docs: add changelog entry

[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 8afd2c36edda1bcb7fe94dcb2b6d1f51c36eac9e..81cadde164c9d4371179546fe6fff1a275bba5a7 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,
@@ -34,7 +37,7 @@ export class LeastBusyWorkerChoiceStrategy<
       average: false,
       median: false
     },
-    elu: false
+    elu: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS
   }
 
   /** @inheritDoc */
@@ -57,25 +60,29 @@ export class LeastBusyWorkerChoiceStrategy<
   }
 
   /** @inheritDoc */
-  public choose (): number {
-    let minTime = Infinity
-    let leastBusyWorkerNodeKey!: number
-    for (const [workerNodeKey, workerNode] of this.pool.workerNodes.entries()) {
-      const workerTime =
-        workerNode.workerUsage.runTime.aggregate +
-        workerNode.workerUsage.waitTime.aggregate
-      if (workerTime === 0) {
-        return workerNodeKey
-      } else if (workerTime < minTime) {
-        minTime = workerTime
-        leastBusyWorkerNodeKey = workerNodeKey
-      }
-    }
-    return leastBusyWorkerNodeKey
+  public choose (): number | undefined {
+    this.setPreviousWorkerNodeKey(this.nextWorkerNodeKey)
+    this.nextWorkerNodeKey = this.leastBusyNextWorkerNodeKey()
+    return this.nextWorkerNodeKey
   }
 
   /** @inheritDoc */
   public remove (): boolean {
     return true
   }
+
+  private leastBusyNextWorkerNodeKey (): number | undefined {
+    return this.pool.workerNodes.reduce(
+      (minWorkerNodeKey, workerNode, workerNodeKey, workerNodes) => {
+        return this.isWorkerNodeReady(workerNodeKey) &&
+          (workerNode.usage.runTime.aggregate ?? 0) +
+            (workerNode.usage.waitTime.aggregate ?? 0) <
+            (workerNodes[minWorkerNodeKey].usage.runTime.aggregate ?? 0) +
+              (workerNodes[minWorkerNodeKey].usage.waitTime.aggregate ?? 0)
+          ? workerNodeKey
+          : minWorkerNodeKey
+      },
+      0
+    )
+  }
 }