| // 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. |
| |
| function EventEmitter() { |
| this._events = this._events || {}; |
| this._maxListeners = this._maxListeners || undefined; |
| } |
| module.exports = EventEmitter; |
| |
| // Backwards-compat with node 0.10.x |
| EventEmitter.EventEmitter = EventEmitter; |
| |
| 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 (!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') { |
| if (!this._events.error || |
| (isObject(this._events.error) && !this._events.error.length)) { |
| er = arguments[1]; |
| 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; |
| } |
| } |
| } |
| |
| handler = this._events[type]; |
| |
| if (isUndefined(handler)) |
| return false; |
| |
| if (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: |
| args = Array.prototype.slice.call(arguments, 1); |
| handler.apply(this, args); |
| } |
| } else if (isObject(handler)) { |
| args = Array.prototype.slice.call(arguments, 1); |
| 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 (!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, |
| 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 (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 (isObject(this._events[type]) && !this._events[type].warned) { |
| if (!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); |
| if (typeof console.trace === 'function') { |
| // not supported in IE 10 |
| console.trace(); |
| } |
| } |
| } |
| |
| return this; |
| }; |
| |
| EventEmitter.prototype.on = EventEmitter.prototype.addListener; |
| |
| EventEmitter.prototype.once = function(type, listener) { |
| if (!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 (!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 || |
| (isFunction(list.listener) && list.listener === listener)) { |
| delete this._events[type]; |
| if (this._events.removeListener) |
| this.emit('removeListener', type, listener); |
| |
| } else if (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 (isFunction(listeners)) { |
| this.removeListener(type, listeners); |
| } else if (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 (isFunction(this._events[type])) |
| ret = [this._events[type]]; |
| else |
| ret = this._events[type].slice(); |
| return ret; |
| }; |
| |
| EventEmitter.prototype.listenerCount = function(type) { |
| if (this._events) { |
| var evlistener = this._events[type]; |
| |
| if (isFunction(evlistener)) |
| return 1; |
| else if (evlistener) |
| return evlistener.length; |
| } |
| return 0; |
| }; |
| |
| EventEmitter.listenerCount = function(emitter, type) { |
| return emitter.listenerCount(type); |
| }; |
| |
| function isFunction(arg) { |
| return typeof arg === 'function'; |
| } |
| |
| function isNumber(arg) { |
| return typeof arg === 'number'; |
| } |
| |
| function isObject(arg) { |
| return typeof arg === 'object' && arg !== null; |
| } |
| |
| function isUndefined(arg) { |
| return arg === void 0; |
| } |