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

   1 import type { IPoolWorker } from '../pool-worker'
   2 import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
   3
   4 /**
   5  * Selects the less recently used worker.
   6  *
   7  * @typeParam Worker - Type of worker which manages the strategy.
   8  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
   9  * @typeParam Response - Type of response of execution. This can only be serializable data.
  10  */
  11 export class LessRecentlyUsedWorkerChoiceStrategy<
  12   Worker extends IPoolWorker,
  13   Data,
  14   Response
  15 > extends AbstractWorkerChoiceStrategy<Worker, Data, Response> {
  16   /** {@inheritDoc} */
  17   public reset (): boolean {
  18     return true
  19   }
  20
  21   /** {@inheritDoc} */
  22   public choose (): Worker {
  23     let minNumberOfTasks = Infinity
  24     // A worker is always found because it picks the one with fewer tasks
  25     let lessRecentlyUsedWorker!: Worker
  26     for (const value of this.pool.workers.values()) {
  27       const worker = value.worker
  28       const tasksUsage = this.pool.getWorkerTasksUsage(worker)
  29       const workerTasks =
  30         (tasksUsage?.run as number) + (tasksUsage?.running as number)
  31       if (!this.isDynamicPool && workerTasks === 0) {
  32         return worker
  33       } else if (workerTasks < minNumberOfTasks) {
  34         minNumberOfTasks = workerTasks
  35         lessRecentlyUsedWorker = worker
  36       }
  37     }
  38     return lessRecentlyUsedWorker
  39   }
  40 }