src/pools/selection-strategies/worker-choice-strategy-context.ts

   1 import type { AbstractPoolWorker } from '../abstract-pool-worker'
   2 import type { IPoolInternal } from '../pool-internal'
   3 import { PoolType } from '../pool-internal'
   4 import { DynamicPoolWorkerChoiceStrategy } from './dynamic-pool-worker-choice-strategy'
   5 import type {
   6   IWorkerChoiceStrategy,
   7   WorkerChoiceStrategy
   8 } from './selection-strategies-types'
   9 import { WorkerChoiceStrategies } from './selection-strategies-types'
  10 import { SelectionStrategiesUtils } from './selection-strategies-utils'
  11
  12 /**
  13  * The worker choice strategy context.
  14  *
  15  * @template Worker Type of worker.
  16  * @template Data Type of data sent to the worker. This can only be serializable data.
  17  * @template Response Type of response of execution. This can only be serializable data.
  18  */
  19 export class WorkerChoiceStrategyContext<
  20   Worker extends AbstractPoolWorker,
  21   Data,
  22   Response
  23 > {
  24   // Will be set by setter in constructor
  25   private workerChoiceStrategy!: IWorkerChoiceStrategy<Worker>
  26
  27   /**
  28    * Worker choice strategy context constructor.
  29    *
  30    * @param pool The pool instance.
  31    * @param createDynamicallyWorkerCallback The worker creation callback for dynamic pool.
  32    * @param workerChoiceStrategy The worker choice strategy.
  33    */
  34   public constructor (
  35     private readonly pool: IPoolInternal<Worker, Data, Response>,
  36     private createDynamicallyWorkerCallback: () => Worker,
  37     workerChoiceStrategy: WorkerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
  38   ) {
  39     this.setWorkerChoiceStrategy(workerChoiceStrategy)
  40   }
  41
  42   /**
  43    * Get the worker choice strategy instance specific to the pool type.
  44    *
  45    * @param workerChoiceStrategy The worker choice strategy.
  46    * @returns The worker choice strategy instance for the pool type.
  47    */
  48   private getPoolWorkerChoiceStrategy (
  49     workerChoiceStrategy: WorkerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
  50   ): IWorkerChoiceStrategy<Worker> {
  51     if (this.pool.type === PoolType.DYNAMIC) {
  52       return new DynamicPoolWorkerChoiceStrategy(
  53         this.pool,
  54         this.createDynamicallyWorkerCallback,
  55         workerChoiceStrategy
  56       )
  57     }
  58     return SelectionStrategiesUtils.getWorkerChoiceStrategy(
  59       this.pool,
  60       workerChoiceStrategy
  61     )
  62   }
  63
  64   /**
  65    * Set the worker choice strategy to use in the context.
  66    *
  67    * @param workerChoiceStrategy The worker choice strategy to set.
  68    */
  69   public setWorkerChoiceStrategy (
  70     workerChoiceStrategy: WorkerChoiceStrategy
  71   ): void {
  72     this.workerChoiceStrategy = this.getPoolWorkerChoiceStrategy(
  73       workerChoiceStrategy
  74     )
  75   }
  76
  77   /**
  78    * Choose a worker with the underlying selection strategy.
  79    *
  80    * @returns The chosen one.
  81    */
  82   public execute (): Worker {
  83     return this.workerChoiceStrategy.choose()
  84   }
  85 }