scala.ref.SoftReference.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.ref
/**
* @author Sean McDirmid
*/
class SoftReference[+T <: AnyRef](value : T, queue : ReferenceQueue[T]) extends ReferenceWrapper[T] {
def this(value : T) = this(value, null)
val underlying: java.lang.ref.SoftReference[_ <: T] =
new SoftReferenceWithWrapper[T](value, queue, this)
}
/**
* A companion object that implements an extractor for `SoftReference` values
* @author Rebecca Claire Murphy
*/
object SoftReference {
/** Creates a `SoftReference` pointing to `value` */
def apply[T <: AnyRef](value: T) = new SoftReference(value)
/** Optionally returns the referenced value, or `None` if that value no longer exists */
def unapply[T <: AnyRef](sr: SoftReference[T]): Option[T] = Option(sr.underlying.get)
}
/**
* @author Philipp Haller
*/
private class SoftReferenceWithWrapper[T <: AnyRef](value: T, queue: ReferenceQueue[T], val wrapper: SoftReference[T])
extends java.lang.ref.SoftReference[T](value, if (queue == null) null else queue.underlying.asInstanceOf[java.lang.ref.ReferenceQueue[T]]) with ReferenceWithWrapper[T]