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.io.IOException;
24
25 import org.apache.directory.mavibot.btree.serializer.ElementSerializer;
26
27
28 /**
29 * A class storing either a key, or an offset to the key on the page's byte[]
30 *
31 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
32 *
33 * <K> The key type
34 */
35 /* No qualifier */class PersistedKeyHolder<K> extends KeyHolder<K>
36 {
37 /** The ByteBuffer storing the key */
38 private byte[] raw;
39
40 /** The Key serializer */
41 private ElementSerializer<K> keySerializer;
42
43
44 /**
45 * Create a new KeyHolder instance
46 * @param keySerializer The KeySerializer instance
47 * @param key The key to store
48 */
49 /* no qualifier */PersistedKeyHolder( ElementSerializer<K> keySerializer, K key )
50 {
51 super( key );
52 this.keySerializer = keySerializer;
53 raw = keySerializer.serialize( key );
54 }
55
56
57 /**
58 * Create a new KeyHolder instance
59 * @param keySerializer The KeySerializer instance
60 * @param raw the bytes representing the serialized key
61 */
62 /* no qualifier */PersistedKeyHolder( ElementSerializer<K> keySerializer, byte[] raw )
63 {
64 super( null );
65 this.keySerializer = keySerializer;
66 this.raw = raw;
67 }
68
69
70 /**
71 * @return the key
72 */
73 /* no qualifier */K getKey()
74 {
75 if ( key == null )
76 {
77 try
78 {
79 key = keySerializer.fromBytes( raw );
80 }
81 catch ( IOException ioe )
82 {
83 // Nothing we can do here...
84 }
85 }
86
87 return key;
88 }
89
90
91 /**
92 * @param key the Key to store in into the KeyHolder
93 */
94 /* no qualifier */void setKey( K key )
95 {
96 this.key = key;
97 raw = keySerializer.serialize( key );
98 }
99
100
101 /**
102 * @return The internal serialized byte[]
103 */
104 /* No qualifier */byte[] getRaw()
105 {
106 return raw;
107 }
108
109
110 /**
111 * @see Object#toString()
112 */
113 public String toString()
114 {
115 StringBuilder sb = new StringBuilder();
116
117 sb.append( "PersistedKeyHolder[" );
118
119 if ( key != null )
120 {
121 sb.append( key );
122 sb.append( ", " );
123 }
124 else if ( raw != null )
125 {
126 K key = getKey();
127 sb.append( ":" ).append( key ).append( ":," );
128 }
129 else
130 {
131 sb.append( "null," );
132 }
133
134 if ( raw != null )
135 {
136 sb.append( raw.length );
137 }
138 else
139 {
140 sb.append( "null" );
141 }
142
143 sb.append( "]" );
144
145 return sb.toString();
146 }
147 }