-import { AsyncResource } from 'node:async_hooks'
import type { Worker } from 'node:cluster'
import type { MessagePort } from 'node:worker_threads'
import { performance } from 'node:perf_hooks'
import type {
MessageValue,
+ Task,
TaskPerformance,
WorkerStatistics
-} from '../utility-types'
-import { EMPTY_FUNCTION, isPlainObject } from '../utils'
+} from '../utility-types.js'
import {
- type KillBehavior,
- KillBehaviors,
- type WorkerOptions
-} from './worker-options'
+ DEFAULT_TASK_NAME,
+ EMPTY_FUNCTION,
+ isAsyncFunction,
+ isPlainObject
+} from '../utils.js'
+import { KillBehaviors, type WorkerOptions } from './worker-options.js'
import type {
+ TaskAsyncFunction,
+ TaskFunction,
+ TaskFunctionOperationResult,
TaskFunctions,
- WorkerAsyncFunction,
- WorkerFunction,
- WorkerSyncFunction
-} from './worker-functions'
+ TaskSyncFunction
+} from './task-functions.js'
+import {
+ checkTaskFunctionName,
+ checkValidTaskFunctionEntry,
+ checkValidWorkerOptions
+} from './utils.js'
-const DEFAULT_FUNCTION_NAME = 'default'
const DEFAULT_MAX_INACTIVE_TIME = 60000
-const DEFAULT_KILL_BEHAVIOR: KillBehavior = KillBehaviors.SOFT
+const DEFAULT_WORKER_OPTIONS: WorkerOptions = {
+ /**
+ * The kill behavior option on this worker or its default value.
+ */
+ killBehavior: KillBehaviors.SOFT,
+ /**
+ * The maximum time to keep this worker active while idle.
+ * The pool automatically checks and terminates this worker when the time expires.
+ */
+ maxInactiveTime: DEFAULT_MAX_INACTIVE_TIME,
+ /**
+ * The function to call when the worker is killed.
+ */
+ killHandler: EMPTY_FUNCTION
+}
/**
* Base class that implements some shared logic for all poolifier workers.
*
* @typeParam MainWorker - Type of main worker.
- * @typeParam Data - Type of data this worker receives from pool's execution. This can only be serializable data.
- * @typeParam Response - Type of response the worker sends back to the main worker. This can only be serializable data.
+ * @typeParam Data - Type of data this worker receives from pool's execution. This can only be structured-cloneable data.
+ * @typeParam Response - Type of response the worker sends back to the main worker. This can only be structured-cloneable data.
*/
export abstract class AbstractWorker<
MainWorker extends Worker | MessagePort,
Data = unknown,
Response = unknown
-> extends AsyncResource {
+> {
+ /**
+ * Worker id.
+ */
+ protected abstract id: number
/**
* Task function(s) processed by the worker when the pool's `execution` function is invoked.
*/
- protected taskFunctions!: Map<string, WorkerFunction<Data, Response>>
+ protected taskFunctions!: Map<string, TaskFunction<Data, Response>>
/**
* Timestamp of the last task processed by this worker.
*/
protected lastTaskTimestamp!: number
/**
- * Performance statistics computation.
+ * Performance statistics computation requirements.
*/
protected statistics!: WorkerStatistics
/**
- * Handler id of the `aliveInterval` worker alive check.
+ * Handler id of the `activeInterval` worker activity check.
*/
- protected readonly aliveInterval?: NodeJS.Timeout
+ protected activeInterval?: NodeJS.Timeout
+
/**
* Constructs a new poolifier worker.
*
- * @param type - The type of async event.
* @param isMain - Whether this is the main worker or not.
- * @param taskFunctions - Task function(s) processed by the worker when the pool's `execution` function is invoked. The first function is the default function.
* @param mainWorker - Reference to main worker.
+ * @param taskFunctions - Task function(s) processed by the worker when the pool's `execution` function is invoked. The first function is the default function.
* @param opts - Options for the worker.
*/
public constructor (
- type: string,
protected readonly isMain: boolean,
- taskFunctions:
- | WorkerFunction<Data, Response>
- | TaskFunctions<Data, Response>,
- protected mainWorker: MainWorker | undefined | null,
- protected readonly opts: WorkerOptions = {
- /**
- * The kill behavior option on this worker or its default value.
- */
- killBehavior: DEFAULT_KILL_BEHAVIOR,
- /**
- * The maximum time to keep this worker alive while idle.
- * The pool automatically checks and terminates this worker when the time expires.
- */
- maxInactiveTime: DEFAULT_MAX_INACTIVE_TIME
- }
+ private readonly mainWorker: MainWorker,
+ taskFunctions: TaskFunction<Data, Response> | TaskFunctions<Data, Response>,
+ protected opts: WorkerOptions = DEFAULT_WORKER_OPTIONS
) {
- super(type)
- this.checkWorkerOptions(this.opts)
+ if (this.isMain == null) {
+ throw new Error('isMain parameter is mandatory')
+ }
this.checkTaskFunctions(taskFunctions)
+ this.checkWorkerOptions(this.opts)
if (!this.isMain) {
- this.lastTaskTimestamp = performance.now()
- this.aliveInterval = setInterval(
- this.checkAlive.bind(this),
- (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) / 2
- )
- this.checkAlive.bind(this)()
+ // Should be once() but Node.js on windows has a bug that prevents it from working
+ this.getMainWorker().on('message', this.handleReadyMessage.bind(this))
}
- this.mainWorker?.on('message', this.messageListener.bind(this))
}
private checkWorkerOptions (opts: WorkerOptions): void {
- this.opts.killBehavior = opts.killBehavior ?? DEFAULT_KILL_BEHAVIOR
- this.opts.maxInactiveTime =
- opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME
- delete this.opts.async
+ checkValidWorkerOptions(opts)
+ this.opts = { ...DEFAULT_WORKER_OPTIONS, ...opts }
}
/**
- * Checks if the `taskFunctions` parameter is passed to the constructor.
+ * Checks if the `taskFunctions` parameter is passed to the constructor and valid.
*
* @param taskFunctions - The task function(s) parameter that should be checked.
*/
private checkTaskFunctions (
- taskFunctions:
- | WorkerFunction<Data, Response>
- | TaskFunctions<Data, Response>
+ taskFunctions: TaskFunction<Data, Response> | TaskFunctions<Data, Response>
): void {
if (taskFunctions == null) {
throw new Error('taskFunctions parameter is mandatory')
}
- this.taskFunctions = new Map<string, WorkerFunction<Data, Response>>()
+ this.taskFunctions = new Map<string, TaskFunction<Data, Response>>()
if (typeof taskFunctions === 'function') {
- this.taskFunctions.set(DEFAULT_FUNCTION_NAME, taskFunctions.bind(this))
+ const boundFn = taskFunctions.bind(this)
+ this.taskFunctions.set(DEFAULT_TASK_NAME, boundFn)
+ this.taskFunctions.set(
+ typeof taskFunctions.name === 'string' &&
+ taskFunctions.name.trim().length > 0
+ ? taskFunctions.name
+ : 'fn1',
+ boundFn
+ )
} else if (isPlainObject(taskFunctions)) {
let firstEntry = true
for (const [name, fn] of Object.entries(taskFunctions)) {
- if (typeof fn !== 'function') {
- throw new TypeError(
- 'A taskFunctions parameter object value is not a function'
- )
- }
- this.taskFunctions.set(name, fn.bind(this))
+ checkValidTaskFunctionEntry<Data, Response>(name, fn)
+ const boundFn = fn.bind(this)
if (firstEntry) {
- this.taskFunctions.set(DEFAULT_FUNCTION_NAME, fn.bind(this))
+ this.taskFunctions.set(DEFAULT_TASK_NAME, boundFn)
firstEntry = false
}
+ this.taskFunctions.set(name, boundFn)
}
if (firstEntry) {
throw new Error('taskFunctions parameter object is empty')
}
/**
- * Worker message listener.
+ * Checks if the worker has a task function with the given name.
*
- * @param message - Message received.
+ * @param name - The name of the task function to check.
+ * @returns Whether the worker has a task function with the given name or not.
*/
- protected messageListener (
- message: MessageValue<Data, Data, MainWorker>
- ): void {
- if (message.id != null && message.data != null) {
- // Task message received
- const fn = this.getTaskFunction(message.name)
- if (fn?.constructor.name === 'AsyncFunction') {
- this.runInAsyncScope(this.runAsync.bind(this), this, fn, message)
- } else {
- this.runInAsyncScope(this.runSync.bind(this), this, fn, message)
+ public hasTaskFunction (name: string): TaskFunctionOperationResult {
+ try {
+ checkTaskFunctionName(name)
+ } catch (error) {
+ return { status: false, error: error as Error }
+ }
+ return { status: this.taskFunctions.has(name) }
+ }
+
+ /**
+ * Adds a task function to the worker.
+ * If a task function with the same name already exists, it is replaced.
+ *
+ * @param name - The name of the task function to add.
+ * @param fn - The task function to add.
+ * @returns Whether the task function was added or not.
+ */
+ public addTaskFunction (
+ name: string,
+ fn: TaskFunction<Data, Response>
+ ): TaskFunctionOperationResult {
+ try {
+ checkTaskFunctionName(name)
+ if (name === DEFAULT_TASK_NAME) {
+ throw new Error(
+ 'Cannot add a task function with the default reserved name'
+ )
+ }
+ if (typeof fn !== 'function') {
+ throw new TypeError('fn parameter is not a function')
+ }
+ const boundFn = fn.bind(this)
+ if (
+ this.taskFunctions.get(name) ===
+ this.taskFunctions.get(DEFAULT_TASK_NAME)
+ ) {
+ this.taskFunctions.set(DEFAULT_TASK_NAME, boundFn)
+ }
+ this.taskFunctions.set(name, boundFn)
+ this.sendTaskFunctionNamesToMainWorker()
+ return { status: true }
+ } catch (error) {
+ return { status: false, error: error as Error }
+ }
+ }
+
+ /**
+ * Removes a task function from the worker.
+ *
+ * @param name - The name of the task function to remove.
+ * @returns Whether the task function existed and was removed or not.
+ */
+ public removeTaskFunction (name: string): TaskFunctionOperationResult {
+ try {
+ checkTaskFunctionName(name)
+ if (name === DEFAULT_TASK_NAME) {
+ throw new Error(
+ 'Cannot remove the task function with the default reserved name'
+ )
+ }
+ if (
+ this.taskFunctions.get(name) ===
+ this.taskFunctions.get(DEFAULT_TASK_NAME)
+ ) {
+ throw new Error(
+ 'Cannot remove the task function used as the default task function'
+ )
+ }
+ const deleteStatus = this.taskFunctions.delete(name)
+ this.sendTaskFunctionNamesToMainWorker()
+ return { status: deleteStatus }
+ } catch (error) {
+ return { status: false, error: error as Error }
+ }
+ }
+
+ /**
+ * Lists the names of the worker's task functions.
+ *
+ * @returns The names of the worker's task functions.
+ */
+ public listTaskFunctionNames (): string[] {
+ const names: string[] = [...this.taskFunctions.keys()]
+ let defaultTaskFunctionName: string = DEFAULT_TASK_NAME
+ for (const [name, fn] of this.taskFunctions) {
+ if (
+ name !== DEFAULT_TASK_NAME &&
+ fn === this.taskFunctions.get(DEFAULT_TASK_NAME)
+ ) {
+ defaultTaskFunctionName = name
+ break
+ }
+ }
+ return [
+ names[names.indexOf(DEFAULT_TASK_NAME)],
+ defaultTaskFunctionName,
+ ...names.filter(
+ name => name !== DEFAULT_TASK_NAME && name !== defaultTaskFunctionName
+ )
+ ]
+ }
+
+ /**
+ * Sets the default task function to use in the worker.
+ *
+ * @param name - The name of the task function to use as default task function.
+ * @returns Whether the default task function was set or not.
+ */
+ public setDefaultTaskFunction (name: string): TaskFunctionOperationResult {
+ try {
+ checkTaskFunctionName(name)
+ if (name === DEFAULT_TASK_NAME) {
+ throw new Error(
+ 'Cannot set the default task function reserved name as the default task function'
+ )
+ }
+ if (!this.taskFunctions.has(name)) {
+ throw new Error(
+ 'Cannot set the default task function to a non-existing task function'
+ )
}
- } else if (message.parent != null) {
- // Main worker reference message received
- this.mainWorker = message.parent
- } else if (message.statistics != null) {
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ this.taskFunctions.set(DEFAULT_TASK_NAME, this.taskFunctions.get(name)!)
+ this.sendTaskFunctionNamesToMainWorker()
+ return { status: true }
+ } catch (error) {
+ return { status: false, error: error as Error }
+ }
+ }
+
+ /**
+ * Handles the ready message sent by the main worker.
+ *
+ * @param message - The ready message.
+ */
+ protected abstract handleReadyMessage (message: MessageValue<Data>): void
+
+ /**
+ * Worker message listener.
+ *
+ * @param message - The received message.
+ */
+ protected messageListener (message: MessageValue<Data>): void {
+ this.checkMessageWorkerId(message)
+ if (message.statistics != null) {
// Statistics message received
this.statistics = message.statistics
- } else if (message.kill != null) {
+ } else if (message.checkActive != null) {
+ // Check active message received
+ message.checkActive ? this.startCheckActive() : this.stopCheckActive()
+ } else if (message.taskFunctionOperation != null) {
+ // Task function operation message received
+ this.handleTaskFunctionOperationMessage(message)
+ } else if (message.taskId != null && message.data != null) {
+ // Task message received
+ this.run(message)
+ } else if (message.kill === true) {
// Kill message received
- this.aliveInterval != null && clearInterval(this.aliveInterval)
- this.emitDestroy()
+ this.handleKillMessage(message)
+ }
+ }
+
+ protected handleTaskFunctionOperationMessage (
+ message: MessageValue<Data>
+ ): void {
+ const { taskFunctionOperation, taskFunctionName, taskFunction } = message
+ let response!: TaskFunctionOperationResult
+ switch (taskFunctionOperation) {
+ case 'add':
+ response = this.addTaskFunction(
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ taskFunctionName!,
+ // eslint-disable-next-line @typescript-eslint/no-implied-eval, no-new-func, @typescript-eslint/no-non-null-assertion
+ new Function(`return ${taskFunction!}`)() as TaskFunction<
+ Data,
+ Response
+ >
+ )
+ break
+ case 'remove':
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ response = this.removeTaskFunction(taskFunctionName!)
+ break
+ case 'default':
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ response = this.setDefaultTaskFunction(taskFunctionName!)
+ break
+ default:
+ response = { status: false, error: new Error('Unknown task operation') }
+ break
+ }
+ this.sendToMainWorker({
+ taskFunctionOperation,
+ taskFunctionOperationStatus: response.status,
+ taskFunctionName,
+ ...(!response.status &&
+ response?.error != null && {
+ workerError: {
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ name: taskFunctionName!,
+ message: this.handleError(response.error as Error | string)
+ }
+ })
+ })
+ }
+
+ /**
+ * Handles a kill message sent by the main worker.
+ *
+ * @param message - The kill message.
+ */
+ protected handleKillMessage (_message: MessageValue<Data>): void {
+ this.stopCheckActive()
+ if (isAsyncFunction(this.opts.killHandler)) {
+ (this.opts.killHandler?.() as Promise<void>)
+ .then(() => {
+ this.sendToMainWorker({ kill: 'success' })
+ return undefined
+ })
+ .catch(() => {
+ this.sendToMainWorker({ kill: 'failure' })
+ })
+ } else {
+ try {
+ // eslint-disable-next-line @typescript-eslint/no-invalid-void-type
+ this.opts.killHandler?.() as void
+ this.sendToMainWorker({ kill: 'success' })
+ } catch {
+ this.sendToMainWorker({ kill: 'failure' })
+ }
+ }
+ }
+
+ /**
+ * Check if the message worker id is set and matches the worker id.
+ *
+ * @param message - The message to check.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the message worker id is not set or does not match the worker id.
+ */
+ private checkMessageWorkerId (message: MessageValue<Data>): void {
+ if (message.workerId == null) {
+ throw new Error('Message worker id is not set')
+ } else if (message.workerId !== this.id) {
+ throw new Error(
+ `Message worker id ${message.workerId} does not match the worker id ${this.id}`
+ )
+ }
+ }
+
+ /**
+ * Starts the worker check active interval.
+ */
+ private startCheckActive (): void {
+ this.lastTaskTimestamp = performance.now()
+ this.activeInterval = setInterval(
+ this.checkActive.bind(this),
+ (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) / 2
+ )
+ }
+
+ /**
+ * Stops the worker check active interval.
+ */
+ private stopCheckActive (): void {
+ if (this.activeInterval != null) {
+ clearInterval(this.activeInterval)
+ delete this.activeInterval
+ }
+ }
+
+ /**
+ * Checks if the worker should be terminated, because its living too long.
+ */
+ private checkActive (): void {
+ if (
+ performance.now() - this.lastTaskTimestamp >
+ (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME)
+ ) {
+ this.sendToMainWorker({ kill: this.opts.killBehavior })
}
}
* Returns the main worker.
*
* @returns Reference to the main worker.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the main worker is not set.
*/
protected getMainWorker (): MainWorker {
if (this.mainWorker == null) {
- throw new Error('Main worker was not set')
+ throw new Error('Main worker not set')
}
return this.mainWorker
}
/**
- * Sends a message to the main worker.
+ * Sends a message to main worker.
*
* @param message - The response message.
*/
): void
/**
- * Checks if the worker should be terminated, because its living too long.
+ * Sends task function names to the main worker.
*/
- protected checkAlive (): void {
- if (
- performance.now() - this.lastTaskTimestamp >
- (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME)
- ) {
- this.sendToMainWorker({ kill: this.opts.killBehavior })
- }
+ protected sendTaskFunctionNamesToMainWorker (): void {
+ this.sendToMainWorker({
+ taskFunctionNames: this.listTaskFunctionNames()
+ })
}
/**
* Handles an error and convert it to a string so it can be sent back to the main worker.
*
- * @param e - The error raised by the worker.
- * @returns Message of the error.
+ * @param error - The error raised by the worker.
+ * @returns The error message.
*/
- protected handleError (e: Error | string): string {
- return e as string
+ protected handleError (error: Error | string): string {
+ return error instanceof Error ? error.message : error
}
/**
- * Runs the given function synchronously.
+ * Runs the given task.
*
- * @param fn - Function that will be executed.
- * @param message - Input data for the given function.
+ * @param task - The task to execute.
*/
- protected runSync (
- fn: WorkerSyncFunction<Data, Response>,
- message: MessageValue<Data>
- ): void {
+ protected readonly run = (task: Task<Data>): void => {
+ const { name, taskId, data } = task
+ const taskFunctionName = name ?? DEFAULT_TASK_NAME
+ if (!this.taskFunctions.has(taskFunctionName)) {
+ this.sendToMainWorker({
+ workerError: {
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ name: name!,
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ message: `Task function '${name!}' not found`,
+ data
+ },
+ taskId
+ })
+ return
+ }
+ const fn = this.taskFunctions.get(taskFunctionName)
+ if (isAsyncFunction(fn)) {
+ this.runAsync(fn as TaskAsyncFunction<Data, Response>, task)
+ } else {
+ this.runSync(fn as TaskSyncFunction<Data, Response>, task)
+ }
+ }
+
+ /**
+ * Runs the given task function synchronously.
+ *
+ * @param fn - Task function that will be executed.
+ * @param task - Input data for the task function.
+ */
+ protected readonly runSync = (
+ fn: TaskSyncFunction<Data, Response>,
+ task: Task<Data>
+ ): void => {
+ const { name, taskId, data } = task
try {
- let taskPerformance = this.beginTaskPerformance()
- const res = fn(message.data)
+ let taskPerformance = this.beginTaskPerformance(name)
+ const res = fn(data)
taskPerformance = this.endTaskPerformance(taskPerformance)
this.sendToMainWorker({
data: res,
taskPerformance,
- id: message.id
+ taskId
})
- } catch (e) {
- const err = this.handleError(e as Error)
+ } catch (error) {
this.sendToMainWorker({
- taskError: {
- message: err,
- data: message.data
+ workerError: {
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ name: name!,
+ message: this.handleError(error as Error | string),
+ data
},
- id: message.id
+ taskId
})
} finally {
- !this.isMain && (this.lastTaskTimestamp = performance.now())
+ this.updateLastTaskTimestamp()
}
}
/**
- * Runs the given function asynchronously.
+ * Runs the given task function asynchronously.
*
- * @param fn - Function that will be executed.
- * @param message - Input data for the given function.
+ * @param fn - Task function that will be executed.
+ * @param task - Input data for the task function.
*/
- protected runAsync (
- fn: WorkerAsyncFunction<Data, Response>,
- message: MessageValue<Data>
- ): void {
- let taskPerformance = this.beginTaskPerformance()
- fn(message.data)
+ protected readonly runAsync = (
+ fn: TaskAsyncFunction<Data, Response>,
+ task: Task<Data>
+ ): void => {
+ const { name, taskId, data } = task
+ let taskPerformance = this.beginTaskPerformance(name)
+ fn(data)
.then(res => {
taskPerformance = this.endTaskPerformance(taskPerformance)
this.sendToMainWorker({
data: res,
taskPerformance,
- id: message.id
+ taskId
})
- return null
+ return undefined
})
- .catch(e => {
- const err = this.handleError(e as Error)
+ .catch(error => {
this.sendToMainWorker({
- taskError: {
- message: err,
- data: message.data
+ workerError: {
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ name: name!,
+ message: this.handleError(error as Error | string),
+ data
},
- id: message.id
+ taskId
})
})
.finally(() => {
- !this.isMain && (this.lastTaskTimestamp = performance.now())
+ this.updateLastTaskTimestamp()
})
.catch(EMPTY_FUNCTION)
}
- /**
- * Gets the task function in the given scope.
- *
- * @param name - Name of the function that will be returned.
- */
- private getTaskFunction (name?: string): WorkerFunction<Data, Response> {
- name = name ?? DEFAULT_FUNCTION_NAME
- const fn = this.taskFunctions.get(name)
- if (fn == null) {
- throw new Error(`Task function '${name}' not found`)
- }
- return fn
- }
-
- private beginTaskPerformance (): TaskPerformance {
+ private beginTaskPerformance (name?: string): TaskPerformance {
+ this.checkStatistics()
return {
+ name: name ?? DEFAULT_TASK_NAME,
timestamp: performance.now(),
...(this.statistics.elu && { elu: performance.eventLoopUtilization() })
}
private endTaskPerformance (
taskPerformance: TaskPerformance
): TaskPerformance {
+ this.checkStatistics()
return {
...taskPerformance,
...(this.statistics.runTime && {
})
}
}
+
+ private checkStatistics (): void {
+ if (this.statistics == null) {
+ throw new Error('Performance statistics computation requirements not set')
+ }
+ }
+
+ private updateLastTaskTimestamp (): void {
+ if (this.activeInterval != null) {
+ this.lastTaskTimestamp = performance.now()
+ }
+ }
}