src/pools/cluster/fixed.ts

   1 import { fork, isMaster, setupMaster, Worker } from 'cluster'
   2 import type { MessageValue } from '../../utility-types'
   3 import type { PoolOptions } from '../abstract-pool'
   4 import { AbstractPool } from '../abstract-pool'
   5
   6 /**
   7  * Options for a poolifier cluster pool.
   8  */
   9 export interface ClusterPoolOptions extends PoolOptions<Worker> {
  10   /**
  11    * Key/value pairs to add to worker process environment.
  12    *
  13    * @see https://nodejs.org/api/cluster.html#cluster_cluster_fork_env
  14    */
  15   // eslint-disable-next-line @typescript-eslint/no-explicit-any
  16   env?: any
  17 }
  18
  19 /**
  20  * A cluster pool with a fixed number of workers.
  21  *
  22  * It is possible to perform tasks in sync or asynchronous mode as you prefer.
  23  *
  24  * This pool selects the workers in a round robin fashion.
  25  *
  26  * @template Data Type of data sent to the worker. This can only be serializable data.
  27  * @template Response Type of response of execution. This can only be serializable data.
  28  *
  29  * @author [Christopher Quadflieg](https://github.com/Shinigami92)
  30  * @since 2.0.0
  31  */
  32 export class FixedClusterPool<
  33   Data = unknown,
  34   Response = unknown
  35 > extends AbstractPool<Worker, Data, Response> {
  36   /**
  37    * Constructs a new poolifier fixed cluster pool.
  38    *
  39    * @param numberOfWorkers Number of workers for this pool.
  40    * @param filePath Path to an implementation of a `ClusterWorker` file, which can be relative or absolute.
  41    * @param opts Options for this fixed cluster pool. Default: `{}`
  42    */
  43   public constructor (
  44     numberOfWorkers: number,
  45     filePath: string,
  46     public readonly opts: ClusterPoolOptions = {}
  47   ) {
  48     super(numberOfWorkers, filePath, opts)
  49   }
  50
  51   protected setupHook (): void {
  52     setupMaster({
  53       exec: this.filePath
  54     })
  55   }
  56
  57   protected isMain (): boolean {
  58     return isMaster
  59   }
  60
  61   /** @inheritdoc */
  62   public destroyWorker (worker: Worker): void {
  63     this.sendToWorker(worker, { kill: 1 })
  64     worker.kill()
  65   }
  66
  67   protected sendToWorker (worker: Worker, message: MessageValue<Data>): void {
  68     worker.send(message)
  69   }
  70
  71   /** @inheritdoc */
  72   public registerWorkerMessageListener<Message extends Data | Response> (
  73     worker: Worker,
  74     listener: (message: MessageValue<Message>) => void
  75   ): void {
  76     worker.on('message', listener)
  77   }
  78
  79   protected createWorker (): Worker {
  80     return fork(this.opts.env)
  81   }
  82
  83   protected afterWorkerSetup (worker: Worker): void {
  84     // Listen worker messages.
  85     this.registerWorkerMessageListener(worker, super.workerListener())
  86   }
  87 }