| 1 | import { EventEmitter } from 'events' |
| 2 | import type { FixedClusterPoolOptions, WorkerWithMessageChannel } from './fixed' |
| 3 | import { FixedClusterPool } from './fixed' |
| 4 | |
| 5 | class MyEmitter extends EventEmitter {} |
| 6 | |
| 7 | export type DynamicClusterPoolOptions = FixedClusterPoolOptions |
| 8 | |
| 9 | /** |
| 10 | * A cluster pool with a min/max number of workers, is possible to execute tasks in sync or async mode as you prefer. |
| 11 | * |
| 12 | * This cluster pool will create new workers when the other ones are busy, until the max number of workers, |
| 13 | * when the max number of workers is reached, an event will be emitted, if you want to listen this event use the emitter method. |
| 14 | * |
| 15 | * @author [Christopher Quadflieg](https://github.com/Shinigami92) |
| 16 | * @since 2.0.0 |
| 17 | */ |
| 18 | export class DynamicClusterPool< |
| 19 | // eslint-disable-next-line @typescript-eslint/no-explicit-any |
| 20 | Data = any, |
| 21 | // eslint-disable-next-line @typescript-eslint/no-explicit-any |
| 22 | Response = any |
| 23 | > extends FixedClusterPool<Data, Response> { |
| 24 | public readonly emitter: MyEmitter |
| 25 | |
| 26 | /** |
| 27 | * @param min Min number of workers that will be always active |
| 28 | * @param max Max number of workers that will be active |
| 29 | * @param filename A file path with implementation of `ClusterWorker` class, relative path is fine. |
| 30 | * @param opts An object with possible options for example `errorHandler`, `onlineHandler`. Default: `{ maxTasks: 1000 }` |
| 31 | */ |
| 32 | public constructor ( |
| 33 | public readonly min: number, |
| 34 | public readonly max: number, |
| 35 | public readonly filename: string, |
| 36 | public readonly opts: DynamicClusterPoolOptions = { maxTasks: 1000 } |
| 37 | ) { |
| 38 | super(min, filename, opts) |
| 39 | |
| 40 | this.emitter = new MyEmitter() |
| 41 | } |
| 42 | |
| 43 | protected chooseWorker (): WorkerWithMessageChannel { |
| 44 | let worker: WorkerWithMessageChannel | undefined |
| 45 | for (const entry of this.tasks) { |
| 46 | if (entry[1] === 0) { |
| 47 | worker = entry[0] |
| 48 | break |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | if (worker) { |
| 53 | // a worker is free, use it |
| 54 | return worker |
| 55 | } else { |
| 56 | if (this.workers.length === this.max) { |
| 57 | this.emitter.emit('FullPool') |
| 58 | return super.chooseWorker() |
| 59 | } |
| 60 | // all workers are busy create a new worker |
| 61 | const worker = this.newWorker() |
| 62 | worker.on('message', (message: { kill?: number }) => { |
| 63 | if (message.kill) { |
| 64 | worker.send({ kill: 1 }) |
| 65 | worker.kill() |
| 66 | // clean workers from data structures |
| 67 | const workerIndex = this.workers.indexOf(worker) |
| 68 | this.workers.splice(workerIndex, 1) |
| 69 | this.tasks.delete(worker) |
| 70 | } |
| 71 | }) |
| 72 | return worker |
| 73 | } |
| 74 | } |
| 75 | } |