X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=src%2Fpools%2Fabstract-pool.ts;h=9d7e4f0c2306ad2dd9970cc7ac7cd9094959b136;hb=1927ee6758147bb8a2479b987322564cea20992b;hp=5ef2eed9f39ed7dd83f0744e75d89725b490c7f3;hpb=3832ad95c98b136ef703a29685fedebe4a5e3ba2;p=poolifier.git diff --git a/src/pools/abstract-pool.ts b/src/pools/abstract-pool.ts index 5ef2eed9..9d7e4f0c 100644 --- a/src/pools/abstract-pool.ts +++ b/src/pools/abstract-pool.ts @@ -1,6 +1,21 @@ -import EventEmitter from 'events' -import type { MessageValue } from '../utility-types' -import type { IPool } from './pool' +import type { + MessageValue, + PromiseWorkerResponseWrapper +} from '../utility-types' +import type { IPoolInternal } from './pool-internal' +import { PoolEmitter } from './pool-internal' +import type { WorkerChoiceStrategy } from './selection-strategies' +import { + WorkerChoiceStrategies, + WorkerChoiceStrategyContext +} from './selection-strategies' + +/** + * An intentional empty function. + */ +const EMPTY_FUNCTION: () => void = () => { + /* Intentionally empty */ +} /** * Callback invoked if the worker raised an error. @@ -68,58 +83,43 @@ export interface PoolOptions { */ exitHandler?: ExitHandler /** - * This is just to avoid non-useful warning messages. - * - * Will be used to set `maxListeners` on event emitters (workers are event emitters). - * - * @default 1000 - * @see [Node events emitter.setMaxListeners(n)](https://nodejs.org/api/events.html#events_emitter_setmaxlisteners_n) + * The work choice strategy to use in this pool. */ - maxTasks?: number + workerChoiceStrategy?: WorkerChoiceStrategy } -/** - * Internal poolifier pool emitter. - */ -class PoolEmitter extends EventEmitter {} - /** * Base class containing some shared logic for all poolifier pools. * * @template Worker Type of worker which manages this pool. - * @template Data Type of data sent to the worker. - * @template Response Type of response of execution. + * @template Data Type of data sent to the worker. This can only be serializable data. + * @template Response Type of response of execution. This can only be serializable data. */ export abstract class AbstractPool< Worker extends IWorker, Data = unknown, Response = unknown -> implements IPool { +> implements IPoolInternal { /** - * List of currently available workers. + * The promise map. + * + * - `key`: This is the message ID of each submitted task. + * - `value`: An object that contains the worker, the resolve function and the reject function. + * + * When we receive a message from the worker we get a map entry and resolve/reject the promise based on the message. */ - public readonly workers: Worker[] = [] + protected promiseMap: Map< + number, + PromiseWorkerResponseWrapper + > = new Map>() - /** - * Index for the next worker. - */ - public nextWorkerIndex: number = 0 + /** @inheritdoc */ + public readonly workers: Worker[] = [] - /** - * The tasks map. - * - * - `key`: The `Worker` - * - `value`: Number of tasks currently in progress on the worker. - */ + /** @inheritdoc */ public readonly tasks: Map = new Map() - /** - * Emitter on which events can be listened to. - * - * Events that can currently be listened to: - * - * - `'FullPool'` - */ + /** @inheritdoc */ public readonly emitter: PoolEmitter /** @@ -127,25 +127,34 @@ export abstract class AbstractPool< */ protected nextMessageId: number = 0 + /** + * Worker choice strategy instance implementing the worker choice algorithm. + * + * Default to a strategy implementing a round robin algorithm. + */ + protected workerChoiceStrategyContext: WorkerChoiceStrategyContext< + Worker, + Data, + Response + > + /** * Constructs a new poolifier pool. * * @param numberOfWorkers Number of workers that this pool should manage. * @param filePath Path to the worker-file. - * @param opts Options for the pool. Default: `{ maxTasks: 1000 }` + * @param opts Options for the pool. */ public constructor ( public readonly numberOfWorkers: number, public readonly filePath: string, - public readonly opts: PoolOptions = { maxTasks: 1000 } + public readonly opts: PoolOptions ) { if (!this.isMain()) { throw new Error('Cannot start a pool from a worker!') } - // TODO christopher 2021-02-07: Improve this check e.g. with a pattern or blank check - if (!this.filePath) { - throw new Error('Please specify a file with a worker implementation') - } + this.checkNumberOfWorkers(this.numberOfWorkers) + this.checkFilePath(this.filePath) this.setupHook() for (let i = 1; i <= this.numberOfWorkers; i++) { @@ -153,35 +162,52 @@ export abstract class AbstractPool< } this.emitter = new PoolEmitter() + this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext( + this, + opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN + ) } - /** - * Number of workers that this pool should manage. - * - * @returns Number of workers that this pool manages. - * @deprecated Only here for backward compatibility. - */ - // eslint-disable-next-line spellcheck/spell-checker - public get numWorkers (): number { - return this.numberOfWorkers + private checkFilePath (filePath: string): void { + if (!filePath) { + throw new Error('Please specify a file with a worker implementation') + } } - /** - * Index for the next worker. - * - * @returns Index for the next worker. - * @deprecated Only here for backward compatibility. - */ - public get nextWorker (): number { - return this.nextWorkerIndex + private checkNumberOfWorkers (numberOfWorkers: number): void { + if (numberOfWorkers == null) { + throw new Error( + 'Cannot instantiate a pool without specifying the number of workers' + ) + } else if (!Number.isSafeInteger(numberOfWorkers)) { + throw new Error( + 'Cannot instantiate a pool with a non integer number of workers' + ) + } else if (numberOfWorkers < 0) { + throw new Error( + 'Cannot instantiate a pool with a negative number of workers' + ) + } else if (!this.isDynamic() && numberOfWorkers === 0) { + throw new Error('Cannot instantiate a fixed pool with no worker') + } } - /** - * Perform the task specified in the constructor with the data parameter. - * - * @param data The input for the specified task. - * @returns Promise that will be resolved when the task is successfully completed. - */ + /** @inheritdoc */ + public isDynamic (): boolean { + return false + } + + /** @inheritdoc */ + public setWorkerChoiceStrategy ( + workerChoiceStrategy: WorkerChoiceStrategy + ): void { + this.opts.workerChoiceStrategy = workerChoiceStrategy + this.workerChoiceStrategyContext.setWorkerChoiceStrategy( + workerChoiceStrategy + ) + } + + /** @inheritdoc */ public execute (data: Data): Promise { // Configure worker to handle message with the specified task const worker = this.chooseWorker() @@ -192,19 +218,13 @@ export abstract class AbstractPool< return res } - /** - * Shut down every current worker in this pool. - */ + /** @inheritdoc */ public async destroy (): Promise { await Promise.all(this.workers.map(worker => this.destroyWorker(worker))) } - /** - * Shut down given worker. - * - * @param worker A worker within `workers`. - */ - protected abstract destroyWorker (worker: Worker): void | Promise + /** @inheritdoc */ + public abstract destroyWorker (worker: Worker): void | Promise /** * Setup hook that can be overridden by a Poolifier pool implementation @@ -222,26 +242,31 @@ export abstract class AbstractPool< /** * Increase the number of tasks that the given workers has done. * - * @param worker Workers whose tasks are increased. + * @param worker Worker whose tasks are increased. */ protected increaseWorkersTask (worker: Worker): void { - const numberOfTasksInProgress = this.tasks.get(worker) - if (numberOfTasksInProgress !== undefined) { - this.tasks.set(worker, numberOfTasksInProgress + 1) - } else { - throw Error('Worker could not be found in tasks map') - } + this.stepWorkerNumberOfTasks(worker, 1) } /** * Decrease the number of tasks that the given workers has done. * - * @param worker Workers whose tasks are decreased. + * @param worker Worker whose tasks are decreased. */ protected decreaseWorkersTasks (worker: Worker): void { + this.stepWorkerNumberOfTasks(worker, -1) + } + + /** + * Step the number of tasks that the given workers has done. + * + * @param worker Worker whose tasks are set. + * @param step Worker number of tasks step. + */ + private stepWorkerNumberOfTasks (worker: Worker, step: number): void { const numberOfTasksInProgress = this.tasks.get(worker) if (numberOfTasksInProgress !== undefined) { - this.tasks.set(worker, numberOfTasksInProgress - 1) + this.tasks.set(worker, numberOfTasksInProgress + step) } else { throw Error('Worker could not be found in tasks map') } @@ -267,12 +292,7 @@ export abstract class AbstractPool< * @returns Worker. */ protected chooseWorker (): Worker { - const chosenWorker = this.workers[this.nextWorkerIndex] - this.nextWorkerIndex = - this.workers.length - 1 === this.nextWorkerIndex - ? 0 - : this.nextWorkerIndex + 1 - return chosenWorker + return this.workerChoiceStrategyContext.execute() } /** @@ -286,11 +306,8 @@ export abstract class AbstractPool< message: MessageValue ): void - protected abstract registerWorkerMessageListener< - Message extends Data | Response - > (worker: Worker, listener: (message: MessageValue) => void): void - - protected abstract unregisterWorkerMessageListener< + /** @inheritdoc */ + public abstract registerWorkerMessageListener< Message extends Data | Response > (worker: Worker, listener: (message: MessageValue) => void): void @@ -298,16 +315,8 @@ export abstract class AbstractPool< worker: Worker, messageId: number ): Promise { - return new Promise((resolve, reject) => { - const listener: (message: MessageValue) => void = message => { - if (message.id === messageId) { - this.unregisterWorkerMessageListener(worker, listener) - this.decreaseWorkersTasks(worker) - if (message.error) reject(message.error) - else resolve(message.data as Response) - } - } - this.registerWorkerMessageListener(worker, listener) + return new Promise((resolve, reject) => { + this.promiseMap.set(messageId, { resolve, reject, worker }) }) } @@ -325,17 +334,13 @@ export abstract class AbstractPool< */ protected abstract afterWorkerSetup (worker: Worker): void - /** - * Creates a new worker for this pool and sets it up completely. - * - * @returns New, completely set up worker. - */ - protected createAndSetupWorker (): Worker { + /** @inheritdoc */ + public createAndSetupWorker (): Worker { const worker: Worker = this.createWorker() - worker.on('error', this.opts.errorHandler ?? (() => {})) - worker.on('online', this.opts.onlineHandler ?? (() => {})) - worker.on('exit', this.opts.exitHandler ?? (() => {})) + worker.on('error', this.opts.errorHandler ?? EMPTY_FUNCTION) + worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION) + worker.on('exit', this.opts.exitHandler ?? EMPTY_FUNCTION) worker.once('exit', () => this.removeWorker(worker)) this.workers.push(worker) @@ -347,4 +352,24 @@ export abstract class AbstractPool< return worker } + + /** + * This function is the listener registered for each worker. + * + * @returns The listener function to execute when a message is sent from a worker. + */ + protected workerListener (): (message: MessageValue) => void { + const listener: (message: MessageValue) => void = message => { + if (message.id) { + const value = this.promiseMap.get(message.id) + if (value) { + this.decreaseWorkersTasks(value.worker) + if (message.error) value.reject(message.error) + else value.resolve(message.data as Response) + this.promiseMap.delete(message.id) + } + } + } + return listener + } }