src/pools/worker.ts

   1 import type { CircularArray } from '../circular-array'
   2 import type { Queue } from '../queue'
   3
   4 /**
   5  * Callback invoked if the worker has received a message.
   6  */
   7 export type MessageHandler<Worker extends IWorker> = (
   8   this: Worker,
   9   m: unknown
  10 ) => void
  11
  12 /**
  13  * Callback invoked if the worker raised an error.
  14  */
  15 export type ErrorHandler<Worker extends IWorker> = (
  16   this: Worker,
  17   e: Error
  18 ) => void
  19
  20 /**
  21  * Callback invoked when the worker has started successfully.
  22  */
  23 export type OnlineHandler<Worker extends IWorker> = (this: Worker) => void
  24
  25 /**
  26  * Callback invoked when the worker exits successfully.
  27  */
  28 export type ExitHandler<Worker extends IWorker> = (
  29   this: Worker,
  30   code: number
  31 ) => void
  32
  33 /**
  34  * Message object that is passed as a task between main worker and worker.
  35  *
  36  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
  37  * @internal
  38  */
  39 export interface Task<Data = unknown> {
  40   /**
  41    * Task name.
  42    */
  43   readonly name?: string
  44   /**
  45    * Task input data that will be passed to the worker.
  46    */
  47   readonly data?: Data
  48   /**
  49    * Submission timestamp.
  50    */
  51   readonly submissionTimestamp?: number
  52   /**
  53    * Message UUID.
  54    */
  55   readonly id?: string
  56 }
  57
  58 /**
  59  * Worker tasks usage statistics.
  60  *
  61  * @internal
  62  */
  63 export interface TasksUsage {
  64   /**
  65    * Number of tasks executed.
  66    */
  67   ran: number
  68   /**
  69    * Number of tasks running.
  70    */
  71   running: number
  72   /**
  73    * Tasks runtime.
  74    */
  75   runTime: number
  76   /**
  77    * Tasks runtime history.
  78    */
  79   runTimeHistory: CircularArray<number>
  80   /**
  81    * Average tasks runtime.
  82    */
  83   avgRunTime: number
  84   /**
  85    * Median tasks runtime.
  86    */
  87   medRunTime: number
  88   /**
  89    * Tasks wait time.
  90    */
  91   waitTime: number
  92   /**
  93    * Tasks wait time history.
  94    */
  95   waitTimeHistory: CircularArray<number>
  96   /**
  97    * Average tasks wait time.
  98    */
  99   avgWaitTime: number
 100   /**
 101    * Median tasks wait time.
 102    */
 103   medWaitTime: number
 104   /**
 105    * Number of tasks errored.
 106    */
 107   error: number
 108 }
 109
 110 /**
 111  * Worker interface.
 112  */
 113 export interface IWorker {
 114   /**
 115    * Register an event listener.
 116    *
 117    * @param event - The event.
 118    * @param handler - The event handler.
 119    */
 120   on: ((event: 'message', handler: MessageHandler<this>) => void) &
 121   ((event: 'error', handler: ErrorHandler<this>) => void) &
 122   ((event: 'online', handler: OnlineHandler<this>) => void) &
 123   ((event: 'exit', handler: ExitHandler<this>) => void)
 124   /**
 125    * Register a listener to the exit event that will only be performed once.
 126    *
 127    * @param event - `'exit'`.
 128    * @param handler - The exit handler.
 129    */
 130   once: (event: 'exit', handler: ExitHandler<this>) => void
 131 }
 132
 133 /**
 134  * Worker node interface.
 135  *
 136  * @typeParam Worker - Type of worker.
 137  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
 138  * @internal
 139  */
 140 export interface WorkerNode<Worker extends IWorker, Data = unknown> {
 141   /**
 142    * Worker node worker.
 143    */
 144   readonly worker: Worker
 145   /**
 146    * Worker node tasks usage statistics.
 147    */
 148   tasksUsage: TasksUsage
 149   /**
 150    * Worker node tasks queue.
 151    */
 152   readonly tasksQueue: Queue<Task<Data>>
 153 }