refactor: sensible defaults for worker choice strategy policy

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

diff --git a/src/pools/selection-strategies/least-busy-worker-choice-strategy.ts b/src/pools/selection-strategies/least-busy-worker-choice-strategy.ts
index dc304c89fd1e5abecb680aa5d519d9a59f6f18ac..224ca540130f49c37e6b28d5de471e5237dddb14 100644 (file)
--- a/src/pools/selection-strategies/least-busy-worker-choice-strategy.ts
+++ b/src/pools/selection-strategies/least-busy-worker-choice-strategy.ts
@@ -1,4 +1,7 @@
-import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils'
+import {
+  DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
+  DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+} from '../../utils'
 import type { IPool } from '../pool'
 import type { IWorker } from '../worker'
 import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
@@ -12,8 +15,8 @@ import type {
  * Selects the least busy worker.
  *
  * @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 LeastBusyWorkerChoiceStrategy<
     Worker extends IWorker,
@@ -34,11 +37,7 @@ export class LeastBusyWorkerChoiceStrategy<
       average: false,
       median: false
     },
-    elu: {
-      aggregate: false,
-      average: false,
-      median: false
-    }
+    elu: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS
   }
 
   /** @inheritDoc */
@@ -57,29 +56,39 @@ export class LeastBusyWorkerChoiceStrategy<
 
   /** @inheritDoc */
   public update (): boolean {
-    let minTime = Infinity
-    for (const [workerNodeKey, workerNode] of this.pool.workerNodes.entries()) {
-      const workerTime =
-        workerNode.workerUsage.runTime.aggregate +
-        workerNode.workerUsage.waitTime.aggregate
-      if (workerTime === 0) {
-        this.nextWorkerNodeId = workerNodeKey
-        return true
-      } else if (workerTime < minTime) {
-        minTime = workerTime
-        this.nextWorkerNodeId = workerNodeKey
-      }
-    }
     return true
   }
 
   /** @inheritDoc */
-  public choose (): number {
-    return this.nextWorkerNodeId
+  public choose (): number | undefined {
+    const chosenWorkerNodeKey = this.leastBusyNextWorkerNodeKey()
+    this.assignChosenWorkerNodeKey(chosenWorkerNodeKey)
+    return this.nextWorkerNodeKey
   }
 
   /** @inheritDoc */
   public remove (): boolean {
     return true
   }
+
+  private leastBusyNextWorkerNodeKey (): number | undefined {
+    let minTime = Infinity
+    let chosenWorkerNodeKey: number | undefined
+    for (const [workerNodeKey, workerNode] of this.pool.workerNodes.entries()) {
+      const workerTime =
+        (workerNode.usage.runTime?.aggregate ?? 0) +
+        (workerNode.usage.waitTime?.aggregate ?? 0)
+      if (this.isWorkerNodeEligible(workerNodeKey) && workerTime === 0) {
+        chosenWorkerNodeKey = workerNodeKey
+        break
+      } else if (
+        this.isWorkerNodeEligible(workerNodeKey) &&
+        workerTime < minTime
+      ) {
+        minTime = workerTime
+        chosenWorkerNodeKey = workerNodeKey
+      }
+    }
+    return chosenWorkerNodeKey
+  }
 }