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 { getWorkerChoiceStrategy } 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 readonly 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 getWorkerChoiceStrategy(this.pool, workerChoiceStrategy)
  58   }
  59
  60   /**
  61    * Gets the worker choice strategy used in the context.
  62    *
  63    * @returns The worker choice strategy.
  64    */
  65   public getWorkerChoiceStrategy (): IWorkerChoiceStrategy<Worker> {
  66     return this.workerChoiceStrategy
  67   }
  68
  69   /**
  70    * Sets the worker choice strategy to use in the context.
  71    *
  72    * @param workerChoiceStrategy The worker choice strategy to set.
  73    */
  74   public setWorkerChoiceStrategy (
  75     workerChoiceStrategy: WorkerChoiceStrategy
  76   ): void {
  77     this.workerChoiceStrategy?.reset()
  78     this.workerChoiceStrategy =
  79       this.getPoolWorkerChoiceStrategy(workerChoiceStrategy)
  80   }
  81
  82   /**
  83    * Chooses a worker with the underlying selection strategy.
  84    *
  85    * @returns The chosen one.
  86    */
  87   public execute (): Worker {
  88     return this.workerChoiceStrategy.choose()
  89   }
  90 }