1 /*
   2  * Copyright 2000-2005 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *  
  23  */
  24 
  25 package sun.jvm.hotspot.oops;
  26 
  27 import java.io.*;
  28 import java.util.*;
  29 
  30 public class ObjectHistogram implements HeapVisitor {
  31 
  32   public ObjectHistogram() { map = new HashMap(); }
  33 
  34   private HashMap map;
  35 
  36   public void prologue(long size) {}
  37 
  38   public boolean doObj(Oop obj) {
  39     Klass klass = obj.getKlass();
  40     if (!map.containsKey(klass)) map.put(klass, new ObjectHistogramElement(klass));
  41     ((ObjectHistogramElement) map.get(klass)).updateWith(obj);
  42         return false;
  43   }
  44 
  45   public void epilogue() {}
  46 
  47   /** Call this after the iteration is complete to obtain the
  48       ObjectHistogramElements in descending order of total heap size
  49       consumed in the form of a List<ObjectHistogramElement>. */
  50   public List getElements() {
  51     List list = new ArrayList();
  52     list.addAll(map.values());
  53     Collections.sort(list, new Comparator() {
  54       public int compare(Object o1, Object o2) {
  55         return ((ObjectHistogramElement) o1).compare((ObjectHistogramElement) o2);
  56       }
  57     });
  58     return list;
  59   }
  60 
  61   public void print() { printOn(System.out); }
  62 
  63   public void printOn(PrintStream tty) {
  64     List list = getElements();
  65     ObjectHistogramElement.titleOn(tty);
  66     Iterator iterator = list.listIterator();
  67     while (iterator.hasNext()) {
  68       ((ObjectHistogramElement) iterator.next()).printOn(tty);
  69     }    
  70   }
  71 }