-import { AsyncResource } from 'async_hooks'
-import type { MessageValue } from '../utility-types'
-import type { WorkerOptions } from './worker-options'
+import { AsyncResource } from 'node:async_hooks'
+import type { Worker } from 'node:cluster'
+import type { MessagePort } from 'node:worker_threads'
+import type {
+ MessageValue,
+ WorkerAsyncFunction,
+ WorkerFunction,
+ WorkerSyncFunction
+} from '../utility-types'
+import { EMPTY_FUNCTION } from '../utils'
+import type { KillBehavior, WorkerOptions } from './worker-options'
+import { KillBehaviors } from './worker-options'
+const DEFAULT_MAX_INACTIVE_TIME = 60000
+const DEFAULT_KILL_BEHAVIOR: KillBehavior = KillBehaviors.SOFT
+
+/**
+ * Base class that implements some shared logic for all poolifier workers.
+ *
+ * @typeParam MainWorker - Type of main worker.
+ * @typeParam Data - Type of data this worker receives from pool's execution. This can only be serializable data.
+ * @typeParam Response - Type of response the worker sends back to the main worker. This can only be serializable data.
+ */
export abstract class AbstractWorker<
- MainWorker,
+ MainWorker extends Worker | MessagePort,
Data = unknown,
Response = unknown
> extends AsyncResource {
- protected readonly maxInactiveTime: number
- protected readonly async: boolean
- protected lastTask: number
- protected readonly interval?: NodeJS.Timeout
-
/**
+ * Timestamp of the last task processed by this worker.
+ */
+ protected lastTaskTimestamp!: number
+ /**
+ * Handler id of the `aliveInterval` worker alive check.
+ */
+ protected readonly aliveInterval?: NodeJS.Timeout
+ /**
+ * Constructs a new poolifier worker.
*
- * @param type The type of async event.
- * @param isMain
- * @param fn
- * @param opts
+ * @param type - The type of async event.
+ * @param isMain - Whether this is the main worker or not.
+ * @param fn - Function processed by the worker when the pool's `execution` function is invoked.
+ * @param mainWorker - Reference to main worker.
+ * @param opts - Options for the worker.
*/
public constructor (
type: string,
- isMain: boolean,
- fn: (data: Data) => Response,
- public readonly opts: WorkerOptions = {}
+ protected readonly isMain: boolean,
+ fn: WorkerFunction<Data, Response>,
+ protected mainWorker: MainWorker | undefined | null,
+ protected readonly opts: WorkerOptions = {
+ /**
+ * The kill behavior option on this worker or its default value.
+ */
+ killBehavior: DEFAULT_KILL_BEHAVIOR,
+ /**
+ * The maximum time to keep this worker alive while idle.
+ * The pool automatically checks and terminates this worker when the time expires.
+ */
+ maxInactiveTime: DEFAULT_MAX_INACTIVE_TIME
+ }
) {
super(type)
-
- this.maxInactiveTime = this.opts.maxInactiveTime ?? 1000 * 60
- this.async = !!this.opts.async
- this.lastTask = Date.now()
- if (!fn) throw new Error('Fn parameter is mandatory')
- // keep the worker active
- if (!isMain) {
- this.interval = setInterval(
+ this.checkWorkerOptions(this.opts)
+ this.checkFunctionInput(fn)
+ if (!this.isMain) {
+ this.lastTaskTimestamp = performance.now()
+ this.aliveInterval = setInterval(
this.checkAlive.bind(this),
- this.maxInactiveTime / 2
+ (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) / 2
)
this.checkAlive.bind(this)()
}
+
+ this.mainWorker?.on(
+ 'message',
+ (message: MessageValue<Data, MainWorker>) => {
+ this.messageListener(message, fn)
+ }
+ )
}
- protected abstract getMainWorker (): MainWorker
+ private checkWorkerOptions (opts: WorkerOptions): void {
+ this.opts.killBehavior = opts.killBehavior ?? DEFAULT_KILL_BEHAVIOR
+ this.opts.maxInactiveTime =
+ opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME
+ this.opts.async = opts.async ?? false
+ }
+
+ /**
+ * Checks if the `fn` parameter is passed to the constructor.
+ *
+ * @param fn - The function that should be defined.
+ */
+ private checkFunctionInput (fn: WorkerFunction<Data, Response>): void {
+ if (fn == null) throw new Error('fn parameter is mandatory')
+ if (typeof fn !== 'function') {
+ throw new TypeError('fn parameter is not a function')
+ }
+ if (fn.constructor.name === 'AsyncFunction' && this.opts.async === false) {
+ throw new Error(
+ 'fn parameter is an async function, please set the async option to true'
+ )
+ }
+ }
+ /**
+ * Worker message listener.
+ *
+ * @param message - Message received.
+ * @param fn - Function processed by the worker when the pool's `execution` function is invoked.
+ */
+ protected messageListener (
+ message: MessageValue<Data, MainWorker>,
+ fn: WorkerFunction<Data, Response>
+ ): void {
+ if (message.id != null && message.data != null) {
+ // Task message received
+ if (this.opts.async === true) {
+ this.runInAsyncScope(this.runAsync.bind(this), this, fn, message)
+ } else {
+ this.runInAsyncScope(this.run.bind(this), this, fn, message)
+ }
+ } else if (message.parent != null) {
+ // Main worker reference message received
+ this.mainWorker = message.parent
+ } else if (message.kill != null) {
+ // Kill message received
+ this.aliveInterval != null && clearInterval(this.aliveInterval)
+ this.emitDestroy()
+ }
+ }
+
+ /**
+ * Returns the main worker.
+ *
+ * @returns Reference to the main worker.
+ */
+ protected getMainWorker (): MainWorker {
+ if (this.mainWorker == null) {
+ throw new Error('Main worker was not set')
+ }
+ return this.mainWorker
+ }
+
+ /**
+ * Sends a message to the main worker.
+ *
+ * @param message - The response message.
+ */
protected abstract sendToMainWorker (message: MessageValue<Response>): void
+ /**
+ * Checks if the worker should be terminated, because its living too long.
+ */
protected checkAlive (): void {
- if (Date.now() - this.lastTask > this.maxInactiveTime) {
- this.sendToMainWorker({ kill: 1 })
+ if (
+ performance.now() - this.lastTaskTimestamp >
+ (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME)
+ ) {
+ this.sendToMainWorker({ kill: this.opts.killBehavior })
}
}
+ /**
+ * Handles an error and convert it to a string so it can be sent back to the main worker.
+ *
+ * @param e - The error raised by the worker.
+ * @returns Message of the error.
+ */
protected handleError (e: Error | string): string {
- return (e as unknown) as string
+ return e as string
}
+ /**
+ * Runs the given function synchronously.
+ *
+ * @param fn - Function that will be executed.
+ * @param message - Input data for the given function.
+ */
protected run (
- fn: (data?: Data) => Response,
- value: MessageValue<Data>
+ fn: WorkerSyncFunction<Data, Response>,
+ message: MessageValue<Data>
): void {
try {
- const res = fn(value.data)
- this.sendToMainWorker({ data: res, id: value.id })
- this.lastTask = Date.now()
+ const startTimestamp = performance.now()
+ const res = fn(message.data)
+ const runTime = performance.now() - startTimestamp
+ this.sendToMainWorker({
+ data: res,
+ id: message.id,
+ runTime
+ })
} catch (e) {
- const err = this.handleError(e)
- this.sendToMainWorker({ error: err, id: value.id })
- this.lastTask = Date.now()
+ const err = this.handleError(e as Error)
+ this.sendToMainWorker({ error: err, id: message.id })
+ } finally {
+ !this.isMain && (this.lastTaskTimestamp = performance.now())
}
}
+ /**
+ * Runs the given function asynchronously.
+ *
+ * @param fn - Function that will be executed.
+ * @param message - Input data for the given function.
+ */
protected runAsync (
- fn: (data?: Data) => Promise<Response>,
- value: MessageValue<Data>
+ fn: WorkerAsyncFunction<Data, Response>,
+ message: MessageValue<Data>
): void {
- fn(value.data)
+ const startTimestamp = performance.now()
+ fn(message.data)
.then(res => {
- this.sendToMainWorker({ data: res, id: value.id })
- this.lastTask = Date.now()
+ const runTime = performance.now() - startTimestamp
+ this.sendToMainWorker({
+ data: res,
+ id: message.id,
+ runTime
+ })
return null
})
.catch(e => {
- const err = this.handleError(e)
- this.sendToMainWorker({ error: err, id: value.id })
- this.lastTask = Date.now()
+ const err = this.handleError(e as Error)
+ this.sendToMainWorker({ error: err, id: message.id })
+ })
+ .finally(() => {
+ !this.isMain && (this.lastTaskTimestamp = performance.now())
})
+ .catch(EMPTY_FUNCTION)
}
}
repositories / poolifier.git / blobdiff