Scala example source code file (SetStorage.scala)

This example Scala source code file (SetStorage.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

cachedfilestorage, cachedfilestorage, file, file, io, node, node, setstorage, unit, unit

The Scala SetStorage.scala source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2002-2011, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */


package scala.xml
package persistent

import scala.collection.mutable
import java.io.File

/** A persistent store with set semantics. This class allows to add and remove 
 *  trees, but never contains two structurally equal trees.
 *
 *  @author Burak Emir
 */
class SetStorage(file: File) extends CachedFileStorage(file) {

  private var theSet: mutable.HashSet[Node] = new mutable.HashSet[Node]

  // initialize

  {
    val it = super.initialNodes
    dirty = it.hasNext
    for(x <- it) {
      theSet += x;
    }
  }

  /* forwarding methods to hashset*/

  def += (e: Node): Unit = synchronized { this.dirty = true; theSet += e }

  def -= (e: Node): Unit = synchronized { this.dirty = true; theSet -= e }

  def nodes = synchronized { theSet.iterator }

}