src/pools/pool-internal.ts

   1 import EventEmitter from 'events'
   2 import type { MessageValue } from '../utility-types'
   3 import type { IWorker } from './abstract-pool'
   4 import type { IPool } from './pool'
   5
   6 /**
   7  * Internal poolifier pool emitter.
   8  */
   9 export class PoolEmitter extends EventEmitter {}
  10
  11 /**
  12  * Internal contract definition for a poolifier pool.
  13  *
  14  * @template Worker Type of worker which manages this pool.
  15  * @template Data Type of data sent to the worker.
  16  * @template Response Type of response of execution.
  17  */
  18 export interface IPoolInternal<
  19   Worker extends IWorker,
  20   Data = unknown,
  21   Response = unknown
  22 > extends IPool<Data, Response> {
  23   /**
  24    * List of currently available workers.
  25    */
  26   readonly workers: Worker[]
  27
  28   /**
  29    * The tasks map.
  30    *
  31    * - `key`: The `Worker`
  32    * - `value`: Number of tasks currently in progress on the worker.
  33    */
  34   readonly tasks: Map<Worker, number>
  35
  36   /**
  37    * Emitter on which events can be listened to.
  38    *
  39    * Events that can currently be listened to:
  40    *
  41    * - `'FullPool'`
  42    */
  43   readonly emitter: PoolEmitter
  44
  45   /**
  46    * Whether the pool is dynamic or not.
  47    *
  48    * If it is dynamic, it provides the `max` property.
  49    */
  50   readonly dynamic: boolean
  51
  52   /**
  53    * Maximum number of workers that can be created by this pool.
  54    */
  55   readonly max?: number
  56
  57   /**
  58    * Creates a new worker for this pool and sets it up completely.
  59    *
  60    * @returns New, completely set up worker.
  61    */
  62   createAndSetupWorker(): Worker
  63
  64   /**
  65    * Shut down given worker.
  66    *
  67    * @param worker A worker within `workers`.
  68    */
  69   destroyWorker(worker: Worker): void | Promise<void>
  70
  71   /**
  72    * Register a listener callback on a given worker.
  73    *
  74    * @param worker A worker.
  75    * @param listener A message listener callback.
  76    */
  77   registerWorkerMessageListener<Message extends Data | Response>(
  78     worker: Worker,
  79     listener: (message: MessageValue<Message>) => void
  80   ): void
  81 }