-import type {
- MessageValue,
- PromiseWorkerResponseWrapper
-} from '../utility-types'
-import { EMPTY_FUNCTION } from '../utils'
+import crypto from 'node:crypto'
+import type { MessageValue, PromiseResponseWrapper } from '../utility-types'
+import { EMPTY_FUNCTION, median } from '../utils'
import { KillBehaviors, isKillBehavior } from '../worker/worker-options'
-import type { PoolOptions } from './pool'
+import { PoolEvents, type PoolOptions } from './pool'
import { PoolEmitter } from './pool'
-import type { IPoolInternal, TasksUsage, WorkerType } from './pool-internal'
+import type { IPoolInternal } from './pool-internal'
import { PoolType } from './pool-internal'
-import type { IPoolWorker } from './pool-worker'
+import type { IWorker, Task, TasksUsage, WorkerNode } from './worker'
import {
WorkerChoiceStrategies,
type WorkerChoiceStrategy
} from './selection-strategies/selection-strategies-types'
import { WorkerChoiceStrategyContext } from './selection-strategies/worker-choice-strategy-context'
+import { CircularArray } from '../circular-array'
/**
* Base class that implements some shared logic for all poolifier pools.
* @typeParam Response - Type of response of execution. This can only be serializable data.
*/
export abstract class AbstractPool<
- Worker extends IPoolWorker,
+ Worker extends IWorker,
Data = unknown,
Response = unknown
> implements IPoolInternal<Worker, Data, Response> {
- /** {@inheritDoc} */
- public readonly workers: Map<number, WorkerType<Worker>> = new Map<
- number,
- WorkerType<Worker>
- >()
+ /** @inheritDoc */
+ public readonly workerNodes: Array<WorkerNode<Worker, Data>> = []
- /** {@inheritDoc} */
+ /** @inheritDoc */
public readonly emitter?: PoolEmitter
/**
- * Id of the next worker.
- */
- protected nextWorkerId: number = 0
-
- /**
- * The promise map.
+ * The promise response 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.
+ * - `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 and resolve/reject the promise based on the message.
+ * When we receive a message from the worker we get a map entry with the promise resolve/reject bound to the message.
*/
- protected promiseMap: Map<
+ protected promiseResponseMap: Map<
string,
- PromiseWorkerResponseWrapper<Worker, Response>
- > = new Map<string, PromiseWorkerResponseWrapper<Worker, Response>>()
+ 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,
this.checkNumberOfWorkers(this.numberOfWorkers)
this.checkFilePath(this.filePath)
this.checkPoolOptions(this.opts)
+
+ this.chooseWorkerNode.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++) {
if (this.opts.enableEvents === true) {
this.emitter = new PoolEmitter()
}
- this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext(
- this,
- () => {
- const workerCreated = this.createAndSetupWorker()
- this.registerWorkerMessageListener(workerCreated, message => {
- if (
- isKillBehavior(KillBehaviors.HARD, message.kill) ||
- this.getWorkerRunningTasks(workerCreated) === 0
- ) {
- // Kill received from the worker, means that no new tasks are submitted to that worker for a while ( > maxInactiveTime)
- void this.destroyWorker(workerCreated)
- }
- })
- return workerCreated
- },
- this.opts.workerChoiceStrategy
- )
+ this.workerChoiceStrategyContext = new WorkerChoiceStrategyContext<
+ Worker,
+ Data,
+ Response
+ >(this, this.opts.workerChoiceStrategy)
}
private checkFilePath (filePath: string): void {
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
}
- /** {@inheritDoc} */
+ 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
- /** {@inheritDoc} */
- public get numberOfRunningTasks (): number {
- return this.promiseMap.size
+ /**
+ * Number of tasks concurrently running in the pool.
+ */
+ private get numberOfRunningTasks (): number {
+ return this.promiseResponseMap.size
}
/**
- * Gets the given worker key.
+ * Gets the given worker its worker node key.
*
* @param worker - The worker.
- * @returns The worker key.
+ * @returns The worker node key if the worker is found in the pool worker nodes, `-1` otherwise.
*/
- private getWorkerKey (worker: Worker): number | undefined {
- return [...this.workers].find(([, value]) => value.worker === worker)?.[0]
- }
-
- /** {@inheritDoc} */
- public getWorkerRunningTasks (worker: Worker): number | undefined {
- return this.workers.get(this.getWorkerKey(worker) as number)?.tasksUsage
- ?.running
- }
-
- /** {@inheritDoc} */
- public getWorkerAverageTasksRunTime (worker: Worker): number | undefined {
- return this.workers.get(this.getWorkerKey(worker) as number)?.tasksUsage
- ?.avgRunTime
+ private getWorkerNodeKey (worker: Worker): number {
+ return this.workerNodes.findIndex(
+ workerNode => workerNode.worker === worker
+ )
}
- /** {@inheritDoc} */
+ /** @inheritDoc */
public setWorkerChoiceStrategy (
workerChoiceStrategy: WorkerChoiceStrategy
): void {
+ this.checkValidWorkerChoiceStrategy(workerChoiceStrategy)
this.opts.workerChoiceStrategy = workerChoiceStrategy
- for (const [key, value] of this.workers) {
- this.setWorker(key, value.worker, {
- run: 0,
- running: 0,
- runTime: 0,
- avgRunTime: 0
- })
+ for (const [index, workerNode] of this.workerNodes.entries()) {
+ this.setWorkerNode(
+ index,
+ workerNode.worker,
+ {
+ run: 0,
+ running: 0,
+ runTime: 0,
+ runTimeHistory: new CircularArray(),
+ avgRunTime: 0,
+ medRunTime: 0,
+ error: 0
+ },
+ workerNode.tasksQueue
+ )
}
this.workerChoiceStrategyContext.setWorkerChoiceStrategy(
workerChoiceStrategy
)
}
- /** {@inheritDoc} */
+ /** @inheritDoc */
+ public abstract get full (): boolean
+
+ /** @inheritDoc */
public abstract get busy (): boolean
- protected internalGetBusyStatus (): boolean {
+ protected internalBusy (): boolean {
return (
this.numberOfRunningTasks >= this.numberOfWorkers &&
- this.findFreeWorker() === false
+ this.findFreeWorkerNodeKey() === -1
)
}
- /** {@inheritDoc} */
- public findFreeWorker (): Worker | false {
- for (const value of this.workers.values()) {
- if (value.tasksUsage.running === 0) {
- // A worker is free, return the matching worker
- return value.worker
- }
- }
- return false
+ /** @inheritDoc */
+ public findFreeWorkerNodeKey (): number {
+ return this.workerNodes.findIndex(workerNode => {
+ return workerNode.tasksUsage?.running === 0
+ })
}
- /** {@inheritDoc} */
+ /** @inheritDoc */
public async execute (data: Data): Promise<Response> {
- const worker = this.chooseWorker()
- const messageId = crypto.randomUUID()
- const res = this.internalExecute(worker, messageId)
- this.checkAndEmitBusy()
- this.sendToWorker(worker, {
+ const [workerNodeKey, workerNode] = this.chooseWorkerNode()
+ const submittedTask: Task<Data> = {
// eslint-disable-next-line @typescript-eslint/consistent-type-assertions
data: data ?? ({} as Data),
- id: messageId
- })
+ id: crypto.randomUUID()
+ }
+ const res = this.internalExecute(workerNodeKey, workerNode, submittedTask)
+ let currentTask: Task<Data>
+ // FIXME: Add sensible conditions to start tasks queuing on the worker node
+ if (this.tasksQueueLength(workerNodeKey) > 0) {
+ currentTask = this.dequeueTask(workerNodeKey) as Task<Data>
+ this.enqueueTask(workerNodeKey, submittedTask)
+ } else {
+ currentTask = submittedTask
+ }
+ this.sendToWorker(workerNode.worker, currentTask)
+ this.checkAndEmitFull()
+ this.checkAndEmitBusy()
// eslint-disable-next-line @typescript-eslint/return-await
return res
}
- /** {@inheritDoc} */
+ /** @inheritDoc */
public async destroy (): Promise<void> {
await Promise.all(
- [...this.workers].map(async ([, value]) => {
- await this.destroyWorker(value.worker)
+ this.workerNodes.map(async workerNode => {
+ await this.destroyWorker(workerNode.worker)
})
)
}
/**
- * Shutdowns given worker.
+ * Shutdowns the given worker.
*
- * @param worker - A worker within `workers`.
+ * @param worker - A worker within `workerNodes`.
*/
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.
+ * Setup hook to run code before worker node are created in the abstract constructor.
+ * Can be overridden
+ *
+ * @virtual
*/
protected setupHook (): void {
- // Can be overridden
+ // Intentionally empty
}
/**
* Hook executed before the worker task promise resolution.
* Can be overridden.
*
- * @param worker - The worker.
+ * @param workerNodeKey - The worker node key.
*/
- protected beforePromiseWorkerResponseHook (worker: Worker): void {
- this.increaseWorkerRunningTasks(worker)
+ protected beforePromiseResponseHook (workerNodeKey: number): void {
+ ++this.workerNodes[workerNodeKey].tasksUsage.running
}
/**
* Hook executed after the worker task promise resolution.
* Can be overridden.
*
+ * @param worker - The worker.
* @param message - The received message.
- * @param promise - The Promise response.
*/
- protected afterPromiseWorkerResponseHook (
- message: MessageValue<Response>,
- promise: PromiseWorkerResponseWrapper<Worker, Response>
+ protected afterPromiseResponseHook (
+ worker: Worker,
+ message: MessageValue<Response>
): void {
- this.decreaseWorkerRunningTasks(promise.worker)
- this.stepWorkerRunTasks(promise.worker, 1)
- this.updateWorkerTasksRunTime(promise.worker, message.taskRunTime)
- }
-
- /**
- * Removes the given worker from the pool.
- *
- * @param worker - The worker that will be removed.
- */
- protected removeWorker (worker: Worker): void {
- this.workers.delete(this.getWorkerKey(worker) as number)
- --this.nextWorkerId
+ 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
+ }
+ if (this.workerChoiceStrategyContext.getRequiredStatistics().medRunTime) {
+ workerTasksUsage.runTimeHistory.push(message.runTime ?? 0)
+ workerTasksUsage.medRunTime = median(workerTasksUsage.runTimeHistory)
+ }
+ }
}
/**
- * Chooses a worker for the next task.
+ * Chooses a worker node 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 node key, worker node].
*/
- protected chooseWorker (): Worker {
- return this.workerChoiceStrategyContext.execute()
+ protected chooseWorkerNode (): [number, WorkerNode<Worker, Data>] {
+ let workerNodeKey: number
+ if (
+ this.type === PoolType.DYNAMIC &&
+ !this.full &&
+ this.findFreeWorkerNodeKey() === -1
+ ) {
+ const workerCreated = this.createAndSetupWorker()
+ this.registerWorkerMessageListener(workerCreated, message => {
+ if (
+ isKillBehavior(KillBehaviors.HARD, message.kill) ||
+ (message.kill != null &&
+ this.getWorkerTasksUsage(workerCreated)?.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(workerCreated)
+ }
+ })
+ workerNodeKey = this.getWorkerNodeKey(workerCreated)
+ } else {
+ workerNodeKey = this.workerChoiceStrategyContext.execute()
+ }
+ return [workerNodeKey, this.workerNodes[workerNodeKey]]
}
/**
): void
/**
- * Registers a listener callback on a given worker.
+ * 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 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.
*
protected abstract afterWorkerSetup (worker: Worker): void
/**
- * Creates a new worker for this pool and sets it up completely.
+ * Creates a new worker and sets it up completely in the pool worker nodes.
*
* @returns New, completely set up worker.
*/
worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
worker.on('exit', this.opts.exitHandler ?? EMPTY_FUNCTION)
worker.once('exit', () => {
- this.removeWorker(worker)
+ this.removeWorkerNode(worker)
})
- this.setWorker(this.nextWorkerId, worker, {
- run: 0,
- running: 0,
- runTime: 0,
- avgRunTime: 0
- })
- ++this.nextWorkerId
+ this.pushWorkerNode(worker)
this.afterWorkerSetup(worker)
*/
protected workerListener (): (message: MessageValue<Response>) => void {
return message => {
- if (message.id !== undefined) {
- const promise = this.promiseMap.get(message.id)
- if (promise !== undefined) {
+ if (message.id != null) {
+ // Task response received
+ const promiseResponse = this.promiseResponseMap.get(message.id)
+ if (promiseResponse != null) {
if (message.error != null) {
- promise.reject(message.error)
+ promiseResponse.reject(message.error)
} else {
- promise.resolve(message.data as Response)
+ promiseResponse.resolve(message.data as Response)
}
- this.afterPromiseWorkerResponseHook(message, promise)
- this.promiseMap.delete(message.id)
+ this.afterPromiseResponseHook(promiseResponse.worker, message)
+ this.promiseResponseMap.delete(message.id)
}
}
}
}
private async internalExecute (
- worker: Worker,
- messageId: string
+ workerNodeKey: number,
+ workerNode: WorkerNode<Worker, Data>,
+ task: Task<Data>
): Promise<Response> {
- this.beforePromiseWorkerResponseHook(worker)
+ this.beforePromiseResponseHook(workerNodeKey)
return await new Promise<Response>((resolve, reject) => {
- this.promiseMap.set(messageId, { resolve, reject, worker })
+ this.promiseResponseMap.set(task.id, {
+ resolve,
+ reject,
+ worker: workerNode.worker
+ })
})
}
private checkAndEmitBusy (): void {
if (this.opts.enableEvents === true && this.busy) {
- this.emitter?.emit('busy')
+ this.emitter?.emit(PoolEvents.busy)
}
}
- /**
- * Increases the number of tasks that the given worker has applied.
- *
- * @param worker - Worker which running tasks is increased.
- */
- private increaseWorkerRunningTasks (worker: Worker): void {
- this.stepWorkerRunningTasks(worker, 1)
- }
-
- /**
- * Decreases the number of tasks that the given worker has applied.
- *
- * @param worker - Worker which running tasks is decreased.
- */
- private decreaseWorkerRunningTasks (worker: Worker): void {
- this.stepWorkerRunningTasks(worker, -1)
+ private checkAndEmitFull (): void {
+ if (
+ this.type === PoolType.DYNAMIC &&
+ this.opts.enableEvents === true &&
+ this.full
+ ) {
+ this.emitter?.emit(PoolEvents.full)
+ }
}
/**
- * Gets tasks usage of the given worker.
+ * Gets the given worker its tasks usage in the pool.
*
- * @param worker - Worker which tasks usage is returned.
+ * @param worker - The worker.
+ * @returns The worker tasks usage.
*/
private getWorkerTasksUsage (worker: Worker): TasksUsage | undefined {
- if (this.checkWorker(worker)) {
- const workerKey = this.getWorkerKey(worker) as number
- const workerEntry = this.workers.get(workerKey) as WorkerType<Worker>
- return workerEntry.tasksUsage
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ if (workerNodeKey !== -1) {
+ return this.workerNodes[workerNodeKey].tasksUsage
}
+ throw new Error('Worker could not be found in the pool worker nodes')
}
/**
- * Steps the number of tasks that the given worker has applied.
+ * Pushes the given worker in the pool worker nodes.
*
- * @param worker - Worker which running tasks are stepped.
- * @param step - Number of running tasks step.
- */
- private stepWorkerRunningTasks (worker: Worker, step: number): void {
- // prettier-ignore
- (this.getWorkerTasksUsage(worker) as TasksUsage).running += step
- }
-
- /**
- * Steps the number of tasks that the given worker has run.
- *
- * @param worker - Worker which has run tasks.
- * @param step - Number of run tasks step.
+ * @param worker - The worker.
+ * @returns The worker nodes length.
*/
- private stepWorkerRunTasks (worker: Worker, step: number): void {
- // prettier-ignore
- (this.getWorkerTasksUsage(worker) as TasksUsage).run += step
+ 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: []
+ })
}
/**
- * Updates tasks runtime for the given worker.
+ * Sets the given worker in the pool worker nodes.
*
- * @param worker - Worker which run the task.
- * @param taskRunTime - Worker task runtime.
+ * @param workerNodeKey - The worker node key.
+ * @param worker - The worker.
+ * @param tasksUsage - The worker tasks usage.
+ * @param tasksQueue - The worker task queue.
*/
- private updateWorkerTasksRunTime (
+ private setWorkerNode (
+ workerNodeKey: number,
worker: Worker,
- taskRunTime: number | undefined
+ tasksUsage: TasksUsage,
+ tasksQueue: Array<Task<Data>>
): void {
- if (
- this.workerChoiceStrategyContext.getWorkerChoiceStrategy()
- .requiredStatistics.runTime
- ) {
- const workerTasksUsage = this.getWorkerTasksUsage(worker) as TasksUsage
- workerTasksUsage.runTime += taskRunTime ?? 0
- if (workerTasksUsage.run !== 0) {
- workerTasksUsage.avgRunTime =
- workerTasksUsage.runTime / workerTasksUsage.run
- }
+ this.workerNodes[workerNodeKey] = {
+ worker,
+ tasksUsage,
+ tasksQueue
}
}
/**
- * Sets the given worker.
+ * Removes the given worker from the pool worker nodes.
*
- * @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.set(workerKey, {
- worker,
- tasksUsage
- })
+ protected removeWorkerNode (worker: Worker): void {
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ this.workerNodes.splice(workerNodeKey, 1)
+ this.workerChoiceStrategyContext.remove(workerNodeKey)
}
- /**
- * Checks if the given worker is registered in the pool.
- *
- * @param worker - Worker to check.
- * @returns `true` if the worker is registered in the pool.
- */
- private checkWorker (worker: Worker): boolean {
- if (this.getWorkerKey(worker) == null) {
- throw new Error('Worker could not be found in the pool')
- }
- return true
+ protected enqueueTask (workerNodeKey: number, task: Task<Data>): void {
+ this.workerNodes[workerNodeKey].tasksQueue.push(task)
+ }
+
+ protected dequeueTask (workerNodeKey: number): Task<Data> | undefined {
+ return this.workerNodes[workerNodeKey].tasksQueue.shift()
+ }
+
+ protected tasksQueueLength (workerNodeKey: number): number {
+ return this.workerNodes[workerNodeKey].tasksQueue.length
}
}