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 java.io.IOException;
  36 import jdk.test.lib.hprof.parser.ReadBuffer;
  37 
  38 /**
  39  * @author      Bill Foote
  40  */
  41 public class JavaObjectArray extends JavaLazyReadObject {
  42 
  43     private Object clazz;  // Long before resolve, the class after resolve
  44 
  45     public JavaObjectArray(long classID, long offset) {
  46         super(offset);
  47         this.clazz = makeId(classID);
  48     }
  49 
  50     public JavaClass getClazz() {
  51         return (JavaClass) clazz;
  52     }
  53 
  54     public void resolve(Snapshot snapshot) {
  55         if (clazz instanceof JavaClass) {
  56             return;
  57         }
  58         long classID = getIdValue((Number)clazz);
  59         if (snapshot.isNewStyleArrayClass()) {
  60             // Modern heap dumps do this
  61             JavaThing t = snapshot.findThing(classID);
  62             if (t instanceof JavaClass) {
  63                 clazz = (JavaClass) t;
  64             }
  65         }
  66         if (!(clazz instanceof JavaClass)) {
  67             JavaThing t = snapshot.findThing(classID);
  68             if (t != null && t instanceof JavaClass) {
  69                 JavaClass el = (JavaClass) t;
  70                 String nm = el.getName();
  71                 if (!nm.startsWith("[")) {
  72                     nm = "L" + el.getName() + ";";
  73                 }
  74                 clazz = snapshot.getArrayClass(nm);
  75             }
  76         }
  77 
  78         if (!(clazz instanceof JavaClass)) {
  79             clazz = snapshot.getOtherArrayType();
  80         }
  81         ((JavaClass)clazz).addInstance(this);
  82         super.resolve(snapshot);
  83     }
  84 
  85     public JavaThing[] getValues() {
  86         return getElements();
  87     }
  88 
  89     public JavaThing[] getElements() {
  90         return getValue();
  91     }
  92 
  93     public int compareTo(JavaThing other) {
  94         if (other instanceof JavaObjectArray) {
  95             return 0;
  96         }
  97         return super.compareTo(other);
  98     }
  99 
 100     public int getLength() {
 101         return (int)(getValueLength() / idSize());
 102     }
 103 
 104     public void visitReferencedObjects(JavaHeapObjectVisitor v) {
 105         super.visitReferencedObjects(v);
 106         JavaThing[] elements = getElements();
 107         for (int i = 0; i < elements.length; i++) {
 108             if (elements[i] != null && elements[i] instanceof JavaHeapObject) {
 109                 v.visit((JavaHeapObject) elements[i]);
 110             }
 111         }
 112     }
 113 
 114     /**
 115      * Describe the reference that this thing has to target.  This will only
 116      * be called if target is in the array returned by getChildrenForRootset.
 117      */
 118     public String describeReferenceTo(JavaThing target, Snapshot ss) {
 119         JavaThing[] elements = getElements();
 120         for (int i = 0; i < elements.length; i++) {
 121             if (elements[i] == target) {
 122                 return "Element " + i + " of " + this;
 123             }
 124         }
 125         return super.describeReferenceTo(target, ss);
 126     }
 127 
 128     /*
 129      * Java object array record (HPROF_GC_OBJ_ARRAY_DUMP)
 130      * looks as below:
 131      *
 132      *     object ID
 133      *     stack trace serial number (int)
 134      *     array length (int)
 135      *     array class ID
 136      *     array element IDs
 137      */
 138     @Override
 139     protected final long readValueLength() throws IOException {
 140         long offset = getOffset() + idSize() + 4;
 141         // length of the array in elements
 142         long len = buf().getInt(offset);
 143         // byte length of array
 144         return len * idSize();
 145         }
 146 
 147     private long dataStartOffset() {
 148         return getOffset() + idSize() + 4 + 4 + idSize();
 149     }
 150 
 151     @Override
 152     protected final JavaThing[] readValue() throws IOException {
 153         Snapshot snapshot = getClazz().getSnapshot();
 154         int len = getLength();
 155         long offset = dataStartOffset();
 156 
 157         JavaThing[] res = new JavaThing[len];
 158         for (int i = 0; i < len; i++) {
 159             long id = objectIdAt(offset);
 160             res[i] = snapshot.findThing(id);
 161             offset += idSize();
 162          }
 163          return res;
 164     }
 165 }