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.js'
7 import { EMPTY_FUNCTION
, workerSetVersion
} from
'./WorkerConstants.js'
14 type WorkerSetElement
,
16 } from
'./WorkerTypes.js'
17 import { randomizeDelay
, sleep
} from
'./WorkerUtils.js'
19 export class WorkerSet
extends WorkerAbstract
<WorkerData
> {
20 public readonly emitter
: EventEmitterAsyncResource
| undefined
21 private readonly workerSet
: Set
<WorkerSetElement
>
22 private started
: boolean
23 private workerStartup
: boolean
26 * Creates a new `WorkerSet`.
28 * @param workerScript -
29 * @param workerOptions -
31 constructor (workerScript
: string, workerOptions
: WorkerOptions
) {
32 super(workerScript
, workerOptions
)
33 if (this.workerOptions
.elementsPerWorker
== null) {
34 throw new TypeError('Elements per worker is not defined')
36 if (!Number.isSafeInteger(this.workerOptions
.elementsPerWorker
)) {
37 throw new TypeError('Elements per worker must be an integer')
39 if (this.workerOptions
.elementsPerWorker
<= 0) {
40 throw new RangeError('Elements per worker must be greater than zero')
42 this.workerSet
= new Set
<WorkerSetElement
>()
43 if (this.workerOptions
.poolOptions
?.enableEvents
=== true) {
44 this.emitter
= new EventEmitterAsyncResource({ name
: 'workerset' })
47 this.workerStartup
= false
50 get
info (): SetInfo
{
52 version
: workerSetVersion
,
56 elementsExecuting
: [...this.workerSet
].reduce(
57 (accumulator
, workerSetElement
) => accumulator
+ workerSetElement
.numberOfWorkerElements
,
60 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
61 elementsPerWorker
: this.maxElementsPerWorker
!
66 return this.workerSet
.size
69 get
maxElementsPerWorker (): number | undefined {
70 return this.workerOptions
.elementsPerWorker
74 public async start (): Promise
<void> {
75 this.addWorkerSetElement()
76 // Add worker set element sequentially to optimize memory at startup
77 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
78 this.workerOptions
.workerStartDelay
! > 0 &&
79 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
80 (await sleep(randomizeDelay(this.workerOptions
.workerStartDelay
!)))
81 this.emitter
?.emit(WorkerSetEvents
.started
, this.info
)
86 public async stop (): Promise
<void> {
87 for (const workerSetElement
of this.workerSet
) {
88 const worker
= workerSetElement
.worker
89 const waitWorkerExit
= new Promise
<void>(resolve
=> {
90 worker
.once('exit', () => {
94 await worker
.terminate()
96 this.emitter
?.emit(WorkerSetEvents
.stopped
, this.info
)
97 this.emitter
?.emitDestroy()
98 this.emitter
?.removeAllListeners()
104 public async addElement (elementData
: WorkerData
): Promise
<void> {
106 throw new Error('Cannot add a WorkerSet element: not started')
108 const workerSetElement
= await this.getWorkerSetElement()
109 workerSetElement
.worker
.postMessage({
110 event
: WorkerMessageEvents
.startWorkerElement
,
113 ++workerSetElement
.numberOfWorkerElements
114 // Add element sequentially to optimize memory at startup
115 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
116 if (this.workerOptions
.elementStartDelay
! > 0) {
117 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
118 await sleep(randomizeDelay(this.workerOptions
.elementStartDelay
!))
123 * Adds a new `WorkerSetElement`.
125 private addWorkerSetElement (): WorkerSetElement
{
126 this.workerStartup
= true
127 const worker
= new Worker(this.workerScript
, {
129 ...this.workerOptions
.poolOptions
?.workerOptions
131 worker
.on('message', this.workerOptions
.poolOptions
?.messageHandler
?? EMPTY_FUNCTION
)
132 worker
.on('message', (message
: WorkerMessage
<WorkerData
>) => {
133 if (message
.event
=== WorkerMessageEvents
.startedWorkerElement
) {
134 this.emitter
?.emit(WorkerSetEvents
.elementStarted
, this.info
)
135 } else if (message
.event
=== WorkerMessageEvents
.startWorkerElementError
) {
136 this.emitter
?.emit(WorkerSetEvents
.elementError
, message
.data
)
139 worker
.on('error', this.workerOptions
.poolOptions
?.errorHandler
?? EMPTY_FUNCTION
)
140 worker
.on('error', error
=> {
141 this.emitter
?.emit(WorkerSetEvents
.error
, error
)
143 this.workerOptions
.poolOptions
?.restartWorkerOnError
=== true &&
147 this.addWorkerSetElement()
150 worker
.on('online', this.workerOptions
.poolOptions
?.onlineHandler
?? EMPTY_FUNCTION
)
151 worker
.on('exit', this.workerOptions
.poolOptions
?.exitHandler
?? EMPTY_FUNCTION
)
152 worker
.once('exit', () => {
153 this.removeWorkerSetElement(this.getWorkerSetElementByWorker(worker
))
155 const workerSetElement
: WorkerSetElement
= { worker
, numberOfWorkerElements
: 0 }
156 this.workerSet
.add(workerSetElement
)
157 this.workerStartup
= false
158 return workerSetElement
161 private removeWorkerSetElement (workerSetElement
: WorkerSetElement
| undefined): void {
162 if (workerSetElement
== null) {
165 this.workerSet
.delete(workerSetElement
)
168 private async getWorkerSetElement (): Promise
<WorkerSetElement
> {
169 let chosenWorkerSetElement
: WorkerSetElement
| undefined
170 for (const workerSetElement
of this.workerSet
) {
171 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
172 if (workerSetElement
.numberOfWorkerElements
< this.workerOptions
.elementsPerWorker
!) {
173 chosenWorkerSetElement
= workerSetElement
177 if (chosenWorkerSetElement
== null) {
178 chosenWorkerSetElement
= this.addWorkerSetElement()
179 // Add worker set element sequentially to optimize memory at startup
180 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
181 this.workerOptions
.workerStartDelay
! > 0 &&
182 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
183 (await sleep(randomizeDelay(this.workerOptions
.workerStartDelay
!)))
185 return chosenWorkerSetElement
188 private getWorkerSetElementByWorker (worker
: Worker
): WorkerSetElement
| undefined {
189 let workerSetElt
: WorkerSetElement
| undefined
190 for (const workerSetElement
of this.workerSet
) {
191 if (workerSetElement
.worker
.threadId
=== worker
.threadId
) {
192 workerSetElt
= workerSetElement