scala.collection.mutable.History.scala Maven / Gradle / Ivy
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2009, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.collection.mutable
/** History[A, B] objects may subscribe to events of
* type A published by an object of type B.
* The history subscriber object records all published events
* up to maximum number of maxHistory events.
*
* @author Matthias Zenger
* @version 1.0, 08/07/2003
*/
@serializable
class History[A, B] extends AnyRef with Subscriber[A, B] with Collection[(B, A)]
{
protected val log: Queue[(B, A)] = new Queue[(B, A)]
val maxHistory: Int = 1000
/**
* @param pub ...
* @param event ...
*/
def notify(pub: B, event: A): Unit = {
if (log.length >= maxHistory)
log.dequeue
log.enqueue((pub, event))
}
override def size: Int = log.length
def iterator: Iterator[(B, A)] = log.iterator
def events: Iterator[A] = log.iterator.map { case (_, e) => e }
def clear(): Unit = log.clear
}