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 if (this.workerSet
== null) {
109 throw new Error("Cannot add a WorkerSet element: 'workerSet' property does not exist")
111 const workerSetElement
= await this.getWorkerSetElement()
112 workerSetElement
.worker
.postMessage({
113 event
: WorkerMessageEvents
.startWorkerElement
,
116 ++workerSetElement
.numberOfWorkerElements
117 // Add element sequentially to optimize memory at startup
118 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
119 if (this.workerOptions
.elementStartDelay
! > 0) {
120 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
121 await sleep(randomizeDelay(this.workerOptions
.elementStartDelay
!))
126 * Adds a new `WorkerSetElement`.
128 private addWorkerSetElement (): WorkerSetElement
{
129 this.workerStartup
= true
130 const worker
= new Worker(this.workerScript
, {
132 ...this.workerOptions
.poolOptions
?.workerOptions
134 worker
.on('message', this.workerOptions
.poolOptions
?.messageHandler
?? EMPTY_FUNCTION
)
135 worker
.on('message', (message
: WorkerMessage
<WorkerData
>) => {
136 if (message
.event
=== WorkerMessageEvents
.startedWorkerElement
) {
137 this.emitter
?.emit(WorkerSetEvents
.elementStarted
, this.info
)
138 } else if (message
.event
=== WorkerMessageEvents
.startWorkerElementError
) {
139 this.emitter
?.emit(WorkerSetEvents
.elementError
, message
.data
)
142 worker
.on('error', this.workerOptions
.poolOptions
?.errorHandler
?? EMPTY_FUNCTION
)
143 worker
.on('error', (error
) => {
144 this.emitter
?.emit(WorkerSetEvents
.error
, error
)
146 this.workerOptions
.poolOptions
?.restartWorkerOnError
=== true &&
150 this.addWorkerSetElement()
153 worker
.on('online', this.workerOptions
.poolOptions
?.onlineHandler
?? EMPTY_FUNCTION
)
154 worker
.on('exit', this.workerOptions
.poolOptions
?.exitHandler
?? EMPTY_FUNCTION
)
155 worker
.once('exit', () => {
156 this.removeWorkerSetElement(this.getWorkerSetElementByWorker(worker
))
158 const workerSetElement
: WorkerSetElement
= { worker
, numberOfWorkerElements
: 0 }
159 this.workerSet
.add(workerSetElement
)
160 this.workerStartup
= false
161 return workerSetElement
164 private removeWorkerSetElement (workerSetElement
: WorkerSetElement
| undefined): void {
165 if (workerSetElement
== null) {
168 this.workerSet
.delete(workerSetElement
)
171 private async getWorkerSetElement (): Promise
<WorkerSetElement
> {
172 let chosenWorkerSetElement
: WorkerSetElement
| undefined
173 for (const workerSetElement
of this.workerSet
) {
174 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
175 if (workerSetElement
.numberOfWorkerElements
< this.workerOptions
.elementsPerWorker
!) {
176 chosenWorkerSetElement
= workerSetElement
180 if (chosenWorkerSetElement
== null) {
181 chosenWorkerSetElement
= this.addWorkerSetElement()
182 // Add worker set element sequentially to optimize memory at startup
183 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
184 this.workerOptions
.workerStartDelay
! > 0 &&
185 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
186 (await sleep(randomizeDelay(this.workerOptions
.workerStartDelay
!)))
188 return chosenWorkerSetElement
191 private getWorkerSetElementByWorker (worker
: Worker
): WorkerSetElement
| undefined {
192 let workerSetElt
: WorkerSetElement
| undefined
193 for (const workerSetElement
of this.workerSet
) {
194 if (workerSetElement
.worker
.threadId
=== worker
.threadId
) {
195 workerSetElt
= workerSetElement