| 1 | import type { Worker } from 'cluster' |
| 2 | import type { JSONValue } from '../../utility-types' |
| 3 | import type { ClusterPoolOptions } from './fixed' |
| 4 | import { FixedClusterPool } from './fixed' |
| 5 | import { killBehaviorTypes } from '../../worker/worker-options' |
| 6 | |
| 7 | /** |
| 8 | * A cluster pool with a dynamic number of workers, but a guaranteed minimum number of workers. |
| 9 | * |
| 10 | * This cluster pool creates new workers when the others are busy, up to the maximum number of workers. |
| 11 | * When the maximum number of workers is reached, an event is emitted. If you want to listen to this event, use the pool's `emitter`. |
| 12 | * |
| 13 | * @template Data Type of data sent to the worker. |
| 14 | * @template Response Type of response of execution. |
| 15 | * |
| 16 | * @author [Christopher Quadflieg](https://github.com/Shinigami92) |
| 17 | * @since 2.0.0 |
| 18 | */ |
| 19 | export class DynamicClusterPool< |
| 20 | Data extends JSONValue = JSONValue, |
| 21 | Response extends JSONValue = JSONValue |
| 22 | > extends FixedClusterPool<Data, Response> { |
| 23 | /** |
| 24 | * Constructs a new poolifier dynamic cluster pool. |
| 25 | * |
| 26 | * @param min Minimum number of workers which are always active. |
| 27 | * @param max Maximum number of workers that can be created by this pool. |
| 28 | * @param filename Path to an implementation of a `ClusterWorker` file, which can be relative or absolute. |
| 29 | * @param opts Options for this fixed cluster pool. Default: `{ maxTasks: 1000 }` |
| 30 | */ |
| 31 | public constructor ( |
| 32 | min: number, |
| 33 | public readonly max: number, |
| 34 | filename: string, |
| 35 | opts: ClusterPoolOptions = { maxTasks: 1000 } |
| 36 | ) { |
| 37 | super(min, filename, opts) |
| 38 | } |
| 39 | |
| 40 | /** |
| 41 | * Choose a worker for the next task. |
| 42 | * |
| 43 | * It will first check for and return an idle worker. |
| 44 | * If all workers are busy, then it will try to create a new one up to the `max` worker count. |
| 45 | * If the max worker count is reached, the emitter will emit a `FullPool` event and it will fall back to using a round robin algorithm to distribute the load. |
| 46 | * |
| 47 | * @returns Cluster worker. |
| 48 | */ |
| 49 | protected chooseWorker (): Worker { |
| 50 | for (const [worker, numberOfTasks] of this.tasks) { |
| 51 | if (numberOfTasks === 0) { |
| 52 | // A worker is free, use it |
| 53 | return worker |
| 54 | } |
| 55 | } |
| 56 | |
| 57 | if (this.workers.length === this.max) { |
| 58 | this.emitter.emit('FullPool') |
| 59 | return super.chooseWorker() |
| 60 | } |
| 61 | |
| 62 | // All workers are busy, create a new worker |
| 63 | const workerCreated = this.createAndSetupWorker() |
| 64 | this.registerWorkerMessageListener<Data>(workerCreated, message => { |
| 65 | const tasksInProgress = this.tasks.get(workerCreated) |
| 66 | const isKillBehaviorOptionHard = message.kill === killBehaviorTypes.HARD |
| 67 | if (isKillBehaviorOptionHard || tasksInProgress === 0) { |
| 68 | // Kill received from the worker, means that no new tasks are submitted to that worker for a while ( > maxInactiveTime) |
| 69 | this.sendToWorker(workerCreated, { kill: 1 }) |
| 70 | void this.destroyWorker(workerCreated) |
| 71 | } |
| 72 | }) |
| 73 | return workerCreated |
| 74 | } |
| 75 | } |