1 /*
   2  * Copyright (c) 2002, 2005, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 package sun.jvm.hotspot.utilities;
  26 
  27 import java.util.*;
  28 import sun.jvm.hotspot.oops.*;
  29 import sun.jvm.hotspot.memory.*;
  30 import sun.jvm.hotspot.runtime.*;
  31 
  32 public class SystemDictionaryHelper {
  33    static {
  34       VM.registerVMInitializedObserver(new Observer() {
  35          public void update(Observable o, Object data) {
  36             initialize();
  37          }
  38       });
  39    }
  40 
  41    private static synchronized void initialize() {
  42       klasses = null;
  43    }
  44 
  45    // Instance klass array sorted by name.
  46    private static InstanceKlass[] klasses;
  47 
  48    // side-effect!. caches the instance klass array.
  49    public static synchronized InstanceKlass[] getAllInstanceKlasses() {
  50       if (klasses != null) {
  51          return klasses;
  52       }
  53 
  54       final Vector tmp = new Vector();
  55       SystemDictionary dict = VM.getVM().getSystemDictionary();
  56       dict.classesDo(new SystemDictionary.ClassVisitor() {
  57                         public void visit(Klass k) {
  58                            if (k instanceof InstanceKlass) {
  59                               InstanceKlass ik = (InstanceKlass) k;
  60                               tmp.add(ik);
  61                            }
  62                         }
  63                      });
  64 
  65       Object[] tmpArray = tmp.toArray();
  66       klasses = new InstanceKlass[tmpArray.length];
  67       System.arraycopy(tmpArray, 0, klasses, 0, tmpArray.length);
  68       Arrays.sort(klasses, new Comparator() {
  69                           public int compare(Object o1, Object o2) {
  70                              InstanceKlass k1 = (InstanceKlass) o1;
  71                              InstanceKlass k2 = (InstanceKlass) o2;
  72                              Symbol s1 = k1.getName();
  73                              Symbol s2 = k2.getName();
  74                              return s1.asString().compareTo(s2.asString());
  75                           }
  76                       });
  77       return klasses;
  78    }
  79 
  80    // returns array of instance klasses whose name contains given namePart
  81    public static InstanceKlass[] findInstanceKlasses(String namePart) {
  82       namePart = namePart.replace('.', '/');
  83       InstanceKlass[] tmpKlasses = getAllInstanceKlasses();
  84 
  85       Vector tmp = new Vector();
  86       for (int i = 0; i < tmpKlasses.length; i++) {
  87          String name = tmpKlasses[i].getName().asString();
  88          if (name.indexOf(namePart) != -1) {
  89             tmp.add(tmpKlasses[i]);
  90          }
  91       }
  92 
  93       Object[] tmpArray = tmp.toArray();
  94       InstanceKlass[] searchResult = new InstanceKlass[tmpArray.length];
  95       System.arraycopy(tmpArray, 0, searchResult, 0, tmpArray.length);
  96       return searchResult;
  97    }
  98 
  99    // find first class whose name matches exactly the given argument.
 100    public static InstanceKlass findInstanceKlass(String className) {
 101       // convert to internal name
 102       className = className.replace('.', '/');
 103       SystemDictionary sysDict = VM.getVM().getSystemDictionary();
 104 
 105       // check whether we have a bootstrap class of given name
 106       Klass klass = sysDict.find(className, null, null);
 107       if (klass != null) {
 108          return (InstanceKlass) klass;
 109       }
 110 
 111       // check whether we have a system class of given name
 112       klass = sysDict.find(className, sysDict.javaSystemLoader(), null);
 113       if (klass != null) {
 114          return (InstanceKlass) klass;
 115       }
 116 
 117       // didn't find bootstrap or system class of given name.
 118       // search through the entire dictionary..
 119       InstanceKlass[] tmpKlasses = getAllInstanceKlasses();
 120       // instance klass array is sorted by name. do binary search
 121       int low = 0;
 122       int high = tmpKlasses.length-1;
 123 
 124       int mid = -1;
 125       while (low <= high) {
 126          mid = (low + high) >> 1;
 127          InstanceKlass midVal = tmpKlasses[mid];
 128          int cmp = midVal.getName().asString().compareTo(className);
 129 
 130          if (cmp < 0) {
 131              low = mid + 1;
 132          } else if (cmp > 0) {
 133              high = mid - 1;
 134          } else { // match found
 135              return tmpKlasses[mid];
 136          }
 137       }
 138       // no match ..
 139       return null;
 140    }
 141 }