+import type { ClusterSettings } from 'node:cluster'
+import type { EventEmitterAsyncResource } from 'node:events'
+import type { TransferListItem, WorkerOptions } from 'node:worker_threads'
+
+import type { TaskFunctionProperties } from '../utility-types.js'
+import type {
+ TaskFunction,
+ TaskFunctionObject,
+} from '../worker/task-functions.js'
+import type {
+ WorkerChoiceStrategy,
+ WorkerChoiceStrategyOptions,
+} from './selection-strategies/selection-strategies-types.js'
import type {
ErrorHandler,
ExitHandler,
+ IWorker,
+ IWorkerNode,
MessageHandler,
- OnlineHandler
-} from './pool-worker'
-import type { WorkerChoiceStrategy } from './selection-strategies/selection-strategies-types'
+ OnlineHandler,
+ WorkerType,
+} from './worker.js'
+
+/**
+ * Enumeration of pool types.
+ */
+export const PoolTypes: Readonly<{
+ fixed: 'fixed'
+ dynamic: 'dynamic'
+}> = Object.freeze({
+ /**
+ * Fixed pool type.
+ */
+ fixed: 'fixed',
+ /**
+ * Dynamic pool type.
+ */
+ dynamic: 'dynamic',
+} as const)
+
+/**
+ * Pool type.
+ */
+export type PoolType = keyof typeof PoolTypes
+
+/**
+ * Enumeration of pool events.
+ */
+export const PoolEvents: Readonly<{
+ ready: 'ready'
+ busy: 'busy'
+ full: 'full'
+ empty: 'empty'
+ destroy: 'destroy'
+ error: 'error'
+ taskError: 'taskError'
+ backPressure: 'backPressure'
+}> = Object.freeze({
+ ready: 'ready',
+ busy: 'busy',
+ full: 'full',
+ empty: 'empty',
+ destroy: 'destroy',
+ error: 'error',
+ taskError: 'taskError',
+ backPressure: 'backPressure',
+} as const)
+
+/**
+ * Pool event.
+ */
+export type PoolEvent = keyof typeof PoolEvents
+
+/**
+ * Pool information.
+ */
+export interface PoolInfo {
+ readonly version: string
+ readonly type: PoolType
+ readonly worker: WorkerType
+ readonly started: boolean
+ readonly ready: boolean
+ readonly defaultStrategy: WorkerChoiceStrategy
+ readonly strategyRetries: number
+ readonly minSize: number
+ readonly maxSize: number
+ /** Pool utilization. */
+ readonly utilization?: number
+ /** Pool total worker nodes. */
+ readonly workerNodes: number
+ /** Pool stealing worker nodes. */
+ readonly stealingWorkerNodes?: number
+ /** Pool idle worker nodes. */
+ readonly idleWorkerNodes: number
+ /** Pool busy worker nodes. */
+ readonly busyWorkerNodes: number
+ readonly executedTasks: number
+ readonly executingTasks: number
+ readonly queuedTasks?: number
+ readonly maxQueuedTasks?: number
+ readonly backPressure?: boolean
+ readonly stolenTasks?: number
+ readonly failedTasks: number
+ readonly runTime?: {
+ readonly minimum: number
+ readonly maximum: number
+ readonly average?: number
+ readonly median?: number
+ }
+ readonly waitTime?: {
+ readonly minimum: number
+ readonly maximum: number
+ readonly average?: number
+ readonly median?: number
+ }
+ readonly elu?: {
+ idle: {
+ readonly minimum: number
+ readonly maximum: number
+ readonly average?: number
+ readonly median?: number
+ }
+ active: {
+ readonly minimum: number
+ readonly maximum: number
+ readonly average?: number
+ readonly median?: number
+ }
+ utilization: {
+ readonly average?: number
+ readonly median?: number
+ }
+ }
+}
+
+/**
+ * Worker node tasks queue options.
+ */
+export interface TasksQueueOptions {
+ /**
+ * Maximum tasks queue size per worker node flagging it as back pressured.
+ * @defaultValue (pool maximum size)^2
+ */
+ readonly size?: number
+ /**
+ * Maximum number of tasks that can be executed concurrently on a worker node.
+ * @defaultValue 1
+ */
+ readonly concurrency?: number
+ /**
+ * Whether to enable task stealing on idle.
+ * @defaultValue true
+ */
+ readonly taskStealing?: boolean
+ /**
+ * Whether to enable tasks stealing under back pressure.
+ * @defaultValue false
+ */
+ readonly tasksStealingOnBackPressure?: boolean
+ /**
+ * Queued tasks finished timeout in milliseconds at worker node termination.
+ * @defaultValue 2000
+ */
+ readonly tasksFinishedTimeout?: number
+}
/**
* Options for a poolifier pool.
+ * @typeParam Worker - Type of worker.
*/
-export interface PoolOptions<Worker> {
+export interface PoolOptions<Worker extends IWorker> {
+ /**
+ * A function that will listen for online event on each worker.
+ * @defaultValue `() => {}`
+ */
+ onlineHandler?: OnlineHandler<Worker>
/**
* A function that will listen for message event on each worker.
+ * @defaultValue `() => {}`
*/
messageHandler?: MessageHandler<Worker>
/**
* A function that will listen for error event on each worker.
+ * @defaultValue `() => {}`
*/
errorHandler?: ErrorHandler<Worker>
- /**
- * A function that will listen for online event on each worker.
- */
- onlineHandler?: OnlineHandler<Worker>
/**
* A function that will listen for exit event on each worker.
+ * @defaultValue `() => {}`
*/
exitHandler?: ExitHandler<Worker>
/**
- * The work choice strategy to use in this pool.
+ * Whether to start the minimum number of workers at pool initialization.
+ * @defaultValue true
+ */
+ startWorkers?: boolean
+ /**
+ * The default worker choice strategy to use in this pool.
+ * @defaultValue WorkerChoiceStrategies.ROUND_ROBIN
*/
workerChoiceStrategy?: WorkerChoiceStrategy
/**
- * Pool events emission.
- *
- * @default true
+ * The worker choice strategy options.
+ */
+ workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
+ /**
+ * Restart worker on error.
+ */
+ restartWorkerOnError?: boolean
+ /**
+ * Pool events integrated with async resource emission.
+ * @defaultValue true
*/
enableEvents?: boolean
+ /**
+ * Pool worker node tasks queue.
+ * @defaultValue false
+ */
+ enableTasksQueue?: boolean
+ /**
+ * Pool worker node tasks queue options.
+ */
+ tasksQueueOptions?: TasksQueueOptions
+ /**
+ * Worker options.
+ * @see https://nodejs.org/api/worker_threads.html#new-workerfilename-options
+ */
+ workerOptions?: WorkerOptions
+ /**
+ * Key/value pairs to add to worker process environment.
+ * @see https://nodejs.org/api/cluster.html#cluster_cluster_fork_env
+ */
+ env?: Record<string, unknown>
+ /**
+ * Cluster settings.
+ * @see https://nodejs.org/api/cluster.html#cluster_cluster_settings
+ */
+ settings?: ClusterSettings
}
/**
* Contract definition for a poolifier pool.
- *
- * @template Data Type of data sent to the worker. This can only be serializable data.
- * @template Response Type of response of execution. This can only be serializable data.
+ * @typeParam Worker - Type of worker which manages this pool.
+ * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
+ * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
*/
-export interface IPool<Data = unknown, Response = unknown> {
+export interface IPool<
+ Worker extends IWorker,
+ Data = unknown,
+ Response = unknown
+> {
/**
- * Performs the task specified in the constructor with the data parameter.
- *
- * @param data The input for the specified task. This can only be serializable data.
- * @returns Promise that will be resolved when the task is successfully completed.
+ * Pool information.
*/
- execute(data: Data): Promise<Response>
+ readonly info: PoolInfo
/**
- * Shutdowns every current worker in this pool.
+ * Pool worker nodes.
+ * @internal
*/
- destroy(): Promise<void>
+ readonly workerNodes: IWorkerNode<Worker, Data>[]
/**
- * Sets the worker choice strategy in this pool.
+ * Pool event emitter integrated with async resource.
+ * The async tracking tooling identifier is `poolifier:<PoolType>-<WorkerType>-pool`.
*
- * @param workerChoiceStrategy The worker choice strategy.
+ * Events that can currently be listened to:
+ *
+ * - `'ready'`: Emitted when the number of workers created in the pool has reached the minimum size expected and are ready. If the pool is dynamic with a minimum number of workers is set to zero, this event is emitted when at least one dynamic worker is ready.
+ * - `'busy'`: Emitted when the number of workers created in the pool has reached the maximum size expected and are executing concurrently their tasks quota.
+ * - `'full'`: Emitted when the pool is dynamic and the number of workers created has reached the maximum size expected.
+ * - `'empty'`: Emitted when the pool is dynamic with a minimum number of workers set to zero and the number of workers has reached the minimum size expected.
+ * - `'destroy'`: Emitted when the pool is destroyed.
+ * - `'error'`: Emitted when an uncaught error occurs.
+ * - `'taskError'`: Emitted when an error occurs while executing a task.
+ * - `'backPressure'`: Emitted when all worker nodes have back pressure (i.e. their tasks queue is full: queue size \>= maximum queue size).
+ */
+ readonly emitter?: EventEmitterAsyncResource
+ /**
+ * Executes the specified function in the worker constructor with the task data input parameter.
+ * @param data - The optional task input data for the specified task function. This can only be structured-cloneable data.
+ * @param name - The optional name of the task function to execute. If not specified, the default task function will be executed.
+ * @param transferList - An optional array of transferable objects to transfer ownership of. Ownership of the transferred objects is given to the chosen pool's worker_threads worker and they should not be used in the main thread afterwards.
+ * @returns Promise with a task function response that will be fulfilled when the task is completed.
+ */
+ readonly execute: (
+ data?: Data,
+ name?: string,
+ transferList?: readonly TransferListItem[]
+ ) => Promise<Response>
+ /**
+ * Executes the specified function in the worker constructor with the tasks data iterable input parameter.
+ * @param data - The tasks iterable input data for the specified task function. This can only be an iterable of structured-cloneable data.
+ * @param name - The optional name of the task function to execute. If not specified, the default task function will be executed.
+ * @param transferList - An optional array of transferable objects to transfer ownership of. Ownership of the transferred objects is given to the chosen pool's worker_threads worker and they should not be used in the main thread afterwards.
+ * @returns Promise with an array of task function responses that will be fulfilled when the tasks are completed.
+ */
+ readonly mapExecute: (
+ data: Iterable<Data>,
+ name?: string,
+ transferList?: readonly TransferListItem[]
+ ) => Promise<Response[]>
+ /**
+ * Starts the minimum number of workers in this pool.
+ */
+ readonly start: () => void
+ /**
+ * Terminates all workers in this pool.
+ */
+ readonly destroy: () => Promise<void>
+ /**
+ * Whether the specified task function exists in this pool.
+ * @param name - The name of the task function.
+ * @returns `true` if the task function exists, `false` otherwise.
+ */
+ readonly hasTaskFunction: (name: string) => boolean
+ /**
+ * Adds a task function to this pool.
+ * If a task function with the same name already exists, it will be overwritten.
+ * @param name - The name of the task function.
+ * @param fn - The task function.
+ * @returns `true` if the task function was added, `false` otherwise.
+ * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `name` parameter is not a string or an empty string.
+ * @throws {@link https://nodejs.org/api/errors.html#class-typeerror} If the `fn` parameter is not a function or task function object.
+ */
+ readonly addTaskFunction: (
+ name: string,
+ fn: TaskFunction<Data, Response> | TaskFunctionObject<Data, Response>
+ ) => Promise<boolean>
+ /**
+ * Removes a task function from this pool.
+ * @param name - The name of the task function.
+ * @returns `true` if the task function was removed, `false` otherwise.
+ */
+ readonly removeTaskFunction: (name: string) => Promise<boolean>
+ /**
+ * Lists the properties of task functions available in this pool.
+ * @returns The properties of task functions available in this pool.
+ */
+ readonly listTaskFunctionsProperties: () => TaskFunctionProperties[]
+ /**
+ * Sets the default task function in this pool.
+ * @param name - The name of the task function.
+ * @returns `true` if the default task function was set, `false` otherwise.
+ */
+ readonly setDefaultTaskFunction: (name: string) => Promise<boolean>
+ /**
+ * Sets the default worker choice strategy in this pool.
+ * @param workerChoiceStrategy - The default worker choice strategy.
+ * @param workerChoiceStrategyOptions - The worker choice strategy options.
+ */
+ readonly setWorkerChoiceStrategy: (
+ workerChoiceStrategy: WorkerChoiceStrategy,
+ workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
+ ) => void
+ /**
+ * Sets the worker choice strategy options in this pool.
+ * @param workerChoiceStrategyOptions - The worker choice strategy options.
+ * @returns `true` if the worker choice strategy options were set, `false` otherwise.
+ */
+ readonly setWorkerChoiceStrategyOptions: (
+ workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
+ ) => boolean
+ /**
+ * Enables/disables the worker node tasks queue in this pool.
+ * @param enable - Whether to enable or disable the worker node tasks queue.
+ * @param tasksQueueOptions - The worker node tasks queue options.
+ */
+ readonly enableTasksQueue: (
+ enable: boolean,
+ tasksQueueOptions?: TasksQueueOptions
+ ) => void
+ /**
+ * Sets the worker node tasks queue options in this pool.
+ * @param tasksQueueOptions - The worker node tasks queue options.
*/
- setWorkerChoiceStrategy(workerChoiceStrategy: WorkerChoiceStrategy): void
+ readonly setTasksQueueOptions: (tasksQueueOptions: TasksQueueOptions) => void
}