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