refactor: add PoolEvents/PoolEvent types

[poolifier.git] / src / pools / selection-strategies / worker-choice-strategy-context.ts

diff --git a/src/pools/selection-strategies/worker-choice-strategy-context.ts b/src/pools/selection-strategies/worker-choice-strategy-context.ts
index 1bba1a55eccdc82a02d6c0849c2413c68b70b9dc..826a89d9d6ce19c3f362f918785653c3056ba42e 100644 (file)
--- a/src/pools/selection-strategies/worker-choice-strategy-context.ts
+++ b/src/pools/selection-strategies/worker-choice-strategy-context.ts
@@ -1,13 +1,16 @@
 import type { IPoolInternal } from '../pool-internal'
-import { PoolType } from '../pool-internal'
 import type { IPoolWorker } from '../pool-worker'
-import { DynamicPoolWorkerChoiceStrategy } from './dynamic-pool-worker-choice-strategy'
+import { FairShareWorkerChoiceStrategy } from './fair-share-worker-choice-strategy'
+import { LessBusyWorkerChoiceStrategy } from './less-busy-worker-choice-strategy'
+import { LessUsedWorkerChoiceStrategy } from './less-used-worker-choice-strategy'
+import { RoundRobinWorkerChoiceStrategy } from './round-robin-worker-choice-strategy'
 import type {
   IWorkerChoiceStrategy,
+  RequiredStatistics,
   WorkerChoiceStrategy
 } from './selection-strategies-types'
 import { WorkerChoiceStrategies } from './selection-strategies-types'
-import { getWorkerChoiceStrategy } from './selection-strategies-utils'
+import { WeightedRoundRobinWorkerChoiceStrategy } from './weighted-round-robin-worker-choice-strategy'
 
 /**
  * The worker choice strategy context.
@@ -18,52 +21,64 @@ import { getWorkerChoiceStrategy } from './selection-strategies-utils'
  */
 export class WorkerChoiceStrategyContext<
   Worker extends IPoolWorker,
-  Data,
-  Response
+  Data = unknown,
+  Response = unknown
 > {
-  private workerChoiceStrategy!: IWorkerChoiceStrategy<Worker>
+  private readonly workerChoiceStrategies: Map<
+  WorkerChoiceStrategy,
+  IWorkerChoiceStrategy
+  >
 
   /**
    * Worker choice strategy context constructor.
    *
    * @param pool - The pool instance.
-   * @param createDynamicallyWorkerCallback - The worker creation callback for dynamic pool.
+   * @param createWorkerCallback - The worker creation callback for dynamic pool.
    * @param workerChoiceStrategy - The worker choice strategy.
    */
   public constructor (
-    private readonly pool: IPoolInternal<Worker, Data, Response>,
-    private readonly createDynamicallyWorkerCallback: () => Worker,
-    workerChoiceStrategy: WorkerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
+    pool: IPoolInternal<Worker, Data, Response>,
+    private workerChoiceStrategyType: WorkerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
   ) {
-    this.setWorkerChoiceStrategy(workerChoiceStrategy)
+    this.execute.bind(this)
+    this.workerChoiceStrategies = new Map<
+    WorkerChoiceStrategy,
+    IWorkerChoiceStrategy
+    >([
+      [
+        WorkerChoiceStrategies.ROUND_ROBIN,
+        new RoundRobinWorkerChoiceStrategy<Worker, Data, Response>(pool)
+      ],
+      [
+        WorkerChoiceStrategies.LESS_USED,
+        new LessUsedWorkerChoiceStrategy<Worker, Data, Response>(pool)
+      ],
+      [
+        WorkerChoiceStrategies.LESS_BUSY,
+        new LessBusyWorkerChoiceStrategy<Worker, Data, Response>(pool)
+      ],
+      [
+        WorkerChoiceStrategies.FAIR_SHARE,
+        new FairShareWorkerChoiceStrategy<Worker, Data, Response>(pool)
+      ],
+      [
+        WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN,
+        new WeightedRoundRobinWorkerChoiceStrategy<Worker, Data, Response>(pool)
+      ]
+    ])
   }
 
   /**
-   * Gets the worker choice strategy instance specific to the pool type.
+   * Gets the worker choice strategy in the context required statistics.
    *
-   * @param workerChoiceStrategy - The worker choice strategy.
-   * @returns The worker choice strategy instance for the pool type.
-   */
-  private getPoolWorkerChoiceStrategy (
-    workerChoiceStrategy: WorkerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
-  ): IWorkerChoiceStrategy<Worker> {
-    if (this.pool.type === PoolType.DYNAMIC) {
-      return new DynamicPoolWorkerChoiceStrategy(
-        this.pool,
-        this.createDynamicallyWorkerCallback,
-        workerChoiceStrategy
-      )
-    }
-    return getWorkerChoiceStrategy(this.pool, workerChoiceStrategy)
-  }
-
-  /**
-   * Gets the worker choice strategy used in the context.
-   *
-   * @returns The worker choice strategy.
+   * @returns The required statistics.
    */
-  public getWorkerChoiceStrategy (): IWorkerChoiceStrategy<Worker> {
-    return this.workerChoiceStrategy
+  public getRequiredStatistics (): RequiredStatistics {
+    return (
+      this.workerChoiceStrategies.get(
+        this.workerChoiceStrategyType
+      ) as IWorkerChoiceStrategy
+    ).requiredStatistics
   }
 
   /**
@@ -74,17 +89,36 @@ export class WorkerChoiceStrategyContext<
   public setWorkerChoiceStrategy (
     workerChoiceStrategy: WorkerChoiceStrategy
   ): void {
-    this.workerChoiceStrategy?.reset()
-    this.workerChoiceStrategy =
-      this.getPoolWorkerChoiceStrategy(workerChoiceStrategy)
+    if (this.workerChoiceStrategyType !== workerChoiceStrategy) {
+      this.workerChoiceStrategyType = workerChoiceStrategy
+    }
+    this.workerChoiceStrategies.get(this.workerChoiceStrategyType)?.reset()
+  }
+
+  /**
+   * Executes the worker choice strategy algorithm in the context.
+   *
+   * @returns The key of the chosen one.
+   */
+  public execute (): number {
+    return (
+      this.workerChoiceStrategies.get(
+        this.workerChoiceStrategyType
+      ) as IWorkerChoiceStrategy
+    ).choose()
   }
 
   /**
-   * Chooses a worker with the underlying selection strategy.
+   * Removes a worker from the worker choice strategy in the context.
    *
-   * @returns The chosen one.
+   * @param workerKey - The key of the worker to remove.
+   * @returns `true` if the removal is successful, `false` otherwise.
    */
-  public execute (): Worker {
-    return this.workerChoiceStrategy.choose()
+  public remove (workerKey: number): boolean {
+    return (
+      this.workerChoiceStrategies.get(
+        this.workerChoiceStrategyType
+      ) as IWorkerChoiceStrategy
+    ).remove(workerKey)
   }
 }