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.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         Snapshot snapshot = getClazz().getSnapshot();
  91         byte[] data = getValue();
  92         final int idSize = snapshot.getIdentifierSize();
  93         final int numElements = data.length / idSize;
  94         JavaThing[] elements = new JavaThing[numElements];
  95         int index = 0;
  96         for (int i = 0; i < elements.length; i++) {
  97             long id = objectIdAt(index, data);
  98             index += idSize;
  99             elements[i] = snapshot.findThing(id);
 100         }
 101         return elements;
 102     }
 103 
 104     public int compareTo(JavaThing other) {
 105         if (other instanceof JavaObjectArray) {
 106             return 0;
 107         }
 108         return super.compareTo(other);
 109     }
 110 
 111     public int getLength() {
 112         return getValueLength() / getClazz().getIdentifierSize();
 113     }
 114 
 115     public void visitReferencedObjects(JavaHeapObjectVisitor v) {
 116         super.visitReferencedObjects(v);
 117         JavaThing[] elements = getElements();
 118         for (int i = 0; i < elements.length; i++) {
 119             if (elements[i] != null && elements[i] instanceof JavaHeapObject) {
 120                 v.visit((JavaHeapObject) elements[i]);
 121             }
 122         }
 123     }
 124 
 125     /**
 126      * Describe the reference that this thing has to target.  This will only
 127      * be called if target is in the array returned by getChildrenForRootset.
 128      */
 129     public String describeReferenceTo(JavaThing target, Snapshot ss) {
 130         JavaThing[] elements = getElements();
 131         for (int i = 0; i < elements.length; i++) {
 132             if (elements[i] == target) {
 133                 return "Element " + i + " of " + this;
 134             }
 135         }
 136         return super.describeReferenceTo(target, ss);
 137     }
 138 
 139     /*
 140      * Java object array record (HPROF_GC_OBJ_ARRAY_DUMP)
 141      * looks as below:
 142      *
 143      *     object ID
 144      *     stack trace serial number (int)
 145      *     array length (int)
 146      *     array class ID
 147      *     array element IDs
 148      */
 149     protected final int readValueLength() throws IOException {
 150         JavaClass cl = getClazz();
 151         ReadBuffer buf = cl.getReadBuffer();
 152         int idSize = cl.getIdentifierSize();
 153         long offset = getOffset() + idSize + 4;
 154         int len = buf.getInt(offset);
 155         return len * cl.getIdentifierSize();
 156     }
 157 
 158     protected final byte[] readValue() throws IOException {
 159         JavaClass cl = getClazz();
 160         ReadBuffer buf = cl.getReadBuffer();
 161         int idSize = cl.getIdentifierSize();
 162         long offset = getOffset() + idSize + 4;
 163         int len = buf.getInt(offset);
 164         if (len == 0) {
 165             return Snapshot.EMPTY_BYTE_ARRAY;
 166         } else {
 167             byte[] res = new byte[len * idSize];
 168             buf.get(offset + 4 + idSize, res);
 169             return res;
 170         }
 171     }
 172 }