japgolly.scalajs.benchmark.engine.Clock.scala Maven / Gradle / Ivy

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package japgolly.scalajs.benchmark.engine

import scala.concurrent.duration._
import scala.scalajs.js
import scala.scalajs.js.annotation.JSName
import scala.util.Try

trait Clock {
  def time(f: => Any): FiniteDuration
}

trait StatelessClock extends Clock {
  type Time
  def get: Time
  def duration(start: Time, end: Time): FiniteDuration

  // val bh = new Blackhole

  override def time(f: => Any): FiniteDuration = {
    val a = get
    val x = f
    val b = get
    // bh.consumeA(x)
    duration(a, b)
  }
}

object Clock {
  object SysNano extends StatelessClock {
    override def toString = "SysNano"
    override type Time                      = Long
    override def get                        = System.nanoTime()
    override def duration(a: Time, b: Time) = FiniteDuration(b - a, NANOSECONDS)
  }

  object SysMilli extends StatelessClock {
    override def toString = "SysMilli"
    override type Time                      = Long
    override def get                        = System.currentTimeMillis()
    override def duration(a: Time, b: Time) = FiniteDuration(b - a, MILLISECONDS)
  }

  @JSName("chrome.Interval")
  @js.native
  class ChromeInterval() extends js.Any {
    def start(): Unit = js.native
    def stop(): Unit = js.native
    def microseconds(): Double = js.native
  }

  val Chrome: Option[Clock] =
    Try(new ChromeInterval()).toOption.map(i =>
      new Clock {
        override def toString = "Chrome"
        override def time(f: => Any): FiniteDuration = {
          i.start()
          val x = f
          i.stop()
          // bh.consumeA(x)
          FiniteDuration(i.microseconds().toLong, MICROSECONDS)
        }
      }
    )

  /*
  From https://github.com/bestiejs/benchmark.js/blob/master/benchmark.js

  // Detect Node.js's nanosecond resolution timer available in Node.js >= 0.8.
  if (processObject && typeof (timer.ns = processObject.hrtime) == 'function') {
    timers.push({ 'ns': timer.ns, 'res': getRes('ns'), 'unit': 'ns' });
  }
  // Detect Wade Simmons' Node.js `microtime` module.
  if (microtimeObject && typeof (timer.ns = microtimeObject.now) == 'function') {
    timers.push({ 'ns': timer.ns,  'res': getRes('us'), 'unit': 'us' });
  }
   */

  val Default: Clock =
    Chrome getOrElse SysNano
}