fix: fix fair share algorithm implementation

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

diff --git a/src/pools/selection-strategies/fair-share-worker-choice-strategy.ts b/src/pools/selection-strategies/fair-share-worker-choice-strategy.ts
index 3f4e95249497897d0f718c4192880fecdc695129..e65575a1e05c805978111cbbf279c5f5a5767e6f 100644 (file)
--- a/src/pools/selection-strategies/fair-share-worker-choice-strategy.ts
+++ b/src/pools/selection-strategies/fair-share-worker-choice-strategy.ts
@@ -1,8 +1,11 @@
+import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils'
+import type { IPool } from '../pool'
 import type { IWorker } from '../worker'
 import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
 import type {
   IWorkerChoiceStrategy,
-  RequiredStatistics
+  RequiredStatistics,
+  WorkerChoiceStrategyOptions
 } from './selection-strategies-types'
 
 /**
@@ -10,7 +13,7 @@ import type {
  */
 interface WorkerVirtualTaskTimestamp {
   start: number
-  end: number
+  end?: number
 }
 
 /**
@@ -36,16 +39,28 @@ export class FairShareWorkerChoiceStrategy<
   }
 
   /**
-   * Worker last virtual task execution timestamp.
+   * Workers' virtual task execution timestamp.
    */
-  private readonly workerLastVirtualTaskTimestamp: Map<
-  number,
-  WorkerVirtualTaskTimestamp
-  > = new Map<number, WorkerVirtualTaskTimestamp>()
+  private workersVirtualTaskTimestamp: WorkerVirtualTaskTimestamp[] = []
+
+  /** @inheritDoc */
+  public constructor (
+    pool: IPool<Worker, Data, Response>,
+    opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+  ) {
+    super(pool, opts)
+    this.checkOptions(this.opts)
+  }
 
   /** @inheritDoc */
   public reset (): boolean {
-    this.workerLastVirtualTaskTimestamp.clear()
+    this.workersVirtualTaskTimestamp = []
+    return true
+  }
+
+  /** @inheritDoc */
+  public update (workerNodeKey: number): boolean {
+    this.computeWorkerVirtualTaskTimestamp(workerNodeKey)
     return true
   }
 
@@ -53,15 +68,12 @@ export class FairShareWorkerChoiceStrategy<
   public choose (): number {
     let minWorkerVirtualTaskEndTimestamp = Infinity
     let chosenWorkerNodeKey!: number
-    for (const [index] of this.pool.workerNodes.entries()) {
-      this.computeWorkerLastVirtualTaskTimestamp(index)
-      const workerLastVirtualTaskEndTimestamp =
-        this.workerLastVirtualTaskTimestamp.get(index)?.end ?? 0
-      if (
-        workerLastVirtualTaskEndTimestamp < minWorkerVirtualTaskEndTimestamp
-      ) {
-        minWorkerVirtualTaskEndTimestamp = workerLastVirtualTaskEndTimestamp
-        chosenWorkerNodeKey = index
+    for (const [workerNodeKey] of this.pool.workerNodes.entries()) {
+      const workerVirtualTaskEndTimestamp =
+        this.workersVirtualTaskTimestamp[workerNodeKey]?.end ?? 0
+      if (workerVirtualTaskEndTimestamp < minWorkerVirtualTaskEndTimestamp) {
+        minWorkerVirtualTaskEndTimestamp = workerVirtualTaskEndTimestamp
+        chosenWorkerNodeKey = workerNodeKey
       }
     }
     return chosenWorkerNodeKey
@@ -69,31 +81,26 @@ export class FairShareWorkerChoiceStrategy<
 
   /** @inheritDoc */
   public remove (workerNodeKey: number): boolean {
-    const deleted = this.workerLastVirtualTaskTimestamp.delete(workerNodeKey)
-    for (const [key, value] of this.workerLastVirtualTaskTimestamp.entries()) {
-      if (key > workerNodeKey) {
-        this.workerLastVirtualTaskTimestamp.set(key - 1, value)
-      }
-    }
-    return deleted
+    this.workersVirtualTaskTimestamp.splice(workerNodeKey, 1)
+    return true
   }
 
   /**
-   * Computes worker last virtual task timestamp.
+   * Computes worker virtual task timestamp.
    *
    * @param workerNodeKey - The worker node key.
    */
-  private computeWorkerLastVirtualTaskTimestamp (workerNodeKey: number): void {
+  private computeWorkerVirtualTaskTimestamp (workerNodeKey: number): void {
     const workerVirtualTaskStartTimestamp = Math.max(
       performance.now(),
-      this.workerLastVirtualTaskTimestamp.get(workerNodeKey)?.end ?? -Infinity
+      this.workersVirtualTaskTimestamp[workerNodeKey]?.end ?? -Infinity
     )
     const workerVirtualTaskTRunTime = this.requiredStatistics.medRunTime
       ? this.pool.workerNodes[workerNodeKey].tasksUsage.medRunTime
       : this.pool.workerNodes[workerNodeKey].tasksUsage.avgRunTime
-    this.workerLastVirtualTaskTimestamp.set(workerNodeKey, {
+    this.workersVirtualTaskTimestamp[workerNodeKey] = {
       start: workerVirtualTaskStartTimestamp,
-      end: workerVirtualTaskStartTimestamp + (workerVirtualTaskTRunTime ?? 0)
-    })
+      end: workerVirtualTaskStartTimestamp + workerVirtualTaskTRunTime
+    }
   }
 }