src/worker/thread-worker.ts

   1 import {
   2   type MessagePort,
   3   isMainThread,
   4   parentPort,
   5   threadId
   6 } from 'node:worker_threads'
   7 import type { MessageValue } from '../utility-types'
   8 import { AbstractWorker } from './abstract-worker'
   9 import type { WorkerOptions } from './worker-options'
  10 import type { TaskFunction, TaskFunctions } from './task-functions'
  11
  12 /**
  13  * A thread worker used by a poolifier `ThreadPool`.
  14  *
  15  * When this worker is inactive for more than the given `maxInactiveTime`,
  16  * it will send a termination request to its main thread.
  17  *
  18  * If you use a `DynamicThreadPool` the extra workers that were created will be terminated,
  19  * but the minimum number of workers will be guaranteed.
  20  *
  21  * @typeParam Data - Type of data this worker receives from pool's execution. This can only be structured-cloneable data.
  22  * @typeParam Response - Type of response the worker sends back to the main thread. This can only be structured-cloneable data.
  23  * @author [Alessandro Pio Ardizio](https://github.com/pioardi)
  24  * @since 0.0.1
  25  */
  26 export class ThreadWorker<
  27   Data = unknown,
  28   Response = unknown
  29 > extends AbstractWorker<MessagePort, Data, Response> {
  30   /**
  31    * Message port used to communicate with the main worker.
  32    */
  33   private port!: MessagePort
  34   /**
  35    * Constructs a new poolifier thread worker.
  36    *
  37    * @param taskFunctions - Task function(s) processed by the worker when the pool's `execution` function is invoked.
  38    * @param opts - Options for the worker.
  39    */
  40   public constructor (
  41     taskFunctions: TaskFunction<Data, Response> | TaskFunctions<Data, Response>,
  42     opts: WorkerOptions = {}
  43   ) {
  44     super(
  45       'worker-thread-pool:poolifier',
  46       isMainThread,
  47       parentPort as MessagePort,
  48       taskFunctions,
  49       opts
  50     )
  51   }
  52
  53   /** @inheritDoc */
  54   protected handleReadyMessage (message: MessageValue<Data>): void {
  55     if (
  56       message.workerId === this.id &&
  57       message.ready === false &&
  58       message.port != null
  59     ) {
  60       try {
  61         this.port = message.port
  62         this.port.on('message', this.messageListener.bind(this))
  63         this.sendToMainWorker({
  64           ready: true,
  65           taskFunctions: this.listTaskFunctions(),
  66           workerId: this.id
  67         })
  68       } catch {
  69         this.sendToMainWorker({
  70           ready: false,
  71           taskFunctions: this.listTaskFunctions(),
  72           workerId: this.id
  73         })
  74       }
  75     }
  76   }
  77
  78   /** @inheritDoc */
  79   protected handleKillMessage (message: MessageValue<Data>): void {
  80     super.handleKillMessage(message)
  81     this.port?.unref()
  82     this.port?.close()
  83   }
  84
  85   /** @inheritDoc */
  86   protected get id (): number {
  87     return threadId
  88   }
  89
  90   /** @inheritDoc */
  91   protected sendToMainWorker (message: MessageValue<Response>): void {
  92     this.port.postMessage(message)
  93   }
  94
  95   /** @inheritDoc */
  96   protected handleError (e: Error | string): string {
  97     return e as string
  98   }
  99 }