src/pools/thread/fixed.ts

   1 import {
   2   type MessageChannel,
   3   type MessagePort,
   4   SHARE_ENV,
   5   Worker,
   6   type WorkerOptions,
   7   isMainThread
   8 } from 'node:worker_threads'
   9 import type { MessageValue } from '../../utility-types'
  10 import { AbstractPool } from '../abstract-pool'
  11 import { type PoolOptions, type PoolType, PoolTypes } from '../pool'
  12 import { type WorkerType, WorkerTypes } from '../worker'
  13
  14 /**
  15  * Options for a poolifier thread pool.
  16  */
  17 export interface ThreadPoolOptions extends PoolOptions<Worker> {
  18   /**
  19    * Worker options.
  20    *
  21    * @see https://nodejs.org/api/worker_threads.html#new-workerfilename-options
  22    */
  23   workerOptions?: WorkerOptions
  24 }
  25
  26 /**
  27  * A thread pool with a fixed number of threads.
  28  *
  29  * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
  30  * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
  31  * @author [Alessandro Pio Ardizio](https://github.com/pioardi)
  32  * @since 0.0.1
  33  */
  34 export class FixedThreadPool<
  35   Data = unknown,
  36   Response = unknown
  37 > extends AbstractPool<Worker, Data, Response> {
  38   /**
  39    * Constructs a new poolifier fixed thread pool.
  40    *
  41    * @param numberOfThreads - Number of threads for this pool.
  42    * @param filePath - Path to an implementation of a `ThreadWorker` file, which can be relative or absolute.
  43    * @param opts - Options for this fixed thread pool.
  44    */
  45   public constructor (
  46     numberOfThreads: number,
  47     filePath: string,
  48     protected readonly opts: ThreadPoolOptions = {}
  49   ) {
  50     super(numberOfThreads, filePath, opts)
  51   }
  52
  53   /** @inheritDoc */
  54   protected isMain (): boolean {
  55     return isMainThread
  56   }
  57
  58   /** @inheritDoc */
  59   protected async destroyWorker (worker: Worker): Promise<void> {
  60     this.sendToWorker(worker, { kill: true, workerId: worker.threadId })
  61     const workerInfo = this.getWorkerInfoByWorker(worker)
  62     workerInfo.messageChannel?.port1.close()
  63     workerInfo.messageChannel?.port2.close()
  64     await worker.terminate()
  65   }
  66
  67   /** @inheritDoc */
  68   protected sendToWorker (worker: Worker, message: MessageValue<Data>): void {
  69     (
  70       this.getWorkerInfoByWorker(worker).messageChannel as MessageChannel
  71     ).port1.postMessage(message)
  72   }
  73
  74   /** @inheritDoc */
  75   protected sendStartupMessageToWorker (worker: Worker): void {
  76     const port2: MessagePort = (
  77       this.getWorkerInfoByWorker(worker).messageChannel as MessageChannel
  78     ).port2
  79     worker.postMessage(
  80       {
  81         ready: false,
  82         workerId: worker.threadId,
  83         port: port2
  84       },
  85       [port2]
  86     )
  87   }
  88
  89   /** @inheritDoc */
  90   protected registerWorkerMessageListener<Message extends Data | Response>(
  91     worker: Worker,
  92     listener: (message: MessageValue<Message>) => void
  93   ): void {
  94     (
  95       this.getWorkerInfoByWorker(worker).messageChannel as MessageChannel
  96     ).port1.on('message', listener)
  97   }
  98
  99   /** @inheritDoc */
 100   protected createWorker (): Worker {
 101     return new Worker(this.filePath, {
 102       env: SHARE_ENV,
 103       ...this.opts.workerOptions
 104     })
 105   }
 106
 107   /** @inheritDoc */
 108   protected get type (): PoolType {
 109     return PoolTypes.fixed
 110   }
 111
 112   /** @inheritDoc */
 113   protected get worker (): WorkerType {
 114     return WorkerTypes.thread
 115   }
 116
 117   /** @inheritDoc */
 118   protected get minSize (): number {
 119     return this.numberOfWorkers
 120   }
 121
 122   /** @inheritDoc */
 123   protected get maxSize (): number {
 124     return this.numberOfWorkers
 125   }
 126
 127   /** @inheritDoc */
 128   protected get busy (): boolean {
 129     return this.internalBusy()
 130   }
 131 }