scala.jdk.javaapi.DurationConverters.scala Maven / Gradle / Ivy

/*
 * Scala (https://www.scala-lang.org)
 *
 * Copyright EPFL and Lightbend, Inc.
 *
 * Licensed under Apache License 2.0
 * (http://www.apache.org/licenses/LICENSE-2.0).
 *
 * See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership.
 */

package scala.jdk.javaapi

import java.time.temporal.ChronoUnit
import java.time.{Duration => JDuration}
import java.util.concurrent.TimeUnit

import scala.concurrent.duration.{Duration, FiniteDuration}

/** This object contains methods that convert between Scala and Java duration types.
  *
  * The explicit conversion methods defined here are intended to be used in Java code. For Scala
  * code, it is recommended to use the extension methods defined in [[scala.jdk.DurationConverters]].
  */
object  DurationConverters {
  /** Convert a Java duration to a Scala duration. If the nanosecond part of the Java duration is
    * zero, the returned duration will have a time unit of seconds. If there is a nanoseconds part,
    * the Scala duration will have a time unit of nanoseconds.
    *
    * @throws IllegalArgumentException If the given Java Duration is out of bounds of what can be
    *                                  expressed by [[scala.concurrent.duration.FiniteDuration]].
    */
  def toScala(duration: JDuration): FiniteDuration = {
    val originalSeconds = duration.getSeconds
    val originalNanos = duration.getNano
    if (originalNanos == 0) {
      if (originalSeconds == 0) Duration.Zero
      else FiniteDuration(originalSeconds, TimeUnit.SECONDS)
    } else if (originalSeconds == 0) {
      FiniteDuration(originalNanos, TimeUnit.NANOSECONDS)
    } else {
      try {
        val secondsAsNanos = Math.multiplyExact(originalSeconds, 1000000000)
        val totalNanos = secondsAsNanos + originalNanos
        if ((totalNanos < 0 && secondsAsNanos < 0) || (totalNanos > 0 && secondsAsNanos > 0))
          FiniteDuration(totalNanos, TimeUnit.NANOSECONDS)
        else
          throw new ArithmeticException()
      } catch {
        case _: ArithmeticException =>
          throw new IllegalArgumentException(s"Java duration $duration cannot be expressed as a Scala duration")
      }
    }
  }

  /** Convert a Scala `FiniteDuration` to a Java duration. Note that the Scala duration keeps the
    * time unit it was created with, while a Java duration always is a pair of seconds and nanos,
    * so the unit it lost.
    */
  def toJava(duration: FiniteDuration): JDuration = {
    if (duration.length == 0) JDuration.ZERO
    else duration.unit match {
      case TimeUnit.NANOSECONDS => JDuration.ofNanos(duration.length)
      case TimeUnit.MICROSECONDS => JDuration.of(duration.length, ChronoUnit.MICROS)
      case TimeUnit.MILLISECONDS => JDuration.ofMillis(duration.length)
      case TimeUnit.SECONDS => JDuration.ofSeconds(duration.length)
      case TimeUnit.MINUTES => JDuration.ofMinutes(duration.length)
      case TimeUnit.HOURS => JDuration.ofHours(duration.length)
      case TimeUnit.DAYS => JDuration.ofDays(duration.length)
    }
  }
}