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// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.
var isArray = Array.isArray;
function EventEmitter() {
if (exports.usingDomains) {
// if there is an active domain, then attach to it.
var domain = require('domain');
if (domain.active && !(this instanceof domain.Domain)) {
this.domain = domain.active;
}
}
}
exports.EventEmitter = EventEmitter;
// 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.
//
// Obviously not all Emitters should be limited to 10. This function allows
// that to be increased. Set to zero for unlimited.
var defaultMaxListeners = 10;
EventEmitter.prototype.setMaxListeners = function(n) {
if (!this._events) this._events = {};
this._maxListeners = n;
};
EventEmitter.prototype.emit = function() {
var type = arguments[0];
// If there is no 'error' event listener then throw.
if (type === 'error') {
if (!this._events || !this._events.error ||
(isArray(this._events.error) && !this._events.error.length))
{
if (this.domain) {
var er = arguments[1];
er.domain_emitter = this;
er.domain = this.domain;
er.domain_thrown = false;
this.domain.emit('error', er);
return false;
}
if (arguments[1] instanceof Error) {
throw arguments[1]; // Unhandled 'error' event
} else {
throw new Error("Uncaught, unspecified 'error' event.");
}
return false;
}
}
if (!this._events) return false;
var handler = this._events[type];
if (!handler) return false;
if (typeof handler == 'function') {
if (this.domain) {
this.domain.enter();
}
switch (arguments.length) {
// fast cases
case 1:
handler.call(this);
break;
case 2:
handler.call(this, arguments[1]);
break;
case 3:
handler.call(this, arguments[1], arguments[2]);
break;
// slower
default:
var l = arguments.length;
var args = new Array(l - 1);
for (var i = 1; i < l; i++) args[i - 1] = arguments[i];
handler.apply(this, args);
}
if (this.domain) {
this.domain.exit();
}
return true;
} else if (isArray(handler)) {
if (this.domain) {
this.domain.enter();
}
var l = arguments.length;
var args = new Array(l - 1);
for (var i = 1; i < l; i++) args[i - 1] = arguments[i];
var listeners = handler.slice();
for (var i = 0, l = listeners.length; i < l; i++) {
listeners[i].apply(this, args);
}
if (this.domain) {
this.domain.exit();
}
return true;
} else {
return false;
}
};
EventEmitter.prototype.addListener = function(type, listener) {
if ('function' !== typeof listener) {
throw new Error('addListener only takes instances of Function');
}
if (!this._events) this._events = {};
// To avoid recursion in the case that type == "newListeners"! Before
// adding it to the listeners, first emit "newListeners".
this.emit('newListener', type, typeof listener.listener === 'function' ?
listener.listener : listener);
if (!this._events[type]) {
// Optimize the case of one listener. Don't need the extra array object.
this._events[type] = listener;
} else if (isArray(this._events[type])) {
// If we've already got an array, just append.
this._events[type].push(listener);
} else {
// Adding the second element, need to change to array.
this._events[type] = [this._events[type], listener];
}
// Check for listener leak
if (isArray(this._events[type]) && !this._events[type].warned) {
var m;
if (this._maxListeners !== undefined) {
m = this._maxListeners;
} else {
m = defaultMaxListeners;
}
if (m && m > 0 && this._events[type].length > m) {
this._events[type].warned = true;
console.error('(node) warning: possible EventEmitter memory ' +
'leak detected. %d listeners added. ' +
'Use emitter.setMaxListeners() to increase limit.',
this._events[type].length);
console.trace();
}
}
return this;
};
EventEmitter.prototype.on = EventEmitter.prototype.addListener;
EventEmitter.prototype.once = function(type, listener) {
if ('function' !== typeof listener) {
throw new Error('.once only takes instances of Function');
}
var self = this;
function g() {
self.removeListener(type, g);
listener.apply(this, arguments);
};
g.listener = listener;
self.on(type, g);
return this;
};
EventEmitter.prototype.removeListener = function(type, listener) {
if ('function' !== typeof listener) {
throw new Error('removeListener only takes instances of Function');
}
// does not use listeners(), so no side effect of creating _events[type]
if (!this._events || !this._events[type]) return this;
var list = this._events[type];
if (isArray(list)) {
var position = -1;
for (var i = 0, length = list.length; i < length; i++) {
if (list[i] === listener ||
(list[i].listener && list[i].listener === listener))
{
position = i;
break;
}
}
if (position < 0) return this;
list.splice(position, 1);
} else if (list === listener ||
(list.listener && list.listener === listener))
{
delete this._events[type];
}
return this;
};
EventEmitter.prototype.removeAllListeners = function(type) {
if (arguments.length === 0) {
this._events = {};
return this;
}
var events = this._events && this._events[type];
if (!events) return this;
if (isArray(events)) {
events.splice(0);
} else {
this._events[type] = null;
}
return this;
};
EventEmitter.prototype.listeners = function(type) {
if (!this._events) this._events = {};
if (!this._events[type]) this._events[type] = [];
if (!isArray(this._events[type])) {
this._events[type] = [this._events[type]];
}
return this._events[type];
};