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,
  18     Response
  19   >
  20   extends AbstractWorkerChoiceStrategy<Worker, Data, Response>
  21   implements IWorkerChoiceStrategy {
  22   /** {@inheritDoc} */
  23   public readonly requiredStatistics: RequiredStatistics = {
  24     runTime: true,
  25     avgRunTime: false
  26   }
  27
  28   /** {@inheritDoc} */
  29   public reset (): boolean {
  30     return true
  31   }
  32
  33   /** {@inheritDoc} */
  34   public choose (): number {
  35     const freeWorkerKey = this.pool.findFreeWorkerKey()
  36     if (!this.isDynamicPool && freeWorkerKey !== -1) {
  37       return freeWorkerKey
  38     }
  39     let minRunTime = Infinity
  40     let lessBusyWorkerKey!: number
  41     for (const [index, workerItem] of this.pool.workers.entries()) {
  42       const workerRunTime = workerItem.tasksUsage.runTime
  43       if (workerRunTime === 0) {
  44         return index
  45       } else if (workerRunTime < minRunTime) {
  46         minRunTime = workerRunTime
  47         lessBusyWorkerKey = index
  48       }
  49     }
  50     return lessBusyWorkerKey
  51   }
  52
  53   /** {@inheritDoc} */
  54   public remove (workerKey: number): boolean {
  55     return true
  56   }
  57 }