src/pools/cluster/fixed.ts

   1 import { fork, isMaster, setupMaster, Worker } from 'cluster'
   2 import type { JSONValue, 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.
  27  * @template Response Type of response of execution.
  28  *
  29  * @author [Christopher Quadflieg](https://github.com/Shinigami92)
  30  * @since 2.0.0
  31  */
  32 export class FixedClusterPool<
  33   Data extends JSONValue = JSONValue,
  34   Response extends JSONValue = JSONValue
  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: `{ maxTasks: 1000 }`
  42    */
  43   public constructor (
  44     numberOfWorkers: number,
  45     filePath: string,
  46     public readonly opts: ClusterPoolOptions = { maxTasks: 1000 }
  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   protected destroyWorker (worker: Worker): void {
  62     worker.kill()
  63   }
  64
  65   protected sendToWorker (worker: Worker, message: MessageValue<Data>): void {
  66     worker.send(message)
  67   }
  68
  69   protected registerWorkerMessageListener (
  70     port: Worker,
  71     listener: (message: MessageValue<Response>) => void
  72   ): void {
  73     port.on('message', listener)
  74   }
  75
  76   protected unregisterWorkerMessageListener (
  77     port: Worker,
  78     listener: (message: MessageValue<Response>) => void
  79   ): void {
  80     port.removeListener('message', listener)
  81   }
  82
  83   protected createWorker (): Worker {
  84     return fork(this.opts.env)
  85   }
  86
  87   protected afterWorkerSetup (worker: Worker): void {
  88     // we will attach a listener for every task,
  89     // when task is completed the listener will be removed but to avoid warnings we are increasing the max listeners size
  90     worker.setMaxListeners(this.opts.maxTasks ?? 1000)
  91   }
  92 }