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

package org.eclipse.jdt.internal.core;

/**********************************************************************
Copyright (c) 2002 IBM Corp. and others.
All rights reserved.   This program and the accompanying materials
are made available under the terms of the Common Public License v0.5
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v05.html
 
Contributors:
    Jerome Lanneluc - Initial implementation
**********************************************************************/

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaModel;
import org.eclipse.jdt.core.IOpenable;

/**
 * The cache of java elements to their respective info.
 */
public class JavaModelCache {
	public static final int PKG_CACHE_SIZE = 500;
	public static final int OPENABLE_CACHE_SIZE = 2000;
	
	/**
	 * Active Java Model Info
	 */
	protected JavaModelInfo modelInfo;
	
	/**
	 * Cache of open projects and package fragment roots.
	 */
	protected Map projectAndRootCache;
	
	/**
	 * Cache of open package fragments
	 */
	protected Map pkgCache;

	/**
	 * Cache of open compilation unit and class files
	 */
	protected OverflowingLRUCache openableCache;

	/**
	 * Cache of open children of openable Java Model Java elements
	 */
	protected Map childrenCache;
	
public JavaModelCache() {
	this.projectAndRootCache = new HashMap(50);
	this.pkgCache = new HashMap(PKG_CACHE_SIZE);
	this.openableCache = new ElementCache(OPENABLE_CACHE_SIZE);
	this.childrenCache = new HashMap(OPENABLE_CACHE_SIZE*20); // average 20 chilren per openable
}

public double openableFillingRate() {
	return this.openableCache.fillingRate();
}
public int pkgSize() {
	return this.pkgCache.size();
}
	
/**
 *  Returns the info for the element.
 */
public Object getInfo(IJavaElement element) {
	switch (element.getElementType()) {
		case IJavaElement.JAVA_MODEL:
			return this.modelInfo;
		case IJavaElement.JAVA_PROJECT:
		case IJavaElement.PACKAGE_FRAGMENT_ROOT:
			return this.projectAndRootCache.get(element);
		case IJavaElement.PACKAGE_FRAGMENT:
			return this.pkgCache.get(element);
		case IJavaElement.COMPILATION_UNIT:
		case IJavaElement.CLASS_FILE:
			return this.openableCache.get(element);
		default:
			return this.childrenCache.get(element);
	}
}
/**
 * Returns the handle to the active Java Model, or <code>null</code> if there
 * is no active Java Model.
 */
public JavaModel getJavaModel() {
	if (this.modelInfo == null) {
		return null;
	} else {
		return this.modelInfo.getJavaModel();
	}
}
/**
 *  Returns the info for this element without
 *  disturbing the cache ordering.
 */
protected Object peekAtInfo(IJavaElement element) {
	switch (element.getElementType()) {
		case IJavaElement.JAVA_MODEL:
			return this.modelInfo;
		case IJavaElement.JAVA_PROJECT:
		case IJavaElement.PACKAGE_FRAGMENT_ROOT:
			return this.projectAndRootCache.get(element);
		case IJavaElement.PACKAGE_FRAGMENT:
			return this.pkgCache.get(element);
		case IJavaElement.COMPILATION_UNIT:
		case IJavaElement.CLASS_FILE:
			return this.openableCache.peek(element);
		default:
			return this.childrenCache.get(element);
	}
}

/**
 * Remember the info for the element.
 */
protected void putInfo(IJavaElement element, Object info) {
	switch (element.getElementType()) {
		case IJavaElement.JAVA_MODEL:
			this.modelInfo = (JavaModelInfo) info;
			break;
		case IJavaElement.JAVA_PROJECT:
		case IJavaElement.PACKAGE_FRAGMENT_ROOT:
			this.projectAndRootCache.put(element, info);
			break;
		case IJavaElement.PACKAGE_FRAGMENT:
			this.pkgCache.put(element, info);
			break;
		case IJavaElement.COMPILATION_UNIT:
		case IJavaElement.CLASS_FILE:
			this.openableCache.put(element, info);
			break;
		default:
			this.childrenCache.put(element, info);
	}
}
/**
 * Removes the info of the element from the cache.
 */
protected void removeInfo(IJavaElement element) {
	switch (element.getElementType()) {
		case IJavaElement.JAVA_MODEL:
			this.modelInfo = null;
			break;
		case IJavaElement.JAVA_PROJECT:
		case IJavaElement.PACKAGE_FRAGMENT_ROOT:
			this.projectAndRootCache.remove(element);
			break;
		case IJavaElement.PACKAGE_FRAGMENT:
			this.pkgCache.remove(element);
			break;
		case IJavaElement.COMPILATION_UNIT:
		case IJavaElement.CLASS_FILE:
			this.openableCache.remove(element);
			break;
		default:
			this.childrenCache.remove(element);
	}
}
}