src/worker/WorkerAbstract.ts

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