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();
48 elementsExecuting
: [...this.workerSet
].reduce(
49 (accumulator
, workerSetElement
) => accumulator
+ workerSetElement
.numberOfWorkerElements
,
52 elementsPerWorker
: this.maxElementsPerWorker
,
57 return this.workerSet
.size
;
60 get
maxElementsPerWorker(): number | undefined {
61 return this.workerOptions
.elementsPerWorker
;
65 public async start(): Promise
<void> {
66 this.addWorkerSetElement();
67 // Add worker set element sequentially to optimize memory at startup
68 this.workerOptions
.workerStartDelay
> 0 && (await sleep(this.workerOptions
.workerStartDelay
));
72 public async stop(): Promise
<void> {
73 for (const workerSetElement
of this.workerSet
) {
74 await workerSetElement
.worker
.terminate();
76 this.workerSet
.clear();
80 public async addElement(elementData
: WorkerData
): Promise
<void> {
81 if (!this.workerSet
) {
82 throw new Error("Cannot add a WorkerSet element: workers' set does not exist");
84 const workerSetElement
= await this.getWorkerSetElement();
85 workerSetElement
.worker
.postMessage({
86 id
: WorkerMessageEvents
.startWorkerElement
,
89 ++workerSetElement
.numberOfWorkerElements
;
90 // Add element sequentially to optimize memory at startup
91 if (this.workerOptions
.elementStartDelay
> 0) {
92 await sleep(this.workerOptions
.elementStartDelay
);
97 * Add a new `WorkerSetElement`.
99 private addWorkerSetElement(): WorkerSetElement
{
100 const worker
= new Worker(this.workerScript
, {
102 ...this.workerOptions
.poolOptions
.workerOptions
,
106 this.workerOptions
?.poolOptions
?.messageHandler
?? WorkerConstants
.EMPTY_FUNCTION
110 this.workerOptions
?.poolOptions
?.errorHandler
?? WorkerConstants
.EMPTY_FUNCTION
112 worker
.on('error', (error
) => {
113 if (this.emitter
!== undefined) {
114 this.emitter
.emit(WorkerSetEvents
.error
, error
);
116 if (this.workerOptions
?.poolOptions
?.restartWorkerOnError
) {
117 this.addWorkerSetElement();
122 this.workerOptions
?.poolOptions
?.onlineHandler
?? WorkerConstants
.EMPTY_FUNCTION
126 this.workerOptions
?.poolOptions
?.exitHandler
?? WorkerConstants
.EMPTY_FUNCTION
128 worker
.once('exit', () => this.workerSet
.delete(this.getWorkerSetElementByWorker(worker
)));
129 const workerSetElement
: WorkerSetElement
= { worker
, numberOfWorkerElements
: 0 };
130 this.workerSet
.add(workerSetElement
);
131 return workerSetElement
;
134 private async getWorkerSetElement(): Promise
<WorkerSetElement
> {
135 let chosenWorkerSetElement
: WorkerSetElement
;
136 for (const workerSetElement
of this.workerSet
) {
137 if (workerSetElement
.numberOfWorkerElements
< this.workerOptions
.elementsPerWorker
) {
138 chosenWorkerSetElement
= workerSetElement
;
142 if (!chosenWorkerSetElement
) {
143 chosenWorkerSetElement
= this.addWorkerSetElement();
144 // Add worker set element sequentially to optimize memory at startup
145 this.workerOptions
.workerStartDelay
> 0 && (await sleep(this.workerOptions
.workerStartDelay
));
147 return chosenWorkerSetElement
;
150 private getWorkerSetElementByWorker(worker
: Worker
): WorkerSetElement
| undefined {
151 let workerSetElt
: WorkerSetElement
;
152 for (const workerSetElement
of this.workerSet
) {
153 if (workerSetElement
.worker
.threadId
=== worker
.threadId
) {
154 workerSetElt
= workerSetElement
;