com.sap.psr.vulas.monitor.LoaderHierarchy Maven / Gradle / Ivy

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/**
 * This file is part of Eclipse Steady.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2018 SAP SE or an SAP affiliate company. All rights reserved.
 */
package com.sap.psr.vulas.monitor;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Offers methods to create and interact with a hierarchy of {@link ClassLoader}s and {@link Loader}s.
 */
public class LoaderHierarchy {
	
	private static final Log log = LogFactory.getLog(LoaderHierarchy.class);

	private Map loaderMap = new HashMap();
	
	/**
	 * add.
	 *
	 * @param _cl a {@link java.lang.ClassLoader} object.
	 * @return a {@link com.sap.psr.vulas.monitor.Loader} object.
	 */
	public Loader add(ClassLoader _cl) {
		Loader l = this.loaderMap.get(_cl); 
		if(l==null) {
			l = new Loader(_cl);
			this.loaderMap.put(_cl, l);
			
			final ClassLoader pcl = _cl.getParent();
			if(pcl!=null) {
				Loader pl = this.add(pcl);
				l.setParent(pl);
				l.createClassPool(pl, _cl);
			}
			else {
				l.createClassPool(null, _cl);
			}
		}
		return l;
	}
	
	/**
	 * getLoader.
	 *
	 * @param _cl a {@link java.lang.ClassLoader} object.
	 * @return a {@link com.sap.psr.vulas.monitor.Loader} object.
	 */
	public Loader getLoader(ClassLoader _cl) {
		return this.loaderMap.get(_cl);
	}
	
	/**
	 * isLeaf.
	 *
	 * @param _cl a {@link java.lang.ClassLoader} object.
	 * @return a boolean.
	 */
	public boolean isLeaf(ClassLoader _cl) {
		final Loader l = this.loaderMap.get(_cl);
		if(l==null)
			throw new IllegalArgumentException();
		else
			return l.isLeaf();
	}
	
	/**
	 * isRoot.
	 *
	 * @param _cl a {@link java.lang.ClassLoader} object.
	 * @return a boolean.
	 */
	public boolean isRoot(ClassLoader _cl) {
		final Loader l = this.loaderMap.get(_cl);
		if(l==null)
			throw new IllegalArgumentException();
		else
			return l.isRoot();
	}
	
	/**
	 * getRoot.
	 *
	 * @return a {@link com.sap.psr.vulas.monitor.Loader} object.
	 */
	public Loader getRoot() {
		Loader r = null;
		for(Loader l : this.loaderMap.values()) {
			if(l.isRoot()) {
				r = l;
				break;
			}
		}
		return r;
	}
	
	/**
	 * logHierarchy.
	 *
	 * @param _l a {@link com.sap.psr.vulas.monitor.Loader} object.
	 * @param _lvl a int.
	 */
	public void logHierarchy(Loader _l, int _lvl) {
		LoaderHierarchy.log.info(_lvl + "    " + this.getIndent(_lvl) + _l.toString());
		for(Loader c : _l.getChilds()) this.logHierarchy(c, _lvl+1);
	}
	
	private String getIndent(int _i) {
		final StringBuilder b = new StringBuilder();
		for(int i=0; i<_i; i++) b.append("    ");
		return b.toString();
	}
}