-// Partial Copyright Jerome Benoit. 2021. All Rights Reserved.
+// Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
-import { WorkerMessageEvents, WorkerOptions, WorkerSetElement } from '../types/Worker';
+import { EventEmitter } from 'node:events';
+import { SHARE_ENV, Worker } from 'node:worker_threads';
-import Utils from '../utils/Utils';
-import { Worker } from 'worker_threads';
-import WorkerAbstract from './WorkerAbstract';
-import { WorkerUtils } from './WorkerUtils';
+import type { ThreadPoolOptions } from 'poolifier';
-export default class WorkerSet<T> extends WorkerAbstract {
- public readonly maxElementsPerWorker: number;
- private readonly messageHandler: (message: unknown) => void | Promise<void>;
- private workerSet: Set<WorkerSetElement>;
+import { WorkerAbstract } from './WorkerAbstract';
+import { WorkerConstants } from './WorkerConstants';
+import {
+ type SetInfo,
+ type WorkerData,
+ type WorkerMessage,
+ WorkerMessageEvents,
+ type WorkerOptions,
+ type WorkerSetElement,
+ WorkerSetEvents,
+} from './WorkerTypes';
+import { sleep } from './WorkerUtils';
+
+const DEFAULT_POOL_OPTIONS: ThreadPoolOptions = {
+ enableEvents: true,
+ restartWorkerOnError: true,
+};
+
+export class WorkerSet extends WorkerAbstract<WorkerData> {
+ public readonly emitter!: EventEmitter;
+ private readonly workerSet: Set<WorkerSetElement>;
/**
- * Create a new `WorkerSet`.
+ * Creates a new `WorkerSet`.
*
- * @param workerScript
- * @param maxElementsPerWorker
- * @param workerStartDelay
- * @param opts
+ * @param workerScript -
+ * @param workerOptions -
*/
- constructor(workerScript: string, maxElementsPerWorker = 1, workerStartDelay?: number, opts?: WorkerOptions) {
- super(workerScript, workerStartDelay);
- this.maxElementsPerWorker = maxElementsPerWorker;
- this.messageHandler = opts?.messageHandler ?? (() => { /* This is intentional */ });
+ constructor(workerScript: string, workerOptions: WorkerOptions) {
+ super(workerScript, workerOptions);
+ this.workerOptions.poolOptions = {
+ ...DEFAULT_POOL_OPTIONS,
+ ...this.workerOptions.poolOptions,
+ };
this.workerSet = new Set<WorkerSetElement>();
+ if (this.workerOptions.poolOptions?.enableEvents) {
+ this.emitter = new EventEmitter();
+ }
+ }
+
+ get info(): SetInfo {
+ return {
+ version: WorkerConstants.version,
+ type: 'set',
+ worker: 'thread',
+ size: this.size,
+ elementsExecuting: [...this.workerSet].reduce(
+ (accumulator, workerSetElement) => accumulator + workerSetElement.numberOfWorkerElements,
+ 0,
+ ),
+ elementsPerWorker: this.maxElementsPerWorker!,
+ };
}
get size(): number {
return this.workerSet.size;
}
- /**
- *
- * @param elementData
- * @returns
- * @public
- */
- public async addElement(elementData: T): Promise<void> {
- if (!this.workerSet) {
- throw new Error('Cannot add a WorkerSet element: workers\' set does not exist');
- }
- if (this.getLastWorkerSetElement().numberOfWorkerElements >= this.maxElementsPerWorker) {
- this.startWorker();
- // Start worker sequentially to optimize memory at startup
- await Utils.sleep(this.workerStartDelay);
- }
- this.getLastWorker().postMessage({ id: WorkerMessageEvents.START_WORKER_ELEMENT, data: elementData });
- this.getLastWorkerSetElement().numberOfWorkerElements++;
+ get maxElementsPerWorker(): number | undefined {
+ return this.workerOptions.elementsPerWorker;
}
- /**
- *
- * @returns
- * @public
- */
+ /** @inheritDoc */
public async start(): Promise<void> {
- this.startWorker();
- // Start worker sequentially to optimize memory at startup
- await Utils.sleep(this.workerStartDelay);
+ 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();
+ const worker = workerSetElement.worker;
+ const workerExitPromise = new Promise<void>((resolve) => {
+ worker.on('exit', () => {
+ resolve();
+ });
+ });
+ await worker.terminate();
+ await workerExitPromise;
+ }
+ }
+
+ /** @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({
+ event: WorkerMessageEvents.startWorkerElement,
+ data: elementData,
+ });
+ ++workerSetElement.numberOfWorkerElements;
+ // Add element sequentially to optimize memory at startup
+ if (this.workerOptions.elementStartDelay! > 0) {
+ await sleep(this.workerOptions.elementStartDelay!);
}
- this.workerSet.clear();
}
/**
- *
- * @private
+ * Adds a new `WorkerSetElement`.
*/
- private startWorker(): void {
- const worker = new Worker(this.workerScript);
- worker.on('message', (msg) => {
- (async () => {
- await this.messageHandler(msg);
- })().catch(() => { /* This is intentional */ });
+ private addWorkerSetElement(): WorkerSetElement {
+ const worker = new Worker(this.workerScript, {
+ env: SHARE_ENV,
+ ...this.workerOptions.poolOptions?.workerOptions,
});
- worker.on('error', () => { /* This is intentional */ });
- worker.on('exit', (code) => {
- WorkerUtils.defaultExitHandler(code);
- this.workerSet.delete(this.getWorkerSetElementByWorker(worker));
+ worker.on(
+ 'message',
+ this.workerOptions.poolOptions?.messageHandler ?? WorkerConstants.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);
+ }
});
- this.workerSet.add({ worker, numberOfWorkerElements: 0 });
+ worker.on(
+ 'error',
+ this.workerOptions.poolOptions?.errorHandler ?? WorkerConstants.EMPTY_FUNCTION,
+ );
+ worker.on('error', (error) => {
+ this.emitter?.emit(WorkerSetEvents.error, error);
+ if (this.workerOptions.poolOptions?.restartWorkerOnError) {
+ this.addWorkerSetElement();
+ }
+ });
+ worker.on(
+ 'online',
+ this.workerOptions.poolOptions?.onlineHandler ?? WorkerConstants.EMPTY_FUNCTION,
+ );
+ worker.on(
+ 'exit',
+ this.workerOptions.poolOptions?.exitHandler ?? WorkerConstants.EMPTY_FUNCTION,
+ );
+ worker.once('exit', () =>
+ this.removeWorkerSetElement(this.getWorkerSetElementByWorker(worker)!),
+ );
+ const workerSetElement: WorkerSetElement = { worker, numberOfWorkerElements: 0 };
+ this.workerSet.add(workerSetElement);
+ return workerSetElement;
}
- private getLastWorkerSetElement(): WorkerSetElement {
- let workerSetElement: WorkerSetElement;
- // eslint-disable-next-line no-empty
- for (workerSetElement of this.workerSet) { /* This is intentional */ }
- return workerSetElement;
+ private removeWorkerSetElement(workerSetElement: WorkerSetElement): void {
+ this.workerSet.delete(workerSetElement);
}
- private getLastWorker(): Worker {
- return this.getLastWorkerSetElement().worker;
+ private async getWorkerSetElement(): Promise<WorkerSetElement> {
+ let chosenWorkerSetElement: WorkerSetElement | undefined;
+ 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 {
- let workerSetElt: WorkerSetElement;
+ private getWorkerSetElementByWorker(worker: Worker): WorkerSetElement | undefined {
+ let workerSetElt: WorkerSetElement | undefined;
for (const workerSetElement of this.workerSet) {
if (workerSetElement.worker.threadId === worker.threadId) {
workerSetElt = workerSetElement;