1 /*
   2  * Copyright 2000-2005 Sun Microsystems, Inc.  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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 package sun.jvm.hotspot.code;
  26 
  27 import java.util.*;
  28 
  29 import sun.jvm.hotspot.debugger.*;
  30 import sun.jvm.hotspot.runtime.VM;
  31 import sun.jvm.hotspot.utilities.*;
  32 
  33 public class DebugInfoReadStream extends CompressedReadStream {
  34   private NMethod code;
  35   private int InvocationEntryBCI;
  36   private List objectPool; // ArrayList<ObjectValue>
  37 
  38   public DebugInfoReadStream(NMethod code, int offset) {
  39     super(code.scopesDataBegin(), offset);
  40     InvocationEntryBCI = VM.getVM().getInvocationEntryBCI();
  41     this.code = code;
  42     this.objectPool = null;
  43   }
  44 
  45   public DebugInfoReadStream(NMethod code, int offset, List objectPool) {
  46     super(code.scopesDataBegin(), offset);
  47     InvocationEntryBCI = VM.getVM().getInvocationEntryBCI();
  48     this.code = code;
  49     this.objectPool = objectPool;
  50   }
  51 
  52   public OopHandle readOopHandle() {
  53     return code.getOopAt(readInt());
  54   }
  55 
  56   ScopeValue readObjectValue() {
  57     int id = readInt();
  58     if (Assert.ASSERTS_ENABLED) {
  59       Assert.that(objectPool != null, "object pool does not exist");
  60       for (Iterator itr = objectPool.iterator(); itr.hasNext();) {
  61         ObjectValue ov = (ObjectValue) itr.next();
  62         Assert.that(ov.id() != id, "should not be read twice");
  63       }
  64     }
  65     ObjectValue result = new ObjectValue(id);
  66     // Cache the object since an object field could reference it.
  67     objectPool.add(result);
  68     result.readObject(this);
  69     return result;
  70   }
  71 
  72   ScopeValue getCachedObject() {
  73     int id = readInt();
  74     Assert.that(objectPool != null, "object pool does not exist");
  75     for (Iterator itr = objectPool.iterator(); itr.hasNext();) {
  76       ObjectValue ov = (ObjectValue) itr.next();
  77       if (ov.id() == id) {
  78         return ov;
  79       }
  80     }
  81     Assert.that(false, "should not reach here");
  82     return null;
  83   }
  84 
  85   public int readBCI() {
  86     return readInt() + InvocationEntryBCI;
  87   }
  88 }