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

   1 import type { IPoolInternal } from '../pool-internal'
   2 import { PoolType } from '../pool-internal'
   3 import type { IPoolWorker } from '../pool-worker'
   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 IPoolWorker,
  21   Data,
  22   Response
  23 > {
  24   private workerChoiceStrategy!: IWorkerChoiceStrategy<Worker>
  25
  26   /**
  27    * Worker choice strategy context constructor.
  28    *
  29    * @param pool The pool instance.
  30    * @param createDynamicallyWorkerCallback The worker creation callback for dynamic pool.
  31    * @param workerChoiceStrategy The worker choice strategy.
  32    */
  33   public constructor (
  34     private readonly pool: IPoolInternal<Worker, Data, Response>,
  35     private createDynamicallyWorkerCallback: () => Worker,
  36     workerChoiceStrategy: WorkerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
  37   ) {
  38     this.setWorkerChoiceStrategy(workerChoiceStrategy)
  39   }
  40
  41   /**
  42    * Gets the worker choice strategy instance specific to the pool type.
  43    *
  44    * @param workerChoiceStrategy The worker choice strategy.
  45    * @returns The worker choice strategy instance for the pool type.
  46    */
  47   private getPoolWorkerChoiceStrategy (
  48     workerChoiceStrategy: WorkerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
  49   ): IWorkerChoiceStrategy<Worker> {
  50     if (this.pool.type === PoolType.DYNAMIC) {
  51       return new DynamicPoolWorkerChoiceStrategy(
  52         this.pool,
  53         this.createDynamicallyWorkerCallback,
  54         workerChoiceStrategy
  55       )
  56     }
  57     return SelectionStrategiesUtils.getWorkerChoiceStrategy(
  58       this.pool,
  59       workerChoiceStrategy
  60     )
  61   }
  62
  63   /**
  64    * Gets the worker choice strategy used in the context.
  65    *
  66    * @returns The worker choice strategy.
  67    */
  68   public getWorkerChoiceStrategy (): IWorkerChoiceStrategy<Worker> {
  69     return this.workerChoiceStrategy
  70   }
  71
  72   /**
  73    * Sets the worker choice strategy to use in the context.
  74    *
  75    * @param workerChoiceStrategy The worker choice strategy to set.
  76    */
  77   public setWorkerChoiceStrategy (
  78     workerChoiceStrategy: WorkerChoiceStrategy
  79   ): void {
  80     this.workerChoiceStrategy?.reset()
  81     this.workerChoiceStrategy = this.getPoolWorkerChoiceStrategy(
  82       workerChoiceStrategy
  83     )
  84   }
  85
  86   /**
  87    * Chooses a worker with the underlying selection strategy.
  88    *
  89    * @returns The chosen one.
  90    */
  91   public execute (): Worker {
  92     return this.workerChoiceStrategy.choose()
  93   }
  94 }