refactor: untangle worker choosing code from worker creation code

[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 3735f9722319c34656d3498389962859ffd2f060..16d5a7be1dd60ca213a873c1571f8335948ac826 100644 (file)
--- a/src/pools/selection-strategies/fair-share-worker-choice-strategy.ts
+++ b/src/pools/selection-strategies/fair-share-worker-choice-strategy.ts
@@ -1,11 +1,14 @@
 import type { IPoolWorker } from '../pool-worker'
 import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
-import type { RequiredStatistics } from './selection-strategies-types'
+import type {
+  IWorkerChoiceStrategy,
+  RequiredStatistics
+} from './selection-strategies-types'
 
 /**
  * Worker virtual task timestamp.
  */
-type WorkerVirtualTaskTimestamp = {
+interface WorkerVirtualTaskTimestamp {
   start: number
   end: number
 }
@@ -14,27 +17,30 @@ type WorkerVirtualTaskTimestamp = {
  * Selects the next worker with a fair share scheduling algorithm.
  * Loosely modeled after the fair queueing algorithm: https://en.wikipedia.org/wiki/Fair_queuing.
  *
- * @template Worker Type of worker which manages the strategy.
- * @template Data Type of data sent to the worker. This can only be serializable data.
- * @template Response Type of response of execution. This can only be serializable data.
+ * @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 response of execution. This can only be serializable data.
  */
 export class FairShareWorkerChoiceStrategy<
-  Worker extends IPoolWorker,
-  Data,
-  Response
-> extends AbstractWorkerChoiceStrategy<Worker, Data, Response> {
+    Worker extends IPoolWorker,
+    Data = unknown,
+    Response = unknown
+  >
+  extends AbstractWorkerChoiceStrategy<Worker, Data, Response>
+  implements IWorkerChoiceStrategy {
   /** @inheritDoc */
   public readonly requiredStatistics: RequiredStatistics = {
-    runTime: true
+    runTime: true,
+    avgRunTime: true
   }
 
   /**
    *  Worker last virtual task execution timestamp.
    */
   private readonly workerLastVirtualTaskTimestamp: Map<
-    Worker,
-    WorkerVirtualTaskTimestamp
-  > = new Map<Worker, WorkerVirtualTaskTimestamp>()
+  number,
+  WorkerVirtualTaskTimestamp
+  > = new Map<number, WorkerVirtualTaskTimestamp>()
 
   /** @inheritDoc */
   public reset (): boolean {
@@ -43,39 +49,49 @@ export class FairShareWorkerChoiceStrategy<
   }
 
   /** @inheritDoc */
-  public choose (): Worker {
-    this.computeWorkerLastVirtualTaskTimestamp()
+  public choose (): number {
     let minWorkerVirtualTaskEndTimestamp = Infinity
-    let chosenWorker!: Worker
-    for (const worker of this.pool.workers) {
+    let chosenWorkerKey!: number
+    for (const [index] of this.pool.workers.entries()) {
+      this.computeWorkerLastVirtualTaskTimestamp(index)
       const workerLastVirtualTaskEndTimestamp =
-        this.workerLastVirtualTaskTimestamp.get(worker)?.end ?? 0
+        this.workerLastVirtualTaskTimestamp.get(index)?.end ?? 0
       if (
         workerLastVirtualTaskEndTimestamp < minWorkerVirtualTaskEndTimestamp
       ) {
         minWorkerVirtualTaskEndTimestamp = workerLastVirtualTaskEndTimestamp
-        chosenWorker = worker
+        chosenWorkerKey = index
       }
     }
-    return chosenWorker
+    return chosenWorkerKey
+  }
+
+  /** @inheritDoc */
+  public remove (workerKey: number): boolean {
+    const workerDeleted = this.workerLastVirtualTaskTimestamp.delete(workerKey)
+    for (const [key, value] of this.workerLastVirtualTaskTimestamp.entries()) {
+      if (key > workerKey) {
+        this.workerLastVirtualTaskTimestamp.set(key - 1, value)
+      }
+    }
+    return workerDeleted
   }
 
   /**
-   * Computes workers last virtual task timestamp.
+   * Computes worker last virtual task timestamp.
+   *
+   * @param workerKey - The worker key.
    */
-  private computeWorkerLastVirtualTaskTimestamp () {
-    for (const worker of this.pool.workers) {
-      const workerVirtualTaskStartTimestamp = Math.max(
-        Date.now(),
-        this.workerLastVirtualTaskTimestamp.get(worker)?.end ?? -Infinity
-      )
-      const workerVirtualTaskEndTimestamp =
+  private computeWorkerLastVirtualTaskTimestamp (workerKey: number): void {
+    const workerVirtualTaskStartTimestamp = Math.max(
+      Date.now(),
+      this.workerLastVirtualTaskTimestamp.get(workerKey)?.end ?? -Infinity
+    )
+    this.workerLastVirtualTaskTimestamp.set(workerKey, {
+      start: workerVirtualTaskStartTimestamp,
+      end:
         workerVirtualTaskStartTimestamp +
-        (this.pool.getWorkerAverageTasksRunTime(worker) ?? 0)
-      this.workerLastVirtualTaskTimestamp.set(worker, {
-        start: workerVirtualTaskStartTimestamp,
-        end: workerVirtualTaskEndTimestamp
-      })
-    }
+        (this.pool.workers[workerKey].tasksUsage.avgRunTime ?? 0)
+    })
   }
 }