-// Partial Copyright Jerome Benoit. 2021. All Rights Reserved.
+// Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
-import { WorkerData, WorkerMessageEvents, WorkerOptions, WorkerSetElement } from '../types/Worker';
+import EventEmitterAsyncResource from 'node:events';
+import { Worker } from 'node:worker_threads';
-import Utils from '../utils/Utils';
-import { Worker } from '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 './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>;
- private readonly messageHandler: (message: unknown) => void | Promise<void>;
/**
* Create a new `WorkerSet`.
*
- * @param workerScript
- * @param workerOptions
+ * @param workerScript -
+ * @param workerOptions -
*/
constructor(workerScript: string, workerOptions?: WorkerOptions) {
super(workerScript, workerOptions);
this.workerSet = new Set<WorkerSetElement>();
- this.messageHandler =
- workerOptions?.messageHandler ??
- (() => {
- /* This is intentional */
- });
+ 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.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++; // should there not be a hanshake to be safer ?
- // 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();
}
/**
- *
- * @private
+ * Add a new `WorkerSetElement`.
*/
- private async startWorker(): Promise<void> {
+ private addWorkerSetElement(): WorkerSetElement {
const worker = new Worker(this.workerScript);
- worker.on('message', (msg) => {
- (async () => {
- await this.messageHandler(msg);
- })().catch(() => {
- /* This is intentional */
- });
+ worker.on(
+ 'message',
+ (this.workerOptions?.messageHandler ?? WorkerConstants.EMPTY_FUNCTION).bind(
+ this
+ ) as MessageHandler<Worker>
+ );
+ worker.on('error', defaultErrorHandler.bind(this) as (err: Error) => void);
+ worker.on('error', (error) => {
+ this.emitter.emit('error', error);
+ this.addWorkerSetElement();
});
- worker.on('error', () => {
- /* This is intentional */
- });
- worker.on('exit', (code) => {
- WorkerUtils.defaultExitHandler(code);
- this.workerSet.delete(this.getWorkerSetElementByWorker(worker));
- });
- 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) {