src/worker/WorkerAbstract.ts

   1 import type { EventEmitter } from 'node:events';
   2 import { existsSync } from 'node:fs';
   3 import type { Worker } from 'node:worker_threads';
   4
   5 import type { ErrorHandler, ExitHandler, PoolEmitter, PoolInfo } from 'poolifier';
   6
   7 import { WorkerConstants } from './WorkerConstants';
   8 import type { SetInfo, WorkerData, WorkerOptions } from './WorkerTypes';
   9 import { defaultErrorHandler, defaultExitHandler } from './WorkerUtils';
  10
  11 export abstract class WorkerAbstract<T extends WorkerData> {
  12   protected readonly workerScript: string;
  13   protected readonly workerOptions: WorkerOptions;
  14   public abstract readonly info: PoolInfo | SetInfo;
  15   public abstract readonly size: number;
  16   public abstract readonly maxElementsPerWorker: number | undefined;
  17   public abstract readonly emitter: EventEmitter | PoolEmitter | undefined;
  18
  19   /**
  20    * `WorkerAbstract` constructor.
  21    *
  22    * @param workerScript -
  23    * @param workerOptions -
  24    */
  25   constructor(
  26     workerScript: string,
  27     workerOptions: WorkerOptions = {
  28       workerStartDelay: WorkerConstants.DEFAULT_WORKER_START_DELAY,
  29       elementStartDelay: WorkerConstants.DEFAULT_ELEMENT_START_DELAY,
  30       poolMinSize: WorkerConstants.DEFAULT_POOL_MIN_SIZE,
  31       poolMaxSize: WorkerConstants.DEFAULT_POOL_MAX_SIZE,
  32       elementsPerWorker: WorkerConstants.DEFAULT_ELEMENTS_PER_WORKER,
  33       poolOptions: {},
  34     }
  35   ) {
  36     if (workerScript === null || workerScript === undefined) {
  37       throw new Error('Worker script is not defined');
  38     }
  39     if (typeof workerScript === 'string' && workerScript.trim().length === 0) {
  40       throw new Error('Worker script is empty');
  41     }
  42     if (!existsSync(workerScript)) {
  43       throw new Error('Worker script file does not exist');
  44     }
  45     this.workerScript = workerScript;
  46     this.workerOptions = workerOptions;
  47     this.workerOptions.poolOptions?.messageHandler?.bind(this);
  48     this.workerOptions.poolOptions.errorHandler = (
  49       this.workerOptions?.poolOptions?.errorHandler ?? defaultErrorHandler
  50     ).bind(this) as ErrorHandler<Worker>;
  51     this.workerOptions.poolOptions?.onlineHandler?.bind(this);
  52     this.workerOptions.poolOptions.exitHandler = (
  53       this.workerOptions?.poolOptions?.exitHandler ?? defaultExitHandler
  54     ).bind(this) as ExitHandler<Worker>;
  55   }
  56
  57   /**
  58    * Starts the worker pool/set.
  59    */
  60   public abstract start(): Promise<void>;
  61   /**
  62    * Stops the worker pool/set.
  63    */
  64   public abstract stop(): Promise<void>;
  65   /**
  66    * Adds a task element to the worker pool/set.
  67    *
  68    * @param elementData -
  69    */
  70   public abstract addElement(elementData: T): Promise<void>;
  71 }