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  * Message object that is passed as a task between main worker and worker.
  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    * Task name.
  41    */
  42   readonly name?: string
  43   /**
  44    * Task input data that will be passed to the worker.
  45    */
  46   readonly data?: Data
  47   /**
  48    * UUID of the message.
  49    */
  50   readonly id?: string
  51 }
  52
  53 /**
  54  * Worker tasks usage statistics.
  55  *
  56  * @internal
  57  */
  58 export interface TasksUsage {
  59   /**
  60    * Number of tasks executed.
  61    */
  62   run: number
  63   /**
  64    * Number of tasks running.
  65    */
  66   running: number
  67   /**
  68    * Tasks runtime.
  69    */
  70   runTime: number
  71   /**
  72    * Tasks runtime history.
  73    */
  74   runTimeHistory: CircularArray<number>
  75   /**
  76    * Average tasks runtime.
  77    */
  78   avgRunTime: number
  79   /**
  80    * Median tasks runtime.
  81    */
  82   medRunTime: number
  83   /**
  84    * Number of tasks errored.
  85    */
  86   error: number
  87 }
  88
  89 /**
  90  * Worker interface.
  91  */
  92 export interface IWorker {
  93   /**
  94    * Register an event listener.
  95    *
  96    * @param event - The event.
  97    * @param handler - The event handler.
  98    */
  99   on: ((event: 'message', handler: MessageHandler<this>) => void) &
 100   ((event: 'error', handler: ErrorHandler<this>) => void) &
 101   ((event: 'online', handler: OnlineHandler<this>) => void) &
 102   ((event: 'exit', handler: ExitHandler<this>) => void)
 103   /**
 104    * Register a listener to the exit event that will only be performed once.
 105    *
 106    * @param event - `'exit'`.
 107    * @param handler - The exit handler.
 108    */
 109   once: (event: 'exit', handler: ExitHandler<this>) => void
 110 }
 111
 112 /**
 113  * Worker node interface.
 114  *
 115  * @typeParam Worker - Type of worker.
 116  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
 117  * @internal
 118  */
 119 export interface WorkerNode<Worker extends IWorker, Data = unknown> {
 120   /**
 121    * Worker node worker.
 122    */
 123   readonly worker: Worker
 124   /**
 125    * Worker node tasks usage statistics.
 126    */
 127   tasksUsage: TasksUsage
 128   /**
 129    * Worker node tasks queue.
 130    */
 131   readonly tasksQueue: Array<Task<Data>>
 132 }