| 1 | import { WorkerData, WorkerEvents, WorkerSetElement } from '../types/Worker'; |
| 2 | |
| 3 | import Constants from '../utils/Constants'; |
| 4 | import Utils from '../utils/Utils'; |
| 5 | import { Worker } from 'worker_threads'; |
| 6 | import Wrk from './Wrk'; |
| 7 | |
| 8 | export default class WorkerSet extends Wrk { |
| 9 | public maxElementsPerWorker: number; |
| 10 | private workers: Set<WorkerSetElement>; |
| 11 | |
| 12 | /** |
| 13 | * Create a new `WorkerSet`. |
| 14 | * |
| 15 | * @param {string} workerScript |
| 16 | * @param {number} maxElementsPerWorker |
| 17 | */ |
| 18 | constructor(workerScript: string, maxElementsPerWorker = 1) { |
| 19 | super(workerScript); |
| 20 | this.workers = new Set<WorkerSetElement>(); |
| 21 | this.maxElementsPerWorker = maxElementsPerWorker; |
| 22 | } |
| 23 | |
| 24 | get size(): number { |
| 25 | return this.workers.size; |
| 26 | } |
| 27 | |
| 28 | /** |
| 29 | * |
| 30 | * @return {Promise<void>} |
| 31 | * @public |
| 32 | */ |
| 33 | public async addElement(elementData: WorkerData): Promise<void> { |
| 34 | if (!this.workers) { |
| 35 | throw Error('Cannot add a WorkerSet element: workers set does not exist'); |
| 36 | } |
| 37 | if (this.getLastWorkerSetElement().numberOfWorkerElements >= this.maxElementsPerWorker) { |
| 38 | void this.startWorker(); |
| 39 | // Start worker sequentially to optimize memory at startup |
| 40 | void Utils.sleep(Constants.START_WORKER_DELAY); |
| 41 | } |
| 42 | this.getLastWorker().postMessage({ id: WorkerEvents.START_WORKER_ELEMENT, workerData: elementData }); |
| 43 | this.getLastWorkerSetElement().numberOfWorkerElements++; |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * |
| 48 | * @return {Promise<void>} |
| 49 | * @public |
| 50 | */ |
| 51 | public async start(): Promise<void> { |
| 52 | await this.startWorker(); |
| 53 | // Start worker sequentially to optimize memory at startup |
| 54 | await Utils.sleep(Constants.START_WORKER_DELAY); |
| 55 | } |
| 56 | |
| 57 | /** |
| 58 | * |
| 59 | * @return {Promise} |
| 60 | * @private |
| 61 | */ |
| 62 | private async startWorker() { |
| 63 | return new Promise((resolve, reject) => { |
| 64 | const worker = new Worker(this.workerScript); |
| 65 | worker.on('message', resolve); |
| 66 | worker.on('error', reject); |
| 67 | worker.on('exit', (code) => { |
| 68 | if (code !== 0) { |
| 69 | reject(new Error(`Worker stopped with exit code ${code}`)); |
| 70 | } |
| 71 | }); |
| 72 | this.workers.add({ worker, numberOfWorkerElements: 0 }); |
| 73 | }); |
| 74 | } |
| 75 | |
| 76 | private getLastWorkerSetElement(): WorkerSetElement { |
| 77 | let workerSetElement: WorkerSetElement; |
| 78 | // eslint-disable-next-line no-empty |
| 79 | for (workerSetElement of this.workers) { } |
| 80 | return workerSetElement; |
| 81 | } |
| 82 | |
| 83 | private getLastWorker(): Worker { |
| 84 | return this.getLastWorkerSetElement().worker; |
| 85 | } |
| 86 | } |