// 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.
'use strict';
var R = typeof Reflect === 'object' ? Reflect : null
var ReflectApply = R && typeof R.apply === 'function'
? R.apply
: function ReflectApply(target, receiver, args) {
return Function.prototype.apply.call(target, receiver, args);
}
var ReflectOwnKeys
if (R && typeof R.ownKeys === 'function') {
ReflectOwnKeys = R.ownKeys
} else if (Object.getOwnPropertySymbols) {
ReflectOwnKeys = function ReflectOwnKeys(target) {
return Object.getOwnPropertyNames(target)
.concat(Object.getOwnPropertySymbols(target));
};
} else {
ReflectOwnKeys = function ReflectOwnKeys(target) {
return Object.getOwnPropertyNames(target);
};
}
function ProcessEmitWarning(warning) {
if (console && console.warn) console.warn(warning);
}
var NumberIsNaN = Number.isNaN || function NumberIsNaN(value) {
return value !== value;
}
function EventEmitter() {
EventEmitter.init.call(this);
}
module.exports = EventEmitter;
module.exports.once = once;
// Backwards-compat with node 0.10.x
EventEmitter.EventEmitter = EventEmitter;
EventEmitter.prototype._events = undefined;
EventEmitter.prototype._eventsCount = 0;
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.
var defaultMaxListeners = 10;
function checkListener(listener) {
if (typeof listener !== 'function') {
throw new TypeError('The "listener" argument must be of type Function. Received type ' + typeof listener);
}
}
Object.defineProperty(EventEmitter, 'defaultMaxListeners', {
enumerable: true,
get: function() {
return defaultMaxListeners;
},
set: function(arg) {
if (typeof arg !== 'number' || arg < 0 || NumberIsNaN(arg)) {
throw new RangeError('The value of "defaultMaxListeners" is out of range. It must be a non-negative number. Received ' + arg + '.');
}
defaultMaxListeners = arg;
}
});
EventEmitter.init = function() {
if (this._events === undefined ||
this._events === Object.getPrototypeOf(this)._events) {
this._events = Object.create(null);
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.
EventEmitter.prototype.setMaxListeners = function setMaxListeners(n) {
if (typeof n !== 'number' || n < 0 || NumberIsNaN(n)) {
throw new RangeError('The value of "n" is out of range. It must be a non-negative number. Received ' + n + '.');
}
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);
};
EventEmitter.prototype.emit = function emit(type) {
var args = [];
for (var i = 1; i < arguments.length; i++) args.push(arguments[i]);
var doError = (type === 'error');
var events = this._events;
if (events !== undefined)
doError = (doError && events.error === undefined);
else if (!doError)
return false;
// If there is no 'error' event listener then throw.
if (doError) {
var er;
if (args.length > 0)
er = args[0];
if (er instanceof Error) {
// Note: The comments on the `throw` lines are intentional, they show
// up in Node's output if this results in an unhandled exception.
throw er; // Unhandled 'error' event
}
// At least give some kind of context to the user
var err = new Error('Unhandled error.' + (er ? ' (' + er.message + ')' : ''));
err.context = er;
throw err; // Unhandled 'error' event
}
var handler = events[type];
if (handler === undefined)
return false;
if (typeof handler === 'function') {
ReflectApply(handler, this, args);
} else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
ReflectApply(listeners[i], this, args);
}
return true;
};
function _addListener(target, type, listener, prepend) {
var m;
var events;
var existing;
checkListener(listener);
events = target._events;
if (events === undefined) {
events = target._events = Object.create(null);
target._eventsCount = 0;
} else {
// To avoid recursion in the case that type === "newListener"! Before
// adding it to the listeners, first emit "newListener".
if (events.newListener !== undefined) {
target.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 = target._events;
}
existing = events[type];
}
if (existing === undefined) {
// Optimize the case of one listener. Don't need the extra array object.
existing = events[type] = listener;
++target._eventsCount;
} else {
if (typeof existing === 'function') {
// Adding the second element, need to change to array.
existing = events[type] =
prepend ? [listener, existing] : [existing, listener];
// If we've already got an array, just append.
} else if (prepend) {
existing.unshift(listener);
} else {
existing.push(listener);
}
// Check for listener leak
m = _getMaxListeners(target);
if (m > 0 && existing.length > m && !existing.warned) {
existing.warned = true;
// No error code for this since it is a Warning
// eslint-disable-next-line no-restricted-syntax
var w = new Error('Possible EventEmitter memory leak detected. ' +
existing.length + ' ' + String(type) + ' listeners ' +
'added. Use emitter.setMaxListeners() to ' +
'increase limit');
w.name = 'MaxListenersExceededWarning';
w.emitter = target;
w.type = type;
w.count = existing.length;
ProcessEmitWarning(w);
}
}
return target;
}
EventEmitter.prototype.addListener = function addListener(type, listener) {
return _addListener(this, type, listener, false);
};
EventEmitter.prototype.on = EventEmitter.prototype.addListener;
EventEmitter.prototype.prependListener =
function prependListener(type, listener) {
return _addListener(this, type, listener, true);
};
function onceWrapper() {
if (!this.fired) {
this.target.removeListener(this.type, this.wrapFn);
this.fired = true;
if (arguments.length === 0)
return this.listener.call(this.target);
return this.listener.apply(this.target, arguments);
}
}
function _onceWrap(target, type, listener) {
var state = { fired: false, wrapFn: undefined, target: target, type: type, listener: listener };
var wrapped = onceWrapper.bind(state);
wrapped.listener = listener;
state.wrapFn = wrapped;
return wrapped;
}
EventEmitter.prototype.once = function once(type, listener) {
checkListener(listener);
this.on(type, _onceWrap(this, type, listener));
return this;
};
EventEmitter.prototype.prependOnceListener =
function prependOnceListener(type, listener) {
checkListener(listener);
this.prependListener(type, _onceWrap(this, type, listener));
return this;
};
// Emits a 'removeListener' event if and only if the listener was removed.
EventEmitter.prototype.removeListener =
function removeListener(type, listener) {
var list, events, position, i, originalListener;
checkListener(listener);
events = this._events;
if (events === undefined)
return this;
list = events[type];
if (list === undefined)
return this;
if (list === listener || list.listener === listener) {
if (--this._eventsCount === 0)
this._events = Object.create(null);
else {
delete events[type];
if (events.removeListener)
this.emit('removeListener', type, list.listener || listener);
}
} else if (typeof list !== 'function') {
position = -1;
for (i = list.length - 1; i >= 0; i--) {
if (list[i] === listener || list[i].listener === listener) {
originalListener = list[i].listener;
position = i;
break;
}
}
if (position < 0)
return this;
if (position === 0)
list.shift();
else {
spliceOne(list, position);
}
if (list.length === 1)
events[type] = list[0];
if (events.removeListener !== undefined)
this.emit('removeListener', type, originalListener || listener);
}
return this;
};
EventEmitter.prototype.off = EventEmitter.prototype.removeListener;
EventEmitter.prototype.removeAllListeners =
function removeAllListeners(type) {
var listeners, events, i;
events = this._events;
if (events === undefined)
return this;
// not listening for removeListener, no need to emit
if (events.removeListener === undefined) {
if (arguments.length === 0) {
this._events = Object.create(null);
this._eventsCount = 0;
} else if (events[type] !== undefined) {
if (--this._eventsCount === 0)
this._events = Object.create(null);
else
delete events[type];
}
return this;
}
// emit removeListener for all listeners on all events
if (arguments.length === 0) {
var keys = Object.keys(events);
var key;
for (i = 0; i < keys.length; ++i) {
key = keys[i];
if (key === 'removeListener') continue;
this.removeAllListeners(key);
}
this.removeAllListeners('removeListener');
this._events = Object.create(null);
this._eventsCount = 0;
return this;
}
listeners = events[type];
if (typeof listeners === 'function') {
this.removeListener(type, listeners);
} else if (listeners !== undefined) {
// LIFO order
for (i = listeners.length - 1; i >= 0; i--) {
this.removeListener(type, listeners[i]);
}
}
return this;
};
function _listeners(target, type, unwrap) {
var events = target._events;
if (events === undefined)
return [];
var evlistener = events[type];
if (evlistener === undefined)
return [];
if (typeof evlistener === 'function')
return unwrap ? [evlistener.listener || evlistener] : [evlistener];
return unwrap ?
unwrapListeners(evlistener) : arrayClone(evlistener, evlistener.length);
}
EventEmitter.prototype.listeners = function listeners(type) {
return _listeners(this, type, true);
};
EventEmitter.prototype.rawListeners = function rawListeners(type) {
return _listeners(this, type, false);
};
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) {
var events = this._events;
if (events !== undefined) {
var evlistener = events[type];
if (typeof evlistener === 'function') {
return 1;
} else if (evlistener !== undefined) {
return evlistener.length;
}
}
return 0;
}
EventEmitter.prototype.eventNames = function eventNames() {
return this._eventsCount > 0 ? ReflectOwnKeys(this._events) : [];
};
function arrayClone(arr, n) {
var copy = new Array(n);
for (var i = 0; i < n; ++i)
copy[i] = arr[i];
return copy;
}
function spliceOne(list, index) {
for (; index + 1 < list.length; index++)
list[index] = list[index + 1];
list.pop();
}
function unwrapListeners(arr) {
var ret = new Array(arr.length);
for (var i = 0; i < ret.length; ++i) {
ret[i] = arr[i].listener || arr[i];
}
return ret;
}
function once(emitter, name) {
return new Promise(function (resolve, reject) {
function errorListener(err) {
emitter.removeListener(name, resolver);
reject(err);
}
function resolver() {
if (typeof emitter.removeListener === 'function') {
emitter.removeListener('error', errorListener);
}
resolve([].slice.call(arguments));
};
eventTargetAgnosticAddListener(emitter, name, resolver, { once: true });
if (name !== 'error') {
addErrorHandlerIfEventEmitter(emitter, errorListener, { once: true });
}
});
}
function addErrorHandlerIfEventEmitter(emitter, handler, flags) {
if (typeof emitter.on === 'function') {
eventTargetAgnosticAddListener(emitter, 'error', handler, flags);
}
}
function eventTargetAgnosticAddListener(emitter, name, listener, flags) {
if (typeof emitter.on === 'function') {
if (flags.once) {
emitter.once(name, listener);
} else {
emitter.on(name, listener);
}
} else if (typeof emitter.addEventListener === 'function') {
// EventTarget does not have `error` event semantics like Node
// EventEmitters, we do not listen for `error` events here.
emitter.addEventListener(name, function wrapListener(arg) {
// IE does not have builtin `{ once: true }` support so we
// have to do it manually.
if (flags.once) {
emitter.removeEventListener(name, wrapListener);
}
listener(arg);
});
} else {
throw new TypeError('The "emitter" argument must be of type EventEmitter. Received type ' + typeof emitter);
}
}