pekko/akka-actor/src/main/scala/akka/routing/Iterators.scala

47 lines
1.3 KiB
Scala

/**
* Copyright (C) 2009-2011 Scalable Solutions AB <http://scalablesolutions.se>
*/
package akka.routing
import akka.actor.ActorRef
import scala.collection.JavaConversions._
/**
* An Iterator that is either always empty or yields an infinite number of Ts.
*/
trait InfiniteIterator[T] extends Iterator[T] {
val items: Seq[T]
}
/**
* CyclicIterator is a round-robin style InfiniteIterator that cycles the supplied List.
*/
case class CyclicIterator[T](val items: Seq[T]) extends InfiniteIterator[T] {
def this(items: java.util.List[T]) = this(items.toSeq)
@volatile private[this] var current: Seq[T] = items
def hasNext = items != Nil
def next = {
val nc = if (current == Nil) items else current
current = nc.tail
nc.head
}
override def exists(f: T => Boolean): Boolean = items.exists(f)
}
/**
* This InfiniteIterator always returns the Actor that has the currently smallest mailbox
* useful for work-stealing.
*/
case class SmallestMailboxFirstIterator(val items : Seq[ActorRef]) extends InfiniteIterator[ActorRef] {
def this(items: java.util.List[ActorRef]) = this(items.toSeq)
def hasNext = items != Nil
def next = items.reduceLeft((a1, a2) => if (a1.mailboxSize < a2.mailboxSize) a1 else a2)
override def exists(f: ActorRef => Boolean): Boolean = items.exists(f)
}