Merge pull request #2602 from t3hnar/Duration.toCoarsest

Add Duration.toCoarsest method

1 files changed, 36 insertions, 0 deletions

diff --git a/src/library/scala/concurrent/duration/Duration.scala b/src/library/scala/concurrent/duration/Duration.scala
index a24266bf19..9a8844b489 100644
--- a/src/library/scala/concurrent/duration/Duration.scala
+++ b/src/library/scala/concurrent/duration/Duration.scala
@@ -221,6 +221,8 @@ object Duration {
     final def toMinutes: Long = fail("toMinutes")
     final def toHours: Long   = fail("toHours")
     final def toDays: Long    = fail("toDays")
+	
+    final def toCoarsest: Duration = this
   }
 
   /**
@@ -520,6 +522,18 @@ sealed abstract class Duration extends Serializable with Ordered[Duration] {
    * $ovf
    */
   def plus(other: Duration)  = this + other
+  /**
+   * Return duration which is equal to this duration but with a coarsest Unit, or self in case it is already the coarsest Unit
+   * <p/>
+   * Examples:
+   * {{{
+   * Duration(60, MINUTES).toCoarsest // Duration(1, HOURS)
+   * Duration(1000, MILLISECONDS).toCoarsest // Duration(1, SECONDS)
+   * Duration(48, HOURS).toCoarsest // Duration(2, DAYS)
+   * Duration(5, SECONDS).toCoarsest // Duration(5, SECONDS)
+   * }}}
+   */  
+  def toCoarsest: Duration
 }
 
 object FiniteDuration {
@@ -691,6 +705,28 @@ final class FiniteDuration(val length: Long, val unit: TimeUnit) extends Duratio
 
   final def isFinite() = true
 
+  final def toCoarsest: Duration = {
+    def loop(length: Long, unit: TimeUnit): FiniteDuration = {
+      def coarserOrThis(coarser: TimeUnit, divider: Int) =
+        if (length % divider == 0) loop(length / divider, coarser)
+        else if (unit == this.unit) this
+        else FiniteDuration(length, unit)
+
+      unit match {
+        case DAYS => FiniteDuration(length, unit)
+        case HOURS => coarserOrThis(DAYS, 24)
+        case MINUTES => coarserOrThis(HOURS, 60)
+        case SECONDS => coarserOrThis(MINUTES, 60)
+        case MILLISECONDS => coarserOrThis(SECONDS, 1000)
+        case MICROSECONDS => coarserOrThis(MILLISECONDS, 1000)
+        case NANOSECONDS => coarserOrThis(MICROSECONDS, 1000)
+      }
+    }
+
+    if (unit == DAYS || length == 0) this
+    else loop(length, unit)
+  }
+
   override def equals(other: Any) = other match {
     case x: FiniteDuration => toNanos == x.toNanos
     case _                 => super.equals(other)