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