| 1 | import { 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 WorkerAbstract from './WorkerAbstract'; |
| 7 | |
| 8 | export default class WorkerSet<T> extends WorkerAbstract { |
| 9 | public maxElementsPerWorker: number; |
| 10 | private workerSet: 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.workerSet = new Set<WorkerSetElement>(); |
| 21 | this.maxElementsPerWorker = maxElementsPerWorker; |
| 22 | } |
| 23 | |
| 24 | get size(): number { |
| 25 | return this.workerSet.size; |
| 26 | } |
| 27 | |
| 28 | /** |
| 29 | * |
| 30 | * @param elementData |
| 31 | * @returns {Promise<void>} |
| 32 | * @public |
| 33 | */ |
| 34 | public async addElement(elementData: T): Promise<void> { |
| 35 | if (!this.workerSet) { |
| 36 | throw Error('Cannot add a WorkerSet element: workers\' set does not exist'); |
| 37 | } |
| 38 | if (this.getLastWorkerSetElement().numberOfWorkerElements >= this.maxElementsPerWorker) { |
| 39 | this.startWorker(); |
| 40 | // Start worker sequentially to optimize memory at startup |
| 41 | await Utils.sleep(Constants.START_WORKER_DELAY); |
| 42 | } |
| 43 | this.getLastWorker().postMessage({ id: WorkerEvents.START_WORKER_ELEMENT, workerData: elementData }); |
| 44 | this.getLastWorkerSetElement().numberOfWorkerElements++; |
| 45 | } |
| 46 | |
| 47 | /** |
| 48 | * |
| 49 | * @returns {Promise<void>} |
| 50 | * @public |
| 51 | */ |
| 52 | public async start(): Promise<void> { |
| 53 | this.startWorker(); |
| 54 | // Start worker sequentially to optimize memory at startup |
| 55 | await Utils.sleep(Constants.START_WORKER_DELAY); |
| 56 | } |
| 57 | |
| 58 | /** |
| 59 | * |
| 60 | * @returns {Promise<void>} |
| 61 | * @public |
| 62 | */ |
| 63 | public async stop(): Promise<void> { |
| 64 | for (const workerSetElement of this.workerSet) { |
| 65 | await workerSetElement.worker.terminate(); |
| 66 | } |
| 67 | this.workerSet.clear(); |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * |
| 72 | * @returns {Promise} |
| 73 | * @private |
| 74 | */ |
| 75 | private startWorker(): void { |
| 76 | const worker = new Worker(this.workerScript); |
| 77 | worker.on('message', () => { }); |
| 78 | worker.on('error', () => { }); |
| 79 | worker.on('exit', (code) => { |
| 80 | if (code !== 0) { |
| 81 | console.error(`Worker stopped with exit code ${code}`); |
| 82 | } |
| 83 | this.workerSet.delete(this.getWorkerSetElementByWorker(worker)); |
| 84 | }); |
| 85 | this.workerSet.add({ worker, numberOfWorkerElements: 0 }); |
| 86 | } |
| 87 | |
| 88 | private getLastWorkerSetElement(): WorkerSetElement { |
| 89 | let workerSetElement: WorkerSetElement; |
| 90 | // eslint-disable-next-line no-empty |
| 91 | for (workerSetElement of this.workerSet) { } |
| 92 | return workerSetElement; |
| 93 | } |
| 94 | |
| 95 | private getLastWorker(): Worker { |
| 96 | return this.getLastWorkerSetElement().worker; |
| 97 | } |
| 98 | |
| 99 | private getWorkerSetElementByWorker(worker: Worker): WorkerSetElement { |
| 100 | let workerSetElt: WorkerSetElement; |
| 101 | this.workerSet.forEach((workerSetElement) => { |
| 102 | if (JSON.stringify(workerSetElement.worker) === JSON.stringify(worker)) { |
| 103 | workerSetElt = workerSetElement; |
| 104 | } |
| 105 | }); |
| 106 | return workerSetElt; |
| 107 | } |
| 108 | } |