src/pools/worker.ts

   1 import type { CircularArray } from '../circular-array'
   2
   3 /**
   4  * Callback invoked if the worker has received a message.
   5  */
   6 export type MessageHandler<Worker extends IWorker> = (
   7   this: Worker,
   8   m: unknown
   9 ) => void
  10
  11 /**
  12  * Callback invoked if the worker raised an error.
  13  */
  14 export type ErrorHandler<Worker extends IWorker> = (
  15   this: Worker,
  16   e: Error
  17 ) => void
  18
  19 /**
  20  * Callback invoked when the worker has started successfully.
  21  */
  22 export type OnlineHandler<Worker extends IWorker> = (this: Worker) => void
  23
  24 /**
  25  * Callback invoked when the worker exits successfully.
  26  */
  27 export type ExitHandler<Worker extends IWorker> = (
  28   this: Worker,
  29   code: number
  30 ) => void
  31
  32 /**
  33  * Worker task interface.
  34  *
  35  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
  36  * @internal
  37  */
  38 export interface Task<Data = unknown> {
  39   /**
  40    * Worker task data.
  41    */
  42   data: Data
  43   /**
  44    * Task UUID.
  45    */
  46   id: string
  47 }
  48
  49 /**
  50  * Worker tasks usage statistics.
  51  */
  52 export interface TasksUsage {
  53   run: number
  54   running: number
  55   runTime: number
  56   runTimeHistory: CircularArray<number>
  57   avgRunTime: number
  58   medRunTime: number
  59   error: number
  60 }
  61
  62 /**
  63  * Worker interface.
  64  */
  65 export interface IWorker {
  66   /**
  67    * Register an event listener.
  68    *
  69    * @param event - The event.
  70    * @param handler - The event listener.
  71    */
  72   on: ((event: 'message', handler: MessageHandler<this>) => void) &
  73   ((event: 'error', handler: ErrorHandler<this>) => void) &
  74   ((event: 'online', handler: OnlineHandler<this>) => void) &
  75   ((event: 'exit', handler: ExitHandler<this>) => void)
  76   /**
  77    * Register a listener to the exit event that will only performed once.
  78    *
  79    * @param event - `'exit'`.
  80    * @param handler - The exit handler.
  81    */
  82   once: (event: 'exit', handler: ExitHandler<this>) => void
  83 }
  84
  85 /**
  86  * Worker node interface.
  87  *
  88  * @typeParam Worker - Type of worker.
  89  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
  90  * @internal
  91  */
  92 export interface WorkerNode<Worker extends IWorker, Data = unknown> {
  93   /**
  94    * Worker node worker.
  95    */
  96   worker: Worker
  97   /**
  98    * Worker node tasks usage statistics.
  99    */
 100   tasksUsage: TasksUsage
 101   /**
 102    * Worker node tasks queue.
 103    */
 104   tasksQueue: Array<Task<Data>>
 105 }