src/utils.ts

   1 import os from 'node:os'
   2 import type {
   3   MeasurementStatisticsRequirements,
   4   WorkerChoiceStrategyOptions
   5 } from './pools/selection-strategies/selection-strategies-types'
   6
   7 /**
   8  * An intentional empty function.
   9  */
  10 export const EMPTY_FUNCTION: () => void = Object.freeze(() => {
  11   /* Intentionally empty */
  12 })
  13
  14 /**
  15  * Default worker choice strategy options.
  16  */
  17 export const DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS: WorkerChoiceStrategyOptions =
  18   {
  19     runTime: { median: false },
  20     waitTime: { median: false },
  21     elu: { median: false }
  22   }
  23
  24 /**
  25  * Default measurement statistics requirements.
  26  */
  27 export const DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS: MeasurementStatisticsRequirements =
  28   {
  29     aggregate: false,
  30     average: false,
  31     median: false
  32   }
  33
  34 /**
  35  * Safe helper to get the host OS optimized maximum pool size.
  36  */
  37 export const availableParallelism = (): number => {
  38   let availableParallelism = 1
  39   try {
  40     availableParallelism = os.availableParallelism()
  41   } catch {
  42     const cpus = os.cpus()
  43     if (Array.isArray(cpus) && cpus.length > 0) {
  44       availableParallelism = cpus.length
  45     }
  46   }
  47   return availableParallelism
  48 }
  49
  50 /**
  51  * Compute the median of the given data set.
  52  *
  53  * @param dataSet - Data set.
  54  * @returns The median of the given data set.
  55  */
  56 export const median = (dataSet: number[]): number => {
  57   if (Array.isArray(dataSet) && dataSet.length === 0) {
  58     return 0
  59   }
  60   if (Array.isArray(dataSet) && dataSet.length === 1) {
  61     return dataSet[0]
  62   }
  63   const sortedDataSet = dataSet.slice().sort((a, b) => a - b)
  64   return (
  65     (sortedDataSet[(sortedDataSet.length - 1) >> 1] +
  66       sortedDataSet[sortedDataSet.length >> 1]) /
  67     2
  68   )
  69 }
  70
  71 /**
  72  * Is the given object a plain object?
  73  *
  74  * @param obj - The object to check.
  75  * @returns `true` if the given object is a plain object, `false` otherwise.
  76  */
  77 export const isPlainObject = (obj: unknown): boolean =>
  78   typeof obj === 'object' &&
  79   obj !== null &&
  80   obj?.constructor === Object &&
  81   Object.prototype.toString.call(obj) === '[object Object]'