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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  
21  package org.apache.directory.server.dhcp.options;
22  
23  
24  import java.util.HashMap;
25  import java.util.Iterator;
26  import java.util.Map;
27  
28  
29  /**
30   * The Dynamic Host Configuration Protocol (DHCP) provides a framework
31   * for passing configuration information to hosts on a TCP/IP network.  
32   * Configuration parameters and other control information are carried in
33   * tagged data items that are stored in the 'options' field of the DHCP
34   * message.  The data items themselves are also called "options."
35   * 
36   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
37   * @version $Rev: 642496 $, $Date: 2008-03-29 04:09:22 +0100 (Sa, 29 Mär 2008) $
38   */
39  public class OptionsField
40  {
41      /**
42       * A map of option code (Integer)->DhcpOption. FIXME: use IntHashtable from
43       * commons collections
44       */
45      private Map options = new HashMap();
46  
47  
48      public void add( DhcpOption option )
49      {
50          options.put( new Integer( option.getTag() ), option );
51      }
52  
53  
54      public boolean isEmpty()
55      {
56          return options.isEmpty();
57      }
58  
59  
60      public Iterator iterator()
61      {
62          return options.values().iterator();
63      }
64  
65  
66      /**
67       * Return the (first) DHCP option matching a given option class or
68       * <code>null</code> of the option isn't set.
69       * 
70       * @param optionClass
71       */
72      public DhcpOption get( Class optionClass )
73      {
74          Integer key = new Integer( DhcpOption.getTagByClass( optionClass ) );
75          return ( DhcpOption ) options.get( key );
76      }
77  
78  
79      /**
80       * Return the (first) DHCP option matching a given tag or <code>null</code>
81       * of the option isn't set.
82       * 
83       * @param tag
84       */
85      public DhcpOption get( int tag )
86      {
87          Integer key = new Integer( tag );
88          return ( DhcpOption ) options.get( key );
89      }
90  
91  
92      /**
93       * Merge the options from the given options field into my options. Existing
94       * options are replaced by the ones from the supplied options field.
95       * 
96       * @param options
97       */
98      public void merge( OptionsField options )
99      {
100         if ( null == options )
101             return;
102 
103         for ( Iterator i = options.iterator(); i.hasNext(); )
104         {
105             DhcpOption option = ( DhcpOption ) i.next();
106             this.options.put( new Integer( option.getTag() ), option );
107         }
108     }
109 
110 
111     /**
112      * Remove instances of the given option class.
113      * 
114      * @param c
115      */
116     public void remove( Class c )
117     {
118         Integer key = new Integer( DhcpOption.getTagByClass( c ) );
119         options.remove( key );
120     }
121 
122 
123     /**
124      * Remove options matching the given tag
125      * 
126      * @param tag
127      */
128     public void remove( int tag )
129     {
130         Integer key = new Integer( tag );
131         options.remove( key );
132     }
133 
134 
135     /**
136      * @see Map#clear()
137      */
138     public void clear()
139     {
140         options.clear();
141     }
142 }