80 lines
1.9 KiB
TypeScript
80 lines
1.9 KiB
TypeScript
/*---------------------------------------------------------------------------------------------
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* Copyright (c) Microsoft Corporation. All rights reserved.
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* Licensed under the MIT License. See License.txt in the project root for license information.
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*--------------------------------------------------------------------------------------------*/
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export interface ITask<T> {
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(): T;
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}
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export class Delayer<T> {
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public defaultDelay: number;
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private timeout: any; // Timer
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private completionPromise: Promise<T> | null;
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private onSuccess: ((value: T | PromiseLike<T> | undefined) => void) | null;
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private task: ITask<T> | null;
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constructor(defaultDelay: number) {
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this.defaultDelay = defaultDelay;
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this.timeout = null;
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this.completionPromise = null;
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this.onSuccess = null;
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this.task = null;
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}
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public trigger(task: ITask<T>, delay: number = this.defaultDelay): Promise<T> {
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this.task = task;
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if (delay >= 0) {
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this.cancelTimeout();
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}
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if (!this.completionPromise) {
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this.completionPromise = new Promise<T | undefined>((resolve) => {
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this.onSuccess = resolve;
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}).then(() => {
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this.completionPromise = null;
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this.onSuccess = null;
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let result = this.task!();
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this.task = null;
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return result;
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});
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}
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if (delay >= 0 || this.timeout === null) {
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this.timeout = setTimeout(() => {
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this.timeout = null;
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this.onSuccess!(undefined);
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}, delay >= 0 ? delay : this.defaultDelay);
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}
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return this.completionPromise;
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}
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public forceDelivery(): Promise<T> | null {
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if (!this.completionPromise) {
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return null;
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}
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this.cancelTimeout();
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let result = this.completionPromise;
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this.onSuccess!(undefined);
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return result;
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}
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public isTriggered(): boolean {
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return this.timeout !== null;
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}
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public cancel(): void {
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this.cancelTimeout();
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this.completionPromise = null;
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}
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private cancelTimeout(): void {
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if (this.timeout !== null) {
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clearTimeout(this.timeout);
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this.timeout = null;
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}
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}
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}
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