refactor: sensible defaults for worker choice strategy policy
[poolifier.git] / src / pools / selection-strategies / interleaved-weighted-round-robin-worker-choice-strategy.ts
index 7d77a21db5340bcd68a72e731f07ef01de76898b..4b59a55461e7e92596c5ead2f7fdaca6eabf9d71 100644 (file)
@@ -11,8 +11,8 @@ import type {
  * Selects the next worker with an interleaved weighted round robin scheduling algorithm.
  *
  * @typeParam Worker - Type of worker which manages the strategy.
- * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
- * @typeParam Response - Type of execution response. This can only be serializable data.
+ * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
+ * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
  */
 export class InterleavedWeightedRoundRobinWorkerChoiceStrategy<
     Worker extends IWorker,
@@ -22,14 +22,10 @@ export class InterleavedWeightedRoundRobinWorkerChoiceStrategy<
   extends AbstractWorkerChoiceStrategy<Worker, Data, Response>
   implements IWorkerChoiceStrategy {
   /**
-   * Worker node id where the current task will be submitted.
-   */
-  private currentWorkerNodeId: number = 0
-  /**
-   * Current round id.
+   * Round id.
    * This is used to determine the current round weight.
    */
-  private currentRoundId: number = 0
+  private roundId: number = 0
   /**
    * Round weights.
    */
@@ -52,8 +48,8 @@ export class InterleavedWeightedRoundRobinWorkerChoiceStrategy<
 
   /** @inheritDoc */
   public reset (): boolean {
-    this.currentWorkerNodeId = 0
-    this.currentRoundId = 0
+    this.nextWorkerNodeKey = 0
+    this.roundId = 0
     return true
   }
 
@@ -63,54 +59,59 @@ export class InterleavedWeightedRoundRobinWorkerChoiceStrategy<
   }
 
   /** @inheritDoc */
-  public choose (): number {
-    let roundId: number | undefined
+  public choose (): number | undefined {
+    let roundId: number = this.roundId
     let workerNodeId: number | undefined
     for (
-      let roundIndex = this.currentRoundId;
+      let roundIndex = this.roundId;
       roundIndex < this.roundWeights.length;
       roundIndex++
     ) {
+      roundId = roundIndex
       for (
-        let workerNodeKey = this.currentWorkerNodeId;
+        let workerNodeKey =
+          this.nextWorkerNodeKey ?? this.previousWorkerNodeKey;
         workerNodeKey < this.pool.workerNodes.length;
         workerNodeKey++
       ) {
         const workerWeight =
           this.opts.weights?.[workerNodeKey] ?? this.defaultWorkerWeight
-        if (workerWeight >= this.roundWeights[roundIndex]) {
-          roundId = roundIndex
+        if (
+          this.isWorkerNodeEligible(workerNodeKey) &&
+          workerWeight >= this.roundWeights[roundIndex]
+        ) {
           workerNodeId = workerNodeKey
           break
         }
       }
     }
-    this.currentRoundId = roundId ?? 0
-    this.currentWorkerNodeId = workerNodeId ?? 0
-    const chosenWorkerNodeKey = this.currentWorkerNodeId
-    if (this.currentWorkerNodeId === this.pool.workerNodes.length - 1) {
-      this.currentWorkerNodeId = 0
-      this.currentRoundId =
-        this.currentRoundId === this.roundWeights.length - 1
-          ? 0
-          : this.currentRoundId + 1
+    this.roundId = roundId
+    if (workerNodeId == null) {
+      this.previousWorkerNodeKey =
+        this.nextWorkerNodeKey ?? this.previousWorkerNodeKey
+    }
+    this.nextWorkerNodeKey = workerNodeId
+    const chosenWorkerNodeKey = this.nextWorkerNodeKey
+    if (this.nextWorkerNodeKey === this.pool.workerNodes.length - 1) {
+      this.nextWorkerNodeKey = 0
+      this.roundId =
+        this.roundId === this.roundWeights.length - 1 ? 0 : this.roundId + 1
     } else {
-      this.currentWorkerNodeId = this.currentWorkerNodeId + 1
+      this.nextWorkerNodeKey =
+        (this.nextWorkerNodeKey ?? this.previousWorkerNodeKey) + 1
     }
     return chosenWorkerNodeKey
   }
 
   /** @inheritDoc */
   public remove (workerNodeKey: number): boolean {
-    if (this.currentWorkerNodeId === workerNodeKey) {
+    if (this.nextWorkerNodeKey === workerNodeKey) {
       if (this.pool.workerNodes.length === 0) {
-        this.currentWorkerNodeId = 0
-      } else if (this.currentWorkerNodeId > this.pool.workerNodes.length - 1) {
-        this.currentWorkerNodeId = this.pool.workerNodes.length - 1
-        this.currentRoundId =
-          this.currentRoundId === this.roundWeights.length - 1
-            ? 0
-            : this.currentRoundId + 1
+        this.nextWorkerNodeKey = 0
+      } else if (this.nextWorkerNodeKey > this.pool.workerNodes.length - 1) {
+        this.nextWorkerNodeKey = this.pool.workerNodes.length - 1
+        this.roundId =
+          this.roundId === this.roundWeights.length - 1 ? 0 : this.roundId + 1
       }
     }
     return true