+ * 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 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
+ )
+}
+
+/**
+ * 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
+ } else if (Array.isArray(dataSet) && dataSet.length === 1) {
+ return dataSet[0]
+ }
+ const sortedDataSet = dataSet.slice().sort((a, b) => a - b)
+ return (
+ (sortedDataSet[(sortedDataSet.length - 1) >> 1] +
+ sortedDataSet[sortedDataSet.length >> 1]) /
+ 2
+ )
+}
+
+/**
+ * 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
+ * @returns A number in the [0,1[ range
+ * @internal