docs: refine README.md

[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 2f1905782f7c4a6c3d6d4c98053b3965eaa8021d..e29c1e38987a49aab6d19e5eba0670cb4b2131c5 100644 (file)
--- a/src/pools/selection-strategies/abstract-worker-choice-strategy.ts
+++ b/src/pools/selection-strategies/abstract-worker-choice-strategy.ts
@@ -19,6 +19,10 @@ export abstract class AbstractWorkerChoiceStrategy<
   Data = unknown,
   Response = unknown
 > implements IWorkerChoiceStrategy {
+  /**
+   * Toggles finding the last free worker node key.
+   */
+  private toggleFindLastFreeWorkerNodeKey: boolean = false
   /** @inheritDoc */
   protected readonly isDynamicPool: boolean
   /** @inheritDoc */
@@ -68,4 +72,55 @@ export abstract class AbstractWorkerChoiceStrategy<
     this.checkOptions(opts)
     this.opts = opts
   }
+
+  /**
+   * Finds a free worker node key.
+   *
+   * @returns The free worker node key or `-1` if there is no free worker node.
+   */
+  protected findFreeWorkerNodeKey (): number {
+    if (this.toggleFindLastFreeWorkerNodeKey) {
+      this.toggleFindLastFreeWorkerNodeKey = false
+      return this.findLastFreeWorkerNodeKey()
+    }
+    this.toggleFindLastFreeWorkerNodeKey = true
+    return this.findFirstFreeWorkerNodeKey()
+  }
+
+  /**
+   * Finds the first free worker node key based on the number of tasks the worker has applied.
+   *
+   * If a worker is found with `0` running tasks, it is detected as free and its worker node key is returned.
+   *
+   * If no free worker is found, `-1` is returned.
+   *
+   * @returns A worker node key if there is one, `-1` otherwise.
+   */
+  private findFirstFreeWorkerNodeKey (): number {
+    return this.pool.workerNodes.findIndex(workerNode => {
+      return workerNode.tasksUsage?.running === 0
+    })
+  }
+
+  /**
+   * Finds the last free worker node key based on the number of tasks the worker has applied.
+   *
+   * If a worker is found with `0` running tasks, it is detected as free and its worker node key is returned.
+   *
+   * If no free worker is found, `-1` is returned.
+   *
+   * @returns A worker node key if there is one, `-1` otherwise.
+   */
+  private findLastFreeWorkerNodeKey (): number {
+    // It requires node >= 18.0.0:
+    // return this.workerNodes.findLastIndex(workerNode => {
+    //   return workerNode.tasksUsage?.running === 0
+    // })
+    for (let i = this.pool.workerNodes.length - 1; i >= 0; i--) {
+      if (this.pool.workerNodes[i].tasksUsage?.running === 0) {
+        return i
+      }
+    }
+    return -1
+  }
 }