build(deps): bump poolifier
[poolifier.git] / src / worker / abstract-worker.ts
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'
5 import type {
6 MessageValue,
7 Task,
8 TaskPerformance,
9 WorkerStatistics
10 } from '../utility-types'
11 import {
12 DEFAULT_TASK_NAME,
13 EMPTY_FUNCTION,
14 isAsyncFunction,
15 isPlainObject
16 } from '../utils'
17 import { KillBehaviors, type WorkerOptions } from './worker-options'
18 import type {
19 TaskAsyncFunction,
20 TaskFunction,
21 TaskFunctions,
22 TaskSyncFunction
23 } from './task-functions'
24
25 const DEFAULT_MAX_INACTIVE_TIME = 60000
26 const DEFAULT_WORKER_OPTIONS: WorkerOptions = {
27 /**
28 * The kill behavior option on this worker or its default value.
29 */
30 killBehavior: KillBehaviors.SOFT,
31 /**
32 * The maximum time to keep this worker active while idle.
33 * The pool automatically checks and terminates this worker when the time expires.
34 */
35 maxInactiveTime: DEFAULT_MAX_INACTIVE_TIME,
36 /**
37 * The function to call when the worker is killed.
38 */
39 killHandler: EMPTY_FUNCTION
40 }
41
42 /**
43 * Base class that implements some shared logic for all poolifier workers.
44 *
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.
48 */
49 export abstract class AbstractWorker<
50 MainWorker extends Worker | MessagePort,
51 Data = unknown,
52 Response = unknown
53 > extends AsyncResource {
54 /**
55 * Worker id.
56 */
57 protected abstract id: number
58 /**
59 * Task function(s) processed by the worker when the pool's `execution` function is invoked.
60 */
61 protected taskFunctions!: Map<string, TaskFunction<Data, Response>>
62 /**
63 * Timestamp of the last task processed by this worker.
64 */
65 protected lastTaskTimestamp!: number
66 /**
67 * Performance statistics computation requirements.
68 */
69 protected statistics!: WorkerStatistics
70 /**
71 * Handler id of the `activeInterval` worker activity check.
72 */
73 protected activeInterval?: NodeJS.Timeout
74 /**
75 * Constructs a new poolifier worker.
76 *
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.
82 */
83 public constructor (
84 type: string,
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
89 ) {
90 super(type)
91 this.checkWorkerOptions(this.opts)
92 this.checkTaskFunctions(taskFunctions)
93 if (!this.isMain) {
94 this.getMainWorker()?.on('message', this.handleReadyMessage.bind(this))
95 }
96 }
97
98 private checkWorkerOptions (opts: WorkerOptions): void {
99 this.opts = { ...DEFAULT_WORKER_OPTIONS, ...opts }
100 delete this.opts.async
101 }
102
103 /**
104 * Checks if the `taskFunctions` parameter is passed to the constructor.
105 *
106 * @param taskFunctions - The task function(s) parameter that should be checked.
107 */
108 private checkTaskFunctions (
109 taskFunctions: TaskFunction<Data, Response> | TaskFunctions<Data, Response>
110 ): void {
111 if (taskFunctions == null) {
112 throw new Error('taskFunctions parameter is mandatory')
113 }
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
121 ? taskFunctions.name
122 : 'fn1',
123 boundFn
124 )
125 } else if (isPlainObject(taskFunctions)) {
126 let firstEntry = true
127 for (const [name, fn] of Object.entries(taskFunctions)) {
128 if (typeof name !== 'string') {
129 throw new TypeError(
130 'A taskFunctions parameter object key is not a string'
131 )
132 }
133 if (typeof name === 'string' && name.trim().length === 0) {
134 throw new TypeError(
135 'A taskFunctions parameter object key an empty string'
136 )
137 }
138 if (typeof fn !== 'function') {
139 throw new TypeError(
140 'A taskFunctions parameter object value is not a function'
141 )
142 }
143 const boundFn = fn.bind(this)
144 if (firstEntry) {
145 this.taskFunctions.set(DEFAULT_TASK_NAME, boundFn)
146 firstEntry = false
147 }
148 this.taskFunctions.set(name, boundFn)
149 }
150 if (firstEntry) {
151 throw new Error('taskFunctions parameter object is empty')
152 }
153 } else {
154 throw new TypeError(
155 'taskFunctions parameter is not a function or a plain object'
156 )
157 }
158 }
159
160 /**
161 * Checks if the worker has a task function with the given name.
162 *
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.
166 */
167 public hasTaskFunction (name: string): boolean {
168 this.checkTaskFunctionName(name)
169 return this.taskFunctions.has(name)
170 }
171
172 /**
173 * Adds a task function to the worker.
174 * If a task function with the same name already exists, it is replaced.
175 *
176 * @param name - The name of the task function to add.
177 * @param fn - The task function to add.
178 * @returns Whether the task function was added or not.
179 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string or an empty string.
180 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name.
181 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `fn` parameter is not a function.
182 */
183 public addTaskFunction (
184 name: string,
185 fn: TaskFunction<Data, Response>
186 ): boolean {
187 this.checkTaskFunctionName(name)
188 if (name === DEFAULT_TASK_NAME) {
189 throw new Error(
190 'Cannot add a task function with the default reserved name'
191 )
192 }
193 if (typeof fn !== 'function') {
194 throw new TypeError('fn parameter is not a function')
195 }
196 try {
197 const boundFn = fn.bind(this)
198 if (
199 this.taskFunctions.get(name) ===
200 this.taskFunctions.get(DEFAULT_TASK_NAME)
201 ) {
202 this.taskFunctions.set(DEFAULT_TASK_NAME, boundFn)
203 }
204 this.taskFunctions.set(name, boundFn)
205 this.sendTaskFunctionsListToMainWorker()
206 return true
207 } catch {
208 return false
209 }
210 }
211
212 /**
213 * Removes a task function from the worker.
214 *
215 * @param name - The name of the task function to remove.
216 * @returns Whether the task function existed and was removed or not.
217 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string or an empty string.
218 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name.
219 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the task function used as default task function.
220 */
221 public removeTaskFunction (name: string): boolean {
222 this.checkTaskFunctionName(name)
223 if (name === DEFAULT_TASK_NAME) {
224 throw new Error(
225 'Cannot remove the task function with the default reserved name'
226 )
227 }
228 if (
229 this.taskFunctions.get(name) === this.taskFunctions.get(DEFAULT_TASK_NAME)
230 ) {
231 throw new Error(
232 'Cannot remove the task function used as the default task function'
233 )
234 }
235 const deleteStatus = this.taskFunctions.delete(name)
236 this.sendTaskFunctionsListToMainWorker()
237 return deleteStatus
238 }
239
240 /**
241 * Lists the names of the worker's task functions.
242 *
243 * @returns The names of the worker's task functions.
244 */
245 public listTaskFunctions (): string[] {
246 const names: string[] = [...this.taskFunctions.keys()]
247 let defaultTaskFunctionName: string = DEFAULT_TASK_NAME
248 for (const [name, fn] of this.taskFunctions) {
249 if (
250 name !== DEFAULT_TASK_NAME &&
251 fn === this.taskFunctions.get(DEFAULT_TASK_NAME)
252 ) {
253 defaultTaskFunctionName = name
254 break
255 }
256 }
257 return [
258 names[names.indexOf(DEFAULT_TASK_NAME)],
259 defaultTaskFunctionName,
260 ...names.filter(
261 (name) => name !== DEFAULT_TASK_NAME && name !== defaultTaskFunctionName
262 )
263 ]
264 }
265
266 /**
267 * Sets the default task function to use in the worker.
268 *
269 * @param name - The name of the task function to use as default task function.
270 * @returns Whether the default task function was set or not.
271 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string or an empty string.
272 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name.
273 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is a non-existing task function.
274 */
275 public setDefaultTaskFunction (name: string): boolean {
276 this.checkTaskFunctionName(name)
277 if (name === DEFAULT_TASK_NAME) {
278 throw new Error(
279 'Cannot set the default task function reserved name as the default task function'
280 )
281 }
282 if (!this.taskFunctions.has(name)) {
283 throw new Error(
284 'Cannot set the default task function to a non-existing task function'
285 )
286 }
287 try {
288 this.taskFunctions.set(
289 DEFAULT_TASK_NAME,
290 this.taskFunctions.get(name) as TaskFunction<Data, Response>
291 )
292 return true
293 } catch {
294 return false
295 }
296 }
297
298 private checkTaskFunctionName (name: string): void {
299 if (typeof name !== 'string') {
300 throw new TypeError('name parameter is not a string')
301 }
302 if (typeof name === 'string' && name.trim().length === 0) {
303 throw new TypeError('name parameter is an empty string')
304 }
305 }
306
307 /**
308 * Handles the ready message sent by the main worker.
309 *
310 * @param message - The ready message.
311 */
312 protected abstract handleReadyMessage (message: MessageValue<Data>): void
313
314 /**
315 * Worker message listener.
316 *
317 * @param message - The received message.
318 */
319 protected messageListener (message: MessageValue<Data>): void {
320 this.checkMessageWorkerId(message)
321 if (message.statistics != null) {
322 // Statistics message received
323 this.statistics = message.statistics
324 } else if (message.checkActive != null) {
325 // Check active message received
326 message.checkActive ? this.startCheckActive() : this.stopCheckActive()
327 } else if (message.taskId != null && message.data != null) {
328 // Task message received
329 this.run(message)
330 } else if (message.kill === true) {
331 // Kill message received
332 this.handleKillMessage(message)
333 }
334 }
335
336 /**
337 * Handles a kill message sent by the main worker.
338 *
339 * @param message - The kill message.
340 */
341 protected handleKillMessage (message: MessageValue<Data>): void {
342 this.stopCheckActive()
343 if (isAsyncFunction(this.opts.killHandler)) {
344 (this.opts.killHandler?.() as Promise<void>)
345 .then(() => {
346 this.sendToMainWorker({ kill: 'success', workerId: this.id })
347 return null
348 })
349 .catch(() => {
350 this.sendToMainWorker({ kill: 'failure', workerId: this.id })
351 })
352 .finally(() => {
353 this.emitDestroy()
354 })
355 .catch(EMPTY_FUNCTION)
356 } else {
357 try {
358 // eslint-disable-next-line @typescript-eslint/no-invalid-void-type
359 this.opts.killHandler?.() as void
360 this.sendToMainWorker({ kill: 'success', workerId: this.id })
361 } catch {
362 this.sendToMainWorker({ kill: 'failure', workerId: this.id })
363 } finally {
364 this.emitDestroy()
365 }
366 }
367 }
368
369 /**
370 * Check if the message worker id is set and matches the worker id.
371 *
372 * @param message - The message to check.
373 * @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.
374 */
375 private checkMessageWorkerId (message: MessageValue<Data>): void {
376 if (message.workerId == null) {
377 throw new Error('Message worker id is not set')
378 } else if (message.workerId != null && message.workerId !== this.id) {
379 throw new Error(
380 `Message worker id ${message.workerId} does not match the worker id ${this.id}`
381 )
382 }
383 }
384
385 /**
386 * Starts the worker check active interval.
387 */
388 private startCheckActive (): void {
389 this.lastTaskTimestamp = performance.now()
390 this.activeInterval = setInterval(
391 this.checkActive.bind(this),
392 (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) / 2
393 )
394 }
395
396 /**
397 * Stops the worker check active interval.
398 */
399 private stopCheckActive (): void {
400 if (this.activeInterval != null) {
401 clearInterval(this.activeInterval)
402 delete this.activeInterval
403 }
404 }
405
406 /**
407 * Checks if the worker should be terminated, because its living too long.
408 */
409 private checkActive (): void {
410 if (
411 performance.now() - this.lastTaskTimestamp >
412 (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME)
413 ) {
414 this.sendToMainWorker({ kill: this.opts.killBehavior, workerId: this.id })
415 }
416 }
417
418 /**
419 * Returns the main worker.
420 *
421 * @returns Reference to the main worker.
422 */
423 protected getMainWorker (): MainWorker {
424 if (this.mainWorker == null) {
425 throw new Error('Main worker not set')
426 }
427 return this.mainWorker
428 }
429
430 /**
431 * Sends a message to main worker.
432 *
433 * @param message - The response message.
434 */
435 protected abstract sendToMainWorker (
436 message: MessageValue<Response, Data>
437 ): void
438
439 /**
440 * Sends the list of task function names to the main worker.
441 */
442 protected sendTaskFunctionsListToMainWorker (): void {
443 this.sendToMainWorker({
444 taskFunctions: this.listTaskFunctions(),
445 workerId: this.id
446 })
447 }
448
449 /**
450 * Handles an error and convert it to a string so it can be sent back to the main worker.
451 *
452 * @param e - The error raised by the worker.
453 * @returns The error message.
454 */
455 protected handleError (e: Error | string): string {
456 return e instanceof Error ? e.message : e
457 }
458
459 /**
460 * Runs the given task.
461 *
462 * @param task - The task to execute.
463 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the task function is not found.
464 */
465 protected run (task: Task<Data>): void {
466 const fn = this.getTaskFunction(task.name)
467 if (isAsyncFunction(fn)) {
468 this.runInAsyncScope(this.runAsync.bind(this), this, fn, task)
469 } else {
470 this.runInAsyncScope(this.runSync.bind(this), this, fn, task)
471 }
472 }
473
474 /**
475 * Runs the given task function synchronously.
476 *
477 * @param fn - Task function that will be executed.
478 * @param task - Input data for the task function.
479 */
480 protected runSync (
481 fn: TaskSyncFunction<Data, Response>,
482 task: Task<Data>
483 ): void {
484 const { name, taskId, data } = task
485 try {
486 let taskPerformance = this.beginTaskPerformance(name)
487 const res = fn(data)
488 taskPerformance = this.endTaskPerformance(taskPerformance)
489 this.sendToMainWorker({
490 data: res,
491 taskPerformance,
492 workerId: this.id,
493 taskId
494 })
495 } catch (e) {
496 const errorMessage = this.handleError(e as Error | string)
497 this.sendToMainWorker({
498 taskError: {
499 name: name as string,
500 message: errorMessage,
501 data
502 },
503 workerId: this.id,
504 taskId
505 })
506 } finally {
507 this.updateLastTaskTimestamp()
508 }
509 }
510
511 /**
512 * Runs the given task function asynchronously.
513 *
514 * @param fn - Task function that will be executed.
515 * @param task - Input data for the task function.
516 */
517 protected runAsync (
518 fn: TaskAsyncFunction<Data, Response>,
519 task: Task<Data>
520 ): void {
521 const { name, taskId, data } = task
522 let taskPerformance = this.beginTaskPerformance(name)
523 fn(data)
524 .then((res) => {
525 taskPerformance = this.endTaskPerformance(taskPerformance)
526 this.sendToMainWorker({
527 data: res,
528 taskPerformance,
529 workerId: this.id,
530 taskId
531 })
532 return null
533 })
534 .catch((e) => {
535 const errorMessage = this.handleError(e as Error | string)
536 this.sendToMainWorker({
537 taskError: {
538 name: name as string,
539 message: errorMessage,
540 data
541 },
542 workerId: this.id,
543 taskId
544 })
545 })
546 .finally(() => {
547 this.updateLastTaskTimestamp()
548 })
549 .catch(EMPTY_FUNCTION)
550 }
551
552 /**
553 * Gets the task function with the given name.
554 *
555 * @param name - Name of the task function that will be returned.
556 * @returns The task function.
557 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the task function is not found.
558 */
559 private getTaskFunction (name?: string): TaskFunction<Data, Response> {
560 name = name ?? DEFAULT_TASK_NAME
561 const fn = this.taskFunctions.get(name)
562 if (fn == null) {
563 throw new Error(`Task function '${name}' not found`)
564 }
565 return fn
566 }
567
568 private beginTaskPerformance (name?: string): TaskPerformance {
569 this.checkStatistics()
570 return {
571 name: name ?? DEFAULT_TASK_NAME,
572 timestamp: performance.now(),
573 ...(this.statistics.elu && { elu: performance.eventLoopUtilization() })
574 }
575 }
576
577 private endTaskPerformance (
578 taskPerformance: TaskPerformance
579 ): TaskPerformance {
580 this.checkStatistics()
581 return {
582 ...taskPerformance,
583 ...(this.statistics.runTime && {
584 runTime: performance.now() - taskPerformance.timestamp
585 }),
586 ...(this.statistics.elu && {
587 elu: performance.eventLoopUtilization(taskPerformance.elu)
588 })
589 }
590 }
591
592 private checkStatistics (): void {
593 if (this.statistics == null) {
594 throw new Error('Performance statistics computation requirements not set')
595 }
596 }
597
598 private updateLastTaskTimestamp (): void {
599 if (this.activeInterval != null) {
600 this.lastTaskTimestamp = performance.now()
601 }
602 }
603 }