signal-desktop/ts/test-node/jobs/TestJobQueueStore.ts
2022-12-21 10:41:48 -08:00

136 lines
3 KiB
TypeScript

// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
/* eslint-disable max-classes-per-file */
/* eslint-disable no-await-in-loop */
import EventEmitter, { once } from 'events';
import type { JobQueueStore, StoredJob } from '../../jobs/types';
import { sleep } from '../../util/sleep';
import { drop } from '../../util/drop';
export class TestJobQueueStore implements JobQueueStore {
events = new EventEmitter();
private openStreams = new Set<string>();
private pipes = new Map<string, Pipe>();
storedJobs: Array<StoredJob> = [];
constructor(jobs: ReadonlyArray<StoredJob> = []) {
jobs.forEach(job => {
drop(this.insert(job));
});
}
async insert(
job: Readonly<StoredJob>,
{ shouldPersist = true }: Readonly<{ shouldPersist?: boolean }> = {}
): Promise<void> {
await fakeDelay();
this.storedJobs.forEach(storedJob => {
if (job.id === storedJob.id) {
throw new Error('Cannot store two jobs with the same ID');
}
});
if (shouldPersist) {
this.storedJobs.push(job);
}
this.getPipe(job.queueType).add(job);
this.events.emit('insert');
}
async delete(id: string): Promise<void> {
await fakeDelay();
this.storedJobs = this.storedJobs.filter(job => job.id !== id);
this.events.emit('delete');
}
stream(queueType: string): Pipe {
if (this.openStreams.has(queueType)) {
throw new Error('Cannot stream the same queueType more than once');
}
this.openStreams.add(queueType);
return this.getPipe(queueType);
}
pauseStream(queueType: string): void {
return this.getPipe(queueType).pause();
}
resumeStream(queueType: string): void {
return this.getPipe(queueType).resume();
}
private getPipe(queueType: string): Pipe {
const existingPipe = this.pipes.get(queueType);
if (existingPipe) {
return existingPipe;
}
const result = new Pipe();
this.pipes.set(queueType, result);
return result;
}
}
class Pipe implements AsyncIterable<StoredJob> {
private queue: Array<StoredJob> = [];
private eventEmitter = new EventEmitter();
private isLocked = false;
private isPaused = false;
add(value: Readonly<StoredJob>) {
this.queue.push(value);
this.eventEmitter.emit('add');
}
async *[Symbol.asyncIterator]() {
if (this.isLocked) {
throw new Error('Cannot iterate over a pipe more than once');
}
this.isLocked = true;
while (true) {
for (const value of this.queue) {
await this.waitForUnpaused();
yield value;
}
this.queue = [];
// We do this because we want to yield values in series.
await once(this.eventEmitter, 'add');
}
}
pause(): void {
this.isPaused = true;
}
resume(): void {
this.isPaused = false;
this.eventEmitter.emit('resume');
}
private async waitForUnpaused() {
if (this.isPaused) {
await once(this.eventEmitter, 'resume');
}
}
}
function fakeDelay(): Promise<void> {
return sleep(0);
}