src/worker/WorkerStaticPool.ts

   1 import { FixedThreadPool, FixedThreadPoolOptions } from 'poolifier';
   2
   3 import Constants from '../utils/Constants';
   4 import Utils from '../utils/Utils';
   5 import { WorkerData } from '../types/Worker';
   6 import Wrk from './Wrk';
   7
   8 export default class WorkerStaticPool<T> extends Wrk {
   9   private pool: StaticPool;
  10
  11   /**
  12    * Create a new `WorkerStaticPool`.
  13    *
  14    * @param {string} workerScript
  15    */
  16   constructor(workerScript: string, numThreads: number) {
  17     super(workerScript);
  18     this.pool = StaticPool.getInstance(numThreads, this.workerScript);
  19   }
  20
  21   get size(): number {
  22     return this.pool.workers.length;
  23   }
  24
  25   get maxElementsPerWorker(): number {
  26     return 1;
  27   }
  28
  29   /**
  30    *
  31    * @return {Promise<void>}
  32    * @public
  33    */
  34   // eslint-disable-next-line @typescript-eslint/no-empty-function
  35   public async start(): Promise<void> { }
  36
  37   /**
  38    *
  39    * @return {Promise<void>}
  40    * @public
  41    */
  42   public async stop(): Promise<void> {
  43     return this.pool.destroy();
  44   }
  45
  46   /**
  47    *
  48    * @return {Promise<void>}
  49    * @public
  50    */
  51   public async addElement(elementData: T): Promise<void> {
  52     await this.pool.execute(elementData);
  53     // Start worker sequentially to optimize memory at startup
  54     await Utils.sleep(Constants.START_WORKER_DELAY);
  55   }
  56 }
  57
  58 class StaticPool extends FixedThreadPool<WorkerData> {
  59   private static instance: StaticPool;
  60
  61   private constructor(numThreads: number, workerScript: string, opts?: FixedThreadPoolOptions) {
  62     super(numThreads, workerScript, opts);
  63   }
  64
  65   public static getInstance(numThreads: number, workerScript: string): StaticPool {
  66     if (!StaticPool.instance) {
  67       StaticPool.instance = new StaticPool(numThreads, workerScript,
  68         {
  69           exitHandler: (code) => {
  70             if (code !== 0) {
  71               console.error(`Worker stopped with exit code ${code}`);
  72             }
  73           }
  74         }
  75       );
  76     }
  77     return StaticPool.instance;
  78   }
  79 }