1 /*
   2  * Copyright (c) 2000, 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.
   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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 package sun.jvm.hotspot.compiler;
  26 
  27 import sun.jvm.hotspot.code.*;
  28 
  29 public class OopMapStream {
  30   private CompressedReadStream stream;
  31   private OopMap oopMap;
  32   private int mask;
  33   private int size;
  34   private int position;
  35   private OopMapValue omv;
  36   private boolean omvValid;
  37 
  38   public OopMapStream(OopMap oopMap) {
  39     this(oopMap, (OopMapValue.OopTypes[]) null);
  40   }
  41 
  42   public OopMapStream(OopMap oopMap, OopMapValue.OopTypes type) {
  43     this(oopMap, (OopMapValue.OopTypes[]) null);
  44     mask = type.getValue();
  45   }
  46 
  47   public OopMapStream(OopMap oopMap, OopMapValue.OopTypes[] types) {
  48     if (oopMap.getOMVData() == null) {
  49       stream = new CompressedReadStream(oopMap.getWriteStream().getBuffer());
  50     } else {
  51       stream = new CompressedReadStream(oopMap.getOMVData());
  52     }
  53     mask = computeMask(types);
  54     size = (int) oopMap.getOMVCount();
  55     position = 0;
  56     omv = new OopMapValue();
  57     omvValid = false;
  58   }
  59 
  60   public boolean isDone() {
  61     if (!omvValid) {
  62       findNext();
  63     }
  64     return !omvValid;
  65   }
  66 
  67   public void next() {
  68     findNext();
  69   }
  70 
  71   public OopMapValue getCurrent() {
  72     return omv;
  73   }
  74 
  75   //--------------------------------------------------------------------------------
  76   // Internals only below this point
  77   //
  78 
  79   private int computeMask(OopMapValue.OopTypes[] types) {
  80     mask = 0;
  81     if (types != null) {
  82       for (int i = 0; i < types.length; i++) {
  83         mask |= types[i].getValue();
  84       }
  85     }
  86     return mask;
  87   }
  88 
  89   private void findNext() {
  90     while (position++ < size) {
  91       omv.readFrom(stream);
  92       if ((omv.getType().getValue() & mask) > 0) {
  93         omvValid = true;
  94         return;
  95       }
  96     }
  97     omvValid = false;
  98   }
  99 }