sam522's picture
node
d4b85c0
// src/MemoryLeakError.ts
var MemoryLeakError = class extends Error {
constructor(emitter, type, count) {
super(
`Possible EventEmitter memory leak detected. ${count} ${type.toString()} listeners added. Use emitter.setMaxListeners() to increase limit`
);
this.emitter = emitter;
this.type = type;
this.count = count;
this.name = "MaxListenersExceededWarning";
}
};
// src/Emitter.ts
var _Emitter = class {
static listenerCount(emitter, eventName) {
return emitter.listenerCount(eventName);
}
constructor() {
this.events = /* @__PURE__ */ new Map();
this.maxListeners = _Emitter.defaultMaxListeners;
this.hasWarnedAboutPotentialMemoryLeak = false;
}
_emitInternalEvent(internalEventName, eventName, listener) {
this.emit(
internalEventName,
...[eventName, listener]
);
}
_getListeners(eventName) {
return Array.prototype.concat.apply([], this.events.get(eventName)) || [];
}
_removeListener(listeners, listener) {
const index = listeners.indexOf(listener);
if (index > -1) {
listeners.splice(index, 1);
}
return [];
}
_wrapOnceListener(eventName, listener) {
const onceListener = (...data) => {
this.removeListener(eventName, onceListener);
return listener.apply(this, data);
};
Object.defineProperty(onceListener, "name", { value: listener.name });
return onceListener;
}
setMaxListeners(maxListeners) {
this.maxListeners = maxListeners;
return this;
}
/**
* Returns the current max listener value for the `Emitter` which is
* either set by `emitter.setMaxListeners(n)` or defaults to
* `Emitter.defaultMaxListeners`.
*/
getMaxListeners() {
return this.maxListeners;
}
/**
* Returns an array listing the events for which the emitter has registered listeners.
* The values in the array will be strings or Symbols.
*/
eventNames() {
return Array.from(this.events.keys());
}
/**
* Synchronously calls each of the listeners registered for the event named `eventName`,
* in the order they were registered, passing the supplied arguments to each.
* Returns `true` if the event has listeners, `false` otherwise.
*
* @example
* const emitter = new Emitter<{ hello: [string] }>()
* emitter.emit('hello', 'John')
*/
emit(eventName, ...data) {
const listeners = this._getListeners(eventName);
listeners.forEach((listener) => {
listener.apply(this, data);
});
return listeners.length > 0;
}
addListener(eventName, listener) {
this._emitInternalEvent("newListener", eventName, listener);
const nextListeners = this._getListeners(eventName).concat(listener);
this.events.set(eventName, nextListeners);
if (this.maxListeners > 0 && this.listenerCount(eventName) > this.maxListeners && !this.hasWarnedAboutPotentialMemoryLeak) {
this.hasWarnedAboutPotentialMemoryLeak = true;
const memoryLeakWarning = new MemoryLeakError(
this,
eventName,
this.listenerCount(eventName)
);
console.warn(memoryLeakWarning);
}
return this;
}
on(eventName, listener) {
return this.addListener(eventName, listener);
}
once(eventName, listener) {
return this.addListener(
eventName,
this._wrapOnceListener(eventName, listener)
);
}
prependListener(eventName, listener) {
const listeners = this._getListeners(eventName);
if (listeners.length > 0) {
const nextListeners = [listener].concat(listeners);
this.events.set(eventName, nextListeners);
} else {
this.events.set(eventName, listeners.concat(listener));
}
return this;
}
prependOnceListener(eventName, listener) {
return this.prependListener(
eventName,
this._wrapOnceListener(eventName, listener)
);
}
removeListener(eventName, listener) {
const listeners = this._getListeners(eventName);
if (listeners.length > 0) {
this._removeListener(listeners, listener);
this.events.set(eventName, listeners);
this._emitInternalEvent("removeListener", eventName, listener);
}
return this;
}
/**
* Alias for `emitter.removeListener()`.
*
* @example
* emitter.off('hello', listener)
*/
off(eventName, listener) {
return this.removeListener(eventName, listener);
}
removeAllListeners(eventName) {
if (eventName) {
this.events.delete(eventName);
} else {
this.events.clear();
}
return this;
}
/**
* Returns a copy of the array of listeners for the event named `eventName`.
*/
listeners(eventName) {
return Array.from(this._getListeners(eventName));
}
/**
* Returns the number of listeners listening to the event named `eventName`.
*/
listenerCount(eventName) {
return this._getListeners(eventName).length;
}
rawListeners(eventName) {
return this.listeners(eventName);
}
};
var Emitter = _Emitter;
Emitter.defaultMaxListeners = 10;
export {
Emitter,
MemoryLeakError
};
//# sourceMappingURL=index.mjs.map