1 // Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
3 import EventEmitterAsyncResource from
'node:events';
4 import { SHARE_ENV
, Worker
} from
'node:worker_threads';
6 import { WorkerAbstract
} from
'./WorkerAbstract';
7 import { WorkerConstants
} from
'./WorkerConstants';
13 type WorkerSetElement
,
15 } from
'./WorkerTypes';
16 import { sleep
} from
'./WorkerUtils';
18 export class WorkerSet
extends WorkerAbstract
<WorkerData
> {
19 public readonly emitter
: EventEmitterAsyncResource
;
20 private readonly workerSet
: Set
<WorkerSetElement
>;
23 * Create a new `WorkerSet`.
25 * @param workerScript -
26 * @param workerOptions -
28 constructor(workerScript
: string, workerOptions
?: WorkerOptions
) {
29 super(workerScript
, workerOptions
);
30 this.workerOptions
.poolOptions
= {
33 restartWorkerOnError
: true,
35 ...this.workerOptions
.poolOptions
,
37 this.workerSet
= new Set
<WorkerSetElement
>();
38 if (this.workerOptions
?.poolOptions
?.enableEvents
) {
39 this.emitter
= new EventEmitterAsyncResource();
46 elementsExecuting
: [...this.workerSet
].reduce(
47 (accumulator
, workerSetElement
) => accumulator
+ workerSetElement
.numberOfWorkerElements
,
50 elementsPerWorker
: this.maxElementsPerWorker
,
55 return this.workerSet
.size
;
58 get
maxElementsPerWorker(): number | undefined {
59 return this.workerOptions
.elementsPerWorker
;
63 public async start(): Promise
<void> {
64 this.addWorkerSetElement();
65 // Add worker set element sequentially to optimize memory at startup
66 this.workerOptions
.workerStartDelay
> 0 && (await sleep(this.workerOptions
.workerStartDelay
));
70 public async stop(): Promise
<void> {
71 for (const workerSetElement
of this.workerSet
) {
72 await workerSetElement
.worker
.terminate();
74 this.workerSet
.clear();
78 public async addElement(elementData
: WorkerData
): Promise
<void> {
79 if (!this.workerSet
) {
80 throw new Error("Cannot add a WorkerSet element: workers' set does not exist");
82 const workerSetElement
= await this.getWorkerSetElement();
83 workerSetElement
.worker
.postMessage({
84 id
: WorkerMessageEvents
.startWorkerElement
,
87 ++workerSetElement
.numberOfWorkerElements
;
88 // Add element sequentially to optimize memory at startup
89 if (this.workerOptions
.elementStartDelay
> 0) {
90 await sleep(this.workerOptions
.elementStartDelay
);
95 * Add a new `WorkerSetElement`.
97 private addWorkerSetElement(): WorkerSetElement
{
98 const worker
= new Worker(this.workerScript
, {
100 ...this.workerOptions
.poolOptions
.workerOptions
,
104 this.workerOptions
?.poolOptions
?.messageHandler
?? WorkerConstants
.EMPTY_FUNCTION
108 this.workerOptions
?.poolOptions
?.errorHandler
?? WorkerConstants
.EMPTY_FUNCTION
110 worker
.on('error', (error
) => {
111 if (this.emitter
!== undefined) {
112 this.emitter
.emit(WorkerSetEvents
.error
, error
);
114 if (this.workerOptions
?.poolOptions
?.restartWorkerOnError
) {
115 this.addWorkerSetElement();
120 this.workerOptions
?.poolOptions
?.onlineHandler
?? WorkerConstants
.EMPTY_FUNCTION
124 this.workerOptions
?.poolOptions
?.exitHandler
?? WorkerConstants
.EMPTY_FUNCTION
126 worker
.once('exit', () => this.workerSet
.delete(this.getWorkerSetElementByWorker(worker
)));
127 const workerSetElement
: WorkerSetElement
= { worker
, numberOfWorkerElements
: 0 };
128 this.workerSet
.add(workerSetElement
);
129 return workerSetElement
;
132 private async getWorkerSetElement(): Promise
<WorkerSetElement
> {
133 let chosenWorkerSetElement
: WorkerSetElement
;
134 for (const workerSetElement
of this.workerSet
) {
135 if (workerSetElement
.numberOfWorkerElements
< this.workerOptions
.elementsPerWorker
) {
136 chosenWorkerSetElement
= workerSetElement
;
140 if (!chosenWorkerSetElement
) {
141 chosenWorkerSetElement
= this.addWorkerSetElement();
142 // Add worker set element sequentially to optimize memory at startup
143 this.workerOptions
.workerStartDelay
> 0 && (await sleep(this.workerOptions
.workerStartDelay
));
145 return chosenWorkerSetElement
;
148 private getWorkerSetElementByWorker(worker
: Worker
): WorkerSetElement
| undefined {
149 let workerSetElt
: WorkerSetElement
;
150 for (const workerSetElement
of this.workerSet
) {
151 if (workerSetElement
.worker
.threadId
=== worker
.threadId
) {
152 workerSetElt
= workerSetElement
;