-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 {
+ DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+ EMPTY_FUNCTION,
+ isPlainObject,
+ median
+} from '../utils'
+import { KillBehaviors, isKillBehavior } from '../worker/worker-options'
+import { CircularArray } from '../circular-array'
+import { Queue } from '../queue'
+import {
+ type IPool,
+ PoolEmitter,
+ PoolEvents,
+ type PoolOptions,
+ PoolType,
+ type TasksQueueOptions
+} from './pool'
+import type { IWorker, Task, TasksUsage, WorkerNode } from './worker'
import {
WorkerChoiceStrategies,
- WorkerChoiceStrategyContext
-} from './selection-strategies'
-
-/**
- * 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
+ type WorkerChoiceStrategy,
+ type WorkerChoiceStrategyOptions
+} from './selection-strategies/selection-strategies-types'
+import { WorkerChoiceStrategyContext } from './selection-strategies/worker-choice-strategy-context'
/**
- * 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 execution response. This can only be serializable data.
*/
export abstract class AbstractPool<
Worker extends IWorker,
Data = unknown,
Response = unknown
-> implements IPoolInternal<Worker, Data, Response> {
- /** @inheritdoc */
- public readonly workers: Worker[] = []
-
- /** @inheritdoc */
- public readonly tasks: Map<Worker, number> = new Map<Worker, number>()
+> implements IPool<Worker, Data, Response> {
+ /** @inheritDoc */
+ public readonly workerNodes: Array<WorkerNode<Worker, Data>> = []
- /** @inheritdoc */
- public readonly emitter: PoolEmitter
+ /** @inheritDoc */
+ public readonly emitter?: PoolEmitter
/**
- * ID of the next message.
+ * The execution response promise map.
+ *
+ * - `key`: The message id of each submitted task.
+ * - `value`: An object that contains the worker, the execution response 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 id.
*/
- 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.chooseWorkerNode = this.chooseWorkerNode.bind(this)
+ this.executeTask = this.executeTask.bind(this)
+ this.enqueueTask = this.enqueueTask.bind(this)
+ this.checkAndEmitEvents = this.checkAndEmitEvents.bind(this)
+
this.setupHook()
for (let i = 1; i <= this.numberOfWorkers; i++) {
this.createAndSetupWorker()
}
- this.emitter = new PoolEmitter()
- this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext(
+ if (this.opts.enableEvents === true) {
+ this.emitter = new PoolEmitter()
+ }
+ this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext<
+ Worker,
+ Data,
+ Response
+ >(
this,
- opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
+ this.opts.workerChoiceStrategy,
+ this.opts.workerChoiceStrategyOptions
)
}
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 safe 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')
+ }
}
- /** @inheritdoc */
- public setWorkerChoiceStrategy (
+ private checkPoolOptions (opts: PoolOptions<Worker>): void {
+ if (isPlainObject(opts)) {
+ this.opts.workerChoiceStrategy =
+ opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
+ this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy)
+ this.opts.workerChoiceStrategyOptions =
+ opts.workerChoiceStrategyOptions ??
+ DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+ this.checkValidWorkerChoiceStrategyOptions(
+ this.opts.workerChoiceStrategyOptions
+ )
+ this.opts.enableEvents = opts.enableEvents ?? true
+ this.opts.enableTasksQueue = opts.enableTasksQueue ?? false
+ if (this.opts.enableTasksQueue) {
+ this.checkValidTasksQueueOptions(
+ opts.tasksQueueOptions as TasksQueueOptions
+ )
+ this.opts.tasksQueueOptions = this.buildTasksQueueOptions(
+ opts.tasksQueueOptions as TasksQueueOptions
+ )
+ }
+ } else {
+ throw new TypeError('Invalid pool options: must be a plain object')
+ }
+ }
+
+ private checkValidWorkerChoiceStrategy (
workerChoiceStrategy: WorkerChoiceStrategy
): void {
- this.workerChoiceStrategyContext.setWorkerChoiceStrategy(
- workerChoiceStrategy
- )
+ if (!Object.values(WorkerChoiceStrategies).includes(workerChoiceStrategy)) {
+ throw new Error(
+ `Invalid worker choice strategy '${workerChoiceStrategy}'`
+ )
+ }
}
- /** @inheritdoc */
- public execute (data: Data): Promise<Response> {
- // Configure worker to handle message with the specified task
- const worker = this.chooseWorker()
- this.increaseWorkersTask(worker)
- const messageId = ++this.nextMessageId
- const res = this.internalExecute(worker, messageId)
- this.sendToWorker(worker, { data: data || ({} as Data), id: messageId })
- return res
+ private checkValidWorkerChoiceStrategyOptions (
+ workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
+ ): void {
+ if (!isPlainObject(workerChoiceStrategyOptions)) {
+ throw new TypeError(
+ 'Invalid worker choice strategy options: must be a plain object'
+ )
+ }
+ if (
+ workerChoiceStrategyOptions.weights != null &&
+ Object.keys(workerChoiceStrategyOptions.weights).length !== this.size
+ ) {
+ throw new Error(
+ 'Invalid worker choice strategy options: must have a weight for each worker node'
+ )
+ }
}
- /** @inheritdoc */
- public async destroy (): Promise<void> {
- await Promise.all(this.workers.map(worker => this.destroyWorker(worker)))
+ private checkValidTasksQueueOptions (
+ tasksQueueOptions: TasksQueueOptions
+ ): void {
+ if (tasksQueueOptions != null && !isPlainObject(tasksQueueOptions)) {
+ throw new TypeError('Invalid tasks queue options: must be a plain object')
+ }
+ if ((tasksQueueOptions?.concurrency as number) <= 0) {
+ throw new Error(
+ `Invalid worker tasks concurrency '${
+ tasksQueueOptions.concurrency as number
+ }'`
+ )
+ }
}
- /** @inheritdoc */
- public abstract destroyWorker (worker: Worker): void | Promise<void>
+ /** @inheritDoc */
+ public abstract get type (): PoolType
+
+ /** @inheritDoc */
+ public abstract get size (): number
/**
- * Setup hook that can be overridden by a Poolifier pool implementation
- * to run code before workers are created in the abstract constructor.
+ * Number of tasks running in the pool.
*/
- protected setupHook (): void {
- // Can be overridden
+ private get numberOfRunningTasks (): number {
+ return this.workerNodes.reduce(
+ (accumulator, workerNode) => accumulator + workerNode.tasksUsage.running,
+ 0
+ )
}
/**
- * Should return whether the worker is the main worker or not.
+ * Number of tasks queued in the pool.
*/
- protected abstract isMain (): boolean
+ private get numberOfQueuedTasks (): number {
+ if (this.opts.enableTasksQueue === false) {
+ return 0
+ }
+ return this.workerNodes.reduce(
+ (accumulator, workerNode) => accumulator + workerNode.tasksQueue.size,
+ 0
+ )
+ }
/**
- * Increase the number of tasks that the given workers has done.
+ * Gets the given worker its worker node key.
*
- * @param worker Worker whose tasks are increased.
+ * @param worker - The worker.
+ * @returns The worker node key if the worker is found in the pool worker nodes, `-1` otherwise.
*/
- protected increaseWorkersTask (worker: Worker): void {
- this.stepWorkerNumberOfTasks(worker, 1)
+ private getWorkerNodeKey (worker: Worker): number {
+ return this.workerNodes.findIndex(
+ workerNode => workerNode.worker === worker
+ )
+ }
+
+ /** @inheritDoc */
+ public setWorkerChoiceStrategy (
+ workerChoiceStrategy: WorkerChoiceStrategy,
+ workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
+ ): void {
+ this.checkValidWorkerChoiceStrategy(workerChoiceStrategy)
+ this.opts.workerChoiceStrategy = workerChoiceStrategy
+ for (const workerNode of this.workerNodes) {
+ this.setWorkerNodeTasksUsage(workerNode, {
+ run: 0,
+ running: 0,
+ runTime: 0,
+ runTimeHistory: new CircularArray(),
+ avgRunTime: 0,
+ medRunTime: 0,
+ error: 0
+ })
+ }
+ this.workerChoiceStrategyContext.setWorkerChoiceStrategy(
+ this.opts.workerChoiceStrategy
+ )
+ if (workerChoiceStrategyOptions != null) {
+ this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
+ }
+ }
+
+ /** @inheritDoc */
+ public setWorkerChoiceStrategyOptions (
+ workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
+ ): void {
+ this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
+ this.opts.workerChoiceStrategyOptions = workerChoiceStrategyOptions
+ this.workerChoiceStrategyContext.setOptions(
+ this.opts.workerChoiceStrategyOptions
+ )
+ }
+
+ /** @inheritDoc */
+ public enableTasksQueue (
+ enable: boolean,
+ tasksQueueOptions?: TasksQueueOptions
+ ): void {
+ if (this.opts.enableTasksQueue === true && !enable) {
+ this.flushTasksQueues()
+ }
+ this.opts.enableTasksQueue = enable
+ this.setTasksQueueOptions(tasksQueueOptions as TasksQueueOptions)
+ }
+
+ /** @inheritDoc */
+ public setTasksQueueOptions (tasksQueueOptions: TasksQueueOptions): void {
+ if (this.opts.enableTasksQueue === true) {
+ this.checkValidTasksQueueOptions(tasksQueueOptions)
+ this.opts.tasksQueueOptions =
+ this.buildTasksQueueOptions(tasksQueueOptions)
+ } else {
+ delete this.opts.tasksQueueOptions
+ }
+ }
+
+ private buildTasksQueueOptions (
+ tasksQueueOptions: TasksQueueOptions
+ ): TasksQueueOptions {
+ return {
+ concurrency: tasksQueueOptions?.concurrency ?? 1
+ }
}
/**
- * Decrease the number of tasks that the given workers has done.
+ * Whether the pool is full or not.
*
- * @param worker Worker whose tasks are decreased.
+ * The pool filling boolean status.
*/
- protected decreaseWorkersTasks (worker: Worker): void {
- this.stepWorkerNumberOfTasks(worker, -1)
- }
+ protected abstract get full (): boolean
/**
- * Step the number of tasks that the given workers has done.
+ * Whether the pool is busy or not.
*
- * @param worker Worker whose tasks are set.
- * @param step Worker number of tasks step.
+ * The pool busyness boolean status.
*/
- private stepWorkerNumberOfTasks (worker: Worker, step: number): void {
- const numberOfTasksInProgress = this.tasks.get(worker)
- if (numberOfTasksInProgress !== undefined) {
- this.tasks.set(worker, numberOfTasksInProgress + step)
+ protected abstract get busy (): boolean
+
+ protected internalBusy (): boolean {
+ return (
+ this.workerNodes.findIndex(workerNode => {
+ return workerNode.tasksUsage.running === 0
+ }) === -1
+ )
+ }
+
+ /** @inheritDoc */
+ public async execute (data?: Data, name?: string): Promise<Response> {
+ const [workerNodeKey, workerNode] = this.chooseWorkerNode()
+ const submittedTask: Task<Data> = {
+ name,
+ // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+ data: data ?? ({} as Data),
+ id: crypto.randomUUID()
+ }
+ const res = new Promise<Response>((resolve, reject) => {
+ this.promiseResponseMap.set(submittedTask.id as string, {
+ resolve,
+ reject,
+ worker: workerNode.worker
+ })
+ })
+ if (
+ this.opts.enableTasksQueue === true &&
+ (this.busy ||
+ this.workerNodes[workerNodeKey].tasksUsage.running >=
+ ((this.opts.tasksQueueOptions as TasksQueueOptions)
+ .concurrency as number))
+ ) {
+ this.enqueueTask(workerNodeKey, submittedTask)
} else {
- throw Error('Worker could not be found in tasks map')
+ this.executeTask(workerNodeKey, submittedTask)
}
+ this.workerChoiceStrategyContext.update(workerNodeKey)
+ this.checkAndEmitEvents()
+ // eslint-disable-next-line @typescript-eslint/return-await
+ return res
}
+ /** @inheritDoc */
+ public async destroy (): Promise<void> {
+ await Promise.all(
+ this.workerNodes.map(async (workerNode, workerNodeKey) => {
+ this.flushTasksQueue(workerNodeKey)
+ await this.destroyWorker(workerNode.worker)
+ })
+ )
+ }
+
+ /**
+ * Shutdowns the given worker.
+ *
+ * @param worker - A worker within `workerNodes`.
+ */
+ protected abstract destroyWorker (worker: Worker): void | Promise<void>
+
/**
- * Removes the given worker from the pool.
+ * Setup hook to execute code before worker node are created in the abstract constructor.
+ * Can be overridden
*
- * @param worker Worker that will be removed.
+ * @virtual
*/
- 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)
+ protected setupHook (): void {
+ // Intentionally empty
}
/**
- * Choose a worker for the next task.
+ * Should return whether the worker is the main worker or not.
+ */
+ protected abstract isMain (): boolean
+
+ /**
+ * Hook executed before the worker task execution.
+ * Can be overridden.
*
- * The default implementation uses a round robin algorithm to distribute the load.
+ * @param workerNodeKey - The worker node key.
+ */
+ protected beforeTaskExecutionHook (workerNodeKey: number): void {
+ ++this.workerNodes[workerNodeKey].tasksUsage.running
+ }
+
+ /**
+ * Hook executed after the worker task execution.
+ * Can be overridden.
*
- * @returns Worker.
+ * @param worker - The worker.
+ * @param message - The received message.
*/
- protected chooseWorker (): Worker {
- return this.workerChoiceStrategyContext.execute()
+ protected afterTaskExecutionHook (
+ worker: Worker,
+ message: MessageValue<Response>
+ ): void {
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ const workerTasksUsage = this.workerNodes[workerNodeKey].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
+ }
+ if (this.workerChoiceStrategyContext.getRequiredStatistics().medRunTime) {
+ workerTasksUsage.runTimeHistory.push(message.runTime ?? 0)
+ workerTasksUsage.medRunTime = median(workerTasksUsage.runTimeHistory)
+ }
+ }
+ }
+
+ /**
+ * Chooses a worker node for the next task.
+ *
+ * The default uses a round robin algorithm to distribute the load.
+ *
+ * @returns [worker node key, worker node].
+ */
+ protected chooseWorkerNode (): [number, WorkerNode<Worker, Data>] {
+ let workerNodeKey: number
+ if (this.type === PoolType.DYNAMIC && !this.full && this.internalBusy()) {
+ const workerCreated = this.createAndSetupWorker()
+ this.registerWorkerMessageListener(workerCreated, message => {
+ const currentWorkerNodeKey = this.getWorkerNodeKey(workerCreated)
+ if (
+ isKillBehavior(KillBehaviors.HARD, message.kill) ||
+ (message.kill != null &&
+ this.workerNodes[currentWorkerNodeKey].tasksUsage.running === 0)
+ ) {
+ // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
+ this.flushTasksQueue(currentWorkerNodeKey)
+ void (this.destroyWorker(workerCreated) as Promise<void>)
+ }
+ })
+ workerNodeKey = this.getWorkerNodeKey(workerCreated)
+ } else {
+ workerNodeKey = this.workerChoiceStrategyContext.execute()
+ }
+ return [workerNodeKey, this.workerNodes[workerNodeKey]]
}
/**
- * 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 the 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.
protected abstract createWorker (): Worker
/**
- * Function that can be hooked up when a worker has been newly created and moved to the workers registry.
+ * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
*
- * 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.
*/
protected abstract afterWorkerSetup (worker: Worker): void
- /** @inheritdoc */
- public createAndSetupWorker (): Worker {
- const worker: Worker = this.createWorker()
+ /**
+ * Creates a new worker and sets it up completely in the pool worker nodes.
+ *
+ * @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.removeWorkerNode(worker)
+ })
- // Init tasks map
- this.tasks.set(worker, 0)
+ this.pushWorkerNode(worker)
this.afterWorkerSetup(worker)
return worker
}
+
+ /**
+ * This function is the listener registered for each worker message.
+ *
+ * @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 execution 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.afterTaskExecutionHook(promiseResponse.worker, message)
+ this.promiseResponseMap.delete(message.id)
+ const workerNodeKey = this.getWorkerNodeKey(promiseResponse.worker)
+ if (
+ this.opts.enableTasksQueue === true &&
+ this.tasksQueueSize(workerNodeKey) > 0
+ ) {
+ this.executeTask(
+ workerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ }
+ }
+ }
+ }
+ }
+
+ private checkAndEmitEvents (): void {
+ if (this.opts.enableEvents === true) {
+ if (this.busy) {
+ this.emitter?.emit(PoolEvents.busy)
+ }
+ if (this.type === PoolType.DYNAMIC && this.full) {
+ this.emitter?.emit(PoolEvents.full)
+ }
+ }
+ }
+
+ /**
+ * Sets the given worker node its tasks usage in the pool.
+ *
+ * @param workerNode - The worker node.
+ * @param tasksUsage - The worker node tasks usage.
+ */
+ private setWorkerNodeTasksUsage (
+ workerNode: WorkerNode<Worker, Data>,
+ tasksUsage: TasksUsage
+ ): void {
+ workerNode.tasksUsage = tasksUsage
+ }
+
+ /**
+ * Pushes the given worker in the pool worker nodes.
+ *
+ * @param worker - The worker.
+ * @returns The worker nodes length.
+ */
+ private pushWorkerNode (worker: Worker): number {
+ return this.workerNodes.push({
+ worker,
+ tasksUsage: {
+ run: 0,
+ running: 0,
+ runTime: 0,
+ runTimeHistory: new CircularArray(),
+ avgRunTime: 0,
+ medRunTime: 0,
+ error: 0
+ },
+ tasksQueue: new Queue<Task<Data>>()
+ })
+ }
+
+ /**
+ * Sets the given worker in the pool worker nodes.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @param worker - The worker.
+ * @param tasksUsage - The worker tasks usage.
+ * @param tasksQueue - The worker task queue.
+ */
+ private setWorkerNode (
+ workerNodeKey: number,
+ worker: Worker,
+ tasksUsage: TasksUsage,
+ tasksQueue: Queue<Task<Data>>
+ ): void {
+ this.workerNodes[workerNodeKey] = {
+ worker,
+ tasksUsage,
+ tasksQueue
+ }
+ }
+
+ /**
+ * Removes the given worker from the pool worker nodes.
+ *
+ * @param worker - The worker.
+ */
+ private removeWorkerNode (worker: Worker): void {
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ this.workerNodes.splice(workerNodeKey, 1)
+ this.workerChoiceStrategyContext.remove(workerNodeKey)
+ }
+
+ private executeTask (workerNodeKey: number, task: Task<Data>): void {
+ this.beforeTaskExecutionHook(workerNodeKey)
+ this.sendToWorker(this.workerNodes[workerNodeKey].worker, task)
+ }
+
+ private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
+ return this.workerNodes[workerNodeKey].tasksQueue.enqueue(task)
+ }
+
+ private dequeueTask (workerNodeKey: number): Task<Data> | undefined {
+ return this.workerNodes[workerNodeKey].tasksQueue.dequeue()
+ }
+
+ private tasksQueueSize (workerNodeKey: number): number {
+ return this.workerNodes[workerNodeKey].tasksQueue.size
+ }
+
+ private flushTasksQueue (workerNodeKey: number): void {
+ if (this.tasksQueueSize(workerNodeKey) > 0) {
+ for (let i = 0; i < this.tasksQueueSize(workerNodeKey); i++) {
+ this.executeTask(
+ workerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ }
+ }
+ }
+
+ private flushTasksQueues (): void {
+ for (const [workerNodeKey] of this.workerNodes.entries()) {
+ this.flushTasksQueue(workerNodeKey)
+ }
+ }
}