-import type { WorkerChoiceStrategyOptions } from './pools/selection-strategies/selection-strategies-types'
+import { getRandomValues } from 'node:crypto'
+import * as os from 'node:os'
+
+import type { KillBehavior } from './worker/worker-options.js'
+
+/**
+ * Default task name.
+ */
+export const DEFAULT_TASK_NAME = 'default'
/**
* An intentional empty function.
})
/**
- * Default worker choice strategy options.
+ * Returns safe host OS optimized estimate of the default amount of parallelism a pool should use.
+ * Always returns a value greater than zero.
+ *
+ * @returns The host OS optimized maximum pool size.
+ */
+export const availableParallelism = (): number => {
+ let availableParallelism = 1
+ try {
+ availableParallelism = os.availableParallelism()
+ } catch {
+ const cpus = os.cpus()
+ if (Array.isArray(cpus) && cpus.length > 0) {
+ availableParallelism = cpus.length
+ }
+ }
+ return availableParallelism
+}
+
+/**
+ * Sleeps for the given amount of milliseconds.
+ *
+ * @param ms - The amount of milliseconds to sleep.
+ * @returns A promise that resolves after the given amount of milliseconds.
+ * @internal
+ */
+export const sleep = async (ms: number): Promise<void> => {
+ await new Promise(resolve => {
+ setTimeout(resolve, ms)
+ })
+}
+
+/**
+ * Computes the retry delay in milliseconds using an exponential back off algorithm.
+ *
+ * @param retryNumber - The number of retries that have already been attempted
+ * @param delayFactor - The base delay factor in milliseconds
+ * @returns Delay in milliseconds
+ * @internal
+ */
+export const exponentialDelay = (
+ retryNumber = 0,
+ delayFactor = 100
+): number => {
+ const delay = Math.pow(2, retryNumber) * delayFactor
+ const randomSum = delay * 0.2 * secureRandom() // 0-20% of the delay
+ return delay + randomSum
+}
+
+/**
+ * Computes the average of the given data set.
+ *
+ * @param dataSet - Data set.
+ * @returns The average of the given data set.
+ * @internal
*/
-export const DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS: WorkerChoiceStrategyOptions =
- {
- medRunTime: false
+export const average = (dataSet: number[]): number => {
+ if (Array.isArray(dataSet) && dataSet.length === 0) {
+ return 0
+ } else if (Array.isArray(dataSet) && dataSet.length === 1) {
+ return dataSet[0]
}
+ return (
+ dataSet.reduce((accumulator, number) => accumulator + number, 0) /
+ dataSet.length
+ )
+}
/**
- * Compute the median of the given data set.
+ * Computes the median of the given data set.
*
* @param dataSet - Data set.
* @returns The median of the given data set.
+ * @internal
*/
export const median = (dataSet: number[]): number => {
if (Array.isArray(dataSet) && dataSet.length === 0) {
return 0
- }
- if (Array.isArray(dataSet) && dataSet.length === 1) {
+ } else if (Array.isArray(dataSet) && dataSet.length === 1) {
return dataSet[0]
}
const sortedDataSet = dataSet.slice().sort((a, b) => a - b)
}
/**
- * Is the given object a plain object?
+ * Rounds the given number to the given scale.
+ * The rounding is done using the "round half away from zero" method.
+ *
+ * @param num - The number to round.
+ * @param scale - The scale to round to.
+ * @returns The rounded number.
+ * @internal
+ */
+export const round = (num: number, scale = 2): number => {
+ const rounder = Math.pow(10, scale)
+ return Math.round(num * rounder * (1 + Number.EPSILON)) / rounder
+}
+
+/**
+ * Is the given value a plain object?
+ *
+ * @param value - The value to check.
+ * @returns `true` if the given value is a plain object, `false` otherwise.
+ * @internal
+ */
+export const isPlainObject = (value: unknown): value is object =>
+ typeof value === 'object' &&
+ value !== null &&
+ value.constructor === Object &&
+ Object.prototype.toString.call(value) === '[object Object]'
+
+/**
+ * Detects whether the given value is a kill behavior or not.
+ *
+ * @typeParam KB - Which specific KillBehavior type to test against.
+ * @param killBehavior - Which kind of kill behavior to detect.
+ * @param value - Unknown value.
+ * @returns `true` if `value` was strictly equals to `killBehavior`, otherwise `false`.
+ * @internal
+ */
+export const isKillBehavior = <KB extends KillBehavior>(
+ killBehavior: KB,
+ value: unknown
+): value is KB => {
+ return value === killBehavior
+}
+
+/**
+ * Detects whether the given value is an asynchronous function or not.
+ *
+ * @param fn - Unknown value.
+ * @returns `true` if `fn` was an asynchronous function, otherwise `false`.
+ * @internal
+ */
+export const isAsyncFunction = (
+ fn: unknown
+): fn is (...args: unknown[]) => Promise<unknown> => {
+ return typeof fn === 'function' && fn.constructor.name === 'AsyncFunction'
+}
+
+/**
+ * Generates a cryptographically secure random number in the [0,1[ range
*
- * @param obj - The object to check.
- * @returns `true` if the given object is a plain object, `false` otherwise.
+ * @returns A number in the [0,1[ range
+ * @internal
*/
-export const isPlainObject = (obj: unknown): boolean =>
- typeof obj === 'object' &&
- obj !== null &&
- obj?.constructor === Object &&
- Object.prototype.toString.call(obj) === '[object Object]'
+export const secureRandom = (): number => {
+ return getRandomValues(new Uint32Array(1))[0] / 0x100000000
+}
+
+/**
+ * Returns the minimum of the given numbers.
+ * If no numbers are given, `Infinity` is returned.
+ *
+ * @param args - The numbers to get the minimum of.
+ * @returns The minimum of the given numbers.
+ * @internal
+ */
+export const min = (...args: number[]): number =>
+ args.reduce((minimum, num) => (minimum < num ? minimum : num), Infinity)
+
+/**
+ * Returns the maximum of the given numbers.
+ * If no numbers are given, `-Infinity` is returned.
+ *
+ * @param args - The numbers to get the maximum of.
+ * @returns The maximum of the given numbers.
+ * @internal
+ */
+export const max = (...args: number[]): number =>
+ args.reduce((maximum, num) => (maximum > num ? maximum : num), -Infinity)
+
+/**
+ * Wraps a function so that it can only be called once.
+ *
+ * @param fn - The function to wrap.
+ * @param context - The context to bind the function to.
+ * @returns The wrapped function.
+ *
+ * @typeParam A - The function's arguments.
+ * @typeParam R - The function's return value.
+ * @typeParam C - The function's context.
+ * @internal
+ */
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export const once = <A extends any[], R, C>(
+ fn: (...args: A) => R,
+ context: C
+): ((...args: A) => R) => {
+ let result: R
+ return (...args: A) => {
+ // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+ if (fn != null) {
+ result = fn.apply<C, A, R>(context, args)
+ ;(fn as unknown as undefined) = (context as unknown as undefined) =
+ undefined
+ }
+ return result
+ }
+}
repositories / poolifier.git / blobdiff