| 1 | // Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved. |
| 2 | |
| 3 | import { EventEmitter } from 'node:events'; |
| 4 | import { SHARE_ENV, Worker } from 'node:worker_threads'; |
| 5 | |
| 6 | import { WorkerAbstract } from './WorkerAbstract'; |
| 7 | import { EMPTY_FUNCTION, workerSetVersion } from './WorkerConstants'; |
| 8 | import { |
| 9 | type SetInfo, |
| 10 | type WorkerData, |
| 11 | type WorkerMessage, |
| 12 | WorkerMessageEvents, |
| 13 | type WorkerOptions, |
| 14 | type WorkerSetElement, |
| 15 | WorkerSetEvents, |
| 16 | } from './WorkerTypes'; |
| 17 | import { randomizeDelay, sleep } from './WorkerUtils'; |
| 18 | |
| 19 | export class WorkerSet extends WorkerAbstract<WorkerData> { |
| 20 | public readonly emitter!: EventEmitter; |
| 21 | private readonly workerSet: Set<WorkerSetElement>; |
| 22 | private started: boolean; |
| 23 | private workerStartup: boolean; |
| 24 | |
| 25 | /** |
| 26 | * Creates a new `WorkerSet`. |
| 27 | * |
| 28 | * @param workerScript - |
| 29 | * @param workerOptions - |
| 30 | */ |
| 31 | constructor(workerScript: string, workerOptions: WorkerOptions) { |
| 32 | super(workerScript, workerOptions); |
| 33 | if ( |
| 34 | this.workerOptions.elementsPerWorker === null || |
| 35 | this.workerOptions.elementsPerWorker === undefined |
| 36 | ) { |
| 37 | throw new TypeError('Elements per worker is not defined'); |
| 38 | } |
| 39 | if (!Number.isSafeInteger(this.workerOptions.elementsPerWorker)) { |
| 40 | throw new TypeError('Elements per worker must be an integer'); |
| 41 | } |
| 42 | if (this.workerOptions.elementsPerWorker <= 0) { |
| 43 | throw new RangeError('Elements per worker must be greater than zero'); |
| 44 | } |
| 45 | this.workerSet = new Set<WorkerSetElement>(); |
| 46 | if (this.workerOptions.poolOptions?.enableEvents) { |
| 47 | this.emitter = new EventEmitter(); |
| 48 | } |
| 49 | this.started = false; |
| 50 | this.workerStartup = false; |
| 51 | } |
| 52 | |
| 53 | get info(): SetInfo { |
| 54 | return { |
| 55 | version: workerSetVersion, |
| 56 | type: 'set', |
| 57 | worker: 'thread', |
| 58 | size: this.size, |
| 59 | elementsExecuting: [...this.workerSet].reduce( |
| 60 | (accumulator, workerSetElement) => accumulator + workerSetElement.numberOfWorkerElements, |
| 61 | 0, |
| 62 | ), |
| 63 | elementsPerWorker: this.maxElementsPerWorker!, |
| 64 | }; |
| 65 | } |
| 66 | |
| 67 | get size(): number { |
| 68 | return this.workerSet.size; |
| 69 | } |
| 70 | |
| 71 | get maxElementsPerWorker(): number | undefined { |
| 72 | return this.workerOptions.elementsPerWorker; |
| 73 | } |
| 74 | |
| 75 | /** @inheritDoc */ |
| 76 | public async start(): Promise<void> { |
| 77 | this.addWorkerSetElement(); |
| 78 | // Add worker set element sequentially to optimize memory at startup |
| 79 | this.workerOptions.workerStartDelay! > 0 && |
| 80 | (await sleep(randomizeDelay(this.workerOptions.workerStartDelay!))); |
| 81 | this.started = true; |
| 82 | } |
| 83 | |
| 84 | /** @inheritDoc */ |
| 85 | public async stop(): Promise<void> { |
| 86 | for (const workerSetElement of this.workerSet) { |
| 87 | const worker = workerSetElement.worker; |
| 88 | const waitWorkerExit = new Promise<void>((resolve) => { |
| 89 | worker.on('exit', () => { |
| 90 | resolve(); |
| 91 | }); |
| 92 | }); |
| 93 | await worker.terminate(); |
| 94 | await waitWorkerExit; |
| 95 | this.started = false; |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | /** @inheritDoc */ |
| 100 | public async addElement(elementData: WorkerData): Promise<void> { |
| 101 | if (!this.started) { |
| 102 | throw new Error('Cannot add a WorkerSet element: not started'); |
| 103 | } |
| 104 | if (!this.workerSet) { |
| 105 | throw new Error("Cannot add a WorkerSet element: 'workerSet' property does not exist"); |
| 106 | } |
| 107 | const workerSetElement = await this.getWorkerSetElement(); |
| 108 | workerSetElement.worker.postMessage({ |
| 109 | event: WorkerMessageEvents.startWorkerElement, |
| 110 | data: elementData, |
| 111 | }); |
| 112 | ++workerSetElement.numberOfWorkerElements; |
| 113 | // Add element sequentially to optimize memory at startup |
| 114 | if (this.workerOptions.elementStartDelay! > 0) { |
| 115 | await sleep(randomizeDelay(this.workerOptions.elementStartDelay!)); |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * Adds a new `WorkerSetElement`. |
| 121 | */ |
| 122 | private addWorkerSetElement(): WorkerSetElement { |
| 123 | this.workerStartup = true; |
| 124 | const worker = new Worker(this.workerScript, { |
| 125 | env: SHARE_ENV, |
| 126 | ...this.workerOptions.poolOptions?.workerOptions, |
| 127 | }); |
| 128 | worker.on('message', this.workerOptions.poolOptions?.messageHandler ?? EMPTY_FUNCTION); |
| 129 | worker.on('message', (message: WorkerMessage<WorkerData>) => { |
| 130 | if (message.event === WorkerMessageEvents.startedWorkerElement) { |
| 131 | this.emitter?.emit(WorkerSetEvents.elementStarted, this.info); |
| 132 | } else if (message.event === WorkerMessageEvents.startWorkerElementError) { |
| 133 | this.emitter?.emit(WorkerSetEvents.elementError, message.data); |
| 134 | } |
| 135 | }); |
| 136 | worker.on('error', this.workerOptions.poolOptions?.errorHandler ?? EMPTY_FUNCTION); |
| 137 | worker.on('error', (error) => { |
| 138 | this.emitter?.emit(WorkerSetEvents.error, error); |
| 139 | if ( |
| 140 | this.workerOptions.poolOptions?.restartWorkerOnError && |
| 141 | this.started && |
| 142 | !this.workerStartup |
| 143 | ) { |
| 144 | this.addWorkerSetElement(); |
| 145 | } |
| 146 | }); |
| 147 | worker.on('online', this.workerOptions.poolOptions?.onlineHandler ?? EMPTY_FUNCTION); |
| 148 | worker.on('exit', this.workerOptions.poolOptions?.exitHandler ?? EMPTY_FUNCTION); |
| 149 | worker.once('exit', () => |
| 150 | this.removeWorkerSetElement(this.getWorkerSetElementByWorker(worker)!), |
| 151 | ); |
| 152 | const workerSetElement: WorkerSetElement = { worker, numberOfWorkerElements: 0 }; |
| 153 | this.workerSet.add(workerSetElement); |
| 154 | this.workerStartup = false; |
| 155 | return workerSetElement; |
| 156 | } |
| 157 | |
| 158 | private removeWorkerSetElement(workerSetElement: WorkerSetElement): void { |
| 159 | this.workerSet.delete(workerSetElement); |
| 160 | } |
| 161 | |
| 162 | private async getWorkerSetElement(): Promise<WorkerSetElement> { |
| 163 | let chosenWorkerSetElement: WorkerSetElement | undefined; |
| 164 | for (const workerSetElement of this.workerSet) { |
| 165 | if (workerSetElement.numberOfWorkerElements < this.workerOptions.elementsPerWorker!) { |
| 166 | chosenWorkerSetElement = workerSetElement; |
| 167 | break; |
| 168 | } |
| 169 | } |
| 170 | if (!chosenWorkerSetElement) { |
| 171 | chosenWorkerSetElement = this.addWorkerSetElement(); |
| 172 | // Add worker set element sequentially to optimize memory at startup |
| 173 | this.workerOptions.workerStartDelay! > 0 && |
| 174 | (await sleep(randomizeDelay(this.workerOptions.workerStartDelay!))); |
| 175 | } |
| 176 | return chosenWorkerSetElement; |
| 177 | } |
| 178 | |
| 179 | private getWorkerSetElementByWorker(worker: Worker): WorkerSetElement | undefined { |
| 180 | let workerSetElt: WorkerSetElement | undefined; |
| 181 | for (const workerSetElement of this.workerSet) { |
| 182 | if (workerSetElement.worker.threadId === worker.threadId) { |
| 183 | workerSetElt = workerSetElement; |
| 184 | break; |
| 185 | } |
| 186 | } |
| 187 | return workerSetElt; |
| 188 | } |
| 189 | } |