1 /*
   2  * Copyright (c) 1997, 2017, 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 jdk.test.lib.hprof.util.Misc;
  36 
  37 /**
  38  * A forward reference to an object.  This is an intermediate representation
  39  * for a JavaThing, when we have the thing's ID, but we might not have read
  40  * the thing yet.
  41  *
  42  * @author      Bill Foote
  43  */
  44 public class JavaObjectRef extends JavaThing {
  45     private long id;
  46 
  47     public JavaObjectRef(long id) {
  48         this.id = id;
  49     }
  50 
  51     public long getId() {
  52         return id;
  53     }
  54 
  55     public boolean isHeapAllocated() {
  56         return true;
  57     }
  58 
  59     public JavaThing dereference(Snapshot snapshot, JavaField field) {
  60         return dereference(snapshot, field, true);
  61     }
  62 
  63     public JavaThing dereference(Snapshot snapshot, JavaField field, boolean verbose) {
  64         if (field != null && !field.hasId()) {
  65             // If this happens, we must be a field that represents an int.
  66             // (This only happens with .bod-style files)
  67             return new JavaLong(id);
  68         }
  69         if (id == 0) {
  70             return snapshot.getNullThing();
  71         }
  72         JavaThing result = snapshot.findThing(id);
  73         if (result == null) {
  74             if (!snapshot.getUnresolvedObjectsOK() && verbose) {
  75                 String msg = "WARNING:  Failed to resolve object id "
  76                                 + Misc.toHex(id);
  77                 if (field != null) {
  78                     msg += " for field " + field.getName()
  79                             + " (signature " + field.getSignature() + ")";
  80                 }
  81                 System.out.println(msg);
  82                 // Thread.dumpStack();
  83             }
  84             result = new HackJavaValue("Unresolved object "
  85                                         + Misc.toHex(id), 0);
  86         }
  87         return result;
  88     }
  89 
  90     @Override
  91     public long getSize() {
  92         return 0;
  93     }
  94 
  95     public String toString() {
  96         return "Unresolved object " + Misc.toHex(id);
  97     }
  98 }