Merge pull request #1495 from poolifier/combined-prs-branch

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

diff --git a/src/pools/selection-strategies/abstract-worker-choice-strategy.ts b/src/pools/selection-strategies/abstract-worker-choice-strategy.ts
index 9c20c5bea63143f3b3e556f2629b635026e32a2a..68e09238b204c35e4f6bb87392021f314e3e2923 100644 (file)
--- a/src/pools/selection-strategies/abstract-worker-choice-strategy.ts
+++ b/src/pools/selection-strategies/abstract-worker-choice-strategy.ts
@@ -28,11 +28,17 @@ export abstract class AbstractWorkerChoiceStrategy<
   /**
    * The next worker node key.
    */
-  protected nextWorkerNodeKey: number = 0
+  protected nextWorkerNodeKey: number | undefined = 0
+
+  /**
+   * The previous worker node key.
+   */
+  protected previousWorkerNodeKey: number = 0
 
   /** @inheritDoc */
   public readonly strategyPolicy: StrategyPolicy = {
-    useDynamicWorker: false
+    dynamicWorkerUsage: false,
+    dynamicWorkerReady: true
   }
 
   /** @inheritDoc */
@@ -52,6 +58,7 @@ export abstract class AbstractWorkerChoiceStrategy<
     protected readonly pool: IPool<Worker, Data, Response>,
     protected opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
   ) {
+    this.opts = { ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS, ...opts }
     this.choose = this.choose.bind(this)
   }
 
@@ -86,6 +93,11 @@ export abstract class AbstractWorkerChoiceStrategy<
     }
   }
 
+  protected resetWorkerNodeKeyProperties (): void {
+    this.nextWorkerNodeKey = 0
+    this.previousWorkerNodeKey = 0
+  }
+
   /** @inheritDoc */
   public abstract reset (): boolean
 
@@ -93,14 +105,14 @@ export abstract class AbstractWorkerChoiceStrategy<
   public abstract update (workerNodeKey: number): boolean
 
   /** @inheritDoc */
-  public abstract choose (): number
+  public abstract choose (): number | undefined
 
   /** @inheritDoc */
   public abstract remove (workerNodeKey: number): boolean
 
   /** @inheritDoc */
   public setOptions (opts: WorkerChoiceStrategyOptions): void {
-    this.opts = opts ?? DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+    this.opts = { ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS, ...opts }
     this.setTaskStatisticsRequirements(this.opts)
   }
 
@@ -110,50 +122,94 @@ export abstract class AbstractWorkerChoiceStrategy<
    * @param workerNodeKey - The worker node key.
    * @returns Whether the worker node is ready or not.
    */
-  protected isWorkerNodeReady (workerNodeKey: number): boolean {
-    return this.pool.workerNodes[workerNodeKey].info.ready
+  private isWorkerNodeReady (workerNodeKey: number): boolean {
+    return this.pool.workerNodes[workerNodeKey]?.info.ready
   }
 
   /**
-   * Gets the worker task runtime.
+   * Whether the worker node has back pressure or not (i.e. its tasks queue is full).
+   *
+   * @param workerNodeKey - The worker node key.
+   * @returns `true` if the worker node has back pressure, `false` otherwise.
+   */
+  private hasWorkerNodeBackPressure (workerNodeKey: number): boolean {
+    return this.pool.hasWorkerNodeBackPressure(workerNodeKey)
+  }
+
+  /**
+   * Whether the worker node is eligible or not.
+   * A worker node is eligible if it is ready and does not have back pressure.
+   *
+   * @param workerNodeKey - The worker node key.
+   * @returns `true` if the worker node is eligible, `false` otherwise.
+   * @see {@link isWorkerNodeReady}
+   * @see {@link hasWorkerNodeBackPressure}
+   */
+  protected isWorkerNodeEligible (workerNodeKey: number): boolean {
+    return (
+      this.isWorkerNodeReady(workerNodeKey) &&
+      !this.hasWorkerNodeBackPressure(workerNodeKey)
+    )
+  }
+
+  /**
+   * Gets the worker node task runtime.
    * If the task statistics require the average runtime, the average runtime is returned.
    * If the task statistics require the median runtime , the median runtime is returned.
    *
    * @param workerNodeKey - The worker node key.
-   * @returns The worker task runtime.
+   * @returns The worker node task runtime.
    */
-  protected getWorkerTaskRunTime (workerNodeKey: number): number {
+  protected getWorkerNodeTaskRunTime (workerNodeKey: number): number {
     return this.taskStatisticsRequirements.runTime.median
-      ? this.pool.workerNodes[workerNodeKey].usage.runTime?.median ?? 0
-      : this.pool.workerNodes[workerNodeKey].usage.runTime?.average ?? 0
+      ? this.pool.workerNodes[workerNodeKey].usage.runTime.median ?? 0
+      : this.pool.workerNodes[workerNodeKey].usage.runTime.average ?? 0
   }
 
   /**
-   * Gets the worker task wait time.
+   * Gets the worker node task wait time.
    * If the task statistics require the average wait time, the average wait time is returned.
    * If the task statistics require the median wait time, the median wait time is returned.
    *
    * @param workerNodeKey - The worker node key.
-   * @returns The worker task wait time.
+   * @returns The worker node task wait time.
    */
-  protected getWorkerTaskWaitTime (workerNodeKey: number): number {
+  protected getWorkerNodeTaskWaitTime (workerNodeKey: number): number {
     return this.taskStatisticsRequirements.waitTime.median
-      ? this.pool.workerNodes[workerNodeKey].usage.waitTime?.median ?? 0
-      : this.pool.workerNodes[workerNodeKey].usage.waitTime?.average ?? 0
+      ? this.pool.workerNodes[workerNodeKey].usage.waitTime.median ?? 0
+      : this.pool.workerNodes[workerNodeKey].usage.waitTime.average ?? 0
   }
 
   /**
-   * Gets the worker task ELU.
+   * Gets the worker node task ELU.
    * If the task statistics require the average ELU, the average ELU is returned.
    * If the task statistics require the median ELU, the median ELU is returned.
    *
    * @param workerNodeKey - The worker node key.
-   * @returns The worker task ELU.
+   * @returns The worker node task ELU.
    */
-  protected getWorkerTaskElu (workerNodeKey: number): number {
+  protected getWorkerNodeTaskElu (workerNodeKey: number): number {
     return this.taskStatisticsRequirements.elu.median
-      ? this.pool.workerNodes[workerNodeKey].usage.elu.active?.median ?? 0
-      : this.pool.workerNodes[workerNodeKey].usage.elu.active?.average ?? 0
+      ? this.pool.workerNodes[workerNodeKey].usage.elu.active.median ?? 0
+      : this.pool.workerNodes[workerNodeKey].usage.elu.active.average ?? 0
+  }
+
+  /**
+   * Sets safely the previous worker node key.
+   *
+   * @param workerNodeKey - The worker node key.
+   */
+  protected setPreviousWorkerNodeKey (workerNodeKey: number | undefined): void {
+    this.previousWorkerNodeKey = workerNodeKey ?? this.previousWorkerNodeKey
+  }
+
+  /**
+   * Check the next worker node eligibility.
+   */
+  protected checkNextWorkerNodeEligibility (): void {
+    if (!this.isWorkerNodeEligible(this.nextWorkerNodeKey as number)) {
+      delete this.nextWorkerNodeKey
+    }
   }
 
   protected computeDefaultWorkerWeight (): number {