X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=src%2Futils.ts;h=efd1f124084776667bd60495f202cec32c7e04a9;hb=0676e5d32c8f8ee5c5b7f5998f4973b0a276460f;hp=d85c5ba58b4988fad867a9b35f9dca5bb5bb2b45;hpb=78099a150dc54d7adab495195fa5f133fd54e114;p=poolifier.git

diff --git a/src/utils.ts b/src/utils.ts
index d85c5ba5..efd1f124 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,3 +1,16 @@
+import * as os from 'node:os'
+import type {
+  MeasurementStatisticsRequirements,
+  WorkerChoiceStrategyOptions
+} from './pools/selection-strategies/selection-strategies-types'
+import type { KillBehavior } from './worker/worker-options'
+import type { MeasurementStatistics } from './pools/worker'
+
+/**
+ * Default task name.
+ */
+export const DEFAULT_TASK_NAME = 'default'
+
 /**
  * An intentional empty function.
  */
@@ -6,19 +19,166 @@ export const EMPTY_FUNCTION: () => void = Object.freeze(() => {
 })
 
 /**
- * Returns the median of the given data set.
+ * Default worker choice strategy options.
+ */
+export const DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS: WorkerChoiceStrategyOptions =
+  {
+    choiceRetries: 6,
+    runTime: { median: false },
+    waitTime: { median: false },
+    elu: { median: false }
+  }
+
+/**
+ * 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 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
+// }
+
+/**
+ * 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 / 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'
+}
+
+/**
+ * Updates the given measurement statistics.
+ *
+ * @param measurementStatistics - The measurement statistics to update.
+ * @param measurementRequirements - The measurement statistics requirements.
+ * @param measurementValue - The measurement value.
+ * @param numberOfMeasurements - The number of measurements.
+ */
+export const updateMeasurementStatistics = (
+  measurementStatistics: MeasurementStatistics,
+  measurementRequirements: MeasurementStatisticsRequirements,
+  measurementValue: number,
+  numberOfMeasurements: number
+): void => {
+  if (measurementRequirements.aggregate) {
+    measurementStatistics.aggregate =
+      (measurementStatistics.aggregate ?? 0) + measurementValue
+    measurementStatistics.minimum = Math.min(
+      measurementValue,
+      measurementStatistics.minimum ?? Infinity
+    )
+    measurementStatistics.maximum = Math.max(
+      measurementValue,
+      measurementStatistics.maximum ?? -Infinity
+    )
+    if (measurementRequirements.average && numberOfMeasurements !== 0) {
+      measurementStatistics.average =
+        measurementStatistics.aggregate / numberOfMeasurements
+    }
+    if (measurementRequirements.median && measurementValue != null) {
+      measurementStatistics.history.push(measurementValue)
+      measurementStatistics.median = median(measurementStatistics.history)
+    }
   }
-  return (sortedDataSet[middleIndex - 1] + sortedDataSet[middleIndex]) / 2
 }