/* * Copyright (c) 1997, 2015, 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. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * 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. */ /* * The Original Code is HAT. The Initial Developer of the * Original Code is Bill Foote, with contributions from others * at JavaSoft/Sun. */ package jdk.test.lib.hprof.model; import java.util.Enumeration; import java.util.Hashtable; /** * * @author Bill Foote */ /** * Represents a java "Thing". A thing is anything that can be the value of * a field. This includes JavaHeapObject, JavaObjectRef, and JavaValue. */ public abstract class JavaThing { protected JavaThing() { } /** * If this is a forward reference, figure out what it really * refers to. * * @param snapshot The snapshot this is for * @param field The field this thing represents. If null, it is * assumed this thing is an object (and never a value). */ public JavaThing dereference(Snapshot shapshot, JavaField field) { return this; } /** * Are we the same type as other? * * @see JavaObject.isSameTypeAs() */ public boolean isSameTypeAs(JavaThing other) { return getClass() == other.getClass(); } /** * @return true iff this represents a heap-allocated object */ abstract public boolean isHeapAllocated(); /** * @return the size of this object, in bytes, including VM overhead */ abstract public int getSize(); /** * @return a human-readable string representation of this thing */ abstract public String toString(); /** * Compare our string representation to other's * @see java.lang.String.compareTo() */ public int compareTo(JavaThing other) { return toString().compareTo(other.toString()); } }