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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  }