1 import { AsyncResource
} from
'node:async_hooks'
2 import type { Worker
} from
'node:cluster'
3 import type { MessagePort
} from
'node:worker_threads'
4 import { performance
} from
'node:perf_hooks'
10 } from
'../utility-types'
17 import { KillBehaviors
, type WorkerOptions
} from
'./worker-options'
23 } from
'./task-functions'
25 const DEFAULT_MAX_INACTIVE_TIME
= 60000
26 const DEFAULT_WORKER_OPTIONS
: WorkerOptions
= {
28 * The kill behavior option on this worker or its default value.
30 killBehavior
: KillBehaviors
.SOFT
,
32 * The maximum time to keep this worker active while idle.
33 * The pool automatically checks and terminates this worker when the time expires.
35 maxInactiveTime
: DEFAULT_MAX_INACTIVE_TIME
,
37 * The function to call when the worker is killed.
39 killHandler
: EMPTY_FUNCTION
43 * Base class that implements some shared logic for all poolifier workers.
45 * @typeParam MainWorker - Type of main worker.
46 * @typeParam Data - Type of data this worker receives from pool's execution. This can only be structured-cloneable data.
47 * @typeParam Response - Type of response the worker sends back to the main worker. This can only be structured-cloneable data.
49 export abstract class AbstractWorker
<
50 MainWorker
extends Worker
| MessagePort
,
53 > extends AsyncResource
{
57 protected abstract id
: number
59 * Task function(s) processed by the worker when the pool's `execution` function is invoked.
61 protected taskFunctions
!: Map
<string, TaskFunction
<Data
, Response
>>
63 * Timestamp of the last task processed by this worker.
65 protected lastTaskTimestamp
!: number
67 * Performance statistics computation requirements.
69 protected statistics
!: WorkerStatistics
71 * Handler id of the `activeInterval` worker activity check.
73 protected activeInterval
?: NodeJS
.Timeout
75 * Constructs a new poolifier worker.
77 * @param type - The type of async event.
78 * @param isMain - Whether this is the main worker or not.
79 * @param mainWorker - Reference to main worker.
80 * @param taskFunctions - Task function(s) processed by the worker when the pool's `execution` function is invoked. The first function is the default function.
81 * @param opts - Options for the worker.
85 protected readonly isMain
: boolean,
86 private readonly mainWorker
: MainWorker
,
87 taskFunctions
: TaskFunction
<Data
, Response
> | TaskFunctions
<Data
, Response
>,
88 protected opts
: WorkerOptions
= DEFAULT_WORKER_OPTIONS
91 this.checkWorkerOptions(this.opts
)
92 this.checkTaskFunctions(taskFunctions
)
94 this.getMainWorker()?.on('message', this.handleReadyMessage
.bind(this))
98 private checkWorkerOptions (opts
: WorkerOptions
): void {
99 this.opts
= { ...DEFAULT_WORKER_OPTIONS
, ...opts
}
100 delete this.opts
.async
104 * Checks if the `taskFunctions` parameter is passed to the constructor.
106 * @param taskFunctions - The task function(s) parameter that should be checked.
108 private checkTaskFunctions (
109 taskFunctions
: TaskFunction
<Data
, Response
> | TaskFunctions
<Data
, Response
>
111 if (taskFunctions
== null) {
112 throw new Error('taskFunctions parameter is mandatory')
114 this.taskFunctions
= new Map
<string, TaskFunction
<Data
, Response
>>()
115 if (typeof taskFunctions
=== 'function') {
116 const boundFn
= taskFunctions
.bind(this)
117 this.taskFunctions
.set(DEFAULT_TASK_NAME
, boundFn
)
118 this.taskFunctions
.set(
119 typeof taskFunctions
.name
=== 'string' &&
120 taskFunctions
.name
.trim().length
> 0
125 } else if (isPlainObject(taskFunctions
)) {
126 let firstEntry
= true
127 for (const [name
, fn
] of Object.entries(taskFunctions
)) {
128 if (typeof name
!== 'string') {
130 'A taskFunctions parameter object key is not a string'
133 if (typeof name
=== 'string' && name
.trim().length
=== 0) {
135 'A taskFunctions parameter object key an empty string'
138 if (typeof fn
!== 'function') {
140 'A taskFunctions parameter object value is not a function'
143 const boundFn
= fn
.bind(this)
145 this.taskFunctions
.set(DEFAULT_TASK_NAME
, boundFn
)
148 this.taskFunctions
.set(name
, boundFn
)
151 throw new Error('taskFunctions parameter object is empty')
155 'taskFunctions parameter is not a function or a plain object'
161 * Checks if the worker has a task function with the given name.
163 * @param name - The name of the task function to check.
164 * @returns Whether the worker has a task function with the given name or not.
165 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string or an empty string.
167 public hasTaskFunction (name
: string): boolean {
168 if (typeof name
!== 'string') {
169 throw new TypeError('name parameter is not a string')
171 if (typeof name
=== 'string' && name
.trim().length
=== 0) {
172 throw new TypeError('name parameter is an empty string')
174 return this.taskFunctions
.has(name
)
178 * Adds a task function to the worker.
179 * If a task function with the same name already exists, it is replaced.
181 * @param name - The name of the task function to add.
182 * @param fn - The task function to add.
183 * @returns Whether the task function was added or not.
184 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string or an empty string.
185 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name.
186 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `fn` parameter is not a function.
188 public addTaskFunction (
190 fn
: TaskFunction
<Data
, Response
>
192 if (typeof name
!== 'string') {
193 throw new TypeError('name parameter is not a string')
195 if (typeof name
=== 'string' && name
.trim().length
=== 0) {
196 throw new TypeError('name parameter is an empty string')
198 if (name
=== DEFAULT_TASK_NAME
) {
200 'Cannot add a task function with the default reserved name'
203 if (typeof fn
!== 'function') {
204 throw new TypeError('fn parameter is not a function')
207 const boundFn
= fn
.bind(this)
209 this.taskFunctions
.get(name
) ===
210 this.taskFunctions
.get(DEFAULT_TASK_NAME
)
212 this.taskFunctions
.set(DEFAULT_TASK_NAME
, boundFn
)
214 this.taskFunctions
.set(name
, boundFn
)
215 this.sendTaskFunctionsListToMainWorker()
223 * Removes a task function from the worker.
225 * @param name - The name of the task function to remove.
226 * @returns Whether the task function existed and was removed or not.
227 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string or an empty string.
228 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name.
229 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the task function used as default task function.
231 public removeTaskFunction (name
: string): boolean {
232 if (typeof name
!== 'string') {
233 throw new TypeError('name parameter is not a string')
235 if (typeof name
=== 'string' && name
.trim().length
=== 0) {
236 throw new TypeError('name parameter is an empty string')
238 if (name
=== DEFAULT_TASK_NAME
) {
240 'Cannot remove the task function with the default reserved name'
244 this.taskFunctions
.get(name
) === this.taskFunctions
.get(DEFAULT_TASK_NAME
)
247 'Cannot remove the task function used as the default task function'
250 const deleteStatus
= this.taskFunctions
.delete(name
)
251 this.sendTaskFunctionsListToMainWorker()
256 * Lists the names of the worker's task functions.
258 * @returns The names of the worker's task functions.
260 public listTaskFunctions (): string[] {
261 const names
: string[] = [...this.taskFunctions
.keys()]
262 let defaultTaskFunctionName
: string = DEFAULT_TASK_NAME
263 for (const [name
, fn
] of this.taskFunctions
) {
265 name
!== DEFAULT_TASK_NAME
&&
266 fn
=== this.taskFunctions
.get(DEFAULT_TASK_NAME
)
268 defaultTaskFunctionName
= name
273 names
[names
.indexOf(DEFAULT_TASK_NAME
)],
274 defaultTaskFunctionName
,
276 (name
) => name
!== DEFAULT_TASK_NAME
&& name
!== defaultTaskFunctionName
282 * Sets the default task function to use in the worker.
284 * @param name - The name of the task function to use as default task function.
285 * @returns Whether the default task function was set or not.
286 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string or an empty string.
287 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name.
288 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is a non-existing task function.
290 public setDefaultTaskFunction (name
: string): boolean {
291 if (typeof name
!== 'string') {
292 throw new TypeError('name parameter is not a string')
294 if (typeof name
=== 'string' && name
.trim().length
=== 0) {
295 throw new TypeError('name parameter is an empty string')
297 if (name
=== DEFAULT_TASK_NAME
) {
299 'Cannot set the default task function reserved name as the default task function'
302 if (!this.taskFunctions
.has(name
)) {
304 'Cannot set the default task function to a non-existing task function'
308 this.taskFunctions
.set(
310 this.taskFunctions
.get(name
) as TaskFunction
<Data
, Response
>
319 * Handles the ready message sent by the main worker.
321 * @param message - The ready message.
323 protected abstract handleReadyMessage (message
: MessageValue
<Data
>): void
326 * Worker message listener.
328 * @param message - The received message.
330 protected messageListener (message
: MessageValue
<Data
>): void {
331 this.checkMessageWorkerId(message
)
332 if (message
.statistics
!= null) {
333 // Statistics message received
334 this.statistics
= message
.statistics
335 } else if (message
.checkActive
!= null) {
336 // Check active message received
337 message
.checkActive
? this.startCheckActive() : this.stopCheckActive()
338 } else if (message
.taskId
!= null && message
.data
!= null) {
339 // Task message received
341 } else if (message
.kill
=== true) {
342 // Kill message received
343 this.handleKillMessage(message
)
348 * Handles a kill message sent by the main worker.
350 * @param message - The kill message.
352 protected handleKillMessage (message
: MessageValue
<Data
>): void {
353 this.stopCheckActive()
354 if (isAsyncFunction(this.opts
.killHandler
)) {
355 (this.opts
.killHandler
?.() as Promise
<void>)
357 this.sendToMainWorker({ kill
: 'success', workerId
: this.id
})
361 this.sendToMainWorker({ kill
: 'failure', workerId
: this.id
})
366 .catch(EMPTY_FUNCTION
)
369 // eslint-disable-next-line @typescript-eslint/no-invalid-void-type
370 this.opts
.killHandler
?.() as void
371 this.sendToMainWorker({ kill
: 'success', workerId
: this.id
})
373 this.sendToMainWorker({ kill
: 'failure', workerId
: this.id
})
381 * Check if the message worker id is set and matches the worker id.
383 * @param message - The message to check.
384 * @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.
386 private checkMessageWorkerId (message
: MessageValue
<Data
>): void {
387 if (message
.workerId
== null) {
388 throw new Error('Message worker id is not set')
389 } else if (message
.workerId
!= null && message
.workerId
!== this.id
) {
391 `Message worker id ${message.workerId} does not match the worker id ${this.id}`
397 * Starts the worker check active interval.
399 private startCheckActive (): void {
400 this.lastTaskTimestamp
= performance
.now()
401 this.activeInterval
= setInterval(
402 this.checkActive
.bind(this),
403 (this.opts
.maxInactiveTime
?? DEFAULT_MAX_INACTIVE_TIME
) / 2
408 * Stops the worker check active interval.
410 private stopCheckActive (): void {
411 if (this.activeInterval
!= null) {
412 clearInterval(this.activeInterval
)
413 delete this.activeInterval
418 * Checks if the worker should be terminated, because its living too long.
420 private checkActive (): void {
422 performance
.now() - this.lastTaskTimestamp
>
423 (this.opts
.maxInactiveTime
?? DEFAULT_MAX_INACTIVE_TIME
)
425 this.sendToMainWorker({ kill
: this.opts
.killBehavior
, workerId
: this.id
})
430 * Returns the main worker.
432 * @returns Reference to the main worker.
434 protected getMainWorker (): MainWorker
{
435 if (this.mainWorker
== null) {
436 throw new Error('Main worker not set')
438 return this.mainWorker
442 * Sends a message to main worker.
444 * @param message - The response message.
446 protected abstract sendToMainWorker (
447 message
: MessageValue
<Response
, Data
>
451 * Sends the list of task function names to the main worker.
453 protected sendTaskFunctionsListToMainWorker (): void {
454 this.sendToMainWorker({
455 taskFunctions
: this.listTaskFunctions(),
461 * Handles an error and convert it to a string so it can be sent back to the main worker.
463 * @param e - The error raised by the worker.
464 * @returns The error message.
466 protected handleError (e
: Error | string): string {
467 return e
instanceof Error ? e
.message
: e
471 * Runs the given task.
473 * @param task - The task to execute.
474 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the task function is not found.
476 protected run (task
: Task
<Data
>): void {
477 const fn
= this.getTaskFunction(task
.name
)
478 if (isAsyncFunction(fn
)) {
479 this.runInAsyncScope(this.runAsync
.bind(this), this, fn
, task
)
481 this.runInAsyncScope(this.runSync
.bind(this), this, fn
, task
)
486 * Runs the given task function synchronously.
488 * @param fn - Task function that will be executed.
489 * @param task - Input data for the task function.
492 fn
: TaskSyncFunction
<Data
, Response
>,
495 const { name
, taskId
, data
} = task
497 let taskPerformance
= this.beginTaskPerformance(name
)
499 taskPerformance
= this.endTaskPerformance(taskPerformance
)
500 this.sendToMainWorker({
507 const errorMessage
= this.handleError(e
as Error | string)
508 this.sendToMainWorker({
510 name
: name
?? DEFAULT_TASK_NAME
,
511 message
: errorMessage
,
518 this.updateLastTaskTimestamp()
523 * Runs the given task function asynchronously.
525 * @param fn - Task function that will be executed.
526 * @param task - Input data for the task function.
529 fn
: TaskAsyncFunction
<Data
, Response
>,
532 const { name
, taskId
, data
} = task
533 let taskPerformance
= this.beginTaskPerformance(name
)
536 taskPerformance
= this.endTaskPerformance(taskPerformance
)
537 this.sendToMainWorker({
546 const errorMessage
= this.handleError(e
as Error | string)
547 this.sendToMainWorker({
549 name
: name
?? DEFAULT_TASK_NAME
,
550 message
: errorMessage
,
558 this.updateLastTaskTimestamp()
560 .catch(EMPTY_FUNCTION
)
564 * Gets the task function with the given name.
566 * @param name - Name of the task function that will be returned.
567 * @returns The task function.
568 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the task function is not found.
570 private getTaskFunction (name
?: string): TaskFunction
<Data
, Response
> {
571 name
= name
?? DEFAULT_TASK_NAME
572 const fn
= this.taskFunctions
.get(name
)
574 throw new Error(`Task function '${name}' not found`)
579 private beginTaskPerformance (name
?: string): TaskPerformance
{
580 this.checkStatistics()
582 name
: name
?? DEFAULT_TASK_NAME
,
583 timestamp
: performance
.now(),
584 ...(this.statistics
.elu
&& { elu
: performance
.eventLoopUtilization() })
588 private endTaskPerformance (
589 taskPerformance
: TaskPerformance
591 this.checkStatistics()
594 ...(this.statistics
.runTime
&& {
595 runTime
: performance
.now() - taskPerformance
.timestamp
597 ...(this.statistics
.elu
&& {
598 elu
: performance
.eventLoopUtilization(taskPerformance
.elu
)
603 private checkStatistics (): void {
604 if (this.statistics
== null) {
605 throw new Error('Performance statistics computation requirements not set')
609 private updateLastTaskTimestamp (): void {
610 if (this.activeInterval
!= null) {
611 this.lastTaskTimestamp
= performance
.now()