src/worker/WorkerDynamicPool.ts

   1 import { DynamicThreadPool, 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 WorkerDynamicPool<T> extends WorkerAbstract {
  10   private pool: DynamicPool;
  11
  12   /**
  13    * Create a new `WorkerDynamicPool`.
  14    *
  15    * @param {string} workerScript
  16    */
  17   constructor(workerScript: string, min: number, max: number,) {
  18     super(workerScript);
  19     this.pool = DynamicPool.getInstance(min, max, this.workerScript);
  20   }
  21
  22   get size(): number {
  23     return this.pool.workers.length;
  24   }
  25
  26   get maxElementsPerWorker(): number {
  27     return 1;
  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   // eslint-disable-next-line @typescript-eslint/require-await
  44   public async stop(): Promise<void> {
  45     return this.pool.destroy();
  46   }
  47
  48   /**
  49    *
  50    * @return {Promise<void>}
  51    * @public
  52    */
  53   public async addElement(elementData: T): Promise<void> {
  54     await this.pool.execute(elementData);
  55     // Start worker sequentially to optimize memory at startup
  56     await Utils.sleep(Constants.START_WORKER_DELAY);
  57   }
  58 }
  59
  60 class DynamicPool extends DynamicThreadPool<WorkerData> {
  61   private static instance: DynamicPool;
  62
  63   private constructor(min: number, max: number, workerScript: string, opts?: PoolOptions<Worker>) {
  64     super(min, max, workerScript, opts);
  65   }
  66
  67   public static getInstance(min: number, max: number, workerScript: string): DynamicPool {
  68     if (!DynamicPool.instance) {
  69       DynamicPool.instance = new DynamicPool(min, max, workerScript,
  70         {
  71           exitHandler: (code) => {
  72             if (code !== 0) {
  73               console.error(`Worker stopped with exit code ${code}`);
  74             }
  75           }
  76         }
  77       );
  78     }
  79     return DynamicPool.instance;
  80   }
  81 }