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Module

std/async/deadline.ts

Deno standard library
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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
import { delay } from "./delay.ts";
export interface DeadlineOptions { /** Signal used to abort the deadline. */ signal?: AbortSignal;}
export class DeadlineError extends Error { constructor() { super("Deadline"); this.name = this.constructor.name; }}
/** * Create a promise which will be rejected with {@linkcode DeadlineError} when a given delay is exceeded. * * NOTE: Prefer to use `AbortSignal.timeout` instead for the APIs accept `AbortSignal`. * * @example * ```typescript * import { deadline } from "https://deno.land/std@$STD_VERSION/async/deadline.ts"; * import { delay } from "https://deno.land/std@$STD_VERSION/async/delay.ts"; * * const delayedPromise = delay(1000); * // Below throws `DeadlineError` after 10 ms * const result = await deadline(delayedPromise, 10); * ``` */export function deadline<T>( p: Promise<T>, ms: number, options: DeadlineOptions = {},): Promise<T> { const controller = new AbortController(); const { signal } = options; if (signal?.aborted) { return Promise.reject(new DeadlineError()); } signal?.addEventListener("abort", () => controller.abort(signal.reason)); const d = delay(ms, { signal: controller.signal }) .catch(() => {}) // Do NOTHING on abort. .then(() => Promise.reject(new DeadlineError())); return Promise.race([p.finally(() => controller.abort()), d]);}