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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.kerberos.shared.messages.value;
21  
22  
23  import java.util.BitSet;
24  
25  
26  /**
27   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
28   * @version $Rev: 540371 $, $Date: 2007-05-22 02:00:43 +0200 (Di, 22 Mai 2007) $
29   */
30  public abstract class Options
31  {
32      private BitSet options;
33      private int maxSize;
34  
35  
36      protected Options( int maxSize )
37      {
38          this.maxSize = maxSize;
39          options = new BitSet( maxSize );
40      }
41  
42  
43      /**
44       * Returns whether the option at a given index matches the option in this {@link Options}.
45       *
46       * @param options
47       * @param option
48       * @return true if two options are the same.
49       */
50      public boolean match( Options options, int option )
51      {
52          return options.get( option ) == this.get( option );
53      }
54  
55  
56      /**
57       * Returns the value of the option at the given index.
58       *
59       * @param index
60       * @return true if the option at the given index is set.
61       */
62      public boolean get( int index )
63      {
64          return options.get( index );
65      }
66  
67  
68      /**
69       * Sets the option at a given index.
70       *
71       * @param index
72       */
73      public void set( int index )
74      {
75          options.set( index );
76      }
77  
78  
79      /**
80       * Clears (sets false) the option at a given index.
81       *
82       * @param index
83       */
84      public void clear( int index )
85      {
86          options.clear( index );
87      }
88  
89  
90      /**
91       * Byte-reversing methods are an anomaly of the BouncyCastle
92       * DERBitString endianness.  Thes methods can be removed if the
93       * Apache Directory Snickers codecs operate differently.
94       * 
95       * @return The raw {@link Options} bytes.
96       */
97      public byte[] getBytes()
98      {
99          byte[] bytes = new byte[maxSize / 8];
100 
101         for ( int ii = 0; ii < maxSize; ii++ )
102         {
103             if ( options.get( reversePosition( ii ) ) )
104             {
105                 bytes[bytes.length - ii / 8 - 1] |= 1 << ( ii % 8 );
106             }
107         }
108         return bytes;
109     }
110 
111 
112     protected void setBytes( byte[] bytes )
113     {
114         for ( int ii = 0; ii < bytes.length * 8; ii++ )
115         {
116             if ( ( bytes[bytes.length - ii / 8 - 1] & ( 1 << ( ii % 8 ) ) ) > 0 )
117             {
118                 options.set( reversePosition( ii ) );
119             }
120         }
121     }
122 
123 
124     private int reversePosition( int position )
125     {
126         return maxSize - 1 - position;
127     }
128 }