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.api.asn1.ber.tlv;
21
22
23 import org.apache.directory.api.i18n.I18n;
24
25
26 /**
27 * Parse and decode a Long value.
28 *
29 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
30 */
31 public final class LongDecoder
32 {
33 /** A mask used to get only the necessary bytes */
34 private static final long[] MASK = new long[]
35 { 0x00000000000000FFL, 0x000000000000FFFFL, 0x0000000000FFFFFFL, 0x00000000FFFFFFFFL, 0x000000FFFFFFFFFFL,
36 0x0000FFFFFFFFFFFFL, 0x00FFFFFFFFFFFFFFL, 0xFFFFFFFFFFFFFFFFL };
37
38
39 private LongDecoder()
40 {
41 }
42
43
44 /**
45 * Parse a byte buffer and send back an long, controlling that this number
46 * is in a specified interval.
47 *
48 * @param value The byte buffer to parse
49 * @param min Lowest value allowed, included
50 * @param max Highest value allowed, included
51 * @return An integer
52 * @throws LongDecoderException Thrown if the byte stream does not contains an integer
53 */
54 public static long parse( BerValue value, long min, long max ) throws LongDecoderException
55 {
56 long result = parseLong( value );
57
58 if ( ( result >= min ) && ( result <= max ) )
59 {
60 return result;
61 }
62 else
63 {
64 throw new LongDecoderException( I18n.err( I18n.ERR_00038_VALUE_NOT_IN_RANGE, min, max ) );
65 }
66 }
67
68
69 /**
70 * Parse a byte buffer and send back an integer
71 *
72 * @param value The byte buffer to parse
73 * @return An integer
74 * @throws LongDecoderException Thrown if the byte stream does not contains an integer
75 */
76 public static long parse( BerValue value ) throws LongDecoderException
77 {
78 return parseLong( value );
79 }
80
81
82 /**
83 * Helper method used to parse the long. We don't check any minimal or maximal
84 * bound.
85 *
86 * @param value The value to parse to a long
87 * @return The decoded long
88 * @throws LongDecoderException If we failed to decode a long
89 */
90 public static long parseLong( BerValue value ) throws LongDecoderException
91 {
92 long result = 0;
93
94 byte[] bytes = value.getData();
95
96 if ( ( bytes == null ) || ( bytes.length == 0 ) )
97 {
98 throw new LongDecoderException( I18n.err( I18n.ERR_00039_0_BYTES_LONG_LONG ) );
99 }
100
101 if ( bytes.length > 8 )
102 {
103 throw new LongDecoderException( I18n.err( I18n.ERR_00039_0_BYTES_LONG_LONG ) );
104 }
105
106 for ( int i = 0; ( i < bytes.length ) && ( i < 9 ); i++ )
107 {
108 result = ( result << 8 ) | ( bytes[i] & 0x00FF );
109 }
110
111 if ( ( bytes[0] & 0x80 ) == 0x80 )
112 {
113 result = -( ( ( ~result ) + 1 ) & MASK[bytes.length - 1] );
114 }
115
116 return result;
117 }
118 }