src/pools/pool-worker.ts

   1 import type { Worker as ClusterWorker } from 'cluster'
   2 import type { Worker as WorkerThread } from 'worker_threads'
   3 import type { Draft } from '../utility-types'
   4
   5 /**
   6  * Poolifier supported worker type.
   7  */
   8 export type WorkerType = WorkerThread & ClusterWorker & Draft<MessageChannel>
   9
  10 /**
  11  * Callback invoked if the worker has received a message.
  12  */
  13 export type MessageHandler<Worker> = (this: Worker, m: unknown) => void
  14
  15 /**
  16  * Callback invoked if the worker raised an error.
  17  */
  18 export type ErrorHandler<Worker> = (this: Worker, e: Error) => void
  19
  20 /**
  21  * Callback invoked when the worker has started successfully.
  22  */
  23 export type OnlineHandler<Worker> = (this: Worker) => void
  24
  25 /**
  26  * Callback invoked when the worker exits successfully.
  27  */
  28 export type ExitHandler<Worker> = (this: Worker, code: number) => void
  29
  30 /**
  31  * Interface that describes the minimum required implementation of listener events for a pool worker.
  32  */
  33 export interface IPoolWorker {
  34   /**
  35    * Register a listener to the message event.
  36    *
  37    * @param event `'message'`.
  38    * @param handler The message handler.
  39    */
  40   on(event: 'message', handler: MessageHandler<this>): void
  41   /**
  42    * Register a listener to the error event.
  43    *
  44    * @param event `'error'`.
  45    * @param handler The error handler.
  46    */
  47   on(event: 'error', handler: ErrorHandler<this>): void
  48   /**
  49    * Register a listener to the online event.
  50    *
  51    * @param event `'online'`.
  52    * @param handler The online handler.
  53    */
  54   on(event: 'online', handler: OnlineHandler<this>): void
  55   /**
  56    * Register a listener to the exit event.
  57    *
  58    * @param event `'exit'`.
  59    * @param handler The exit handler.
  60    */
  61   on(event: 'exit', handler: ExitHandler<this>): void
  62   /**
  63    * Register a listener to the exit event that will only performed once.
  64    *
  65    * @param event `'exit'`.
  66    * @param handler The exit handler.
  67    */
  68   once(event: 'exit', handler: ExitHandler<this>): void
  69 }