1 // Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
3 import { EventEmitter
} from
'node:events';
4 import { SHARE_ENV
, Worker
} from
'node:worker_threads';
6 import type { ThreadPoolOptions
} from
'poolifier';
8 import { WorkerAbstract
} from
'./WorkerAbstract';
9 import { WorkerConstants
} from
'./WorkerConstants';
16 type WorkerSetElement
,
18 } from
'./WorkerTypes';
19 import { sleep
} from
'./WorkerUtils';
21 const DEFAULT_POOL_OPTIONS
: ThreadPoolOptions
= {
23 restartWorkerOnError
: true,
26 export class WorkerSet
extends WorkerAbstract
<WorkerData
> {
27 public readonly emitter
!: EventEmitter
;
28 private readonly workerSet
: Set
<WorkerSetElement
>;
31 * Creates a new `WorkerSet`.
33 * @param workerScript -
34 * @param workerOptions -
36 constructor(workerScript
: string, workerOptions
: WorkerOptions
) {
37 super(workerScript
, workerOptions
);
38 this.workerOptions
.poolOptions
= {
39 ...DEFAULT_POOL_OPTIONS
,
40 ...this.workerOptions
.poolOptions
,
42 this.workerSet
= new Set
<WorkerSetElement
>();
43 if (this.workerOptions
.poolOptions
?.enableEvents
) {
44 this.emitter
= new EventEmitter();
50 version
: WorkerConstants
.version
,
54 elementsExecuting
: [...this.workerSet
].reduce(
55 (accumulator
, workerSetElement
) => accumulator
+ workerSetElement
.numberOfWorkerElements
,
58 elementsPerWorker
: this.maxElementsPerWorker
!,
63 return this.workerSet
.size
;
66 get
maxElementsPerWorker(): number | undefined {
67 return this.workerOptions
.elementsPerWorker
;
71 public async start(): Promise
<void> {
72 this.addWorkerSetElement();
73 // Add worker set element sequentially to optimize memory at startup
74 this.workerOptions
.workerStartDelay
! > 0 && (await sleep(this.workerOptions
.workerStartDelay
!));
78 public async stop(): Promise
<void> {
79 for (const workerSetElement
of this.workerSet
) {
80 const worker
= workerSetElement
.worker
;
81 const waitWorkerExit
= new Promise
<void>((resolve
) => {
82 worker
.on('exit', () => {
86 await worker
.terminate();
92 public async addElement(elementData
: WorkerData
): Promise
<void> {
93 if (!this.workerSet
) {
94 throw new Error("Cannot add a WorkerSet element: workers' set does not exist");
96 const workerSetElement
= await this.getWorkerSetElement();
97 workerSetElement
.worker
.postMessage({
98 event
: WorkerMessageEvents
.startWorkerElement
,
101 ++workerSetElement
.numberOfWorkerElements
;
102 // Add element sequentially to optimize memory at startup
103 if (this.workerOptions
.elementStartDelay
! > 0) {
104 await sleep(this.workerOptions
.elementStartDelay
!);
109 * Adds a new `WorkerSetElement`.
111 private addWorkerSetElement(): WorkerSetElement
{
112 const worker
= new Worker(this.workerScript
, {
114 ...this.workerOptions
.poolOptions
?.workerOptions
,
118 this.workerOptions
.poolOptions
?.messageHandler
?? WorkerConstants
.EMPTY_FUNCTION
,
120 worker
.on('message', (message
: WorkerMessage
<WorkerData
>) => {
121 if (message
.event
=== WorkerMessageEvents
.startedWorkerElement
) {
122 this.emitter
?.emit(WorkerSetEvents
.elementStarted
, this.info
);
123 } else if (message
.event
=== WorkerMessageEvents
.startWorkerElementError
) {
124 this.emitter
?.emit(WorkerSetEvents
.elementError
, message
.data
);
129 this.workerOptions
.poolOptions
?.errorHandler
?? WorkerConstants
.EMPTY_FUNCTION
,
131 worker
.on('error', (error
) => {
132 this.emitter
?.emit(WorkerSetEvents
.error
, error
);
133 if (this.workerOptions
.poolOptions
?.restartWorkerOnError
) {
134 this.addWorkerSetElement();
139 this.workerOptions
.poolOptions
?.onlineHandler
?? WorkerConstants
.EMPTY_FUNCTION
,
143 this.workerOptions
.poolOptions
?.exitHandler
?? WorkerConstants
.EMPTY_FUNCTION
,
145 worker
.once('exit', () =>
146 this.removeWorkerSetElement(this.getWorkerSetElementByWorker(worker
)!),
148 const workerSetElement
: WorkerSetElement
= { worker
, numberOfWorkerElements
: 0 };
149 this.workerSet
.add(workerSetElement
);
150 return workerSetElement
;
153 private removeWorkerSetElement(workerSetElement
: WorkerSetElement
): void {
154 this.workerSet
.delete(workerSetElement
);
157 private async getWorkerSetElement(): Promise
<WorkerSetElement
> {
158 let chosenWorkerSetElement
: WorkerSetElement
| undefined;
159 for (const workerSetElement
of this.workerSet
) {
160 if (workerSetElement
.numberOfWorkerElements
< this.workerOptions
.elementsPerWorker
!) {
161 chosenWorkerSetElement
= workerSetElement
;
165 if (!chosenWorkerSetElement
) {
166 chosenWorkerSetElement
= this.addWorkerSetElement();
167 // Add worker set element sequentially to optimize memory at startup
168 this.workerOptions
.workerStartDelay
! > 0 &&
169 (await sleep(this.workerOptions
.workerStartDelay
!));
171 return chosenWorkerSetElement
;
174 private getWorkerSetElementByWorker(worker
: Worker
): WorkerSetElement
| undefined {
175 let workerSetElt
: WorkerSetElement
| undefined;
176 for (const workerSetElement
of this.workerSet
) {
177 if (workerSetElement
.worker
.threadId
=== worker
.threadId
) {
178 workerSetElt
= workerSetElement
;