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,
+ 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 } from '../utils'
-import type { KillBehavior, WorkerOptions } from './worker-options'
-import { KillBehaviors } from './worker-options'
+} from './worker-functions'
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.
+ */
+ protected taskFunctions!: Map<string, WorkerFunction<Data, Response>>
/**
* 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.
*
* @param type - The type of async event.
* @param isMain - Whether this is the main worker or not.
- * @param fn - Function processed by the worker when the pool's `execution` function is invoked.
+ * @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 opts - Options for the worker.
*/
public constructor (
type: string,
protected readonly isMain: boolean,
- fn: WorkerFunction<Data, Response>,
- protected mainWorker: MainWorker | undefined | null,
+ taskFunctions:
+ | WorkerFunction<Data, Response>
+ | TaskFunctions<Data, Response>,
+ protected readonly mainWorker: MainWorker,
protected readonly opts: WorkerOptions = {
/**
* The kill behavior option on this worker or its default value.
) {
super(type)
this.checkWorkerOptions(this.opts)
- this.checkFunctionInput(fn)
+ 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',
- (message: MessageValue<Data, MainWorker>) => {
- this.messageListener(message, fn)
+ 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
+ }
+
+ /**
+ * Checks if the `taskFunctions` parameter is passed to the constructor.
+ *
+ * @param taskFunctions - The task function(s) parameter that should be checked.
+ */
+ private checkTaskFunctions (
+ taskFunctions:
+ | WorkerFunction<Data, Response>
+ | TaskFunctions<Data, Response>
+ ): void {
+ if (taskFunctions == null) {
+ throw new Error('taskFunctions parameter is mandatory')
+ }
+ this.taskFunctions = new Map<string, WorkerFunction<Data, Response>>()
+ if (typeof taskFunctions === 'function') {
+ 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 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_TASK_NAME, fn.bind(this))
+ firstEntry = false
+ }
}
- )
+ if (firstEntry) {
+ throw new Error('taskFunctions parameter object is empty')
+ }
+ } else {
+ throw new TypeError(
+ 'taskFunctions parameter is not a function or a plain object'
+ )
+ }
}
/**
* Worker message listener.
*
* @param message - Message received.
- * @param fn - Function processed by the worker when the pool's `execution` function is invoked.
*/
- protected messageListener (
- message: MessageValue<Data, MainWorker>,
- fn: WorkerFunction<Data, Response>
- ): void {
- if (message.id != null && message.data != null) {
- // Task message received
- if (this.opts.async === true) {
- this.runInAsyncScope(this.runAsync.bind(this), this, fn, message)
- } else {
- this.runInAsyncScope(this.run.bind(this), this, fn, message)
+ 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
+ const fn = this.getTaskFunction(message.name)
+ if (isAsyncFunction(fn)) {
+ this.runInAsyncScope(this.runAsync.bind(this), this, fn, message)
+ } else {
+ this.runInAsyncScope(this.runSync.bind(this), this, fn, message)
+ }
+ } else if (message.kill === true) {
+ // Kill message received
+ this.stopCheckAlive()
+ this.emitDestroy()
}
- } 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()
}
}
- 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
+ /**
+ * Notifies the main worker that this worker is ready to process tasks.
+ */
+ protected workerReady (): void {
+ !this.isMain && this.sendToMainWorker({ ready: true, workerId: this.id })
}
/**
- * Checks if the `fn` parameter is passed to the constructor.
- *
- * @param fn - The function that should be defined.
+ * Starts the worker alive check interval.
*/
- private checkFunctionInput (fn: WorkerFunction<Data, Response>): void {
- if (fn == null) throw new Error('fn parameter is mandatory')
- if (typeof fn !== 'function') {
- throw new TypeError('fn parameter is not a function')
- }
- if (fn.constructor.name === 'AsyncFunction' && this.opts.async === false) {
- throw new Error(
- 'fn parameter is an async function, please set the async option to true'
- )
+ 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.
+ */
+ private checkAlive (): void {
+ if (
+ performance.now() - this.lastTaskTimestamp >
+ (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME)
+ ) {
+ this.sendToMainWorker({ kill: this.opts.killBehavior, workerId: this.id })
}
}
*/
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
}
*
* @param message - The response message.
*/
- protected abstract sendToMainWorker (message: MessageValue<Response>): void
-
- /**
- * Checks if the worker should be terminated, because its living too long.
- */
- protected checkAlive (): void {
- if (
- performance.now() - this.lastTaskTimestamp >
- (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME)
- ) {
- this.sendToMainWorker({ kill: this.opts.killBehavior })
- }
- }
+ 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
}
/**
* @param fn - Function that will be executed.
* @param message - Input data for the given function.
*/
- protected run (
+ protected runSync (
fn: WorkerSyncFunction<Data, Response>,
message: MessageValue<Data>
): void {
try {
- const startTimestamp = performance.now()
+ let taskPerformance = this.beginTaskPerformance(message.name)
const res = fn(message.data)
- const runTime = performance.now() - startTimestamp
+ taskPerformance = this.endTaskPerformance(taskPerformance)
this.sendToMainWorker({
data: res,
- id: message.id,
- runTime
+ taskPerformance,
+ workerId: this.id,
+ id: message.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: message.name ?? DEFAULT_TASK_NAME,
+ message: errorMessage,
+ data: message.data
+ },
+ workerId: this.id,
+ id: message.id
+ })
} finally {
- !this.isMain && (this.lastTaskTimestamp = performance.now())
+ if (!this.isMain && this.aliveInterval != null) {
+ this.lastTaskTimestamp = performance.now()
+ }
}
}
fn: WorkerAsyncFunction<Data, Response>,
message: MessageValue<Data>
): void {
- const startTimestamp = performance.now()
+ let taskPerformance = this.beginTaskPerformance()
fn(message.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: message.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: message.name ?? DEFAULT_TASK_NAME,
+ message: errorMessage,
+ data: message.data
+ },
+ workerId: this.id,
+ id: message.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.
+ *
+ * @param name - Name of the task function that will be returned.
+ */
+ private getTaskFunction (name?: string): WorkerFunction<Data, Response> {
+ name = name ?? DEFAULT_TASK_NAME
+ const fn = this.taskFunctions.get(name)
+ if (fn == null) {
+ 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')
+ }
+ }
}