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 {
+ DEFAULT_TASK_NAME,
+ EMPTY_FUNCTION,
+ isAsyncFunction,
+ isPlainObject
+} from '../utils'
+import {
+ type KillBehavior,
+ KillBehaviors,
+ type WorkerOptions
+} from './worker-options'
+import type {
TaskFunctions,
WorkerAsyncFunction,
WorkerFunction,
WorkerSyncFunction
-} from '../utility-types'
-import { EMPTY_FUNCTION, isPlainObject } from '../utils'
-import type { KillBehavior, WorkerOptions } from './worker-options'
-import { KillBehaviors } from './worker-options'
+} from './worker-functions'
-const DEFAULT_FUNCTION_NAME = 'default'
const DEFAULT_MAX_INACTIVE_TIME = 60000
const DEFAULT_KILL_BEHAVIOR: KillBehavior = KillBehaviors.SOFT
* 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.
*/
* Timestamp of the last task processed by this worker.
*/
protected lastTaskTimestamp!: number
+ /**
+ * Performance statistics computation requirements.
+ */
+ protected statistics!: WorkerStatistics
/**
* Handler id of the `aliveInterval` worker alive check.
*/
- protected readonly aliveInterval?: NodeJS.Timeout
+ protected aliveInterval?: NodeJS.Timeout
/**
* Constructs a new poolifier worker.
*
taskFunctions:
| WorkerFunction<Data, Response>
| TaskFunctions<Data, Response>,
- protected mainWorker: MainWorker | undefined | null,
+ protected readonly mainWorker: MainWorker,
protected readonly opts: WorkerOptions = {
/**
* The kill behavior option on this worker or its default value.
this.checkWorkerOptions(this.opts)
this.checkTaskFunctions(taskFunctions)
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)()
+ this.mainWorker?.on('message', this.messageListener.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
- this.opts.async = opts.async ?? false
+ delete this.opts.async
}
/**
}
this.taskFunctions = new Map<string, WorkerFunction<Data, Response>>()
if (typeof taskFunctions === 'function') {
- this.taskFunctions.set(DEFAULT_FUNCTION_NAME, taskFunctions.bind(this))
+ this.taskFunctions.set(DEFAULT_TASK_NAME, taskFunctions.bind(this))
} else if (isPlainObject(taskFunctions)) {
let firstEntry = true
for (const [name, fn] of Object.entries(taskFunctions)) {
+ if (typeof name !== 'string') {
+ throw new TypeError(
+ 'A taskFunctions parameter object key is not a string'
+ )
+ }
if (typeof fn !== 'function') {
throw new TypeError(
'A taskFunctions parameter object value is not a function'
}
this.taskFunctions.set(name, fn.bind(this))
if (firstEntry) {
- this.taskFunctions.set(DEFAULT_FUNCTION_NAME, fn.bind(this))
+ this.taskFunctions.set(DEFAULT_TASK_NAME, fn.bind(this))
firstEntry = false
}
}
}
/**
- * 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.
+ * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string.
*/
- protected messageListener (message: MessageValue<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): boolean {
+ if (typeof name !== 'string') {
+ throw new TypeError('name parameter is not a string')
+ }
+ return 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.
+ * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name.
+ * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `fn` parameter is not a function.
+ */
+ public addTaskFunction (
+ name: string,
+ fn: WorkerFunction<Data, Response>
+ ): boolean {
+ if (typeof name !== 'string') {
+ throw new TypeError('name parameter is not a string')
+ }
+ 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')
+ }
+ try {
+ if (
+ this.taskFunctions.get(name) ===
+ this.taskFunctions.get(DEFAULT_TASK_NAME)
+ ) {
+ this.taskFunctions.set(DEFAULT_TASK_NAME, fn.bind(this))
}
- } else if (message.parent != null) {
- // Main worker reference message received
- this.mainWorker = message.parent
- } else if (message.kill != null) {
- // Kill message received
- this.aliveInterval != null && clearInterval(this.aliveInterval)
- this.emitDestroy()
+ this.taskFunctions.set(name, fn.bind(this))
+ return true
+ } catch {
+ return false
}
}
/**
- * Returns the main worker.
+ * Removes a task function from the worker.
*
- * @returns Reference to the main worker.
+ * @param name - The name of the task function to remove.
+ * @returns Whether the task function existed and was removed or not.
+ * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the task function used as default task function.
*/
- protected getMainWorker (): MainWorker {
- if (this.mainWorker == null) {
- throw new Error('Main worker was not set')
+ public removeTaskFunction (name: string): boolean {
+ if (typeof name !== 'string') {
+ throw new TypeError('name parameter is not a string')
}
- return this.mainWorker
+ 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'
+ )
+ }
+ return this.taskFunctions.delete(name)
}
/**
- * Sends a message to the main worker.
+ * Sets the default task function to use when no task function name is specified.
*
- * @param message - The response message.
+ * @param name - The name of the task function to use as default task function.
+ * @returns Whether the default task function was set or not.
+ * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is a non-existing task function.
+ */
+ public setDefaultTaskFunction (name: string): boolean {
+ if (typeof name !== 'string') {
+ throw new TypeError('name parameter is not a string')
+ }
+ 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'
+ )
+ }
+ try {
+ this.taskFunctions.set(
+ DEFAULT_TASK_NAME,
+ this.taskFunctions.get(name)?.bind(this) as WorkerFunction<
+ Data,
+ Response
+ >
+ )
+ return true
+ } catch {
+ return false
+ }
+ }
+
+ /**
+ * Worker message listener.
+ *
+ * @param message - Message received.
+ */
+ protected messageListener (message: MessageValue<Data, Data>): void {
+ if (message.workerId === this.id) {
+ if (message.ready != null) {
+ // Startup message received
+ this.workerReady()
+ } else if (message.statistics != null) {
+ // Statistics message received
+ this.statistics = message.statistics
+ } else if (message.checkAlive != null) {
+ // Check alive message received
+ message.checkAlive ? this.startCheckAlive() : this.stopCheckAlive()
+ } else if (message.id != null && message.data != null) {
+ // Task message received
+ this.run(message)
+ } else if (message.kill === true) {
+ // Kill message received
+ this.stopCheckAlive()
+ this.emitDestroy()
+ }
+ }
+ }
+
+ /**
+ * Notifies the main worker that this worker is ready to process tasks.
+ */
+ protected workerReady (): void {
+ !this.isMain && this.sendToMainWorker({ ready: true, workerId: this.id })
+ }
+
+ /**
+ * Starts the worker alive check interval.
*/
- protected abstract sendToMainWorker (message: MessageValue<Response>): void
+ private startCheckAlive (): void {
+ this.lastTaskTimestamp = performance.now()
+ this.aliveInterval = setInterval(
+ this.checkAlive.bind(this),
+ (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) / 2
+ )
+ this.checkAlive.bind(this)()
+ }
+
+ /**
+ * Stops the worker alive check interval.
+ */
+ private stopCheckAlive (): void {
+ this.aliveInterval != null && clearInterval(this.aliveInterval)
+ }
/**
* Checks if the worker should be terminated, because its living too long.
*/
- protected checkAlive (): void {
+ private checkAlive (): void {
if (
performance.now() - this.lastTaskTimestamp >
(this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME)
) {
- this.sendToMainWorker({ kill: this.opts.killBehavior })
+ this.sendToMainWorker({ kill: this.opts.killBehavior, workerId: this.id })
}
}
+ /**
+ * Returns the main worker.
+ *
+ * @returns Reference to the main worker.
+ */
+ protected getMainWorker (): MainWorker {
+ if (this.mainWorker == null) {
+ throw new Error('Main worker not set')
+ }
+ return this.mainWorker
+ }
+
+ /**
+ * Sends a message to the main worker.
+ *
+ * @param message - The response message.
+ */
+ protected abstract sendToMainWorker (
+ message: MessageValue<Response, Data>
+ ): void
+
/**
* 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.
+ * @returns The error message.
*/
protected handleError (e: Error | string): string {
- return e as string
+ return e instanceof Error ? e.message : e
+ }
+
+ /**
+ * Runs the given task.
+ *
+ * @param task - The task to execute.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the task function is not found.
+ */
+ protected run (task: Task<Data>): void {
+ const fn = this.getTaskFunction(task.name)
+ if (isAsyncFunction(fn)) {
+ this.runInAsyncScope(this.runAsync.bind(this), this, fn, task)
+ } else {
+ this.runInAsyncScope(this.runSync.bind(this), this, fn, task)
+ }
}
/**
- * Runs the given function synchronously.
+ * Runs the given task function synchronously.
*
- * @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 runSync (
fn: WorkerSyncFunction<Data, Response>,
- message: MessageValue<Data>
+ task: Task<Data>
): void {
try {
- const startTimestamp = performance.now()
- const res = fn(message.data)
- const runTime = performance.now() - startTimestamp
+ let taskPerformance = this.beginTaskPerformance(task.name)
+ const res = fn(task.data)
+ taskPerformance = this.endTaskPerformance(taskPerformance)
this.sendToMainWorker({
data: res,
- id: message.id,
- runTime
+ taskPerformance,
+ workerId: this.id,
+ id: task.id
})
} catch (e) {
- const err = this.handleError(e as Error)
- this.sendToMainWorker({ error: err, id: message.id })
+ const errorMessage = this.handleError(e as Error | string)
+ this.sendToMainWorker({
+ taskError: {
+ name: task.name ?? DEFAULT_TASK_NAME,
+ message: errorMessage,
+ data: task.data
+ },
+ workerId: this.id,
+ id: task.id
+ })
} finally {
- !this.isMain && (this.lastTaskTimestamp = performance.now())
+ if (!this.isMain && this.aliveInterval != null) {
+ this.lastTaskTimestamp = performance.now()
+ }
}
}
/**
- * 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>
+ task: Task<Data>
): void {
- const startTimestamp = performance.now()
- fn(message.data)
+ let taskPerformance = this.beginTaskPerformance(task.name)
+ fn(task.data)
.then(res => {
- const runTime = performance.now() - startTimestamp
+ taskPerformance = this.endTaskPerformance(taskPerformance)
this.sendToMainWorker({
data: res,
- id: message.id,
- runTime
+ taskPerformance,
+ workerId: this.id,
+ id: task.id
})
return null
})
.catch(e => {
- const err = this.handleError(e as Error)
- this.sendToMainWorker({ error: err, id: message.id })
+ const errorMessage = this.handleError(e as Error | string)
+ this.sendToMainWorker({
+ taskError: {
+ name: task.name ?? DEFAULT_TASK_NAME,
+ message: errorMessage,
+ data: task.data
+ },
+ workerId: this.id,
+ id: task.id
+ })
})
.finally(() => {
- !this.isMain && (this.lastTaskTimestamp = performance.now())
+ if (!this.isMain && this.aliveInterval != null) {
+ this.lastTaskTimestamp = performance.now()
+ }
})
.catch(EMPTY_FUNCTION)
}
/**
- * Gets the task function in the given scope.
+ * Gets the task function with the given name.
*
- * @param name - Name of the function that will be returned.
+ * @param name - Name of the task function that will be returned.
+ * @returns The task function.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the task function is not found.
*/
private getTaskFunction (name?: string): WorkerFunction<Data, Response> {
- name = name ?? DEFAULT_FUNCTION_NAME
+ name = name ?? DEFAULT_TASK_NAME
const fn = this.taskFunctions.get(name)
if (fn == null) {
- throw new Error(`Task function "${name}" not found`)
+ throw new Error(`Task function '${name}' not found`)
}
return fn
}
+
+ 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 && {
+ runTime: performance.now() - taskPerformance.timestamp
+ }),
+ ...(this.statistics.elu && {
+ elu: performance.eventLoopUtilization(taskPerformance.elu)
+ })
+ }
+ }
+
+ private checkStatistics (): void {
+ if (this.statistics == null) {
+ throw new Error('Performance statistics computation requirements not set')
+ }
+ }
}