src/worker/WorkerStaticPool.ts

   1 import { FixedThreadPool, PoolOptions } from 'poolifier';
   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 import { WorkerData } from '../types/Worker';
   8
   9 export default class WorkerStaticPool<T> extends WorkerAbstract {
  10   private pool: StaticPool;
  11
  12   /**
  13    * Create a new `WorkerStaticPool`.
  14    *
  15    * @param {string} workerScript
  16    */
  17   constructor(workerScript: string, numberOfThreads: number) {
  18     super(workerScript);
  19     this.pool = StaticPool.getInstance(numberOfThreads, this.workerScript);
  20   }
  21
  22   get size(): number {
  23     return this.pool.workers.length;
  24   }
  25
  26   get maxElementsPerWorker(): number {
  27     return null;
  28   }
  29
  30   /**
  31    *
  32    * @return {Promise<void>}
  33    * @public
  34    */
  35   // eslint-disable-next-line @typescript-eslint/no-empty-function
  36   public async start(): Promise<void> { }
  37
  38   /**
  39    *
  40    * @return {Promise<void>}
  41    * @public
  42    */
  43   public async stop(): Promise<void> {
  44     return this.pool.destroy();
  45   }
  46
  47   /**
  48    *
  49    * @return {Promise<void>}
  50    * @public
  51    */
  52   public async addElement(elementData: T): Promise<void> {
  53     await this.pool.execute(elementData);
  54     // Start worker sequentially to optimize memory at startup
  55     await Utils.sleep(Constants.START_WORKER_DELAY);
  56   }
  57 }
  58
  59 class StaticPool extends FixedThreadPool<WorkerData> {
  60   private static instance: StaticPool;
  61
  62   private constructor(numberOfThreads: number, workerScript: string, opts?: PoolOptions<Worker>) {
  63     super(numberOfThreads, workerScript, opts);
  64   }
  65
  66   public static getInstance(numberOfThreads: number, workerScript: string): StaticPool {
  67     if (!StaticPool.instance) {
  68       StaticPool.instance = new StaticPool(numberOfThreads, workerScript,
  69         {
  70           exitHandler: (code) => {
  71             if (code !== 0) {
  72               console.error(`Worker stopped with exit code ${code}`);
  73             }
  74           }
  75         }
  76       );
  77     }
  78     return StaticPool.instance;
  79   }
  80 }