-import type { MessageValue } from '../utility-types'
-import type { IPoolInternal } from './pool-internal'
-import { PoolEmitter } from './pool-internal'
-import type { WorkerChoiceStrategy } from './selection-strategies'
+import crypto from 'node:crypto'
+import type { MessageValue, PromiseResponseWrapper } from '../utility-types'
+import { EMPTY_FUNCTION } from '../utils'
+import { KillBehaviors, isKillBehavior } from '../worker/worker-options'
+import { PoolEvents, type PoolOptions } from './pool'
+import { PoolEmitter } from './pool'
+import type { IPoolInternal, TasksUsage, WorkerType } from './pool-internal'
+import { PoolType } from './pool-internal'
+import type { IPoolWorker } from './pool-worker'
import {
WorkerChoiceStrategies,
- WorkerChoiceStrategyContext
-} from './selection-strategies'
+ type WorkerChoiceStrategy
+} from './selection-strategies/selection-strategies-types'
+import { WorkerChoiceStrategyContext } from './selection-strategies/worker-choice-strategy-context'
/**
- * An intentional empty function.
- */
-const EMPTY_FUNCTION: () => void = () => {
- /* Intentionally empty */
-}
-
-/**
- * Callback invoked if the worker raised an error.
- */
-export type ErrorHandler<Worker> = (this: Worker, e: Error) => void
-
-/**
- * Callback invoked when the worker has started successfully.
- */
-export type OnlineHandler<Worker> = (this: Worker) => void
-
-/**
- * Callback invoked when the worker exits successfully.
- */
-export type ExitHandler<Worker> = (this: Worker, code: number) => void
-
-/**
- * Basic interface that describes the minimum required implementation of listener events for a pool-worker.
- */
-export interface IWorker {
- /**
- * Register a listener to the error event.
- *
- * @param event `'error'`.
- * @param handler The error handler.
- */
- on(event: 'error', handler: ErrorHandler<this>): void
- /**
- * Register a listener to the online event.
- *
- * @param event `'online'`.
- * @param handler The online handler.
- */
- on(event: 'online', handler: OnlineHandler<this>): void
- /**
- * Register a listener to the exit event.
- *
- * @param event `'exit'`.
- * @param handler The exit handler.
- */
- on(event: 'exit', handler: ExitHandler<this>): void
- /**
- * Register a listener to the exit event that will only performed once.
- *
- * @param event `'exit'`.
- * @param handler The exit handler.
- */
- once(event: 'exit', handler: ExitHandler<this>): void
-}
-
-/**
- * Options for a poolifier pool.
- */
-export interface PoolOptions<Worker> {
- /**
- * A function that will listen for error event on each worker.
- */
- errorHandler?: ErrorHandler<Worker>
- /**
- * A function that will listen for online event on each worker.
- */
- onlineHandler?: OnlineHandler<Worker>
- /**
- * A function that will listen for exit event on each worker.
- */
- exitHandler?: ExitHandler<Worker>
- /**
- * 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)
- */
- maxTasks?: number
- /**
- * The work choice strategy to use in this pool.
- */
- workerChoiceStrategy?: WorkerChoiceStrategy
-}
-
-/**
- * Base class containing some shared logic for all poolifier pools.
+ * Base class that implements 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. This can only be serializable data.
- * @template Response Type of response of execution. This can only be serializable data.
+ * @typeParam Worker - Type of worker which manages this pool.
+ * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
+ * @typeParam Response - Type of response of execution. This can only be serializable data.
*/
export abstract class AbstractPool<
- Worker extends IWorker,
+ Worker extends IPoolWorker,
Data = unknown,
Response = unknown
> implements IPoolInternal<Worker, Data, Response> {
- /** @inheritdoc */
- public readonly workers: Worker[] = []
+ /** @inheritDoc */
+ public readonly workers: Array<WorkerType<Worker>> = []
- /** @inheritdoc */
- public readonly tasks: Map<Worker, number> = new Map<Worker, number>()
-
- /** @inheritdoc */
- public readonly emitter: PoolEmitter
+ /** @inheritDoc */
+ public readonly emitter?: PoolEmitter
/**
- * ID of the next message.
+ * The promise response map.
+ *
+ * - `key`: The message id of each submitted task.
+ * - `value`: An object that contains the worker, the promise resolve and reject callbacks.
+ *
+ * When we receive a message from the worker we get a map entry with the promise resolve/reject bound to the message.
*/
- protected nextMessageId: number = 0
+ protected promiseResponseMap: Map<
+ string,
+ PromiseResponseWrapper<Worker, Response>
+ > = new Map<string, PromiseResponseWrapper<Worker, Response>>()
/**
- * Worker choice strategy instance implementing the worker choice algorithm.
+ * Worker choice strategy context referencing a worker choice algorithm implementation.
*
- * Default to a strategy implementing a round robin algorithm.
+ * Default to a round robin algorithm.
*/
protected workerChoiceStrategyContext: WorkerChoiceStrategyContext<
- Worker,
- Data,
- Response
+ 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 numberOfWorkers - Number of workers that this pool should manage.
+ * @param filePath - Path to the worker-file.
+ * @param opts - Options for the pool.
*/
public constructor (
public readonly numberOfWorkers: number,
public readonly filePath: string,
- public readonly opts: PoolOptions<Worker> = { maxTasks: 1000 }
+ public readonly opts: PoolOptions<Worker>
) {
if (!this.isMain()) {
throw new Error('Cannot start a pool from a worker!')
}
+ this.checkNumberOfWorkers(this.numberOfWorkers)
this.checkFilePath(this.filePath)
+ this.checkPoolOptions(this.opts)
+
+ this.chooseWorker.bind(this)
+ this.internalExecute.bind(this)
+ this.checkAndEmitFull.bind(this)
+ this.checkAndEmitBusy.bind(this)
+ this.sendToWorker.bind(this)
+
this.setupHook()
for (let i = 1; i <= this.numberOfWorkers; i++) {
this.createAndSetupWorker()
}
- this.emitter = new PoolEmitter()
- this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext(
- this,
- opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
- )
+ if (this.opts.enableEvents === true) {
+ this.emitter = new PoolEmitter()
+ }
+ this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext<
+ Worker,
+ Data,
+ Response
+ >(this, this.opts.workerChoiceStrategy)
}
private checkFilePath (filePath: string): void {
- if (!filePath) {
+ if (
+ filePath == null ||
+ (typeof filePath === 'string' && filePath.trim().length === 0)
+ ) {
throw new Error('Please specify a file with a worker implementation')
}
}
- /** @inheritdoc */
- public isDynamic (): boolean {
- return false
+ 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 TypeError(
+ 'Cannot instantiate a pool with a non integer number of workers'
+ )
+ } else if (numberOfWorkers < 0) {
+ throw new RangeError(
+ 'Cannot instantiate a pool with a negative number of workers'
+ )
+ } else if (this.type === PoolType.FIXED && numberOfWorkers === 0) {
+ throw new Error('Cannot instantiate a fixed pool with no worker')
+ }
+ }
+
+ private checkPoolOptions (opts: PoolOptions<Worker>): void {
+ this.opts.workerChoiceStrategy =
+ opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
+ this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy)
+ this.opts.enableEvents = opts.enableEvents ?? true
+ }
+
+ private checkValidWorkerChoiceStrategy (
+ workerChoiceStrategy: WorkerChoiceStrategy
+ ): void {
+ if (!Object.values(WorkerChoiceStrategies).includes(workerChoiceStrategy)) {
+ throw new Error(
+ `Invalid worker choice strategy '${workerChoiceStrategy}'`
+ )
+ }
+ }
+
+ /** @inheritDoc */
+ public abstract get type (): PoolType
+
+ /**
+ * Number of tasks concurrently running in the pool.
+ */
+ private get numberOfRunningTasks (): number {
+ return this.promiseResponseMap.size
+ }
+
+ /**
+ * Gets the given worker key.
+ *
+ * @param worker - The worker.
+ * @returns The worker key if the worker is found in the pool, `-1` otherwise.
+ */
+ private getWorkerKey (worker: Worker): number {
+ return this.workers.findIndex(workerItem => workerItem.worker === worker)
}
- /** @inheritdoc */
+ /** @inheritDoc */
public setWorkerChoiceStrategy (
workerChoiceStrategy: WorkerChoiceStrategy
): void {
+ this.checkValidWorkerChoiceStrategy(workerChoiceStrategy)
+ this.opts.workerChoiceStrategy = workerChoiceStrategy
+ for (const [index, workerItem] of this.workers.entries()) {
+ this.setWorker(index, workerItem.worker, {
+ run: 0,
+ running: 0,
+ runTime: 0,
+ avgRunTime: 0,
+ error: 0
+ })
+ }
this.workerChoiceStrategyContext.setWorkerChoiceStrategy(
workerChoiceStrategy
)
}
- /** @inheritdoc */
- public execute (data: Data): Promise<Response> {
- // Configure worker to handle message with the specified task
- const worker = this.chooseWorker()
- this.increaseWorkersTask(worker)
- const messageId = ++this.nextMessageId
- const res = this.internalExecute(worker, messageId)
- this.sendToWorker(worker, { data: data || ({} as Data), id: messageId })
+ /** @inheritDoc */
+ public abstract get full (): boolean
+
+ /** @inheritDoc */
+ public abstract get busy (): boolean
+
+ protected internalBusy (): boolean {
+ return (
+ this.numberOfRunningTasks >= this.numberOfWorkers &&
+ this.findFreeWorkerKey() === -1
+ )
+ }
+
+ /** @inheritDoc */
+ public findFreeWorkerKey (): number {
+ return this.workers.findIndex(workerItem => {
+ return workerItem.tasksUsage.running === 0
+ })
+ }
+
+ /** @inheritDoc */
+ public async execute (data: Data): Promise<Response> {
+ const [workerKey, worker] = this.chooseWorker()
+ const messageId = crypto.randomUUID()
+ const res = this.internalExecute(workerKey, worker, messageId)
+ this.checkAndEmitFull()
+ this.checkAndEmitBusy()
+ this.sendToWorker(worker, {
+ // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+ data: data ?? ({} as Data),
+ id: messageId
+ })
+ // eslint-disable-next-line @typescript-eslint/return-await
return res
}
- /** @inheritdoc */
+ /** @inheritDoc */
public async destroy (): Promise<void> {
- await Promise.all(this.workers.map(worker => this.destroyWorker(worker)))
+ await Promise.all(
+ this.workers.map(async workerItem => {
+ await this.destroyWorker(workerItem.worker)
+ })
+ )
}
- /** @inheritdoc */
- public abstract destroyWorker (worker: Worker): void | Promise<void>
+ /**
+ * Shutdowns given worker in the pool.
+ *
+ * @param worker - A worker within `workers`.
+ */
+ protected abstract destroyWorker (worker: Worker): void | Promise<void>
/**
* Setup hook that can be overridden by a Poolifier pool implementation
* to run code before workers are created in the abstract constructor.
+ * Can be overridden
+ *
+ * @virtual
*/
protected setupHook (): void {
- // Can be overridden
+ // Intentionally empty
}
/**
protected abstract isMain (): boolean
/**
- * Increase the number of tasks that the given workers has done.
+ * Hook executed before the worker task promise resolution.
+ * Can be overridden.
*
- * @param worker Worker whose tasks are increased.
+ * @param workerKey - The worker key.
*/
- protected increaseWorkersTask (worker: Worker): void {
- this.stepWorkerNumberOfTasks(worker, 1)
+ protected beforePromiseResponseHook (workerKey: number): void {
+ ++this.workers[workerKey].tasksUsage.running
}
/**
- * Decrease the number of tasks that the given workers has done.
+ * Hook executed after the worker task promise resolution.
+ * Can be overridden.
*
- * @param worker Worker whose tasks are decreased.
+ * @param worker - The worker.
+ * @param message - The received message.
*/
- 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 + step)
- } else {
- throw Error('Worker could not be found in tasks map')
+ protected afterPromiseResponseHook (
+ worker: Worker,
+ message: MessageValue<Response>
+ ): void {
+ const workerTasksUsage = this.getWorkerTasksUsage(worker) as TasksUsage
+ --workerTasksUsage.running
+ ++workerTasksUsage.run
+ if (message.error != null) {
+ ++workerTasksUsage.error
+ }
+ if (this.workerChoiceStrategyContext.getRequiredStatistics().runTime) {
+ workerTasksUsage.runTime += message.runTime ?? 0
+ if (
+ this.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime &&
+ workerTasksUsage.run !== 0
+ ) {
+ workerTasksUsage.avgRunTime =
+ workerTasksUsage.runTime / workerTasksUsage.run
+ }
}
}
/**
- * Removes the given worker from the pool.
- *
- * @param worker Worker that will be removed.
- */
- protected removeWorker (worker: Worker): void {
- // Clean worker from data structure
- const workerIndex = this.workers.indexOf(worker)
- this.workers.splice(workerIndex, 1)
- this.tasks.delete(worker)
- }
-
- /**
- * Choose a worker for the next task.
+ * Chooses a worker for the next task.
*
- * The default implementation uses a round robin algorithm to distribute the load.
+ * The default uses a round robin algorithm to distribute the load.
*
- * @returns Worker.
+ * @returns [worker key, worker].
*/
- protected chooseWorker (): Worker {
- return this.workerChoiceStrategyContext.execute()
+ protected chooseWorker (): [number, Worker] {
+ let workerKey: number
+ if (
+ this.type === PoolType.DYNAMIC &&
+ !this.full &&
+ this.findFreeWorkerKey() === -1
+ ) {
+ const createdWorker = this.createAndSetupWorker()
+ this.registerWorkerMessageListener(createdWorker, message => {
+ if (
+ isKillBehavior(KillBehaviors.HARD, message.kill) ||
+ (message.kill != null &&
+ this.getWorkerTasksUsage(createdWorker)?.running === 0)
+ ) {
+ // Kill message received from the worker, means that no new tasks are submitted to that worker for a while ( > maxInactiveTime)
+ void this.destroyWorker(createdWorker)
+ }
+ })
+ workerKey = this.getWorkerKey(createdWorker)
+ } else {
+ workerKey = this.workerChoiceStrategyContext.execute()
+ }
+ return [workerKey, this.workers[workerKey].worker]
}
/**
- * Send a message to the given worker.
+ * Sends a message to the given worker.
*
- * @param worker The worker which should receive the message.
- * @param message The message.
+ * @param worker - The worker which should receive the message.
+ * @param message - The message.
*/
protected abstract sendToWorker (
worker: Worker,
message: MessageValue<Data>
): void
- /** @inheritdoc */
- public abstract registerWorkerMessageListener<
- Message extends Data | Response
- > (worker: Worker, listener: (message: MessageValue<Message>) => void): void
-
- protected abstract unregisterWorkerMessageListener<
+ /**
+ * Registers a listener callback on a given worker.
+ *
+ * @param worker - The worker which should register a listener.
+ * @param listener - The message listener callback.
+ */
+ protected abstract registerWorkerMessageListener<
Message extends Data | Response
- > (worker: Worker, listener: (message: MessageValue<Message>) => void): void
-
- protected internalExecute (
- worker: Worker,
- messageId: number
- ): Promise<Response> {
- return new Promise((resolve, reject) => {
- const listener: (message: MessageValue<Response>) => 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)
- })
- }
+ >(worker: Worker, listener: (message: MessageValue<Message>) => void): void
/**
* Returns a newly created worker.
/**
* Function that can be hooked up when a worker has been newly created and moved to the workers registry.
*
- * Can be used to update the `maxListeners` or binding the `main-worker`<->`worker` connection if not bind by default.
+ * Can be used to update the `maxListeners` or binding the `main-worker`\<-\>`worker` connection if not bind by default.
*
- * @param worker The newly created worker.
+ * @param worker - The newly created worker.
+ * @virtual
*/
protected abstract afterWorkerSetup (worker: Worker): void
- /** @inheritdoc */
- public createAndSetupWorker (): Worker {
- const worker: Worker = this.createWorker()
+ /**
+ * Creates a new worker for this pool and sets it up completely.
+ *
+ * @returns New, completely set up worker.
+ */
+ protected createAndSetupWorker (): Worker {
+ const worker = this.createWorker()
+ worker.on('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
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)
+ worker.once('exit', () => {
+ this.removeWorker(worker)
+ })
- // Init tasks map
- this.tasks.set(worker, 0)
+ this.pushWorker(worker, {
+ run: 0,
+ running: 0,
+ runTime: 0,
+ avgRunTime: 0,
+ error: 0
+ })
this.afterWorkerSetup(worker)
return worker
}
+
+ /**
+ * This function is the listener registered for each worker.
+ *
+ * @returns The listener function to execute when a message is received from a worker.
+ */
+ protected workerListener (): (message: MessageValue<Response>) => void {
+ return message => {
+ if (message.id != null) {
+ // Task response received
+ const promiseResponse = this.promiseResponseMap.get(message.id)
+ if (promiseResponse != null) {
+ if (message.error != null) {
+ promiseResponse.reject(message.error)
+ } else {
+ promiseResponse.resolve(message.data as Response)
+ }
+ this.afterPromiseResponseHook(promiseResponse.worker, message)
+ this.promiseResponseMap.delete(message.id)
+ }
+ }
+ }
+ }
+
+ private async internalExecute (
+ workerKey: number,
+ worker: Worker,
+ messageId: string
+ ): Promise<Response> {
+ this.beforePromiseResponseHook(workerKey)
+ return await new Promise<Response>((resolve, reject) => {
+ this.promiseResponseMap.set(messageId, { resolve, reject, worker })
+ })
+ }
+
+ private checkAndEmitBusy (): void {
+ if (this.opts.enableEvents === true && this.busy) {
+ this.emitter?.emit(PoolEvents.busy)
+ }
+ }
+
+ private checkAndEmitFull (): void {
+ if (
+ this.type === PoolType.DYNAMIC &&
+ this.opts.enableEvents === true &&
+ this.full
+ ) {
+ this.emitter?.emit(PoolEvents.full)
+ }
+ }
+
+ /**
+ * Gets the given worker tasks usage in the pool.
+ *
+ * @param worker - The worker.
+ * @returns The worker tasks usage.
+ */
+ private getWorkerTasksUsage (worker: Worker): TasksUsage | undefined {
+ const workerKey = this.getWorkerKey(worker)
+ if (workerKey !== -1) {
+ return this.workers[workerKey].tasksUsage
+ }
+ throw new Error('Worker could not be found in the pool')
+ }
+
+ /**
+ * Pushes the given worker in the pool.
+ *
+ * @param worker - The worker.
+ * @param tasksUsage - The worker tasks usage.
+ */
+ private pushWorker (worker: Worker, tasksUsage: TasksUsage): void {
+ this.workers.push({
+ worker,
+ tasksUsage
+ })
+ }
+
+ /**
+ * Sets the given worker in the pool.
+ *
+ * @param workerKey - The worker key.
+ * @param worker - The worker.
+ * @param tasksUsage - The worker tasks usage.
+ */
+ private setWorker (
+ workerKey: number,
+ worker: Worker,
+ tasksUsage: TasksUsage
+ ): void {
+ this.workers[workerKey] = {
+ worker,
+ tasksUsage
+ }
+ }
+
+ /**
+ * Removes the given worker from the pool.
+ *
+ * @param worker - The worker that will be removed.
+ */
+ protected removeWorker (worker: Worker): void {
+ const workerKey = this.getWorkerKey(worker)
+ this.workers.splice(workerKey, 1)
+ this.workerChoiceStrategyContext.remove(workerKey)
+ }
}
repositories / poolifier.git / blobdiff