net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/core/ElementCache.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package net.sourceforge.phpdt.internal.core;
  12
  13 import net.sourceforge.phpdt.core.IOpenable;
  14 import net.sourceforge.phpdt.core.JavaModelException;
  15 import net.sourceforge.phpdt.internal.core.util.LRUCache;
  16
  17 /**
  18  * An LRU cache of <code>JavaElements</code>.
  19  */
  20 public class ElementCache extends OverflowingLRUCache {
  21         /**
  22          * Constructs a new element cache of the given size.
  23          */
  24         public ElementCache(int size) {
  25                 super(size);
  26         }
  27
  28         /**
  29          * Constructs a new element cache of the given size.
  30          */
  31         public ElementCache(int size, int overflow) {
  32                 super(size, overflow);
  33         }
  34
  35         /**
  36          * Returns true if the element is successfully closed and removed from the
  37          * cache, otherwise false.
  38          *
  39          * <p>
  40          * NOTE: this triggers an external removal of this element by closing the
  41          * element.
  42          */
  43         protected boolean close(LRUCacheEntry entry) {
  44                 IOpenable element = (IOpenable) entry._fKey;
  45                 try {
  46                         if (element.hasUnsavedChanges()) {
  47                                 return false;
  48                         } else {
  49                                 // We must close an entire JarPackageFragmentRoot at once.
  50                                 // if (element instanceof JarPackageFragment) {
  51                                 // JarPackageFragment packageFragment= (JarPackageFragment)
  52                                 // element;
  53                                 // JarPackageFragmentRoot root = (JarPackageFragmentRoot)
  54                                 // packageFragment.getParent();
  55                                 // root.close();
  56                                 // } else {
  57                                 element.close();
  58                                 // }
  59                                 return true;
  60                         }
  61                 } catch (JavaModelException npe) {
  62                         return false;
  63                 }
  64         }
  65
  66         /**
  67          * Returns a new instance of the reciever.
  68          */
  69         protected LRUCache newInstance(int size, int overflow) {
  70                 return new ElementCache(size, overflow);
  71         }
  72 }