src/pools/selection-strategies/less-busy-worker-choice-strategy.ts

   1 import type { IPoolWorker } from '../pool-worker'
   2 import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
   3 import type {
   4   IWorkerChoiceStrategy,
   5   RequiredStatistics
   6 } from './selection-strategies-types'
   7
   8 /**
   9  * Selects the less busy worker.
  10  *
  11  * @typeParam Worker - Type of worker which manages the strategy.
  12  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
  13  * @typeParam Response - Type of response of execution. This can only be serializable data.
  14  */
  15 export class LessBusyWorkerChoiceStrategy<
  16     Worker extends IPoolWorker,
  17     Data = unknown,
  18     Response = unknown
  19   >
  20   extends AbstractWorkerChoiceStrategy<Worker, Data, Response>
  21   implements IWorkerChoiceStrategy {
  22   /** @inheritDoc */
  23   public readonly requiredStatistics: RequiredStatistics = {
  24     runTime: true,
  25     avgRunTime: false,
  26     medRunTime: false
  27   }
  28
  29   /** @inheritDoc */
  30   public reset (): boolean {
  31     return true
  32   }
  33
  34   /** @inheritDoc */
  35   public choose (): number {
  36     const freeWorkerKey = this.pool.findFreeWorkerKey()
  37     if (freeWorkerKey !== -1) {
  38       return freeWorkerKey
  39     }
  40     let minRunTime = Infinity
  41     let lessBusyWorkerKey!: number
  42     for (const [index, workerItem] of this.pool.workers.entries()) {
  43       const workerRunTime = workerItem.tasksUsage.runTime
  44       if (workerRunTime === 0) {
  45         return index
  46       } else if (workerRunTime < minRunTime) {
  47         minRunTime = workerRunTime
  48         lessBusyWorkerKey = index
  49       }
  50     }
  51     return lessBusyWorkerKey
  52   }
  53
  54   /** @inheritDoc */
  55   public remove (workerKey: number): boolean {
  56     return true
  57   }
  58 }