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Java > Open Source Codes > com > db4o > defragment > TreeIDMapping


1 /* Copyright (C) 2004 - 2006 db4objects Inc. http://www.db4o.com
2
3 This file is part of the db4o open source object database.
4
5 db4o is free software; you can redistribute it and/or modify it under
6 the terms of version 2 of the GNU General Public License as published
7 by the Free Software Foundation and as clarified by db4objects' GPL
8 interpretation policy, available at
9 http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
10 Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
11 Suite 350, San Mateo, CA 94403, USA.
12
13 db4o is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21 package com.db4o.defragment;
22
23 import com.db4o.*;
24 import com.db4o.foundation.*;
25
26
27 /**
28  * In-memory mapping for IDs during a defragmentation run.
29  *
30  * @see Defragment
31  */
32 class TreeIDMapping extends AbstractContextIDMapping {
33     
34     private Tree _tree;
35     
36     public int mappedID(int oldID, boolean lenient) {
37         int classID = mappedClassID(oldID);
38         if(classID != 0) {
39             return classID;
40         }
41         TreeIntObject res = (TreeIntObject) TreeInt.find(_tree, oldID);
42         if(res != null){
43             return ((Integer JavaDoc)res._object).intValue();
44         }
45         if(lenient){
46             TreeIntObject nextSmaller = (TreeIntObject) Tree.findSmaller(_tree, new TreeInt(oldID));
47             if(nextSmaller != null){
48                 int baseOldID = nextSmaller._key;
49                 int baseNewID = ((Integer JavaDoc)nextSmaller._object).intValue();
50                 return baseNewID + oldID - baseOldID;
51             }
52         }
53         return 0;
54     }
55
56     public void open() {
57     }
58     
59     public void close() {
60     }
61
62     protected void mapNonClassIDs(int origID, int mappedID) {
63         _tree = Tree.add(_tree, new TreeIntObject(origID, new Integer JavaDoc(mappedID)));
64     }
65 }
66
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