refactor: add task function name to task performance

[poolifier.git] / src / utils.ts

diff --git a/src/utils.ts b/src/utils.ts
index ed118da6b5e10165d23c2f6820af73e9ed7f02bb..128b65da06f6c17b9fd12659521db3d8437a655b 100644 (file)
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,4 +1,9 @@
-import type { WorkerChoiceStrategyOptions } from './pools/selection-strategies/selection-strategies-types'
+import * as os from 'node:os'
+import type {
+  MeasurementStatisticsRequirements,
+  WorkerChoiceStrategyOptions
+} from './pools/selection-strategies/selection-strategies-types'
+import type { KillBehavior } from './worker/worker-options'
 
 /**
  * An intentional empty function.
@@ -12,29 +17,109 @@ export const EMPTY_FUNCTION: () => void = Object.freeze(() => {
  */
 export const DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS: WorkerChoiceStrategyOptions =
   {
-    medRunTime: false
+    runTime: { median: false },
+    waitTime: { median: false },
+    elu: { median: false }
   }
 
 /**
- * Compute the median of the given data set.
+ * Default measurement statistics requirements.
+ */
+export const DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS: MeasurementStatisticsRequirements =
+  {
+    aggregate: false,
+    average: false,
+    median: false
+  }
+
+/**
+ * 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 numberOfCpus = os.cpus()
+    if (Array.isArray(numberOfCpus) && numberOfCpus.length > 0) {
+      availableParallelism = numberOfCpus.length
+    }
+  }
+  return availableParallelism
+}
+
+/**
+ * Computes the median of the given data set.
  *
  * @param dataSet - Data set.
  * @returns The median of the given data set.
  */
 export const median = (dataSet: number[]): number => {
+  if (Array.isArray(dataSet) && dataSet.length === 0) {
+    return 0
+  }
   if (Array.isArray(dataSet) && dataSet.length === 1) {
     return dataSet[0]
   }
   const sortedDataSet = dataSet.slice().sort((a, b) => a - b)
-  const middleIndex = Math.floor(sortedDataSet.length / 2)
-  if (sortedDataSet.length % 2 === 0) {
-    return sortedDataSet[middleIndex]
-  }
-  return (sortedDataSet[middleIndex - 1] + sortedDataSet[middleIndex]) / 2
+  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.
+ */
+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 object a plain object?
+ *
+ * @param obj - The object to check.
+ * @returns `true` if the given object is a plain object, `false` otherwise.
+ */
 export const isPlainObject = (obj: unknown): boolean =>
   typeof obj === 'object' &&
   obj !== null &&
   obj?.constructor === Object &&
   Object.prototype.toString.call(obj) === '[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 - Any value.
+ * @returns `true` if `value` was strictly equals to `killBehavior`, otherwise `false`.
+ */
+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 - Any value.
+ * @returns `true` if `fn` was an asynchronous function, otherwise `false`.
+ */
+export const isAsyncFunction = (
+  fn: unknown
+): fn is (...args: unknown[]) => Promise<unknown> => {
+  return typeof fn === 'function' && fn.constructor.name === 'AsyncFunction'
+}