-// Partial Copyright Jerome Benoit. 2021. All Rights Reserved.
+// Partial Copyright Jerome Benoit. 2021-2024. All Rights Reserved.
-import { WorkerData, WorkerMessageEvents, WorkerOptions, WorkerSetElement } from '../types/Worker';
+import { randomUUID } from 'node:crypto'
+import { EventEmitterAsyncResource } 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 { WorkerAbstract } from './WorkerAbstract.js'
+import { EMPTY_FUNCTION, workerSetVersion } from './WorkerConstants.js'
+import {
+ type SetInfo,
+ type WorkerData,
+ type WorkerMessage,
+ WorkerMessageEvents,
+ type WorkerOptions,
+ type WorkerSetElement,
+ WorkerSetEvents
+} from './WorkerTypes.js'
+import { randomizeDelay, sleep } from './WorkerUtils.js'
-export default class WorkerSet extends WorkerAbstract<WorkerData> {
- private readonly workerSet: Set<WorkerSetElement>;
- private readonly messageHandler: (message: unknown) => void | Promise<void>;
+interface ResponseWrapper<R extends WorkerData> {
+ resolve: (value: R | PromiseLike<R>) => void
+ reject: (reason?: unknown) => void
+ workerSetElement: WorkerSetElement
+}
+
+export class WorkerSet<D extends WorkerData, R extends WorkerData> extends WorkerAbstract<D, R> {
+ public readonly emitter: EventEmitterAsyncResource | undefined
+ private readonly workerSet: Set<WorkerSetElement>
+ private readonly promiseResponseMap: Map<
+ `${string}-${string}-${string}-${string}`,
+ ResponseWrapper<R>
+ >
+
+ private started: boolean
+ private workerStartup: boolean
/**
- * Create a new `WorkerSet`.
+ * Creates 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 */
- });
+ constructor (workerScript: string, workerOptions: WorkerOptions) {
+ super(workerScript, workerOptions)
+ if (this.workerOptions.elementsPerWorker == null) {
+ 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.promiseResponseMap = new Map<
+ `${string}-${string}-${string}-${string}`,
+ ResponseWrapper<R>
+ >()
+ if (this.workerOptions.poolOptions?.enableEvents === true) {
+ this.emitter = new EventEmitterAsyncResource({ name: 'workerset' })
+ }
+ this.started = false
+ this.workerStartup = false
}
- get size(): number {
- return this.workerSet.size;
+ get info (): SetInfo {
+ return {
+ version: workerSetVersion,
+ type: 'set',
+ worker: 'thread',
+ started: this.started,
+ size: this.size,
+ elementsExecuting: [...this.workerSet].reduce(
+ (accumulator, workerSetElement) => accumulator + workerSetElement.numberOfWorkerElements,
+ 0
+ ),
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ elementsPerWorker: this.maxElementsPerWorker!
+ }
}
- get maxElementsPerWorker(): number | null {
- return this.workerOptions.elementsPerWorker;
+ get size (): number {
+ return this.workerSet.size
}
- /**
- *
- * @param elementData
- * @returns
- * @public
- */
- 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,
- data: elementData,
- });
- this.getLastWorkerSetElement().numberOfWorkerElements++; // should there not be a hanshake to be safer ?
- // Start element sequentially to optimize memory at startup
- if (this.workerOptions.elementStartDelay > 0) {
- await Utils.sleep(this.workerOptions.elementStartDelay);
- }
+ get maxElementsPerWorker (): number | undefined {
+ return this.workerOptions.elementsPerWorker
}
- /**
- *
- * @returns
- * @public
- */
- public async start(): Promise<void> {
- await this.startWorker();
+ /** @inheritDoc */
+ public async start (): Promise<void> {
+ this.addWorkerSetElement()
+ // Add worker set element sequentially to optimize memory at startup
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ this.workerOptions.workerStartDelay! > 0 &&
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ (await sleep(randomizeDelay(this.workerOptions.workerStartDelay!)))
+ this.emitter?.emit(WorkerSetEvents.started, this.info)
+ this.started = true
}
- /**
- *
- * @returns
- * @public
- */
- public async stop(): Promise<void> {
+ /** @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()
+ })
+ })
+ worker.unref()
+ await worker.terminate()
+ await waitWorkerExit
+ }
+ this.emitter?.emit(WorkerSetEvents.stopped, this.info)
+ this.started = false
+ this.emitter?.emitDestroy()
+ }
+
+ /** @inheritDoc */
+ public async addElement (elementData: D): Promise<R> {
+ if (!this.started) {
+ throw new Error('Cannot add a WorkerSet element: not started')
+ }
+ const workerSetElement = await this.getWorkerSetElement()
+ const sendMessageToWorker = new Promise<R>((resolve, reject) => {
+ const message = {
+ uuid: randomUUID(),
+ event: WorkerMessageEvents.addWorkerElement,
+ data: elementData
+ } satisfies WorkerMessage<D>
+ workerSetElement.worker.postMessage(message)
+ this.promiseResponseMap.set(message.uuid, {
+ resolve,
+ reject,
+ workerSetElement
+ })
+ })
+ const response = await sendMessageToWorker
+ // Add element sequentially to optimize memory at startup
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ if (this.workerOptions.elementAddDelay! > 0) {
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ await sleep(randomizeDelay(this.workerOptions.elementAddDelay!))
}
- this.workerSet.clear();
+ return response
}
/**
- *
- * @private
+ * Adds a new `WorkerSetElement`.
*/
- private async startWorker(): Promise<void> {
- const worker = new Worker(this.workerScript);
- worker.on('message', (msg) => {
- (async () => {
- await this.messageHandler(msg);
- })().catch(() => {
- /* This is intentional */
- });
- });
- 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 addWorkerSetElement (): WorkerSetElement {
+ 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<R>) => {
+ const { uuid, event, data } = message
+ if (this.promiseResponseMap.has(uuid)) {
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ const { resolve, reject, workerSetElement } = this.promiseResponseMap.get(uuid)!
+ switch (event) {
+ case WorkerMessageEvents.addedWorkerElement:
+ this.emitter?.emit(WorkerSetEvents.elementAdded, this.info)
+ ++workerSetElement.numberOfWorkerElements
+ resolve(data)
+ break
+ case WorkerMessageEvents.workerElementError:
+ this.emitter?.emit(WorkerSetEvents.elementError, data)
+ reject(data)
+ break
+ default:
+ reject(
+ new Error(
+ `Unknown worker message event: '${event}' received with data: '${JSON.stringify(
+ data,
+ undefined,
+ 2
+ )}'`
+ )
+ )
+ }
+ this.promiseResponseMap.delete(uuid)
+ }
+ })
+ worker.on('error', this.workerOptions.poolOptions?.errorHandler ?? EMPTY_FUNCTION)
+ worker.once('error', error => {
+ this.emitter?.emit(WorkerSetEvents.error, error)
+ if (
+ this.workerOptions.poolOptions?.restartWorkerOnError === true &&
+ this.started &&
+ !this.workerStartup
+ ) {
+ this.addWorkerSetElement()
+ }
+ worker.unref()
+ worker.terminate().catch((error: unknown) => this.emitter?.emit(WorkerSetEvents.error, error))
+ })
+ 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 getLastWorkerSetElement(): WorkerSetElement {
- let workerSetElement: WorkerSetElement;
- for (workerSetElement of this.workerSet) {
- /* This is intentional */
+ private removeWorkerSetElement (workerSetElement: WorkerSetElement | undefined): void {
+ if (workerSetElement == null) {
+ return
}
- return workerSetElement;
+ 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) {
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ if (workerSetElement.numberOfWorkerElements < this.workerOptions.elementsPerWorker!) {
+ chosenWorkerSetElement = workerSetElement
+ break
+ }
+ }
+ if (chosenWorkerSetElement == null) {
+ chosenWorkerSetElement = this.addWorkerSetElement()
+ // Add worker set element sequentially to optimize memory at startup
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ this.workerOptions.workerStartDelay! > 0 &&
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ (await sleep(randomizeDelay(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;
- break;
+ workerSetElt = workerSetElement
+ break
}
}
- return workerSetElt;
+ return workerSetElt
}
}