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1   /*
2    *   Licensed to the Apache Software Foundation (ASF) under one
3    *   or more contributor license agreements.  See the NOTICE file
4    *   distributed with this work for additional information
5    *   regarding copyright ownership.  The ASF licenses this file
6    *   to you under the Apache License, Version 2.0 (the
7    *   "License"); you may not use this file except in compliance
8    *   with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *   Unless required by applicable law or agreed to in writing,
13   *   software distributed under the License is distributed on an
14   *   "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *   KIND, either express or implied.  See the License for the
16   *   specific language governing permissions and limitations
17   *   under the License.
18   *
19   */
20  
21  package org.apache.directory.mavibot.btree.managed;
22  
23  
24  import java.io.IOException;
25  
26  
27  /**
28   * A class containing utility methods to be used internally. 
29   *
30   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
31   */
32  @SuppressWarnings("all")
33  /* No qualifier */class InternalUtil
34  {
35  
36      /**
37       * Sets the multi-value container(a.k.a dupsContainer) of the key at the given position.
38       * 
39       * This method will not update the existing value of 'dupsPos'. To change this value
40       * use {@link #changeNextDupsContainer(ParentPos, BTree)} or {@link #changePrevDupsContainer(ParentPos, BTree)}
41       *  
42       * @param parentPos the parent position object
43       * @param btree the BTree
44       */
45      public static void setDupsContainer( ParentPos parentPos, BTree btree )
46      {
47          if ( !btree.isAllowDuplicates() )
48          {
49              return;
50          }
51  
52          if ( parentPos.dupsContainer == null )
53          {
54              Leaf leaf = ( Leaf ) ( parentPos.page );
55              ValueHolder valueHolder = leaf.values[parentPos.pos];
56  
57          }
58      }
59  
60  
61      /**
62       * Sets the multi-value container(a.k.a dupsContainer) of the key at the given position
63       * and resets the 'dupsPos' to zero. This is mostly used by Cursor while navigating using
64       * next() 
65       *
66       * @param parentPos the parent position object
67       * @param btree the BTree
68       */
69      public static void changeNextDupsContainer( ParentPos parentPos, BTree btree ) throws IOException
70      {
71          if ( !btree.isAllowDuplicates() )
72          {
73              return;
74          }
75  
76          if ( parentPos.pos < parentPos.page.getNbElems() )
77          {
78              Leaf leaf = ( Leaf ) ( parentPos.page );
79              ValueHolder valueHolder = leaf.values[parentPos.pos];
80          }
81      }
82  
83  
84      /**
85       * Sets the multi-value container(a.k.a dupsContainer) of the key at the index below the given position( i.e pos - 1)
86       * and resets the 'dupsPos' to the number of elements present in the multi-value container.
87       * This is used by Cursor while navigating using prev() 
88       *
89       * @param parentPos the parent position object
90       * @param btree the BTree
91       */
92      public static void changePrevDupsContainer( ParentPos parentPos, BTree btree ) throws IOException
93      {
94          if ( !btree.isAllowDuplicates() )
95          {
96              return;
97          }
98  
99          int index = parentPos.pos - 1;
100 
101         if ( index >= 0 )
102         {
103             Leaf leaf = ( Leaf ) ( parentPos.page );
104             ValueHolder valueHolder = leaf.values[index];
105         }
106     }
107 
108 
109     /**
110      * Same as @see #changePrevDupsContainer(ParentPos, BTree) but with a different name
111      * to make it sound semantically right when used inside {@link BTreeFactory#getPathToRightMostLeaf(BTree)} 
112      */
113     public static void setLastDupsContainer( ParentPos parentPos, BTree btree ) throws IOException
114     {
115         changePrevDupsContainer( parentPos, btree );
116     }
117 }