Merge pull request #830 from poolifier/dependabot/npm_and_yarn/examples/typescript...
[poolifier.git] / src / pools / pool.ts
1 import { EventEmitter } from 'node:events'
2 import { type TransferListItem } from 'node:worker_threads'
3 import type {
4 ErrorHandler,
5 ExitHandler,
6 IWorker,
7 IWorkerNode,
8 MessageHandler,
9 OnlineHandler,
10 WorkerType
11 } from './worker'
12 import type {
13 WorkerChoiceStrategy,
14 WorkerChoiceStrategyOptions
15 } from './selection-strategies/selection-strategies-types'
16
17 /**
18 * Enumeration of pool types.
19 */
20 export const PoolTypes = Object.freeze({
21 /**
22 * Fixed pool type.
23 */
24 fixed: 'fixed',
25 /**
26 * Dynamic pool type.
27 */
28 dynamic: 'dynamic'
29 } as const)
30
31 /**
32 * Pool type.
33 */
34 export type PoolType = keyof typeof PoolTypes
35
36 /**
37 * Pool events emitter.
38 */
39 export class PoolEmitter extends EventEmitter {}
40
41 /**
42 * Enumeration of pool events.
43 */
44 export const PoolEvents = Object.freeze({
45 full: 'full',
46 ready: 'ready',
47 busy: 'busy',
48 error: 'error',
49 taskError: 'taskError'
50 } as const)
51
52 /**
53 * Pool event.
54 */
55 export type PoolEvent = keyof typeof PoolEvents
56
57 /**
58 * Pool information.
59 */
60 export interface PoolInfo {
61 readonly version: string
62 readonly type: PoolType
63 readonly worker: WorkerType
64 readonly ready: boolean
65 readonly strategy: WorkerChoiceStrategy
66 readonly minSize: number
67 readonly maxSize: number
68 /** Pool utilization. */
69 readonly utilization?: number
70 /** Pool total worker nodes. */
71 readonly workerNodes: number
72 /** Pool idle worker nodes. */
73 readonly idleWorkerNodes: number
74 /** Pool busy worker nodes. */
75 readonly busyWorkerNodes: number
76 readonly executedTasks: number
77 readonly executingTasks: number
78 readonly queuedTasks?: number
79 readonly maxQueuedTasks?: number
80 readonly failedTasks: number
81 readonly runTime?: {
82 readonly minimum: number
83 readonly maximum: number
84 readonly average: number
85 readonly median?: number
86 }
87 readonly waitTime?: {
88 readonly minimum: number
89 readonly maximum: number
90 readonly average: number
91 readonly median?: number
92 }
93 }
94
95 /**
96 * Worker tasks queue options.
97 */
98 export interface TasksQueueOptions {
99 /**
100 * Maximum number of tasks that can be executed concurrently on a worker.
101 *
102 * @defaultValue 1
103 */
104 readonly concurrency?: number
105 }
106
107 /**
108 * Options for a poolifier pool.
109 *
110 * @typeParam Worker - Type of worker.
111 */
112 export interface PoolOptions<Worker extends IWorker> {
113 /**
114 * A function that will listen for message event on each worker.
115 */
116 messageHandler?: MessageHandler<Worker>
117 /**
118 * A function that will listen for error event on each worker.
119 */
120 errorHandler?: ErrorHandler<Worker>
121 /**
122 * A function that will listen for online event on each worker.
123 */
124 onlineHandler?: OnlineHandler<Worker>
125 /**
126 * A function that will listen for exit event on each worker.
127 */
128 exitHandler?: ExitHandler<Worker>
129 /**
130 * The worker choice strategy to use in this pool.
131 *
132 * @defaultValue WorkerChoiceStrategies.ROUND_ROBIN
133 */
134 workerChoiceStrategy?: WorkerChoiceStrategy
135 /**
136 * The worker choice strategy options.
137 */
138 workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
139 /**
140 * Restart worker on error.
141 */
142 restartWorkerOnError?: boolean
143 /**
144 * Pool events emission.
145 *
146 * @defaultValue true
147 */
148 enableEvents?: boolean
149 /**
150 * Pool worker tasks queue.
151 *
152 * @defaultValue false
153 */
154 enableTasksQueue?: boolean
155 /**
156 * Pool worker tasks queue options.
157 */
158 tasksQueueOptions?: TasksQueueOptions
159 }
160
161 /**
162 * Contract definition for a poolifier pool.
163 *
164 * @typeParam Worker - Type of worker which manages this pool.
165 * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
166 * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
167 */
168 export interface IPool<
169 Worker extends IWorker,
170 Data = unknown,
171 Response = unknown
172 > {
173 /**
174 * Pool information.
175 */
176 readonly info: PoolInfo
177 /**
178 * Pool worker nodes.
179 */
180 readonly workerNodes: Array<IWorkerNode<Worker, Data>>
181 /**
182 * Emitter on which events can be listened to.
183 *
184 * Events that can currently be listened to:
185 *
186 * - `'full'`: Emitted when the pool is dynamic and the number of workers created has reached the maximum size expected.
187 * - `'ready'`: Emitted when the number of workers created in the pool has reached the minimum size expected and are ready.
188 * - `'busy'`: Emitted when the number of workers created in the pool has reached the maximum size expected and are executing at least one task.
189 * - `'error'`: Emitted when an uncaught error occurs.
190 * - `'taskError'`: Emitted when an error occurs while executing a task.
191 */
192 readonly emitter?: PoolEmitter
193 /**
194 * Executes the specified function in the worker constructor with the task data input parameter.
195 *
196 * @param data - The optional task input data for the specified task function. This can only be structured-cloneable data.
197 * @param name - The optional name of the task function to execute. If not specified, the default task function will be executed.
198 * @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.
199 * @returns Promise that will be fulfilled when the task is completed.
200 */
201 readonly execute: (
202 data?: Data,
203 name?: string,
204 transferList?: TransferListItem[]
205 ) => Promise<Response>
206 /**
207 * Terminates all workers in this pool.
208 */
209 readonly destroy: () => Promise<void>
210 /**
211 * Sets the worker choice strategy in this pool.
212 *
213 * @param workerChoiceStrategy - The worker choice strategy.
214 * @param workerChoiceStrategyOptions - The worker choice strategy options.
215 */
216 readonly setWorkerChoiceStrategy: (
217 workerChoiceStrategy: WorkerChoiceStrategy,
218 workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
219 ) => void
220 /**
221 * Sets the worker choice strategy options in this pool.
222 *
223 * @param workerChoiceStrategyOptions - The worker choice strategy options.
224 */
225 readonly setWorkerChoiceStrategyOptions: (
226 workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
227 ) => void
228 /**
229 * Enables/disables the worker tasks queue in this pool.
230 *
231 * @param enable - Whether to enable or disable the worker tasks queue.
232 * @param tasksQueueOptions - The worker tasks queue options.
233 */
234 readonly enableTasksQueue: (
235 enable: boolean,
236 tasksQueueOptions?: TasksQueueOptions
237 ) => void
238 /**
239 * Sets the worker tasks queue options in this pool.
240 *
241 * @param tasksQueueOptions - The worker tasks queue options.
242 */
243 readonly setTasksQueueOptions: (tasksQueueOptions: TasksQueueOptions) => void
244 }