model/org/eclipse/jdt/internal/core/ElementCache.java

package org.eclipse.jdt.internal.core;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved.
 */
import org.eclipse.core.resources.*;

import org.eclipse.jdt.core.IOpenable;
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 {
/**
 * 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) {
	IOpenable element = (IOpenable) entry._fKey;
	synchronized (element) {
		try {
			if (element.hasUnsavedChanges()) {
				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;
		}
	}
}
	/**
	 * Returns a new instance of the reciever.
	 */
	protected LRUCache newInstance(int size, int overflow) {
		return new ElementCache(size, overflow);
	}
}