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.server.xdbm;
21
22
23 import java.util.concurrent.atomic.AtomicInteger;
24
25 import org.apache.directory.api.ldap.model.schema.AttributeType;
26 import org.apache.directory.server.i18n.I18n;
27
28
29 /**
30 * A generic index implementation that is just used to hold the index configuration
31 * parameters (attributeId, cacheSize, wkDirPath). All other methods are not working.
32 *
33 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
34 */
35 public abstract class AbstractIndex<K, E> implements Index<K, E>
36 {
37 /** The attribute identifier for this index */
38 protected String attributeId;
39
40 /** the attribute type resolved for this JdbmIndex */
41 protected AttributeType attributeType;
42
43 /** the size (number of index entries) for the cache */
44 protected int cacheSize = DEFAULT_INDEX_CACHE_SIZE;
45
46 /** whether or not this index has been initialized */
47 protected boolean initialized;
48
49 /** Tells if this index has a Reverse table */
50 protected boolean withReverse;
51
52 /** A counter used to differ the commit on disk after N operations */
53 protected AtomicInteger commitNumber;
54
55
56 /**
57 * Creates a new instance of AbstractIndex.
58 */
59 protected AbstractIndex()
60 {
61 this( null, true );
62 }
63
64
65 /**
66 * Creates a new instance of AbstractIndex.
67 *
68 * @param withReverse If we should create a reverse index
69 */
70 protected AbstractIndex( boolean withReverse )
71 {
72 this( null, withReverse );
73 }
74
75
76 /**
77 * Creates a new instance of AbstractIndex.
78 *
79 * @param attributeId the attribute ID
80 * @param withReverse If we should create a reverse index
81 */
82 protected AbstractIndex( String attributeId, boolean withReverse )
83 {
84 this.attributeId = attributeId;
85 this.withReverse = withReverse;
86 commitNumber = new AtomicInteger( 0 );
87 }
88
89
90 public String getAttributeId()
91 {
92 return attributeId;
93 }
94
95
96 /**
97 * {@inheritDoc}
98 */
99 public AttributeType getAttribute()
100 {
101 return attributeType;
102 }
103
104
105 public void setAttributeId( String attributeId )
106 {
107 protect( "attributeId" );
108 this.attributeId = attributeId;
109 }
110
111
112 /**
113 * {@inheritDoc}
114 */
115 public boolean isDupsEnabled()
116 {
117 return !attributeType.isSingleValued();
118 }
119
120
121 /**
122 * Gets the size of the index cache in terms of the number of index entries to be cached.
123 *
124 * @return the size of the index cache
125 */
126 public int getCacheSize()
127 {
128 return cacheSize;
129 }
130
131
132 /**
133 * Sets the size of the index cache in terms of the number of index entries to be cached.
134 *
135 * @param cacheSize the size of the index cache
136 */
137 public void setCacheSize( int cacheSize )
138 {
139 protect( "cacheSize" );
140 this.cacheSize = cacheSize;
141 }
142
143
144 /**
145 * Protects configuration properties from being set after initialization.
146 *
147 * @param property the property to protect
148 */
149 protected void protect( String property )
150 {
151 if ( initialized )
152 {
153 throw new IllegalStateException( I18n.err( I18n.ERR_575, property ) );
154 }
155 }
156
157
158 /**
159 * {@inheritDoc}
160 */
161 public boolean hasReverse()
162 {
163 return withReverse;
164 }
165 }