'use strict';
/**
* @module events
*/
/**
* NodeJS like EventEmitter. See also <a href="http://nodejs.org/api/events.html">NodeJS events documentation</a>
*
* To add event emitting ability to any object:
*
var myObject = {},
//compatibility EventEmitter = require('events').EventEmitter;
EventEmitter = require('events');
// add EventEmitter to myObject
EventEmitter.call(myObject);
var util = require('util');
util._extend(myObject, EventEmitter.prototype);
* In case object created via constructor function
function MyObject() {
EventEmitter.call(this);
}
util.inherits(MyObject, EventEmitter);
var myObject = new MyObject();
* Usage:
myObject.on('myEvent', function(num, str){console.log(num, str) });
myObject.emit('myEvent', 1, 'two'); // output: 1 two
*
* @class EventEmitter
* @mixin
*/
function EventEmitter() {
EventEmitter.init.call(this);
}
module.exports = EventEmitter;
// Backwards-compat with node 0.10.x
EventEmitter.EventEmitter = EventEmitter;
/*
* @deprecated This property not used (===false) in UB. Also deprecated in Node
*/
EventEmitter.usingDomains = false;
//UB EventEmitter.prototype.domain = undefined;
/**
* Private collection of events.
* @private
*/
EventEmitter.prototype._events = undefined;
/**
* Use set/get MaxListeners instead direct access
* @private
*/
EventEmitter.prototype._maxListeners = undefined;
// By default EventEmitters will print a warning if more than 10 listeners are
// added to it. This is a useful default which helps finding memory leaks.
EventEmitter.defaultMaxListeners = 10;
/**
* @private
*/
EventEmitter.init = function() {
//UB this.domain = null;
//if (EventEmitter.usingDomains) {
// // if there is an active domain, then attach to it.
// domain = domain || require('domain');
// if (domain.active && !(this instanceof domain.Domain)) {
// this.domain = domain.active;
// }
//}
if (!this._events || this._events === Object.getPrototypeOf(this)._events) {
this._events = {};
this._eventsCount = 0;
}
this._maxListeners = this._maxListeners || undefined;
};
/**
* Obviously not all Emitters should be limited to 10. This function allows
* that to be increased. Set to zero for unlimited.
* @param {Number} n
*/
EventEmitter.prototype.setMaxListeners = function setMaxListeners(n) {
if (typeof n !== 'number' || n < 0 || isNaN(n))
throw new TypeError('n must be a positive number');
this._maxListeners = n;
return this;
};
function $getMaxListeners(that) {
if (that._maxListeners === undefined)
return EventEmitter.defaultMaxListeners;
return that._maxListeners;
}
/**
*
* @return {Number}
*/
EventEmitter.prototype.getMaxListeners = function getMaxListeners() {
return $getMaxListeners(this);
};
// These standalone emit* functions are used to optimize calling of event
// handlers for fast cases because emit() itself often has a variable number of
// arguments and can be deoptimized because of that. These functions always have
// the same number of arguments and thus do not get deoptimized, so the code
// inside them can execute faster.
function emitNone(handler, isFn, self) {
if (isFn)
handler.call(self);
else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
listeners[i].call(self);
}
}
function emitOne(handler, isFn, self, arg1) {
if (isFn)
handler.call(self, arg1);
else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
listeners[i].call(self, arg1);
}
}
function emitTwo(handler, isFn, self, arg1, arg2) {
if (isFn)
handler.call(self, arg1, arg2);
else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
listeners[i].call(self, arg1, arg2);
}
}
function emitThree(handler, isFn, self, arg1, arg2, arg3) {
if (isFn)
handler.call(self, arg1, arg2, arg3);
else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
listeners[i].call(self, arg1, arg2, arg3);
}
}
function emitMany(handler, isFn, self, args) {
if (isFn)
handler.apply(self, args);
else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
listeners[i].apply(self, args);
}
}
/**
* Execute each of the listeners in order with the supplied arguments.
* Returns true if event had listeners, false otherwise.
*
* @param {String} type Event name
* @param {...*} eventArgs Arguments, passed to listeners
* @return {boolean}
*/
EventEmitter.prototype.emit = function emit(type) {
var er, handler, len, args, i, events/*UB domain*/;
//UB var needDomainExit = false;
var doError = (type === 'error');
events = this._events;
if (events)
doError = (doError && events.error == null);
else if (!doError)
return false;
//UB domain = this.domain;
// If there is no 'error' event listener then throw.
if (doError) {
er = arguments[1];
//UB
//if (domain) {
// if (!er)
// er = new Error('Uncaught, unspecified "error" event.');
// er.domainEmitter = this;
// er.domain = domain;
// er.domainThrown = false;
// domain.emit('error', er);
//} else
if (er instanceof Error) {
throw er; // Unhandled 'error' event
} else {
// At least give some kind of context to the user
var err = new Error('Uncaught, unspecified "error" event. (' + er + ')');
err.context = er;
throw err;
}
return false;
}
handler = events[type];
if (!handler)
return false;
//UB
//if (domain && this !== process) {
// domain.enter();
// needDomainExit = true;
//}
var isFn = typeof handler === 'function';
len = arguments.length;
switch (len) {
// fast cases
case 1:
emitNone(handler, isFn, this);
break;
case 2:
emitOne(handler, isFn, this, arguments[1]);
break;
case 3:
emitTwo(handler, isFn, this, arguments[1], arguments[2]);
break;
case 4:
emitThree(handler, isFn, this, arguments[1], arguments[2], arguments[3]);
break;
// slower
default:
args = new Array(len - 1);
for (i = 1; i < len; i++)
args[i - 1] = arguments[i];
emitMany(handler, isFn, this, args);
}
//UB if (needDomainExit)
// domain.exit();
return true;
};
/**
* Adds a listener to the end of the listeners array for the specified event.
* Will emit `newListener` event on success.
*
* Usage sample:
*
* Session.on('login', function () {
* console.log('someone connected!');
* });
*
* Returns emitter, so calls can be chained.
*
* @param {String} type Event name
* @param {Function} listener
* @return {EventEmitter}
*/
EventEmitter.prototype.addListener = function addListener(type, listener) {
var m;
var events;
var existing;
if (typeof listener !== 'function')
throw new TypeError('listener must be a function');
events = this._events;
if (!events) {
events = this._events = {};
this._eventsCount = 0;
} else {
// To avoid recursion in the case that type === "newListener"! Before
// adding it to the listeners, first emit "newListener".
if (events.newListener) {
/** @fires newListener */
this.emit('newListener', type,
listener.listener ? listener.listener : listener);
// Re-assign `events` because a newListener handler could have caused the
// this._events to be assigned to a new object
events = this._events;
}
existing = events[type];
}
if (!existing) {
// Optimize the case of one listener. Don't need the extra array object.
existing = events[type] = listener;
++this._eventsCount;
} else {
if (typeof existing === 'function') {
// Adding the second element, need to change to array.
existing = events[type] = [existing, listener];
} else {
// If we've already got an array, just append.
existing.push(listener);
}
// Check for listener leak
if (!existing.warned) {
m = $getMaxListeners(this);
if (m && m > 0 && existing.length > m) {
existing.warned = true;
console.error('(node) warning: possible EventEmitter memory ' +
'leak detected. %d %s listeners added. ' +
'Use emitter.setMaxListeners() to increase limit.',
existing.length, type);
console.trace();
}
}
}
return this;
};
/**
* Alias for {@link EventEmitter#addListener addListener}
* @method
* @param {String} type Event name
* @param {Function} listener
* @return {EventEmitter}
*/
EventEmitter.prototype.on = EventEmitter.prototype.addListener;
/**
* Adds a one time listener for the event. This listener is invoked only the next time the event is fired, after which it is removed.
* @param {String} type Event name
* @param {Function} listener
* @return {EventEmitter}
*/
EventEmitter.prototype.once = function once(type, listener) {
if (typeof listener !== 'function')
throw new TypeError('listener must be a function');
var fired = false;
function g() {
this.removeListener(type, g);
if (!fired) {
fired = true;
listener.apply(this, arguments);
}
}
g.listener = listener;
this.on(type, g);
return this;
};
/**
* Remove a listener from the listener array for the specified event.
* Caution: changes array indices in the listener array behind the listener.
* Emits a 'removeListener' event if the listener was removed.
*
* @param {String} type Event name
* @param {Function} listener
*/
EventEmitter.prototype.removeListener =
function removeListener(type, listener) {
var list, events, position, i;
if (typeof listener !== 'function')
throw new TypeError('listener must be a function');
events = this._events;
if (!events)
return this;
list = events[type];
if (!list)
return this;
if (list === listener || (list.listener && list.listener === listener)) {
if (--this._eventsCount === 0)
this._events = {};
else {
delete events[type];
if (events.removeListener)
/** @fires removeListener */
this.emit('removeListener', type, listener);
}
} else if (typeof list !== 'function') {
position = -1;
for (i = list.length; i-- > 0;) {
if (list[i] === listener ||
(list[i].listener && list[i].listener === listener)) {
position = i;
break;
}
}
if (position < 0)
return this;
if (list.length === 1) {
list[0] = undefined;
if (--this._eventsCount === 0) {
this._events = {};
return this;
} else {
delete events[type];
}
} else {
spliceOne(list, position);
}
if (events.removeListener)
this.emit('removeListener', type, listener);
}
return this;
};
/**
* Removes all listeners, or those of the specified event.
* It's not a good idea to remove listeners that were added elsewhere in the code,
* especially when it's on an emitter that you didn't create (e.g. sockets or file streams).
*
* Returns emitter, so calls can be chained.
* @param {String} type Event name
* @return {EventEmitter}
*/
EventEmitter.prototype.removeAllListeners =
function removeAllListeners(type) {
var listeners, events;
events = this._events;
if (!events)
return this;
// not listening for removeListener, no need to emit
if (!events.removeListener) {
if (arguments.length === 0) {
this._events = {};
this._eventsCount = 0;
} else if (events[type]) {
if (--this._eventsCount === 0)
this._events = {};
else
delete events[type];
}
return this;
}
// emit removeListener for all listeners on all events
if (arguments.length === 0) {
var keys = Object.keys(events);
for (var i = 0, key; i < keys.length; ++i) {
key = keys[i];
if (key === 'removeListener') continue;
this.removeAllListeners(key);
}
this.removeAllListeners('removeListener');
this._events = {};
this._eventsCount = 0;
return this;
}
listeners = events[type];
if (typeof listeners === 'function') {
this.removeListener(type, listeners);
} else if (listeners) {
// LIFO order
do {
this.removeListener(type, listeners[listeners.length - 1]);
} while (listeners[0]);
}
return this;
};
/**
* Returns an array of listeners for the specified event.
* @param {String} type Event name
* @return {Array.<Function>}
*/
EventEmitter.prototype.listeners = function listeners(type) {
var evlistener;
var ret;
var events = this._events;
if (!events)
ret = [];
else {
evlistener = events[type];
if (!evlistener)
ret = [];
else if (typeof evlistener === 'function')
ret = [evlistener];
else
ret = arrayClone(evlistener, evlistener.length);
}
return ret;
};
/**
* Return the number of listeners for a given event.
* @param {EventEmitter} emitter
* @param {String} type
* @return {Number}
*/
EventEmitter.listenerCount = function(emitter, type) {
if (typeof emitter.listenerCount === 'function') {
return emitter.listenerCount(type);
} else {
return listenerCount.call(emitter, type);
}
};
EventEmitter.prototype.listenerCount = listenerCount;
function listenerCount(type) {
const events = this._events;
if (events) {
const evlistener = events[type];
if (typeof evlistener === 'function') {
return 1;
} else if (evlistener) {
return evlistener.length;
}
}
return 0;
}
// About 1.5x faster than the two-arg version of Array#splice().
function spliceOne(list, index) {
for (var i = index, k = i + 1, n = list.length; k < n; i += 1, k += 1)
list[i] = list[k];
list.pop();
}
function arrayClone(arr, i) {
var copy = new Array(i);
while (i--)
copy[i] = arr[i];
return copy;
}