the receiver
function realHandler(data) {
self.bytesReceived += data.length;
self._receiver.add(data);
}
ultron.on('data', firstHandler);
// if data was passed along with the http upgrade,
// this will schedule a push of that on to the receiver.
// this has to be done on next tick, since the caller
// hasn't had a chance to set event handlers on this client
// object yet.
process.nextTick(firstHandler);
// receiver event handlers
self._receiver.ontext = function ontext(data, flags) {
flags = flags || {};
self.emit('message', data, flags);
};
self._receiver.onbinary = function onbinary(data, flags) {
flags = flags || {};
flags.binary = true;
self.emit('message', data, flags);
};
self._receiver.onping = function onping(data, flags) {
flags = flags || {};
self.pong(data, {
mask: !self._isServer,
binary: flags.binary === true
}, true);
self.emit('ping', data, flags);
};
self._receiver.onpong = function onpong(data, flags) {
self.emit('pong', data, flags || {});
};
self._receiver.onclose = function onclose(code, data, flags) {
flags = flags || {};
self._closeReceived = true;
self.close(code, data);
};
self._receiver.onerror = function onerror(reason, errorCode) {
// close the connection when the receiver reports a HyBi error code
self.close(typeof errorCode !== 'undefined' ? errorCode : 1002, '');
self.emit('error', (reason instanceof Error) ? reason : (new Error(reason)));
};
// finalize the client
this._sender = new SenderClass(socket, this.extensions);
this._sender.on('error', function onerror(error) {
self.close(1002, '');
self.emit('error', error);
});
this.readyState = WebSocket.OPEN;
this.emit('open');
}
function startQueue(instance) {
instance._queue = instance._queue || [];
}
function executeQueueSends(instance) {
var queue = instance._queue;
if (typeof queue === 'undefined') return;
delete instance._queue;
for (var i = 0, l = queue.length; i < l; ++i) {
queue[i]();
}
}
function sendStream(instance, stream, options, cb) {
stream.on('data', function incoming(data) {
if (instance.readyState !== WebSocket.OPEN) {
if (typeof cb === 'function') cb(new Error('not opened'));
else {
delete instance._queue;
instance.emit('error', new Error('not opened'));
}
return;
}
options.fin = false;
instance._sender.send(data, options);
});
stream.on('end', function end() {
if (instance.readyState !== WebSocket.OPEN) {
if (typeof cb === 'function') cb(new Error('not opened'));
else {
delete instance._queue;
instance.emit('error', new Error('not opened'));
}
return;
}
options.fin = true;
instance._sender.send(null, options);
if (typeof cb === 'function') cb(null);
});
}
function cleanupWebsocketResources(error) {
if (this.readyState === WebSocket.CLOSED) return;
this.readyState = WebSocket.CLOSED;
clearTimeout(this._closeTimer);
this._closeTimer = null;
// If the connection was closed abnormally (with an error), or if
// the close control frame was not received then the close code
// must default to 1006.
if (error || !this._closeReceived) {
this._closeCode = 1006;
}
this.emit('close', this._closeCode || 1000, this._closeMessage || '');
if (this._socket) {
if (this._ultron) this._ultron.destroy();
this._socket.on('error', function onerror() {
try { this.destroy(); }
catch (e) {}
});
try {
if (!error) this._socket.end();
else this._socket.destroy();
} catch (e) { /* Ignore termination errors */ }
this._socket = null;
this._ultron = null;
}
if (this._sender) {
this._sender.removeAllListeners();
this._sender = null;
}
if (this._receiver) {
this._receiver.cleanup();
this._receiver = null;
}
if (this.extensions[PerMessageDeflate.extensionName]) {
this.extensions[PerMessageDeflate.extensionName].cleanup();
}
this.extensions = null;
this.removeAllListeners();
this.on('error', function onerror() {}); // catch all errors after this
delete this._queue;
}