angular-docs-cn/packages/service-worker/worker/src/idle.ts

90 lines
2.1 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {Adapter} from './adapter';
import {DebugLogger} from './api';
export interface IdleTask {
run: () => Promise<void>;
desc: string;
}
interface ScheduledRun {
cancel: boolean;
}
export class IdleScheduler {
private queue: IdleTask[] = [];
private scheduled: ScheduledRun|null = null;
empty: Promise<void> = Promise.resolve();
private emptyResolve: Function|null = null;
lastTrigger: number|null = null;
lastRun: number|null = null;
constructor(private adapter: Adapter, private threshold: number, private debug: DebugLogger) {}
async trigger(): Promise<void> {
this.lastTrigger = this.adapter.time;
if (this.queue.length === 0) {
return;
}
if (this.scheduled !== null) {
this.scheduled.cancel = true;
}
const scheduled = {
cancel: false,
};
this.scheduled = scheduled;
await this.adapter.timeout(this.threshold);
if (scheduled.cancel) {
return;
}
this.scheduled = null;
await this.execute();
}
async execute(): Promise<void> {
this.lastRun = this.adapter.time;
while (this.queue.length > 0) {
const queue = this.queue;
this.queue = [];
await queue.reduce(async(previous, task) => {
await previous;
try {
await task.run();
} catch (err) {
this.debug.log(err, `while running idle task ${task.desc}`);
}
}, Promise.resolve());
}
if (this.emptyResolve !== null) {
this.emptyResolve();
this.emptyResolve = null;
}
this.empty = Promise.resolve();
}
schedule(desc: string, run: () => Promise<void>): void {
this.queue.push({desc, run});
if (this.emptyResolve === null) {
this.empty = new Promise(resolve => { this.emptyResolve = resolve; });
}
}
get size(): number { return this.queue.length; }
get taskDescriptions(): string[] { return this.queue.map(task => task.desc); }
}