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'use strict';
var domain;
function EventEmitter() {
EventEmitter.init.call(this);
}
module.exports = EventEmitter;
// Backwards-compat with node 0.10.x
EventEmitter.EventEmitter = EventEmitter;
EventEmitter.usingDomains = false;
EventEmitter.prototype.domain = undefined;
EventEmitter.prototype._events = undefined;
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;
EventEmitter.init = function() {
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._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.
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;
}
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);
}
}
EventEmitter.prototype.emit = function emit(type) {
var er, handler, len, args, i, listeners, events, domain;
var needDomainExit = false;
events = this._events;
if (!events)
events = this._events = {};
domain = this.domain;
// If there is no 'error' event listener then throw.
if (type === 'error' && !events.error) {
er = arguments[1];
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 {
throw Error('Uncaught, unspecified "error" event.');
}
return false;
}
handler = events[type];
if (!handler)
return false;
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];
if (isFn)
handler.apply(this, args);
else {
len = handler.length;
listeners = arrayClone(handler, len);
for (i = 0; i < len; ++i)
listeners[i].apply(this, args);
}
}
if (needDomainExit)
domain.exit();
return true;
};
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 = {};
else {
// To avoid recursion in the case that type === "newListener"! Before
// adding it to the listeners, first emit "newListener".
if (events.newListener) {
this.emit('newListener', type,
typeof listener.listener === 'function' ?
listener.listener : listener);
}
existing = events[type];
}
if (!existing)
// Optimize the case of one listener. Don't need the extra array object.
existing = events[type] = listener;
else if (typeof existing !== 'function')
// If we've already got an array, just append.
existing.push(listener);
else
// Adding the second element, need to change to array.
existing = events[type] = [existing, listener];
// Check for listener leak
if (typeof existing !== 'function' && !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;
};
EventEmitter.prototype.on = EventEmitter.prototype.addListener;
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;
};
// emits a 'removeListener' event iff the listener was removed
EventEmitter.prototype.removeListener =
function removeListener(type, listener) {
var list, events, position, length, 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;
length = list.length;
position = -1;
if (list === listener ||
(typeof list.listener === 'function' && list.listener === listener)) {
delete events[type];
if (events.removeListener)
this.emit('removeListener', type, listener);
} else if (typeof list !== 'function') {
for (i = 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.length = 0;
delete events[type];
} else {
spliceOne(list, position);
}
if (events.removeListener)
this.emit('removeListener', type, listener);
}
return this;
};
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 = {};
else if (events[type])
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 = {};
return this;
}
listeners = events[type];
if (typeof listeners === 'function') {
this.removeListener(type, listeners);
} else if (Array.isArray(listeners)) {
// LIFO order
while (listeners.length)
this.removeListener(type, listeners[listeners.length - 1]);
}
delete events[type];
return this;
};
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);
}
return ret;
};
EventEmitter.listenerCount = function(emitter, type) {
var evlistener;
var ret = 0;
var events = emitter._events;
if (events) {
evlistener = events[type];
if (typeof evlistener === 'function')
ret = 1;
else if (evlistener)
ret = evlistener.length;
}
return ret;
};
// 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, len) {
var ret;
if (len === undefined)
len = arr.length;
if (len >= 50)
ret = arr.slice();
else {
ret = new Array(len);
for (var i = 0; i < len; i += 1)
ret[i] = arr[i];
}
return ret;
}