import * as os from 'node:os'
+import { webcrypto } from 'node:crypto'
import type {
MeasurementStatisticsRequirements,
WorkerChoiceStrategyOptions
* Always returns a value greater than zero.
*
* @returns The host OS optimized maximum pool size.
+ * @internal
*/
export const availableParallelism = (): number => {
let availableParallelism = 1
return availableParallelism
}
-// /**
-// * Computes the retry delay in milliseconds using an exponential back off algorithm.
-// *
-// * @param retryNumber - The number of retries that have already been attempted
-// * @param maxDelayRatio - The maximum ratio of the delay that can be randomized
-// * @returns Delay in milliseconds
-// */
-// export const exponentialDelay = (
-// retryNumber = 0,
-// maxDelayRatio = 0.2
-// ): number => {
-// const delay = Math.pow(2, retryNumber) * 100
-// const randomSum = delay * maxDelayRatio * Math.random() // 0-(maxDelayRatio*100)% of the delay
-// return delay + randomSum
-// }
+/**
+ * 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.
+ */
+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 average = (dataSet: number[]): number => {
+ if (Array.isArray(dataSet) && dataSet.length === 0) {
+ return 0
+ }
+ if (Array.isArray(dataSet) && dataSet.length === 1) {
+ return dataSet[0]
+ }
+ return (
+ dataSet.reduce((accumulator, number) => accumulator + number, 0) /
+ dataSet.length
+ )
+}
/**
* 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) {
* @param killBehavior - Which kind of kill behavior to detect.
* @param value - Any value.
* @returns `true` if `value` was strictly equals to `killBehavior`, otherwise `false`.
+ * @internal
*/
export const isKillBehavior = <KB extends KillBehavior>(
killBehavior: KB,
* @param measurementRequirements - The measurement statistics requirements.
* @param measurementValue - The measurement value.
* @param numberOfMeasurements - The number of measurements.
+ * @internal
*/
export const updateMeasurementStatistics = (
measurementStatistics: MeasurementStatistics,
measurementRequirements: MeasurementStatisticsRequirements,
- measurementValue: number,
- numberOfMeasurements: number
+ measurementValue: number
): void => {
if (measurementRequirements.aggregate) {
measurementStatistics.aggregate =
measurementValue,
measurementStatistics.maximum ?? -Infinity
)
- if (measurementRequirements.average && numberOfMeasurements !== 0) {
- measurementStatistics.average =
- measurementStatistics.aggregate / numberOfMeasurements
- }
- if (measurementRequirements.median && measurementValue != null) {
+ if (
+ (measurementRequirements.average || measurementRequirements.median) &&
+ measurementValue != null
+ ) {
measurementStatistics.history.push(measurementValue)
- measurementStatistics.median = median(measurementStatistics.history)
+ if (measurementRequirements.average) {
+ measurementStatistics.average = average(measurementStatistics.history)
+ }
+ if (measurementRequirements.median) {
+ measurementStatistics.median = median(measurementStatistics.history)
+ }
+ }
+ }
+}
+
+/**
+ * Executes a function once at a time.
+ *
+ * @param fn - The function to execute.
+ * @param context - The context to bind the function to.
+ * @returns The function to execute.
+ */
+export const once = (
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ fn: (...args: any[]) => void,
+ context: unknown
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+): ((...args: any[]) => void) => {
+ let called = false
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ return function (...args: any[]): void {
+ if (!called) {
+ called = true
+ fn.apply(context, args)
+ called = false
}
}
}
+
+/**
+ * Generate a cryptographically secure random number in the [0,1[ range
+ *
+ * @returns A number in the [0,1[ range
+ */
+export const secureRandom = (): number => {
+ return webcrypto.getRandomValues(new Uint32Array(1))[0] / 0x100000000
+}