118 lines
3.6 KiB
JavaScript
Raw Normal View History

2022-07-12 09:00:22 +02:00
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.
import { AbortSignal, abortSignal } from "./AbortSignal";
/**
* This error is thrown when an asynchronous operation has been aborted.
* Check for this error by testing the `name` that the name property of the
* error matches `"AbortError"`.
*
* @example
* ```ts
* const controller = new AbortController();
* controller.abort();
* try {
* doAsyncWork(controller.signal)
* } catch (e) {
* if (e.name === 'AbortError') {
* // handle abort error here.
* }
* }
* ```
*/
export class AbortError extends Error {
constructor(message) {
super(message);
this.name = "AbortError";
}
}
/**
* An AbortController provides an AbortSignal and the associated controls to signal
* that an asynchronous operation should be aborted.
*
* @example
* Abort an operation when another event fires
* ```ts
* const controller = new AbortController();
* const signal = controller.signal;
* doAsyncWork(signal);
* button.addEventListener('click', () => controller.abort());
* ```
*
* @example
* Share aborter cross multiple operations in 30s
* ```ts
* // Upload the same data to 2 different data centers at the same time,
* // abort another when any of them is finished
* const controller = AbortController.withTimeout(30 * 1000);
* doAsyncWork(controller.signal).then(controller.abort);
* doAsyncWork(controller.signal).then(controller.abort);
*```
*
* @example
* Cascaded aborting
* ```ts
* // All operations can't take more than 30 seconds
* const aborter = Aborter.timeout(30 * 1000);
*
* // Following 2 operations can't take more than 25 seconds
* await doAsyncWork(aborter.withTimeout(25 * 1000));
* await doAsyncWork(aborter.withTimeout(25 * 1000));
* ```
*/
export class AbortController {
// eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
constructor(parentSignals) {
this._signal = new AbortSignal();
if (!parentSignals) {
return;
}
// coerce parentSignals into an array
if (!Array.isArray(parentSignals)) {
// eslint-disable-next-line prefer-rest-params
parentSignals = arguments;
}
for (const parentSignal of parentSignals) {
// if the parent signal has already had abort() called,
// then call abort on this signal as well.
if (parentSignal.aborted) {
this.abort();
}
else {
// when the parent signal aborts, this signal should as well.
parentSignal.addEventListener("abort", () => {
this.abort();
});
}
}
}
/**
* The AbortSignal associated with this controller that will signal aborted
* when the abort method is called on this controller.
*
* @readonly
*/
get signal() {
return this._signal;
}
/**
* Signal that any operations passed this controller's associated abort signal
* to cancel any remaining work and throw an `AbortError`.
*/
abort() {
abortSignal(this._signal);
}
/**
* Creates a new AbortSignal instance that will abort after the provided ms.
* @param ms - Elapsed time in milliseconds to trigger an abort.
*/
static timeout(ms) {
const signal = new AbortSignal();
const timer = setTimeout(abortSignal, ms, signal);
// Prevent the active Timer from keeping the Node.js event loop active.
if (typeof timer.unref === "function") {
timer.unref();
}
return signal;
}
}
//# sourceMappingURL=AbortController.js.map