/**
* Module dependencies.
*/
var transports = require('./transports/index');
var Emitter = require('component-emitter');
var debug = require('debug')('engine.io-client:socket');
var index = require('indexof');
var parser = require('engine.io-parser');
var parseuri = require('parseuri');
var parseqs = require('parseqs');
/**
* Module exports.
*/
module.exports = Socket;
/**
* Socket constructor.
*
* @param {String|Object} uri or options
* @param {Object} options
* @api public
*/
function Socket (uri, opts) {
if (!(this instanceof Socket)) return new Socket(uri, opts);
opts = opts || {};
if (uri && 'object' === typeof uri) {
opts = uri;
uri = null;
}
if (uri) {
uri = parseuri(uri);
opts.hostname = uri.host;
opts.secure = uri.protocol === 'https' || uri.protocol === 'wss';
opts.port = uri.port;
if (uri.query) opts.query = uri.query;
} else if (opts.host) {
opts.hostname = parseuri(opts.host).host;
}
this.secure = null != opts.secure ? opts.secure
: (typeof location !== 'undefined' && 'https:' === location.protocol);
if (opts.hostname && !opts.port) {
// if no port is specified manually, use the protocol default
opts.port = this.secure ? '443' : '80';
}
this.agent = opts.agent || false;
this.hostname = opts.hostname ||
(typeof location !== 'undefined' ? location.hostname : 'localhost');
this.port = opts.port || (typeof location !== 'undefined' && location.port
? location.port
: (this.secure ? 443 : 80));
this.query = opts.query || {};
if ('string' === typeof this.query) this.query = parseqs.decode(this.query);
this.upgrade = false !== opts.upgrade;
this.path = (opts.path || '/engine.io').replace(/\/$/, '') + '/';
this.forceJSONP = !!opts.forceJSONP;
this.jsonp = false !== opts.jsonp;
this.forceBase64 = !!opts.forceBase64;
this.enablesXDR = !!opts.enablesXDR;
this.withCredentials = false !== opts.withCredentials;
this.timestampParam = opts.timestampParam || 't';
this.timestampRequests = opts.timestampRequests;
this.transports = opts.transports || ['polling', 'websocket'];
this.transportOptions = opts.transportOptions || {};
this.readyState = '';
this.writeBuffer = [];
this.prevBufferLen = 0;
this.policyPort = opts.policyPort || 843;
this.rememberUpgrade = opts.rememberUpgrade || false;
this.binaryType = null;
this.onlyBinaryUpgrades = opts.onlyBinaryUpgrades;
this.perMessageDeflate = false !== opts.perMessageDeflate ? (opts.perMessageDeflate || {}) : false;
if (true === this.perMessageDeflate) this.perMessageDeflate = {};
if (this.perMessageDeflate && null == this.perMessageDeflate.threshold) {
this.perMessageDeflate.threshold = 1024;
}
// SSL options for Node.js client
this.pfx = opts.pfx || null;
this.key = opts.key || null;
this.passphrase = opts.passphrase || null;
this.cert = opts.cert || null;
this.ca = opts.ca || null;
this.ciphers = opts.ciphers || null;
this.rejectUnauthorized = opts.rejectUnauthorized === undefined ? true : opts.rejectUnauthorized;
this.forceNode = !!opts.forceNode;
// detect ReactNative environment
this.isReactNative = (typeof navigator !== 'undefined' && typeof navigator.product === 'string' && navigator.product.toLowerCase() === 'reactnative');
// other options for Node.js or ReactNative client
if (typeof self === 'undefined' || this.isReactNative) {
if (opts.extraHeaders && Object.keys(opts.extraHeaders).length > 0) {
this.extraHeaders = opts.extraHeaders;
}
if (opts.localAddress) {
this.localAddress = opts.localAddress;
}
}
// set on handshake
this.id = null;
this.upgrades = null;
this.pingInterval = null;
this.pingTimeout = null;
// set on heartbeat
this.pingIntervalTimer = null;
this.pingTimeoutTimer = null;
this.open();
}
Socket.priorWebsocketSuccess = false;
/**
* Mix in `Emitter`.
*/
Emitter(Socket.prototype);
/**
* Protocol version.
*
* @api public
*/
Socket.protocol = parser.protocol; // this is an int
/**
* Expose deps for legacy compatibility
* and standalone browser access.
*/
Socket.Socket = Socket;
Socket.Transport = require('./transport');
Socket.transports = require('./transports/index');
Socket.parser = require('engine.io-parser');
/**
* Creates transport of the given type.
*
* @param {String} transport name
* @return {Transport}
* @api private
*/
Socket.prototype.createTransport = function (name) {
debug('creating transport "%s"', name);
var query = clone(this.query);
// append engine.io protocol identifier
query.EIO = parser.protocol;
// transport name
query.transport = name;
// per-transport options
var options = this.transportOptions[name] || {};
// session id if we already have one
if (this.id) query.sid = this.id;
var transport = new transports[name]({
query: query,
socket: this,
agent: options.agent || this.agent,
hostname: options.hostname || this.hostname,
port: options.port || this.port,
secure: options.secure || this.secure,
path: options.path || this.path,
forceJSONP: options.forceJSONP || this.forceJSONP,
jsonp: options.jsonp || this.jsonp,
forceBase64: options.forceBase64 || this.forceBase64,
enablesXDR: options.enablesXDR || this.enablesXDR,
withCredentials: options.withCredentials || this.withCredentials,
timestampRequests: options.timestampRequests || this.timestampRequests,
timestampParam: options.timestampParam || this.timestampParam,
policyPort: options.policyPort || this.policyPort,
pfx: options.pfx || this.pfx,
key: options.key || this.key,
passphrase: options.passphrase || this.passphrase,
cert: options.cert || this.cert,
ca: options.ca || this.ca,
ciphers: options.ciphers || this.ciphers,
rejectUnauthorized: options.rejectUnauthorized || this.rejectUnauthorized,
perMessageDeflate: options.perMessageDeflate || this.perMessageDeflate,
extraHeaders: options.extraHeaders || this.extraHeaders,
forceNode: options.forceNode || this.forceNode,
localAddress: options.localAddress || this.localAddress,
requestTimeout: options.requestTimeout || this.requestTimeout,
protocols: options.protocols || void (0),
isReactNative: this.isReactNative
});
return transport;
};
function clone (obj) {
var o = {};
for (var i in obj) {
if (obj.hasOwnProperty(i)) {
o[i] = obj[i];
}
}
return o;
}
/**
* Initializes transport to use and starts probe.
*
* @api private
*/
Socket.prototype.open = function () {
var transport;
if (this.rememberUpgrade && Socket.priorWebsocketSuccess && this.transports.indexOf('websocket') !== -1) {
transport = 'websocket';
} else if (0 === this.transports.length) {
// Emit error on next tick so it can be listened to
var self = this;
setTimeout(function () {
self.emit('error', 'No transports available');
}, 0);
return;
} else {
transport = this.transports[0];
}
this.readyState = 'opening';
// Retry with the next transport if the transport is disabled (jsonp: false)
try {
transport = this.createTransport(transport);
} catch (e) {
this.transports.shift();
this.open();
return;
}
transport.open();
this.setTransport(transport);
};
/**
* Sets the current transport. Disables the existing one (if any).
*
* @api private
*/
Socket.prototype.setTransport = function (transport) {
debug('setting transport %s', transport.name);
var self = this;
if (this.transport) {
debug('clearing existing transport %s', this.transport.name);
this.transport.removeAllListeners();
}
// set up transport
this.transport = transport;
// set up transport listeners
transport
.on('drain', function () {
self.onDrain();
})
.on('packet', function (packet) {
self.onPacket(packet);
})
.on('error', function (e) {
self.onError(e);
})
.on('close', function () {
self.onClose('transport close');
});
};
/**
* Probes a transport.
*
* @param {String} transport name
* @api private
*/
Socket.prototype.probe = function (name) {
debug('probing transport "%s"', name);
var transport = this.createTransport(name, { probe: 1 });
var failed = false;
var self = this;
Socket.priorWebsocketSuccess = false;
function onTransportOpen () {
if (self.onlyBinaryUpgrades) {
var upgradeLosesBinary = !this.supportsBinary && self.transport.supportsBinary;
failed = failed || upgradeLosesBinary;
}
if (failed) return;
debug('probe transport "%s" opened', name);
transport.send([{ type: 'ping', data: 'probe' }]);
transport.once('packet', function (msg) {
if (failed) return;
if ('pong' === msg.type && 'probe' === msg.data) {
debug('probe transport "%s" pong', name);
self.upgrading = true;
self.emit('upgrading', transport);
if (!transport) return;
Socket.priorWebsocketSuccess = 'websocket' === transport.name;
debug('pausing current transport "%s"', self.transport.name);
self.transport.pause(function () {
if (failed) return;
if ('closed' === self.readyState) return;
debug('changing transport and sending upgrade packet');
cleanup();
self.setTransport(transport);
transport.send([{ type: 'upgrade' }]);
self.emit('upgrade', transport);
transport = null;
self.upgrading = false;
self.flush();
});
} else {
debug('probe transport "%s" failed', name);
var err = new Error('probe error');
err.transport = transport.name;
self.emit('upgradeError', err);
}
});
}
function freezeTransport () {
if (failed) return;
// Any callback called by transport should be ignored since now
failed = true;
cleanup();
transport.close();
transport = null;
}
// Handle any error that happens while probing
function onerror (err) {
var error = new Error('probe error: ' + err);
error.transport = transport.name;
freezeTransport();
debug('probe transport "%s" failed because of error: %s', name, err);
self.emit('upgradeError', error);
}
function onTransportClose () {
onerror('transport closed');
}
// When the socket is closed while we're probing
function onclose () {
onerror('socket closed');
}
// When the socket is upgraded while we're probing
function onupgrade (to) {
if (transport && to.name !== transport.name) {
debug('"%s" works - aborting "%s"', to.name, transport.name);
freezeTransport();
}
}
// Remove all listeners on the transport and on self
function cleanup () {
transport.removeListener('open', onTransportOpen);
transport.removeListener('error', onerror);
transport.removeListener('close', onTransportClose);
self.removeListener('close', onclose);
self.removeListener('upgrading', onupgrade);
}
transport.once('open', onTransportOpen);
transport.once('error', onerror);
transport.once('close', onTransportClose);
this.once('close', onclose);
this.once('upgrading', onupgrade);
transport.open();
};
/**
* Called when connection is deemed open.
*
* @api public
*/
Socket.prototype.onOpen = function () {
debug('socket open');
this.readyState = 'open';
Socket.priorWebsocketSuccess = 'websocket' === this.transport.name;
this.emit('open');
this.flush();
// we check for `readyState` in case an `open`
// listener already closed the socket
if ('open' === this.readyState && this.upgrade && this.transport.pause) {
debug('starting upgrade probes');
for (var i = 0, l = this.upgrades.length; i < l; i++) {
this.probe(this.upgrades[i]);
}
}
};
/**
* Handles a packet.
*
* @api private
*/
Socket.prototype.onPacket = function (packet) {
if ('opening' === this.readyState || 'open' === this.readyState ||
'closing' === this.readyState) {
debug('socket receive: type "%s", data "%s"', packet.type, packet.data);
this.emit('packet', packet);
// Socket is live - any packet counts
this.emit('heartbeat');
switch (packet.type) {
case 'open':
this.onHandshake(JSON.parse(packet.data));
break;
case 'pong':
this.setPing();
this.emit('pong');
break;
case 'error':
var err = new Error('server error');
err.code = packet.data;
this.onError(err);
break;
case 'message':
this.emit('data', packet.data);
this.emit('message', packet.data);
break;
}
} else {
debug('packet received with socket readyState "%s"', this.readyState);
}
};
/**
* Called upon handshake completion.
*
* @param {Object} handshake obj
* @api private
*/
Socket.prototype.onHandshake = function (data) {
this.emit('handshake', data);
this.id = data.sid;
this.transport.query.sid = data.sid;
this.upgrades = this.filterUpgrades(data.upgrades);
this.pingInterval = data.pingInterval;
this.pingTimeout = data.pingTimeout;
this.onOpen();
// In case open handler closes socket
if ('closed' === this.readyState) return;
this.setPing();
// Prolong liveness of socket on heartbeat
this.removeListener('heartbeat', this.onHeartbeat);
this.on('heartbeat', this.onHeartbeat);
};
/**
* Resets ping timeout.
*
* @api private
*/
Socket.prototype.onHeartbeat = function (timeout) {
clearTimeout(this.pingTimeoutTimer);
var self = this;
self.pingTimeoutTimer = setTimeout(function () {
if ('closed' === self.readyState) return;
self.onClose('ping timeout');
}, timeout || (self.pingInterval + self.pingTimeout));
};
/**
* Pings server every `this.pingInterval` and expects response
* within `this.pingTimeout` or closes connection.
*
* @api private
*/
Socket.prototype.setPing = function () {
var self = this;
clearTimeout(self.pingIntervalTimer);
self.pingIntervalTimer = setTimeout(function () {
debug('writing ping packet - expecting pong within %sms', self.pingTimeout);
self.ping();
self.onHeartbeat(self.pingTimeout);
}, self.pingInterval);
};
/**
* Sends a ping packet.
*
* @api private
*/
Socket.prototype.ping = function () {
var self = this;
this.sendPacket('ping', function () {
self.emit('ping');
});
};
/**
* Called on `drain` event
*
* @api private
*/
Socket.prototype.onDrain = function () {
this.writeBuffer.splice(0, this.prevBufferLen);
// setting prevBufferLen = 0 is very important
// for example, when upgrading, upgrade packet is sent over,
// and a nonzero prevBufferLen could cause problems on `drain`
this.prevBufferLen = 0;
if (0 === this.writeBuffer.length) {
this.emit('drain');
} else {
this.flush();
}
};
/**
* Flush write buffers.
*
* @api private
*/
Socket.prototype.flush = function () {
if ('closed' !== this.readyState && this.transport.writable &&
!this.upgrading && this.writeBuffer.length) {
debug('flushing %d packets in socket', this.writeBuffer.length);
this.transport.send(this.writeBuffer);
// keep track of current length of writeBuffer
// splice writeBuffer and callbackBuffer on `drain`
this.prevBufferLen = this.writeBuffer.length;
this.emit('flush');
}
};
/**
* Sends a message.
*
* @param {String} message.
* @param {Function} callback function.
* @param {Object} options.
* @return {Socket} for chaining.
* @api public
*/
Socket.prototype.write =
Socket.prototype.send = function (msg, options, fn) {
this.sendPacket('message', msg, options, fn);
return this;
};
/**
* Sends a packet.
*
* @param {String} packet type.
* @param {String} data.
* @param {Object} options.
* @param {Function} callback function.
* @api private
*/
Socket.prototype.sendPacket = function (type, data, options, fn) {
if ('function' === typeof data) {
fn = data;
data = undefined;
}
if ('function' === typeof options) {
fn = options;
options = null;
}
if ('closing' === this.readyState || 'closed' === this.readyState) {
return;
}
options = options || {};
options.compress = false !== options.compress;
var packet = {
type: type,
data: data,
options: options
};
this.emit('packetCreate', packet);
this.writeBuffer.push(packet);
if (fn) this.once('flush', fn);
this.flush();
};
/**
* Closes the connection.
*
* @api private
*/
Socket.prototype.close = function () {
if ('opening' === this.readyState || 'open' === this.readyState) {
this.readyState = 'closing';
var self = this;
if (this.writeBuffer.length) {
this.once('drain', function () {
if (this.upgrading) {
waitForUpgrade();
} else {
close();
}
});
} else if (this.upgrading) {
waitForUpgrade();
} else {
close();
}
}
function close () {
self.onClose('forced close');
debug('socket closing - telling transport to close');
self.transport.close();
}
function cleanupAndClose () {
self.removeListener('upgrade', cleanupAndClose);
self.removeListener('upgradeError', cleanupAndClose);
close();
}
function waitForUpgrade () {
// wait for upgrade to finish since we can't send packets while pausing a transport
self.once('upgrade', cleanupAndClose);
self.once('upgradeError', cleanupAndClose);
}
return this;
};
/**
* Called upon transport error
*
* @api private
*/
Socket.prototype.onError = function (err) {
debug('socket error %j', err);
Socket.priorWebsocketSuccess = false;
this.emit('error', err);
this.onClose('transport error', err);
};
/**
* Called upon transport close.
*
* @api private
*/
Socket.prototype.onClose = function (reason, desc) {
if ('opening' === this.readyState || 'open' === this.readyState || 'closing' === this.readyState) {
debug('socket close with reason: "%s"', reason);
var self = this;
// clear timers
clearTimeout(this.pingIntervalTimer);
clearTimeout(this.pingTimeoutTimer);
// stop event from firing again for transport
this.transport.removeAllListeners('close');
// ensure transport won't stay open
this.transport.close();
// ignore further transport communication
this.transport.removeAllListeners();
// set ready state
this.readyState = 'closed';
// clear session id
this.id = null;
// emit close event
this.emit('close', reason, desc);
// clean buffers after, so users can still
// grab the buffers on `close` event
self.writeBuffer = [];
self.prevBufferLen = 0;
}
};
/**
* Filters upgrades, returning only those matching client transports.
*
* @param {Array} server upgrades
* @api private
*
*/
Socket.prototype.filterUpgrades = function (upgrades) {
var filteredUpgrades = [];
for (var i = 0, j = upgrades.length; i < j; i++) {
if (~index(this.transports, upgrades[i])) filteredUpgrades.push(upgrades[i]);
}
return filteredUpgrades;
};