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 package org.apache.directory.api.util;
20
21
22 /**
23 * A class containing static methods used to serialize and deserialize base types
24 *
25 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
26 */
27 public final class Serialize
28 {
29 /** The serialized value for TRUE */
30 public static final byte TRUE = 0x01;
31
32 /** The serialized value for FALSE */
33 public static final byte FALSE = 0x00;
34
35
36 private Serialize()
37 {
38 }
39
40
41 /**
42 * Write an integer into a buffer at a given position
43 *
44 * @param value The value to serialize
45 * @param buffer The buffer to store the value into
46 * @param pos The position where we serialize the integer
47 * @return The new position in the byte[]
48 */
49 public static int serialize( int value, byte[] buffer, int pos )
50 {
51 if ( buffer.length - pos < 4 )
52 {
53 throw new ArrayIndexOutOfBoundsException();
54 }
55
56 buffer[pos++] = ( byte ) ( ( value >>> 24 ) & 0xFF );
57 buffer[pos++] = ( byte ) ( ( value >>> 16 ) & 0xFF );
58 buffer[pos++] = ( byte ) ( ( value >>> 8 ) & 0xFF );
59 buffer[pos++] = ( byte ) ( ( value >>> 0 ) & 0xFF );
60
61 return pos;
62 }
63
64
65 /**
66 * Write a byte[] into a buffer at a given position
67 *
68 * @param value The value to serialize
69 * @param buffer The buffer to store the value into
70 * @param pos The position where we serialize the byte[]
71 * @return The new position in the byte[]
72 */
73 public static int serialize( byte[] value, byte[] buffer, int pos )
74 {
75 if ( buffer.length - pos < 4 + value.length )
76 {
77 throw new ArrayIndexOutOfBoundsException();
78 }
79
80 buffer[pos++] = ( byte ) ( ( value.length >>> 24 ) & 0xFF );
81 buffer[pos++] = ( byte ) ( ( value.length >>> 16 ) & 0xFF );
82 buffer[pos++] = ( byte ) ( ( value.length >>> 8 ) & 0xFF );
83 buffer[pos++] = ( byte ) ( ( value.length >>> 0 ) & 0xFF );
84
85 System.arraycopy( value, 0, buffer, pos, value.length );
86
87 return pos + value.length;
88 }
89
90
91 /**
92 * Read an integer from a buffer at a given position
93 *
94 * @param buffer The buffer containing the serialized integer
95 * @param pos The position from which we will read an integer
96 * @return the deserialized integer
97 */
98 public static int deserializeInt( byte[] buffer, int pos )
99 {
100 if ( buffer.length - pos < 4 )
101 {
102 throw new ArrayIndexOutOfBoundsException();
103 }
104
105 return ( buffer[pos] << 24 ) + ( buffer[pos + 1] << 16 ) + ( buffer[pos + 2] << 8 ) + ( buffer[pos + 3] << 0 );
106 }
107
108
109 /**
110 * Read a byte[] from a buffer at a given position
111 *
112 * @param buffer The buffer containing the serialized byte[]
113 * @param pos The position from which we will read a byte[]
114 * @return the deserialized byte[]
115 */
116 public static byte[] deserializeBytes( byte[] buffer, int pos )
117 {
118 if ( buffer.length - pos < 4 )
119 {
120 throw new ArrayIndexOutOfBoundsException();
121 }
122
123 int len = deserializeInt( buffer, pos );
124 pos += 4;
125
126 if ( len > 0 )
127 {
128 if ( buffer.length - pos < len )
129 {
130 throw new ArrayIndexOutOfBoundsException();
131 }
132
133 byte[] result = new byte[len];
134
135 System.arraycopy( buffer, pos, result, 0, len );
136
137 return result;
138 }
139 else
140 {
141 return Strings.EMPTY_BYTES;
142 }
143 }
144
145
146 /**
147 * Read a boolean from a buffer at a given position
148 *
149 * @param buffer The buffer containing the serialized boolean
150 * @param pos The position from which we will read a boolean
151 * @return the deserialized boolean
152 */
153 public static boolean deserializeBoolean( byte[] buffer, int pos )
154 {
155 if ( buffer.length - pos < 1 )
156 {
157 throw new ArrayIndexOutOfBoundsException();
158 }
159
160 byte value = buffer[pos];
161
162 return ( value != 0x00 );
163 }
164 }