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 package org.apache.directory.mavibot.btree;
21
22
23 import java.util.List;
24
25
26 /**
27 * The result of a delete operation, when the child has not been merged, and when
28 * we have borrowed an element from the left sibling. It contains the
29 * reference to the modified page, and the removed element.
30 *
31 * @param <K> The type for the Key
32 * @param <V> The type for the stored value
33 *
34 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
35 */
36 /* No qualifier*/abstract class AbstractBorrowedFromSiblingResult<K, V> extends AbstractDeleteResult<K, V> implements
37 BorrowedFromSiblingResult<K, V>
38 {
39 /** The modified sibling reference */
40 private Page<K, V> modifiedSibling;
41
42 /** Tells if the sibling is the left or right one */
43 protected SiblingPosition position;
44
45 /** The two possible position for the sibling */
46 protected enum SiblingPosition
47 {
48 LEFT,
49 RIGHT
50 }
51
52
53 /**
54 * The default constructor for RemoveResult.
55 *
56 * @param modifiedPage The modified page
57 * @param modifiedSibling The modified sibling
58 * @param removedElement The removed element (can be null if the key wasn't present in the tree)
59 */
60 /* No qualifier*/AbstractBorrowedFromSiblingResult( Page<K, V> modifiedPage, Page<K, V> modifiedSibling,
61 Tuple<K, V> removedElement, SiblingPosition position )
62 {
63 super( modifiedPage, removedElement );
64 this.modifiedSibling = modifiedSibling;
65 this.position = position;
66 }
67
68
69 /**
70 * A constructor for RemoveResult with a list of copied pages.
71 *
72 * @param copiedPages the list of copied pages
73 * @param modifiedPage The modified page
74 * @param modifiedSibling The modified sibling
75 * @param removedElement The removed element (can be null if the key wasn't present in the tree)
76 */
77 /* No qualifier*/AbstractBorrowedFromSiblingResult( List<Page<K, V>> copiedPages, Page<K, V> modifiedPage,
78 Page<K, V> modifiedSibling,
79 Tuple<K, V> removedElement, SiblingPosition position )
80 {
81 super( copiedPages, modifiedPage, removedElement );
82 this.modifiedSibling = modifiedSibling;
83 this.position = position;
84 }
85
86
87 /**
88 * {@inheritDoc}
89 */
90 public Page<K, V> getModifiedSibling()
91 {
92 return modifiedSibling;
93 }
94
95
96 /**
97 * {@inheritDoc}
98 */
99 public boolean isFromLeft()
100 {
101 return position == SiblingPosition.LEFT;
102 }
103
104
105 /**
106 * {@inheritDoc}
107 */
108 public boolean isFromRight()
109 {
110 return position == SiblingPosition.RIGHT;
111 }
112
113
114 /**
115 * @see Object#toString()
116 */
117 public String toString()
118 {
119 StringBuilder sb = new StringBuilder();
120
121 sb.append( "\n removed element : " ).append( getRemovedElement() );
122 sb.append( "\n modifiedPage : " ).append( getModifiedPage() );
123 sb.append( "\n modifiedSibling : " ).append( getModifiedSibling() );
124
125 return sb.toString();
126 }
127 }