| 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 | TaskPerformance, |
| 8 | WorkerStatistics |
| 9 | } from '../utility-types' |
| 10 | import { |
| 11 | DEFAULT_TASK_NAME, |
| 12 | EMPTY_FUNCTION, |
| 13 | isAsyncFunction, |
| 14 | isPlainObject |
| 15 | } from '../utils' |
| 16 | import { |
| 17 | type KillBehavior, |
| 18 | KillBehaviors, |
| 19 | type WorkerOptions |
| 20 | } from './worker-options' |
| 21 | import type { |
| 22 | TaskFunctions, |
| 23 | WorkerAsyncFunction, |
| 24 | WorkerFunction, |
| 25 | WorkerSyncFunction |
| 26 | } from './worker-functions' |
| 27 | |
| 28 | const DEFAULT_MAX_INACTIVE_TIME = 60000 |
| 29 | const DEFAULT_KILL_BEHAVIOR: KillBehavior = KillBehaviors.SOFT |
| 30 | |
| 31 | /** |
| 32 | * Base class that implements some shared logic for all poolifier workers. |
| 33 | * |
| 34 | * @typeParam MainWorker - Type of main worker. |
| 35 | * @typeParam Data - Type of data this worker receives from pool's execution. This can only be structured-cloneable data. |
| 36 | * @typeParam Response - Type of response the worker sends back to the main worker. This can only be structured-cloneable data. |
| 37 | */ |
| 38 | export abstract class AbstractWorker< |
| 39 | MainWorker extends Worker | MessagePort, |
| 40 | Data = unknown, |
| 41 | Response = unknown |
| 42 | > extends AsyncResource { |
| 43 | /** |
| 44 | * Worker id. |
| 45 | */ |
| 46 | protected abstract id: number |
| 47 | /** |
| 48 | * Task function(s) processed by the worker when the pool's `execution` function is invoked. |
| 49 | */ |
| 50 | protected taskFunctions!: Map<string, WorkerFunction<Data, Response>> |
| 51 | /** |
| 52 | * Timestamp of the last task processed by this worker. |
| 53 | */ |
| 54 | protected lastTaskTimestamp!: number |
| 55 | /** |
| 56 | * Performance statistics computation requirements. |
| 57 | */ |
| 58 | protected statistics!: WorkerStatistics |
| 59 | /** |
| 60 | * Handler id of the `aliveInterval` worker alive check. |
| 61 | */ |
| 62 | protected aliveInterval?: NodeJS.Timeout |
| 63 | /** |
| 64 | * Constructs a new poolifier worker. |
| 65 | * |
| 66 | * @param type - The type of async event. |
| 67 | * @param isMain - Whether this is the main worker or not. |
| 68 | * @param taskFunctions - Task function(s) processed by the worker when the pool's `execution` function is invoked. The first function is the default function. |
| 69 | * @param mainWorker - Reference to main worker. |
| 70 | * @param opts - Options for the worker. |
| 71 | */ |
| 72 | public constructor ( |
| 73 | type: string, |
| 74 | protected readonly isMain: boolean, |
| 75 | taskFunctions: |
| 76 | | WorkerFunction<Data, Response> |
| 77 | | TaskFunctions<Data, Response>, |
| 78 | protected readonly mainWorker: MainWorker, |
| 79 | protected readonly opts: WorkerOptions = { |
| 80 | /** |
| 81 | * The kill behavior option on this worker or its default value. |
| 82 | */ |
| 83 | killBehavior: DEFAULT_KILL_BEHAVIOR, |
| 84 | /** |
| 85 | * The maximum time to keep this worker alive while idle. |
| 86 | * The pool automatically checks and terminates this worker when the time expires. |
| 87 | */ |
| 88 | maxInactiveTime: DEFAULT_MAX_INACTIVE_TIME |
| 89 | } |
| 90 | ) { |
| 91 | super(type) |
| 92 | this.checkWorkerOptions(this.opts) |
| 93 | this.checkTaskFunctions(taskFunctions) |
| 94 | if (!this.isMain) { |
| 95 | this.mainWorker?.on('message', this.messageListener.bind(this)) |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | private checkWorkerOptions (opts: WorkerOptions): void { |
| 100 | this.opts.killBehavior = opts.killBehavior ?? DEFAULT_KILL_BEHAVIOR |
| 101 | this.opts.maxInactiveTime = |
| 102 | opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME |
| 103 | delete this.opts.async |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * Checks if the `taskFunctions` parameter is passed to the constructor. |
| 108 | * |
| 109 | * @param taskFunctions - The task function(s) parameter that should be checked. |
| 110 | */ |
| 111 | private checkTaskFunctions ( |
| 112 | taskFunctions: |
| 113 | | WorkerFunction<Data, Response> |
| 114 | | TaskFunctions<Data, Response> |
| 115 | ): void { |
| 116 | if (taskFunctions == null) { |
| 117 | throw new Error('taskFunctions parameter is mandatory') |
| 118 | } |
| 119 | this.taskFunctions = new Map<string, WorkerFunction<Data, Response>>() |
| 120 | if (typeof taskFunctions === 'function') { |
| 121 | this.taskFunctions.set(DEFAULT_TASK_NAME, taskFunctions.bind(this)) |
| 122 | } else if (isPlainObject(taskFunctions)) { |
| 123 | let firstEntry = true |
| 124 | for (const [name, fn] of Object.entries(taskFunctions)) { |
| 125 | if (typeof fn !== 'function') { |
| 126 | throw new TypeError( |
| 127 | 'A taskFunctions parameter object value is not a function' |
| 128 | ) |
| 129 | } |
| 130 | this.taskFunctions.set(name, fn.bind(this)) |
| 131 | if (firstEntry) { |
| 132 | this.taskFunctions.set(DEFAULT_TASK_NAME, fn.bind(this)) |
| 133 | firstEntry = false |
| 134 | } |
| 135 | } |
| 136 | if (firstEntry) { |
| 137 | throw new Error('taskFunctions parameter object is empty') |
| 138 | } |
| 139 | } else { |
| 140 | throw new TypeError( |
| 141 | 'taskFunctions parameter is not a function or a plain object' |
| 142 | ) |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | /** |
| 147 | * Checks if the worker has a task function with the given name. |
| 148 | * |
| 149 | * @param name - The name of the task function to check. |
| 150 | * @returns Whether the worker has a task function with the given name or not. |
| 151 | * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string. |
| 152 | */ |
| 153 | public hasTaskFunction (name: string): boolean { |
| 154 | if (typeof name !== 'string') { |
| 155 | throw new TypeError('name parameter is not a string') |
| 156 | } |
| 157 | return this.taskFunctions.has(name) |
| 158 | } |
| 159 | |
| 160 | /** |
| 161 | * Adds a task function to the worker. |
| 162 | * If a task function with the same name already exists, it is replaced. |
| 163 | * |
| 164 | * @param name - The name of the task function to add. |
| 165 | * @param fn - The task function to add. |
| 166 | * @returns Whether the task function was added or not. |
| 167 | * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string. |
| 168 | * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name. |
| 169 | * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `fn` parameter is not a function. |
| 170 | */ |
| 171 | public addTaskFunction ( |
| 172 | name: string, |
| 173 | fn: WorkerFunction<Data, Response> |
| 174 | ): boolean { |
| 175 | if (typeof name !== 'string') { |
| 176 | throw new TypeError('name parameter is not a string') |
| 177 | } |
| 178 | if (name === DEFAULT_TASK_NAME) { |
| 179 | throw new Error( |
| 180 | 'Cannot add a task function with the default reserved name' |
| 181 | ) |
| 182 | } |
| 183 | if (typeof fn !== 'function') { |
| 184 | throw new TypeError('fn parameter is not a function') |
| 185 | } |
| 186 | try { |
| 187 | if ( |
| 188 | this.taskFunctions.get(name) === |
| 189 | this.taskFunctions.get(DEFAULT_TASK_NAME) |
| 190 | ) { |
| 191 | this.taskFunctions.set(DEFAULT_TASK_NAME, fn.bind(this)) |
| 192 | } |
| 193 | this.taskFunctions.set(name, fn.bind(this)) |
| 194 | return true |
| 195 | } catch { |
| 196 | return false |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | /** |
| 201 | * Removes a task function from the worker. |
| 202 | * |
| 203 | * @param name - The name of the task function to remove. |
| 204 | * @returns Whether the task function existed and was removed or not. |
| 205 | * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string. |
| 206 | * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name. |
| 207 | * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the task function used as default task function. |
| 208 | */ |
| 209 | public removeTaskFunction (name: string): boolean { |
| 210 | if (typeof name !== 'string') { |
| 211 | throw new TypeError('name parameter is not a string') |
| 212 | } |
| 213 | if (name === DEFAULT_TASK_NAME) { |
| 214 | throw new Error( |
| 215 | 'Cannot remove the task function with the default reserved name' |
| 216 | ) |
| 217 | } |
| 218 | if ( |
| 219 | this.taskFunctions.get(name) === this.taskFunctions.get(DEFAULT_TASK_NAME) |
| 220 | ) { |
| 221 | throw new Error( |
| 222 | 'Cannot remove the task function used as the default task function' |
| 223 | ) |
| 224 | } |
| 225 | return this.taskFunctions.delete(name) |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Sets the default task function to use when no task function name is specified. |
| 230 | * |
| 231 | * @param name - The name of the task function to use as default task function. |
| 232 | * @returns Whether the default task function was set or not. |
| 233 | * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string. |
| 234 | * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is the default task function reserved name. |
| 235 | * @throws {@link https://nodejs.org/api/errors.html#class-error} If the `name` parameter is a non-existing task function. |
| 236 | */ |
| 237 | public setDefaultTaskFunction (name: string): boolean { |
| 238 | if (typeof name !== 'string') { |
| 239 | throw new TypeError('name parameter is not a string') |
| 240 | } |
| 241 | if (name === DEFAULT_TASK_NAME) { |
| 242 | throw new Error( |
| 243 | 'Cannot set the default task function reserved name as the default task function' |
| 244 | ) |
| 245 | } |
| 246 | if (!this.taskFunctions.has(name)) { |
| 247 | throw new Error( |
| 248 | 'Cannot set the default task function to a non-existing task function' |
| 249 | ) |
| 250 | } |
| 251 | try { |
| 252 | this.taskFunctions.set( |
| 253 | DEFAULT_TASK_NAME, |
| 254 | this.taskFunctions.get(name)?.bind(this) as WorkerFunction< |
| 255 | Data, |
| 256 | Response |
| 257 | > |
| 258 | ) |
| 259 | return true |
| 260 | } catch { |
| 261 | return false |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | /** |
| 266 | * Worker message listener. |
| 267 | * |
| 268 | * @param message - Message received. |
| 269 | */ |
| 270 | protected messageListener (message: MessageValue<Data, Data>): void { |
| 271 | if (message.workerId === this.id) { |
| 272 | if (message.ready != null) { |
| 273 | // Startup message received |
| 274 | this.workerReady() |
| 275 | } else if (message.statistics != null) { |
| 276 | // Statistics message received |
| 277 | this.statistics = message.statistics |
| 278 | } else if (message.checkAlive != null) { |
| 279 | // Check alive message received |
| 280 | message.checkAlive ? this.startCheckAlive() : this.stopCheckAlive() |
| 281 | } else if (message.id != null && message.data != null) { |
| 282 | // Task message received |
| 283 | const fn = this.getTaskFunction(message.name) |
| 284 | if (isAsyncFunction(fn)) { |
| 285 | this.runInAsyncScope(this.runAsync.bind(this), this, fn, message) |
| 286 | } else { |
| 287 | this.runInAsyncScope(this.runSync.bind(this), this, fn, message) |
| 288 | } |
| 289 | } else if (message.kill === true) { |
| 290 | // Kill message received |
| 291 | this.stopCheckAlive() |
| 292 | this.emitDestroy() |
| 293 | } |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * Notifies the main worker that this worker is ready to process tasks. |
| 299 | */ |
| 300 | protected workerReady (): void { |
| 301 | !this.isMain && this.sendToMainWorker({ ready: true, workerId: this.id }) |
| 302 | } |
| 303 | |
| 304 | /** |
| 305 | * Starts the worker alive check interval. |
| 306 | */ |
| 307 | private startCheckAlive (): void { |
| 308 | this.lastTaskTimestamp = performance.now() |
| 309 | this.aliveInterval = setInterval( |
| 310 | this.checkAlive.bind(this), |
| 311 | (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) / 2 |
| 312 | ) |
| 313 | this.checkAlive.bind(this)() |
| 314 | } |
| 315 | |
| 316 | /** |
| 317 | * Stops the worker alive check interval. |
| 318 | */ |
| 319 | private stopCheckAlive (): void { |
| 320 | this.aliveInterval != null && clearInterval(this.aliveInterval) |
| 321 | } |
| 322 | |
| 323 | /** |
| 324 | * Checks if the worker should be terminated, because its living too long. |
| 325 | */ |
| 326 | private checkAlive (): void { |
| 327 | if ( |
| 328 | performance.now() - this.lastTaskTimestamp > |
| 329 | (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) |
| 330 | ) { |
| 331 | this.sendToMainWorker({ kill: this.opts.killBehavior, workerId: this.id }) |
| 332 | } |
| 333 | } |
| 334 | |
| 335 | /** |
| 336 | * Returns the main worker. |
| 337 | * |
| 338 | * @returns Reference to the main worker. |
| 339 | */ |
| 340 | protected getMainWorker (): MainWorker { |
| 341 | if (this.mainWorker == null) { |
| 342 | throw new Error('Main worker not set') |
| 343 | } |
| 344 | return this.mainWorker |
| 345 | } |
| 346 | |
| 347 | /** |
| 348 | * Sends a message to the main worker. |
| 349 | * |
| 350 | * @param message - The response message. |
| 351 | */ |
| 352 | protected abstract sendToMainWorker ( |
| 353 | message: MessageValue<Response, Data> |
| 354 | ): void |
| 355 | |
| 356 | /** |
| 357 | * Handles an error and convert it to a string so it can be sent back to the main worker. |
| 358 | * |
| 359 | * @param e - The error raised by the worker. |
| 360 | * @returns The error message. |
| 361 | */ |
| 362 | protected handleError (e: Error | string): string { |
| 363 | return e instanceof Error ? e.message : e |
| 364 | } |
| 365 | |
| 366 | /** |
| 367 | * Runs the given function synchronously. |
| 368 | * |
| 369 | * @param fn - Function that will be executed. |
| 370 | * @param message - Input data for the given function. |
| 371 | */ |
| 372 | protected runSync ( |
| 373 | fn: WorkerSyncFunction<Data, Response>, |
| 374 | message: MessageValue<Data> |
| 375 | ): void { |
| 376 | try { |
| 377 | let taskPerformance = this.beginTaskPerformance(message.name) |
| 378 | const res = fn(message.data) |
| 379 | taskPerformance = this.endTaskPerformance(taskPerformance) |
| 380 | this.sendToMainWorker({ |
| 381 | data: res, |
| 382 | taskPerformance, |
| 383 | workerId: this.id, |
| 384 | id: message.id |
| 385 | }) |
| 386 | } catch (e) { |
| 387 | const errorMessage = this.handleError(e as Error | string) |
| 388 | this.sendToMainWorker({ |
| 389 | taskError: { |
| 390 | name: message.name ?? DEFAULT_TASK_NAME, |
| 391 | message: errorMessage, |
| 392 | data: message.data |
| 393 | }, |
| 394 | workerId: this.id, |
| 395 | id: message.id |
| 396 | }) |
| 397 | } finally { |
| 398 | if (!this.isMain && this.aliveInterval != null) { |
| 399 | this.lastTaskTimestamp = performance.now() |
| 400 | } |
| 401 | } |
| 402 | } |
| 403 | |
| 404 | /** |
| 405 | * Runs the given function asynchronously. |
| 406 | * |
| 407 | * @param fn - Function that will be executed. |
| 408 | * @param message - Input data for the given function. |
| 409 | */ |
| 410 | protected runAsync ( |
| 411 | fn: WorkerAsyncFunction<Data, Response>, |
| 412 | message: MessageValue<Data> |
| 413 | ): void { |
| 414 | let taskPerformance = this.beginTaskPerformance(message.name) |
| 415 | fn(message.data) |
| 416 | .then(res => { |
| 417 | taskPerformance = this.endTaskPerformance(taskPerformance) |
| 418 | this.sendToMainWorker({ |
| 419 | data: res, |
| 420 | taskPerformance, |
| 421 | workerId: this.id, |
| 422 | id: message.id |
| 423 | }) |
| 424 | return null |
| 425 | }) |
| 426 | .catch(e => { |
| 427 | const errorMessage = this.handleError(e as Error | string) |
| 428 | this.sendToMainWorker({ |
| 429 | taskError: { |
| 430 | name: message.name ?? DEFAULT_TASK_NAME, |
| 431 | message: errorMessage, |
| 432 | data: message.data |
| 433 | }, |
| 434 | workerId: this.id, |
| 435 | id: message.id |
| 436 | }) |
| 437 | }) |
| 438 | .finally(() => { |
| 439 | if (!this.isMain && this.aliveInterval != null) { |
| 440 | this.lastTaskTimestamp = performance.now() |
| 441 | } |
| 442 | }) |
| 443 | .catch(EMPTY_FUNCTION) |
| 444 | } |
| 445 | |
| 446 | /** |
| 447 | * Gets the task function in the given scope. |
| 448 | * |
| 449 | * @param name - Name of the task function that will be returned. |
| 450 | */ |
| 451 | private getTaskFunction (name?: string): WorkerFunction<Data, Response> { |
| 452 | name = name ?? DEFAULT_TASK_NAME |
| 453 | const fn = this.taskFunctions.get(name) |
| 454 | if (fn == null) { |
| 455 | throw new Error(`Task function '${name}' not found`) |
| 456 | } |
| 457 | return fn |
| 458 | } |
| 459 | |
| 460 | private beginTaskPerformance (name?: string): TaskPerformance { |
| 461 | this.checkStatistics() |
| 462 | return { |
| 463 | name: name ?? DEFAULT_TASK_NAME, |
| 464 | timestamp: performance.now(), |
| 465 | ...(this.statistics.elu && { elu: performance.eventLoopUtilization() }) |
| 466 | } |
| 467 | } |
| 468 | |
| 469 | private endTaskPerformance ( |
| 470 | taskPerformance: TaskPerformance |
| 471 | ): TaskPerformance { |
| 472 | this.checkStatistics() |
| 473 | return { |
| 474 | ...taskPerformance, |
| 475 | ...(this.statistics.runTime && { |
| 476 | runTime: performance.now() - taskPerformance.timestamp |
| 477 | }), |
| 478 | ...(this.statistics.elu && { |
| 479 | elu: performance.eventLoopUtilization(taskPerformance.elu) |
| 480 | }) |
| 481 | } |
| 482 | } |
| 483 | |
| 484 | private checkStatistics (): void { |
| 485 | if (this.statistics == null) { |
| 486 | throw new Error('Performance statistics computation requirements not set') |
| 487 | } |
| 488 | } |
| 489 | } |