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