build: cleanup eslint configuration
[e-mobility-charging-stations-simulator.git] / src / worker / WorkerSet.ts
index b16b95424ec7d8eca5996e7b05ddf4759ef2df13..17b5b6dde201c85f4c0af0cbaf3574d33968fb03 100644 (file)
@@ -1,44 +1,66 @@
 // Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
 
-import EventEmitterAsyncResource from 'node:events';
-import { Worker } from 'node:worker_threads';
+import { EventEmitterAsyncResource } from 'node:events';
+import { SHARE_ENV, Worker } from 'node:worker_threads';
 
 import { WorkerAbstract } from './WorkerAbstract';
-import { WorkerConstants } from './WorkerConstants';
+import { EMPTY_FUNCTION, workerSetVersion } from './WorkerConstants';
 import {
-  type MessageHandler,
   type SetInfo,
   type WorkerData,
+  type WorkerMessage,
   WorkerMessageEvents,
   type WorkerOptions,
   type WorkerSetElement,
+  WorkerSetEvents,
 } from './WorkerTypes';
-import { defaultErrorHandler, defaultExitHandler, sleep } from './WorkerUtils';
+import { randomizeDelay, sleep } from './WorkerUtils';
 
 export class WorkerSet extends WorkerAbstract<WorkerData> {
-  public readonly emitter: EventEmitterAsyncResource;
+  public readonly emitter: EventEmitterAsyncResource | undefined;
   private readonly workerSet: Set<WorkerSetElement>;
+  private started: boolean;
+  private workerStartup: boolean;
 
   /**
-   * Create a new `WorkerSet`.
+   * Creates a new `WorkerSet`.
    *
    * @param workerScript -
    * @param workerOptions -
    */
-  constructor(workerScript: string, workerOptions?: WorkerOptions) {
+  constructor(workerScript: string, workerOptions: WorkerOptions) {
     super(workerScript, workerOptions);
+    if (
+      this.workerOptions.elementsPerWorker === null ||
+      this.workerOptions.elementsPerWorker === undefined
+    ) {
+      throw new TypeError('Elements per worker is not defined');
+    }
+    if (!Number.isSafeInteger(this.workerOptions.elementsPerWorker)) {
+      throw new TypeError('Elements per worker must be an integer');
+    }
+    if (this.workerOptions.elementsPerWorker <= 0) {
+      throw new RangeError('Elements per worker must be greater than zero');
+    }
     this.workerSet = new Set<WorkerSetElement>();
-    this.emitter = new EventEmitterAsyncResource();
+    if (this.workerOptions.poolOptions?.enableEvents) {
+      this.emitter = new EventEmitterAsyncResource({ name: 'workerset' });
+    }
+    this.started = false;
+    this.workerStartup = false;
   }
 
   get info(): SetInfo {
     return {
+      version: workerSetVersion,
+      type: 'set',
+      worker: 'thread',
       size: this.size,
-      runningElements: [...this.workerSet].reduce(
+      elementsExecuting: [...this.workerSet].reduce(
         (accumulator, workerSetElement) => accumulator + workerSetElement.numberOfWorkerElements,
-        0
+        0,
       ),
-      elementsPerWorker: this.maxElementsPerWorker,
+      elementsPerWorker: this.maxElementsPerWorker!,
     };
   }
 
@@ -50,65 +72,101 @@ export class WorkerSet extends WorkerAbstract<WorkerData> {
     return this.workerOptions.elementsPerWorker;
   }
 
-  /** @inheritDoc */
-  public async addElement(elementData: WorkerData): Promise<void> {
-    if (!this.workerSet) {
-      throw new Error("Cannot add a WorkerSet element: workers' set does not exist");
-    }
-    const workerSetElement = await this.getWorkerSetElement();
-    workerSetElement.worker.postMessage({
-      id: WorkerMessageEvents.startWorkerElement,
-      data: elementData,
-    });
-    ++workerSetElement.numberOfWorkerElements;
-    // Add element sequentially to optimize memory at startup
-    if (this.workerOptions.elementStartDelay > 0) {
-      await sleep(this.workerOptions.elementStartDelay);
-    }
-  }
-
   /** @inheritDoc */
   public async start(): Promise<void> {
     this.addWorkerSetElement();
     // Add worker set element sequentially to optimize memory at startup
-    this.workerOptions.workerStartDelay > 0 && (await sleep(this.workerOptions.workerStartDelay));
+    this.workerOptions.workerStartDelay! > 0 &&
+      (await sleep(randomizeDelay(this.workerOptions.workerStartDelay!)));
+    this.emitter?.emit(WorkerSetEvents.started, this.info);
+    this.started = true;
   }
 
   /** @inheritDoc */
   public async stop(): Promise<void> {
     for (const workerSetElement of this.workerSet) {
-      await workerSetElement.worker.terminate();
+      const worker = workerSetElement.worker;
+      const waitWorkerExit = new Promise<void>((resolve) => {
+        worker.once('exit', () => {
+          resolve();
+        });
+      });
+      await worker.terminate();
+      await waitWorkerExit;
+      this.emitter?.emit(WorkerSetEvents.stopped, this.info);
+      this.emitter?.emitDestroy();
+      this.emitter?.removeAllListeners();
+      this.started = false;
+    }
+  }
+
+  /** @inheritDoc */
+  public async addElement(elementData: WorkerData): Promise<void> {
+    if (!this.started) {
+      throw new Error('Cannot add a WorkerSet element: not started');
+    }
+    if (this.workerSet == null) {
+      throw new Error("Cannot add a WorkerSet element: 'workerSet' property does not exist");
+    }
+    const workerSetElement = await this.getWorkerSetElement();
+    workerSetElement.worker.postMessage({
+      event: WorkerMessageEvents.startWorkerElement,
+      data: elementData,
+    });
+    ++workerSetElement.numberOfWorkerElements;
+    // Add element sequentially to optimize memory at startup
+    if (this.workerOptions.elementStartDelay! > 0) {
+      await sleep(randomizeDelay(this.workerOptions.elementStartDelay!));
     }
-    this.workerSet.clear();
   }
 
   /**
-   * Add a new `WorkerSetElement`.
+   * Adds a new `WorkerSetElement`.
    */
   private addWorkerSetElement(): WorkerSetElement {
-    const worker = new Worker(this.workerScript);
-    worker.on(
-      'message',
-      (this.workerOptions?.messageHandler ?? WorkerConstants.EMPTY_FUNCTION).bind(
-        this
-      ) as MessageHandler<Worker>
-    );
-    worker.on('error', defaultErrorHandler.bind(this) as (err: Error) => void);
+    this.workerStartup = true;
+    const worker = new Worker(this.workerScript, {
+      env: SHARE_ENV,
+      ...this.workerOptions.poolOptions?.workerOptions,
+    });
+    worker.on('message', this.workerOptions.poolOptions?.messageHandler ?? EMPTY_FUNCTION);
+    worker.on('message', (message: WorkerMessage<WorkerData>) => {
+      if (message.event === WorkerMessageEvents.startedWorkerElement) {
+        this.emitter?.emit(WorkerSetEvents.elementStarted, this.info);
+      } else if (message.event === WorkerMessageEvents.startWorkerElementError) {
+        this.emitter?.emit(WorkerSetEvents.elementError, message.data);
+      }
+    });
+    worker.on('error', this.workerOptions.poolOptions?.errorHandler ?? EMPTY_FUNCTION);
     worker.on('error', (error) => {
-      this.emitter.emit('error', error);
-      this.addWorkerSetElement();
+      this.emitter?.emit(WorkerSetEvents.error, error);
+      if (
+        this.workerOptions.poolOptions?.restartWorkerOnError &&
+        this.started &&
+        !this.workerStartup
+      ) {
+        this.addWorkerSetElement();
+      }
     });
-    worker.on('exit', defaultExitHandler.bind(this) as (exitCode: number) => void);
-    worker.on('exit', () => this.workerSet.delete(this.getWorkerSetElementByWorker(worker)));
+    worker.on('online', this.workerOptions.poolOptions?.onlineHandler ?? EMPTY_FUNCTION);
+    worker.on('exit', this.workerOptions.poolOptions?.exitHandler ?? EMPTY_FUNCTION);
+    worker.once('exit', () =>
+      this.removeWorkerSetElement(this.getWorkerSetElementByWorker(worker)!),
+    );
     const workerSetElement: WorkerSetElement = { worker, numberOfWorkerElements: 0 };
     this.workerSet.add(workerSetElement);
+    this.workerStartup = false;
     return workerSetElement;
   }
 
+  private removeWorkerSetElement(workerSetElement: WorkerSetElement): void {
+    this.workerSet.delete(workerSetElement);
+  }
+
   private async getWorkerSetElement(): Promise<WorkerSetElement> {
-    let chosenWorkerSetElement: WorkerSetElement;
+    let chosenWorkerSetElement: WorkerSetElement | undefined;
     for (const workerSetElement of this.workerSet) {
-      if (workerSetElement.numberOfWorkerElements < this.workerOptions.elementsPerWorker) {
+      if (workerSetElement.numberOfWorkerElements < this.workerOptions.elementsPerWorker!) {
         chosenWorkerSetElement = workerSetElement;
         break;
       }
@@ -116,13 +174,14 @@ export class WorkerSet extends WorkerAbstract<WorkerData> {
     if (!chosenWorkerSetElement) {
       chosenWorkerSetElement = this.addWorkerSetElement();
       // Add worker set element sequentially to optimize memory at startup
-      this.workerOptions.workerStartDelay > 0 && (await sleep(this.workerOptions.workerStartDelay));
+      this.workerOptions.workerStartDelay! > 0 &&
+        (await sleep(randomizeDelay(this.workerOptions.workerStartDelay!)));
     }
     return chosenWorkerSetElement;
   }
 
   private getWorkerSetElementByWorker(worker: Worker): WorkerSetElement | undefined {
-    let workerSetElt: WorkerSetElement;
+    let workerSetElt: WorkerSetElement | undefined;
     for (const workerSetElement of this.workerSet) {
       if (workerSetElement.worker.threadId === worker.threadId) {
         workerSetElt = workerSetElement;