/*

 * Copyright 2000-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

package sun.jvm.hotspot.oops;

import java.io.*;

import java.util.*;

import sun.jvm.hotspot.memory.*;

import sun.jvm.hotspot.runtime.*;

public class ObjectHistogramElement {

  private Klass klass;

  private long  count; // Number of instances of klass

  private long  size;  // Total size of all these instances

  public ObjectHistogramElement(Klass k) {

     klass = k;

     count = 0;

     size  = 0;

  }

  public void updateWith(Oop obj) {

    count = count + 1;

    size  = size  + obj.getObjectSize();

  }

  public int compare(ObjectHistogramElement other) {

    return (int) (other.size - size);

  }

  /** Klass for this ObjectHistogramElement */

  public Klass getKlass() {

    return klass;

  }

  /** Number of instances of klass */

  public long getCount() {

    return count;

  }

  /** Total size of all these instances */

  public long getSize() {

    return size;

  }

  private String getInternalName(Klass k) {

    ByteArrayOutputStream bos = new ByteArrayOutputStream();

    getKlass().printValueOn(new PrintStream(bos));

    // '*' is used to denote VM internal klasses.

    return "* " + bos.toString();

  }

  /** Human readable description **/

  public String getDescription() {

     Klass k = getKlass();

     if (k instanceof InstanceKlass) {

        return k.getName().asString().replace('/', '.');

     } else if (k instanceof ArrayKlass) {

       ArrayKlass ak = (ArrayKlass) k;

       if (k instanceof TypeArrayKlass) {

          TypeArrayKlass tak = (TypeArrayKlass) ak;

          return tak.getElementTypeName() + "[]";

       } else if (k instanceof ObjArrayKlass) {

          ObjArrayKlass oak = (ObjArrayKlass) ak;

          // See whether it's a "system objArray"

          if (oak.equals(VM.getVM().getUniverse().systemObjArrayKlassObj())) {

            return "* System ObjArray";

          }

          Klass bottom = oak.getBottomKlass();

          int dim = (int) oak.getDimension();

          StringBuffer buf = new StringBuffer();

          if (bottom instanceof TypeArrayKlass) {

            buf.append(((TypeArrayKlass) bottom).getElementTypeName());

          } else if (bottom instanceof InstanceKlass) {

            buf.append(bottom.getName().asString().replace('/', '.'));

          } else {

            throw new RuntimeException("should not reach here");

          }

          for (int i=0; i < dim; i++) {

            buf.append("[]");

          }

          return buf.toString();

       }

    }

    return getInternalName(k);

  }

  public static void titleOn(PrintStream tty) {

    tty.println("Object Histogram:");

    tty.println();

  }

  public void printOn(PrintStream tty) {

    tty.print(getDescription());

    tty.println();

  }

}