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