| /******************************************************************************* |
| * Copyright (c) 2000, 2004 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.core; |
| |
| import org.eclipse.jdt.core.IJavaElement; |
| import org.eclipse.jdt.core.JavaModelException; |
| import org.eclipse.jdt.internal.core.util.LRUCache; |
| |
| /** |
| * An LRU cache of <code>JavaElements</code>. |
| */ |
| public class ElementCache extends OverflowingLRUCache { |
| |
| IJavaElement spaceLimitParent = null; |
| |
| /** |
| * Constructs a new element cache of the given size. |
| */ |
| public ElementCache(int size) { |
| super(size); |
| } |
| /** |
| * Constructs a new element cache of the given size. |
| */ |
| public ElementCache(int size, int overflow) { |
| super(size, overflow); |
| } |
| /** |
| * Returns true if the element is successfully closed and |
| * removed from the cache, otherwise false. |
| * |
| * <p>NOTE: this triggers an external removal of this element |
| * by closing the element. |
| */ |
| protected boolean close(LRUCacheEntry entry) { |
| Openable element = (Openable) entry._fKey; |
| try { |
| if (!element.canBeRemovedFromCache()) { |
| return false; |
| } else { |
| // We must close an entire JarPackageFragmentRoot at once. |
| if (element instanceof JarPackageFragment) { |
| JarPackageFragment packageFragment= (JarPackageFragment) element; |
| JarPackageFragmentRoot root = (JarPackageFragmentRoot) packageFragment.getParent(); |
| root.close(); |
| } else { |
| element.close(); |
| } |
| return true; |
| } |
| } catch (JavaModelException npe) { |
| return false; |
| } |
| } |
| |
| /* |
| * Ensures that there is enough room for adding the given number of children. |
| * If the space limit must be increased, record the parent that needed this space limit. |
| */ |
| protected void ensureSpaceLimit(int childrenSize, IJavaElement parent) { |
| // ensure the children can be put without closing other elements |
| int spaceNeeded = 1 + (int)((1 + fLoadFactor) * (childrenSize + fOverflow)); |
| if (fSpaceLimit < spaceNeeded) { |
| // parent is being opened with more children than the space limit |
| shrink(); // remove overflow |
| setSpaceLimit(spaceNeeded); |
| this.spaceLimitParent = parent; |
| } |
| } |
| |
| /* |
| * If the given parent was the one that increased the space limit, reset |
| * the space limit to the given default value. |
| */ |
| protected void resetSpaceLimit(int defaultLimit, IJavaElement parent) { |
| if (parent.equals(this.spaceLimitParent)) { |
| setSpaceLimit(defaultLimit); |
| this.spaceLimitParent = null; |
| } |
| } |
| |
| /** |
| * Returns a new instance of the reciever. |
| */ |
| protected LRUCache newInstance(int size, int overflow) { |
| return new ElementCache(size, overflow); |
| } |
| |
| } |