/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

package com.sun.org.apache.bcel.internal.util;


import java.io.*;

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

import com.sun.org.apache.bcel.internal.classfile.*;

/**
 * The repository maintains information about which classes have
 * been loaded.
 *
 * It loads its data from the ClassLoader implementation
 * passed into its constructor.
 *
 * @see com.sun.org.apache.bcel.internal.Repository
 *
 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @author David Dixon-Peugh
 */
public class ClassLoaderRepository
  implements Repository
{
  private java.lang.ClassLoader loader;
  private HashMap loadedClasses =
    new HashMap(); // CLASSNAME X JAVACLASS

  public ClassLoaderRepository( java.lang.ClassLoader loader ) {
    this.loader = loader;
  }

  /**
   * Store a new JavaClass into this Repository.
   */
  public void storeClass( JavaClass clazz ) {
    loadedClasses.put( clazz.getClassName(),
                       clazz );
    clazz.setRepository( this );
  }

  /**
   * Remove class from repository
   */
  public void removeClass(JavaClass clazz) {
    loadedClasses.remove(clazz.getClassName());
  }

  /**
   * Find an already defined JavaClass.
   */
  public JavaClass findClass( String className ) {
    if ( loadedClasses.containsKey( className )) {
      return (JavaClass) loadedClasses.get( className );
    } else {
      return null;
    }
  }

  /**
   * Lookup a JavaClass object from the Class Name provided.
   */
  public JavaClass loadClass( String className )
    throws ClassNotFoundException
  {
    String classFile = className.replace('.', '/');

    JavaClass RC = findClass( className );
    if (RC != null) { return RC; }

    try {
      InputStream is =
        loader.getResourceAsStream( classFile + ".class" );

      if(is == null) {
        throw new ClassNotFoundException(className + " not found.");
      }

      ClassParser parser = new ClassParser( is, className );
      RC = parser.parse();

      storeClass( RC );

      return RC;
    } catch (IOException e) {
      throw new ClassNotFoundException( e.toString() );
    }
  }

  public JavaClass loadClass(Class clazz) throws ClassNotFoundException {
    return loadClass(clazz.getName());
  }

  /** Clear all entries from cache.
   */
  public void clear() {
    loadedClasses.clear();
  }
}