build(deps): apply updates
[e-mobility-charging-stations-simulator.git] / src / worker / WorkerSet.ts
index c82e79fcfb81a41f795b34617f7b0cb5658072b4..ff172d63cd158b5ce7ed3541f2eaf7702bace5b5 100644 (file)
@@ -1,19 +1,21 @@
 // Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
 
-import { Worker } from 'worker_threads';
+import EventEmitterAsyncResource from 'node:events';
+import { Worker } from 'node:worker_threads';
 
-import WorkerAbstract from './WorkerAbstract';
-import { WorkerUtils } from './WorkerUtils';
+import { WorkerAbstract } from './WorkerAbstract';
+import { WorkerConstants } from './WorkerConstants';
 import {
   type MessageHandler,
   type WorkerData,
   WorkerMessageEvents,
   type WorkerOptions,
   type WorkerSetElement,
-} from '../types/Worker';
-import Utils from '../utils/Utils';
+} from './WorkerTypes';
+import { defaultErrorHandler, defaultExitHandler, sleep } from './WorkerUtils';
 
-export default class WorkerSet extends WorkerAbstract<WorkerData> {
+export class WorkerSet extends WorkerAbstract<WorkerData> {
+  public readonly emitter: EventEmitterAsyncResource;
   private readonly workerSet: Set<WorkerSetElement>;
 
   /**
@@ -25,57 +27,42 @@ export default class WorkerSet extends WorkerAbstract<WorkerData> {
   constructor(workerScript: string, workerOptions?: WorkerOptions) {
     super(workerScript, workerOptions);
     this.workerSet = new Set<WorkerSetElement>();
+    this.emitter = new EventEmitterAsyncResource();
   }
 
   get size(): number {
     return this.workerSet.size;
   }
 
-  get maxElementsPerWorker(): number | null {
+  get maxElementsPerWorker(): number | undefined {
     return this.workerOptions.elementsPerWorker;
   }
 
-  /**
-   *
-   * @param elementData -
-   * @returns
-   * @public
-   */
+  /** @inheritDoc */
   public async addElement(elementData: WorkerData): Promise<void> {
     if (!this.workerSet) {
       throw new Error("Cannot add a WorkerSet element: workers' set does not exist");
     }
-    if (
-      this.workerSet.size === 0 ||
-      this.getLastWorkerSetElement().numberOfWorkerElements >= this.workerOptions.elementsPerWorker
-    ) {
-      await this.startWorker();
-    }
-    this.getLastWorker().postMessage({
-      id: WorkerMessageEvents.START_WORKER_ELEMENT,
+    const workerSetElement = await this.getWorkerSetElement();
+    workerSetElement.worker.postMessage({
+      id: WorkerMessageEvents.startWorkerElement,
       data: elementData,
     });
-    this.getLastWorkerSetElement().numberOfWorkerElements++;
-    // Start element sequentially to optimize memory at startup
+    ++workerSetElement.numberOfWorkerElements;
+    // Add element sequentially to optimize memory at startup
     if (this.workerOptions.elementStartDelay > 0) {
-      await Utils.sleep(this.workerOptions.elementStartDelay);
+      await sleep(this.workerOptions.elementStartDelay);
     }
   }
 
-  /**
-   *
-   * @returns
-   * @public
-   */
+  /** @inheritDoc */
   public async start(): Promise<void> {
-    await this.startWorker();
+    this.addWorkerSetElement();
+    // Add worker set element sequentially to optimize memory at startup
+    this.workerOptions.workerStartDelay > 0 && (await sleep(this.workerOptions.workerStartDelay));
   }
 
-  /**
-   *
-   * @returns
-   * @public
-   */
+  /** @inheritDoc */
   public async stop(): Promise<void> {
     for (const workerSetElement of this.workerSet) {
       await workerSetElement.worker.terminate();
@@ -84,43 +71,45 @@ export default class WorkerSet extends WorkerAbstract<WorkerData> {
   }
 
   /**
-   * Start a new `Worker`.
+   * Add a new `WorkerSetElement`.
    */
-  private async startWorker(): Promise<void> {
+  private addWorkerSetElement(): WorkerSetElement {
     const worker = new Worker(this.workerScript);
     worker.on(
       'message',
-      (
-        this.workerOptions?.messageHandler ??
-        (() => {
-          /* This is intentional */
-        })
-      ).bind(this) as MessageHandler<Worker>
+      (this.workerOptions?.messageHandler ?? WorkerConstants.EMPTY_FUNCTION).bind(
+        this
+      ) as MessageHandler<Worker>
     );
-    worker.on('error', WorkerUtils.defaultErrorHandler.bind(this) as (err: Error) => void);
-    worker.on('exit', (code) => {
-      WorkerUtils.defaultExitHandler(code);
-      this.workerSet.delete(this.getWorkerSetElementByWorker(worker));
+    worker.on('error', defaultErrorHandler.bind(this) as (err: Error) => void);
+    worker.on('error', (error) => {
+      this.emitter.emit('error', error);
+      this.addWorkerSetElement();
     });
-    this.workerSet.add({ worker, numberOfWorkerElements: 0 });
-    // Start worker sequentially to optimize memory at startup
-    this.workerOptions.workerStartDelay > 0 &&
-      (await Utils.sleep(this.workerOptions.workerStartDelay));
-  }
-
-  private getLastWorkerSetElement(): WorkerSetElement {
-    let workerSetElement: WorkerSetElement;
-    for (workerSetElement of this.workerSet) {
-      /* This is intentional */
-    }
+    worker.on('exit', defaultExitHandler.bind(this) as (exitCode: number) => void);
+    worker.on('exit', () => this.workerSet.delete(this.getWorkerSetElementByWorker(worker)));
+    const workerSetElement: WorkerSetElement = { worker, numberOfWorkerElements: 0 };
+    this.workerSet.add(workerSetElement);
     return workerSetElement;
   }
 
-  private getLastWorker(): Worker {
-    return this.getLastWorkerSetElement().worker;
+  private async getWorkerSetElement(): Promise<WorkerSetElement> {
+    let chosenWorkerSetElement: WorkerSetElement;
+    for (const workerSetElement of this.workerSet) {
+      if (workerSetElement.numberOfWorkerElements < this.workerOptions.elementsPerWorker) {
+        chosenWorkerSetElement = workerSetElement;
+        break;
+      }
+    }
+    if (!chosenWorkerSetElement) {
+      chosenWorkerSetElement = this.addWorkerSetElement();
+      // Add worker set element sequentially to optimize memory at startup
+      this.workerOptions.workerStartDelay > 0 && (await sleep(this.workerOptions.workerStartDelay));
+    }
+    return chosenWorkerSetElement;
   }
 
-  private getWorkerSetElementByWorker(worker: Worker): WorkerSetElement {
+  private getWorkerSetElementByWorker(worker: Worker): WorkerSetElement | undefined {
     let workerSetElt: WorkerSetElement;
     for (const workerSetElement of this.workerSet) {
       if (workerSetElement.worker.threadId === worker.threadId) {