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Scala example source code file (TwoWayCache.scala)
The TwoWayCache.scala Scala example source codepackage scala package reflect package runtime import scala.collection.mutable.WeakHashMap import java.lang.ref.WeakReference /** A cache that maintains a bijection between Java reflection type `J` * and Scala reflection type `S`. * * The cache is two-way weak (i.e. is powered by weak references), * so that neither Java artifacts prevent Scala artifacts from being garbage collected, * nor the other way around. */ private[runtime] class TwoWayCache[J, S] { private val toScalaMap = new WeakHashMap[J, WeakReference[S]] private val toJavaMap = new WeakHashMap[S, WeakReference[J]] def enter(j: J, s: S) = synchronized { // debugInfo("cached: "+j+"/"+s) toScalaMap(j) = new WeakReference(s) toJavaMap(s) = new WeakReference(j) } private object SomeRef { def unapply[T](optRef: Option[WeakReference[T]]): Option[T] = if (optRef.nonEmpty) { val result = optRef.get.get if (result != null) Some(result) else None } else None } def toScala(key: J)(body: => S): S = synchronized { toScalaMap get key match { case SomeRef(v) => v case _ => val result = body enter(key, result) result } } def toJava(key: S)(body: => J): J = synchronized { toJavaMap get key match { case SomeRef(v) => v case _ => val result = body enter(result, key) result } } } Other Scala source code examplesHere is a short list of links related to this Scala TwoWayCache.scala source code file: |
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