Merge branch 'master' of github.com:poolifier/poolifier
[poolifier.git] / src / pools / pool.ts
CommitLineData
2845f2a5 1import { EventEmitter } from 'node:events'
7d91a8cd 2import { type TransferListItem } from 'node:worker_threads'
6703b9f4 3import type { TaskFunction } from '../worker/task-functions'
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4import type {
5 ErrorHandler,
6 ExitHandler,
50e66724 7 IWorker,
4b628b48 8 IWorkerNode,
bdaf31cd 9 MessageHandler,
c4855468 10 OnlineHandler,
4b628b48 11 WorkerType
f06e48d8 12} from './worker'
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13import type {
14 WorkerChoiceStrategy,
15 WorkerChoiceStrategyOptions
16} from './selection-strategies/selection-strategies-types'
bdaf31cd 17
c4855468 18/**
6b27d407 19 * Enumeration of pool types.
c4855468 20 */
6b27d407 21export const PoolTypes = Object.freeze({
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22 /**
23 * Fixed pool type.
24 */
6b27d407 25 fixed: 'fixed',
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26 /**
27 * Dynamic pool type.
28 */
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29 dynamic: 'dynamic'
30} as const)
31
32/**
33 * Pool type.
34 */
35export type PoolType = keyof typeof PoolTypes
c4855468 36
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37/**
38 * Pool events emitter.
39 */
2845f2a5 40export class PoolEmitter extends EventEmitter {}
b4904890 41
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42/**
43 * Enumeration of pool events.
44 */
45export const PoolEvents = Object.freeze({
2431bdb4 46 ready: 'ready',
1f68cede 47 busy: 'busy',
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48 full: 'full',
49 destroy: 'destroy',
91ee39ed 50 error: 'error',
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51 taskError: 'taskError',
52 backPressure: 'backPressure'
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53} as const)
54
55/**
56 * Pool event.
57 */
58export type PoolEvent = keyof typeof PoolEvents
59
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60/**
61 * Pool information.
62 */
63export interface PoolInfo {
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64 readonly version: string
65 readonly type: PoolType
66 readonly worker: WorkerType
47352846 67 readonly started: boolean
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68 readonly ready: boolean
69 readonly strategy: WorkerChoiceStrategy
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70 readonly minSize: number
71 readonly maxSize: number
aa9eede8 72 /** Pool utilization. */
4b628b48 73 readonly utilization?: number
01a59f3c 74 /** Pool total worker nodes. */
4b628b48 75 readonly workerNodes: number
01a59f3c 76 /** Pool idle worker nodes. */
4b628b48 77 readonly idleWorkerNodes: number
01a59f3c 78 /** Pool busy worker nodes. */
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79 readonly busyWorkerNodes: number
80 readonly executedTasks: number
81 readonly executingTasks: number
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82 readonly queuedTasks?: number
83 readonly maxQueuedTasks?: number
a1763c54 84 readonly backPressure?: boolean
68cbdc84 85 readonly stolenTasks?: number
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86 readonly failedTasks: number
87 readonly runTime?: {
88 readonly minimum: number
89 readonly maximum: number
3baa0837 90 readonly average?: number
4b628b48 91 readonly median?: number
1dcf8b7b 92 }
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93 readonly waitTime?: {
94 readonly minimum: number
95 readonly maximum: number
3baa0837 96 readonly average?: number
4b628b48 97 readonly median?: number
1dcf8b7b 98 }
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99}
100
7171d33f 101/**
20c6f652 102 * Worker node tasks queue options.
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103 */
104export interface TasksQueueOptions {
105 /**
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106 * Maximum tasks queue size per worker node flagging it as back pressured.
107 *
108 * @defaultValue (pool maximum size)^2
109 */
ff3f866a 110 readonly size?: number
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111 /**
112 * Maximum number of tasks that can be executed concurrently on a worker node.
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113 *
114 * @defaultValue 1
115 */
eb7bf744 116 readonly concurrency?: number
47352846 117 /**
dbd73092 118 * Whether to enable task stealing.
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119 *
120 * @defaultValue true
121 */
dbd73092 122 readonly taskStealing?: boolean
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123 /**
124 * Whether to enable tasks stealing on back pressure.
125 *
126 * @defaultValue true
127 */
128 readonly tasksStealingOnBackPressure?: boolean
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129}
130
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131/**
132 * Options for a poolifier pool.
c319c66b 133 *
d480d708 134 * @typeParam Worker - Type of worker.
bdaf31cd 135 */
50e66724 136export interface PoolOptions<Worker extends IWorker> {
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137 /**
138 * A function that will listen for online event on each worker.
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139 *
140 * @defaultValue `() => {}`
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141 */
142 onlineHandler?: OnlineHandler<Worker>
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143 /**
144 * A function that will listen for message event on each worker.
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145 *
146 * @defaultValue `() => {}`
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147 */
148 messageHandler?: MessageHandler<Worker>
149 /**
150 * A function that will listen for error event on each worker.
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151 *
152 * @defaultValue `() => {}`
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153 */
154 errorHandler?: ErrorHandler<Worker>
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155 /**
156 * A function that will listen for exit event on each worker.
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157 *
158 * @defaultValue `() => {}`
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159 */
160 exitHandler?: ExitHandler<Worker>
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161 /**
162 * Whether to start the minimum number of workers at pool initialization.
163 *
8ff61e33 164 * @defaultValue true
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165 */
166 startWorkers?: boolean
bdaf31cd 167 /**
46e857ca 168 * The worker choice strategy to use in this pool.
d29bce7c 169 *
95ec6006 170 * @defaultValue WorkerChoiceStrategies.ROUND_ROBIN
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171 */
172 workerChoiceStrategy?: WorkerChoiceStrategy
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173 /**
174 * The worker choice strategy options.
175 */
176 workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
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177 /**
178 * Restart worker on error.
179 */
180 restartWorkerOnError?: boolean
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181 /**
182 * Pool events emission.
183 *
38e795c1 184 * @defaultValue true
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185 */
186 enableEvents?: boolean
ff733df7 187 /**
20c6f652 188 * Pool worker node tasks queue.
ff733df7 189 *
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190 * @defaultValue false
191 */
192 enableTasksQueue?: boolean
7171d33f 193 /**
20c6f652 194 * Pool worker node tasks queue options.
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195 */
196 tasksQueueOptions?: TasksQueueOptions
bdaf31cd 197}
a35560ba 198
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199/**
200 * Contract definition for a poolifier pool.
201 *
c4855468 202 * @typeParam Worker - Type of worker which manages this pool.
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203 * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
204 * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
729c563d 205 */
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206export interface IPool<
207 Worker extends IWorker,
208 Data = unknown,
209 Response = unknown
210> {
08f3f44c 211 /**
6b27d407 212 * Pool information.
08f3f44c 213 */
6b27d407 214 readonly info: PoolInfo
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215 /**
216 * Pool worker nodes.
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217 *
218 * @internal
c4855468 219 */
4b628b48 220 readonly workerNodes: Array<IWorkerNode<Worker, Data>>
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221 /**
222 * Whether the worker node has back pressure (i.e. its tasks queue is full).
223 *
224 * @param workerNodeKey - The worker node key.
225 * @returns `true` if the worker node has back pressure, `false` otherwise.
9768f49f 226 * @internal
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227 */
228 readonly hasWorkerNodeBackPressure: (workerNodeKey: number) => boolean
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229 /**
230 * Emitter on which events can be listened to.
231 *
232 * Events that can currently be listened to:
233 *
d5024c00 234 * - `'ready'`: Emitted when the number of workers created in the pool has reached the minimum size expected and are ready.
a9780ad2 235 * - `'busy'`: Emitted when the number of workers created in the pool has reached the maximum size expected and are executing concurrently their tasks quota.
ef3891a3 236 * - `'full'`: Emitted when the pool is dynamic and the number of workers created has reached the maximum size expected.
033f1776 237 * - `'destroy'`: Emitted when the pool is destroyed.
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238 * - `'error'`: Emitted when an uncaught error occurs.
239 * - `'taskError'`: Emitted when an error occurs while executing a task.
d92f3ddf 240 * - `'backPressure'`: Emitted when all worker nodes have back pressure (i.e. their tasks queue is full: queue size \>= maximum queue size).
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241 */
242 readonly emitter?: PoolEmitter
729c563d 243 /**
61aa11a6 244 * Executes the specified function in the worker constructor with the task data input parameter.
729c563d 245 *
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246 * @param data - The optional task input data for the specified task function. This can only be structured-cloneable data.
247 * @param name - The optional name of the task function to execute. If not specified, the default task function will be executed.
248 * @param transferList - An optional array of transferable objects to transfer ownership of. Ownership of the transferred objects is given to the pool's worker_threads worker and they should not be used in the main thread afterwards.
ef41a6e6 249 * @returns Promise that will be fulfilled when the task is completed.
729c563d 250 */
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251 readonly execute: (
252 data?: Data,
253 name?: string,
254 transferList?: TransferListItem[]
255 ) => Promise<Response>
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256 /**
257 * Starts the minimum number of workers in this pool.
258 */
259 readonly start: () => void
280c2a77 260 /**
aa9eede8 261 * Terminates all workers in this pool.
280c2a77 262 */
4b628b48 263 readonly destroy: () => Promise<void>
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264 /**
265 * Whether the specified task function exists in this pool.
266 *
267 * @param name - The name of the task function.
268 * @returns `true` if the task function exists, `false` otherwise.
269 */
270 readonly hasTaskFunction: (name: string) => boolean
271 /**
272 * Adds a task function to this pool.
273 * If a task function with the same name already exists, it will be overwritten.
274 *
275 * @param name - The name of the task function.
3feeab69 276 * @param fn - The task function.
6703b9f4 277 * @returns `true` if the task function was added, `false` otherwise.
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278 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string or an empty string.
279 * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `fn` parameter is not a function.
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280 */
281 readonly addTaskFunction: (
282 name: string,
3feeab69 283 fn: TaskFunction<Data, Response>
e81c38f2 284 ) => Promise<boolean>
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285 /**
286 * Removes a task function from this pool.
287 *
288 * @param name - The name of the task function.
289 * @returns `true` if the task function was removed, `false` otherwise.
290 */
e81c38f2 291 readonly removeTaskFunction: (name: string) => Promise<boolean>
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292 /**
293 * Lists the names of task function available in this pool.
294 *
295 * @returns The names of task function available in this pool.
296 */
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297 readonly listTaskFunctionNames: () => string[]
298 /**
299 * Sets the default task function in this pool.
300 *
301 * @param name - The name of the task function.
302 * @returns `true` if the default task function was set, `false` otherwise.
303 */
e81c38f2 304 readonly setDefaultTaskFunction: (name: string) => Promise<boolean>
a35560ba 305 /**
bdede008 306 * Sets the worker choice strategy in this pool.
a35560ba 307 *
38e795c1 308 * @param workerChoiceStrategy - The worker choice strategy.
59219cbb 309 * @param workerChoiceStrategyOptions - The worker choice strategy options.
a35560ba 310 */
4b628b48 311 readonly setWorkerChoiceStrategy: (
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312 workerChoiceStrategy: WorkerChoiceStrategy,
313 workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
314 ) => void
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315 /**
316 * Sets the worker choice strategy options in this pool.
317 *
318 * @param workerChoiceStrategyOptions - The worker choice strategy options.
319 */
4b628b48 320 readonly setWorkerChoiceStrategyOptions: (
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321 workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
322 ) => void
323 /**
20c6f652 324 * Enables/disables the worker node tasks queue in this pool.
a20f0ba5 325 *
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326 * @param enable - Whether to enable or disable the worker node tasks queue.
327 * @param tasksQueueOptions - The worker node tasks queue options.
a20f0ba5 328 */
4b628b48 329 readonly enableTasksQueue: (
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330 enable: boolean,
331 tasksQueueOptions?: TasksQueueOptions
332 ) => void
a20f0ba5 333 /**
20c6f652 334 * Sets the worker node tasks queue options in this pool.
a20f0ba5 335 *
20c6f652 336 * @param tasksQueueOptions - The worker node tasks queue options.
a20f0ba5 337 */
4b628b48 338 readonly setTasksQueueOptions: (tasksQueueOptions: TasksQueueOptions) => void
c97c7edb 339}