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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 domain;
var util = require('util');
function EventEmitter() {
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;
}
}
this._events = this._events || {};
this._maxListeners = this._maxListeners || undefined;
}
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;
// 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(n) {
if (!util.isNumber(n) || n < 0 || isNaN(n))
throw TypeError('n must be a positive number');
this._maxListeners = n;
return this;
};
EventEmitter.prototype.emit = function(type) {
var er, handler, len, args, i, listeners;
if (!this._events)
this._events = {};
// If there is no 'error' event listener then throw.
if (type === 'error' && !this._events.error) {
er = arguments[1];
if (this.domain) {
if (!er)
er = new Error('Uncaught, unspecified "error" event.');
er.domainEmitter = this;
er.domain = this.domain;
er.domainThrown = false;
this.domain.emit('error', er);
} else if (er instanceof Error) {
throw er; // Unhandled 'error' event
} else {
throw Error('Uncaught, unspecified "error" event.');
}
return false;
}
handler = this._events[type];
if (util.isUndefined(handler))
return false;
if (util.isFunction(handler)) {
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:
len = arguments.length;
args = new Array(len - 1);
for (i = 1; i < len; i++)
args[i - 1] = arguments[i];
handler.apply(this, args);
}
} else if (util.isObject(handler)) {
len = arguments.length;
args = new Array(len - 1);
for (i = 1; i < len; i++)
args[i - 1] = arguments[i];
listeners = handler.slice();
len = listeners.length;
for (i = 0; i < len; i++)
listeners[i].apply(this, args);
}
return true;
};
EventEmitter.prototype.addListener = function(type, listener) {
var m;
if (!util.isFunction(listener))
throw TypeError('listener must be a function');
if (!this._events)
this._events = {};
// To avoid recursion in the case that type === "newListener"! Before
// adding it to the listeners, first emit "newListener".
if (this._events.newListener)
this.emit('newListener', type,
util.isFunction(listener.listener) ?
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 (util.isObject(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 (util.isObject(this._events[type]) && !this._events[type].warned) {
var m;
if (!util.isUndefined(this._maxListeners)) {
m = this._maxListeners;
} else {
m = EventEmitter.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 (!util.isFunction(listener))
throw 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(type, listener) {
var list, position, length, i;
if (!util.isFunction(listener))
throw TypeError('listener must be a function');
if (!this._events || !this._events[type])
return this;
list = this._events[type];
length = list.length;
position = -1;
if (list === listener ||
(util.isFunction(list.listener) && list.listener === listener)) {
delete this._events[type];
if (this._events.removeListener)
this.emit('removeListener', type, listener);
} else if (util.isObject(list)) {
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 this._events[type];
} else {
list.splice(position, 1);
}
if (this._events.removeListener)
this.emit('removeListener', type, listener);
}
return this;
};
EventEmitter.prototype.removeAllListeners = function(type) {
var key, listeners;
if (!this._events)
return this;
// not listening for removeListener, no need to emit
if (!this._events.removeListener) {
if (arguments.length === 0)
this._events = {};
else if (this._events[type])
delete this._events[type];
return this;
}
// emit removeListener for all listeners on all events
if (arguments.length === 0) {
for (key in this._events) {
if (key === 'removeListener') continue;
this.removeAllListeners(key);
}
this.removeAllListeners('removeListener');
this._events = {};
return this;
}
listeners = this._events[type];
if (util.isFunction(listeners)) {
this.removeListener(type, listeners);
} else if (Array.isArray(listeners)) {
// LIFO order
while (listeners.length)
this.removeListener(type, listeners[listeners.length - 1]);
}
delete this._events[type];
return this;
};
EventEmitter.prototype.listeners = function(type) {
var ret;
if (!this._events || !this._events[type])
ret = [];
else if (util.isFunction(this._events[type]))
ret = [this._events[type]];
else
ret = this._events[type].slice();
return ret;
};
EventEmitter.listenerCount = function(emitter, type) {
var ret;
if (!emitter._events || !emitter._events[type])
ret = 0;
else if (util.isFunction(emitter._events[type]))
ret = 1;
else
ret = emitter._events[type].length;
return ret;
};