/*

 * Copyright (c) 2002, 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

package sun.jvm.hotspot.utilities;

import java.util.*;

import sun.jvm.hotspot.classfile.*;

import sun.jvm.hotspot.oops.*;

import sun.jvm.hotspot.memory.*;

import sun.jvm.hotspot.runtime.*;

public class SystemDictionaryHelper {

   static {

      VM.registerVMInitializedObserver(new Observer() {

         public void update(Observable o, Object data) {

            initialize();

         }

      });

   }

   private static synchronized void initialize() {

      klasses = null;

   }

   // Instance klass array sorted by name.

   private static InstanceKlass[] klasses;

   // side-effect!. caches the instance klass array.

   public static synchronized InstanceKlass[] getAllInstanceKlasses() {

      if (klasses != null) {

         return klasses;

      }

      final Vector tmp = new Vector();

      ClassLoaderDataGraph cldg = VM.getVM().getClassLoaderDataGraph();

      cldg.classesDo(new ClassLoaderDataGraph.ClassVisitor() {

                        public void visit(Klass k) {

                           if (k instanceof InstanceKlass) {

                              InstanceKlass ik = (InstanceKlass) k;

                              tmp.add(ik);

                           }

                        }

                     });

      Object[] tmpArray = tmp.toArray();

      klasses = new InstanceKlass[tmpArray.length];

      System.arraycopy(tmpArray, 0, klasses, 0, tmpArray.length);

      Arrays.sort(klasses, new Comparator() {

                          public int compare(Object o1, Object o2) {

                             InstanceKlass k1 = (InstanceKlass) o1;

                             InstanceKlass k2 = (InstanceKlass) o2;

                             Symbol s1 = k1.getName();

                             Symbol s2 = k2.getName();

                             return s1.asString().compareTo(s2.asString());

                          }

                      });

      return klasses;

   }

   // returns array of instance klasses whose name contains given namePart

   public static InstanceKlass[] findInstanceKlasses(String namePart) {

      namePart = namePart.replace('.', '/');

      InstanceKlass[] tmpKlasses = getAllInstanceKlasses();

      Vector tmp = new Vector();

      for (int i = 0; i < tmpKlasses.length; i++) {

         String name = tmpKlasses[i].getName().asString();

         if (name.indexOf(namePart) != -1) {

            tmp.add(tmpKlasses[i]);

         }

      }

      Object[] tmpArray = tmp.toArray();

      InstanceKlass[] searchResult = new InstanceKlass[tmpArray.length];

      System.arraycopy(tmpArray, 0, searchResult, 0, tmpArray.length);

      return searchResult;

   }

   // find first class whose name matches exactly the given argument.

   public static InstanceKlass findInstanceKlass(String className) {

      // convert to internal name

      className = className.replace('.', '/');

      ClassLoaderDataGraph cldg = VM.getVM().getClassLoaderDataGraph();

      // check whether we have a class of given name

      Klass klass = cldg.find(className);

      if (klass != null && klass instanceof InstanceKlass) {

         return (InstanceKlass) klass;

      } else {

        // no match ..

        return null;

      }

   }

}