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 ImmutableOopMap 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(ImmutableOopMap oopMap) {
  39     this(oopMap, (OopMapValue.OopTypes[]) null);
  40   }
  41 
  42   public OopMapStream(ImmutableOopMap oopMap, OopMapValue.OopTypes type) {
  43     this(oopMap, (OopMapValue.OopTypes[]) null);
  44     mask = type.getValue();
  45   }
  46 
  47   public OopMapStream(ImmutableOopMap oopMap, OopMapValue.OopTypes[] types) {
  48     stream = new CompressedReadStream(oopMap.getData());
  49     mask = computeMask(types);
  50     size = (int) oopMap.getCount();
  51     position = 0;
  52     omv = new OopMapValue();
  53     omvValid = false;
  54   }
  55 
  56   public boolean isDone() {
  57     if (!omvValid) {
  58       findNext();
  59     }
  60     return !omvValid;
  61   }
  62 
  63   public void next() {
  64     findNext();
  65   }
  66 
  67   public OopMapValue getCurrent() {
  68     return omv;
  69   }
  70 
  71   //--------------------------------------------------------------------------------
  72   // Internals only below this point
  73   //
  74 
  75   private int computeMask(OopMapValue.OopTypes[] types) {
  76     mask = 0;
  77     if (types != null) {
  78       for (int i = 0; i < types.length; i++) {
  79         mask |= types[i].getValue();
  80       }
  81     }
  82     return mask;
  83   }
  84 
  85   private void findNext() {
  86     while (position++ < size) {
  87       omv.readFrom(stream);
  88       if ((omv.getType().getValue() & mask) > 0) {
  89         omvValid = true;
  90         return;
  91       }
  92     }
  93     omvValid = false;
  94   }
  95 }