1 /*
   2  * Copyright (c) 1997, 2015, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 
  27 /*
  28  * The Original Code is HAT. The Initial Developer of the
  29  * Original Code is Bill Foote, with contributions from others
  30  * at JavaSoft/Sun.
  31  */
  32 
  33 package jdk.test.lib.hprof.model;
  34 
  35 import java.util.Enumeration;
  36 import java.util.Hashtable;
  37 
  38 
  39 /**
  40  *
  41  * @author      Bill Foote
  42  */
  43 
  44 
  45 /**
  46  * Represents a java "Thing".  A thing is anything that can be the value of
  47  * a field.  This includes JavaHeapObject, JavaObjectRef, and JavaValue.
  48  */
  49 
  50 public abstract class JavaThing {
  51 
  52     protected JavaThing() {
  53     }
  54 
  55     /**
  56      * If this is a forward reference, figure out what it really
  57      * refers to.
  58      *
  59      * @param snapshot  The snapshot this is for
  60      * @param field     The field this thing represents.  If null, it is
  61      *                  assumed this thing is an object (and never a value).
  62      */
  63     public JavaThing dereference(Snapshot shapshot, JavaField field) {
  64         return this;
  65     }
  66 
  67 
  68     /**
  69      * Are we the same type as other?
  70      *
  71      * @see JavaObject.isSameTypeAs()
  72      */
  73     public boolean isSameTypeAs(JavaThing other) {
  74         return getClass() == other.getClass();
  75     }
  76     /**
  77      * @return true iff this represents a heap-allocated object
  78      */
  79     abstract public boolean isHeapAllocated();
  80 
  81     /**
  82      * @return the size of this object, in bytes, including VM overhead
  83      */
  84     abstract public int getSize();
  85 
  86     /**
  87      * @return a human-readable string representation of this thing
  88      */
  89     abstract public String toString();
  90 
  91     /**
  92      * Compare our string representation to other's
  93      * @see java.lang.String.compareTo()
  94      */
  95     public int compareTo(JavaThing other) {
  96         return toString().compareTo(other.toString());
  97     }
  98 
  99 }