src/pools/pool-internal.ts

   1 import EventEmitter from 'events'
   2 import type { IPool } from './pool'
   3 import type { IPoolWorker } from './pool-worker'
   4
   5 /**
   6  * Pool types.
   7  */
   8 export enum PoolType {
   9   FIXED = 'fixed',
  10   DYNAMIC = 'dynamic'
  11 }
  12
  13 /**
  14  * Tasks usage statistics.
  15  */
  16 export interface TasksUsage {
  17   run: number
  18   running: number
  19   runTime: number
  20   avgRunTime: number
  21 }
  22
  23 /**
  24  * Internal poolifier pool emitter.
  25  */
  26 export class PoolEmitter extends EventEmitter {}
  27
  28 /**
  29  * Internal contract definition for a poolifier pool.
  30  *
  31  * @template Worker Type of worker which manages this pool.
  32  * @template Data Type of data sent to the worker.
  33  * @template Response Type of response of execution.
  34  */
  35 export interface IPoolInternal<
  36   Worker extends IPoolWorker,
  37   Data = unknown,
  38   Response = unknown
  39 > extends IPool<Data, Response> {
  40   /**
  41    * List of currently available workers.
  42    */
  43   readonly workers: Worker[]
  44
  45   /**
  46    * The workers tasks usage map.
  47    *
  48    *  `key`: The `Worker`
  49    *  `value`: Worker tasks usage statistics.
  50    */
  51   readonly workersTasksUsage: Map<Worker, TasksUsage>
  52
  53   /**
  54    * Emitter on which events can be listened to.
  55    *
  56    * Events that can currently be listened to:
  57    *
  58    * - `'busy'`
  59    */
  60   readonly emitter?: PoolEmitter
  61
  62   /**
  63    * Pool type.
  64    *
  65    * If it is `'dynamic'`, it provides the `max` property.
  66    */
  67   readonly type: PoolType
  68
  69   /**
  70    * Maximum number of workers that can be created by this pool.
  71    */
  72   readonly max?: number
  73
  74   /**
  75    * Whether the pool is busy or not.
  76    *
  77    * The pool busyness boolean status.
  78    */
  79   readonly busy: boolean
  80
  81   /**
  82    * Number of tasks currently concurrently running.
  83    */
  84   readonly numberOfRunningTasks: number
  85
  86   /**
  87    * Finds a free worker based on the number of tasks the worker has applied.
  88    *
  89    * If a worker is found with `0` running tasks, it is detected as free and returned.
  90    *
  91    * If no free worker is found, `false` is returned.
  92    *
  93    * @returns A free worker if there is one, otherwise `false`.
  94    */
  95   findFreeWorker(): Worker | false
  96
  97   /**
  98    * Gets worker index.
  99    *
 100    * @param worker The worker.
 101    * @returns The worker index.
 102    */
 103   getWorkerIndex(worker: Worker): number
 104
 105   /**
 106    * Gets worker running tasks.
 107    *
 108    * @param worker The worker.
 109    * @returns The number of tasks currently running on the worker.
 110    */
 111   getWorkerRunningTasks(worker: Worker): number | undefined
 112
 113   /**
 114    * Gets worker average tasks runtime.
 115    *
 116    * @param worker The worker.
 117    * @returns The average tasks runtime on the worker.
 118    */
 119   getWorkerAverageTasksRunTime(worker: Worker): number | undefined
 120 }