001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one
003     *  or more contributor license agreements.  See the NOTICE file
004     *  distributed with this work for additional information
005     *  regarding copyright ownership.  The ASF licenses this file
006     *  to you under the Apache License, Version 2.0 (the
007     *  "License"); you may not use this file except in compliance
008     *  with the License.  You may obtain a copy of the License at
009     *
010     *       http://www.apache.org/licenses/LICENSE-2.0
011     *
012     *  Unless required by applicable law or agreed to in writing,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License. 
018     *
019     */
020    
021    package org.apache.directory.server.dhcp.options;
022    
023    
024    import java.util.HashMap;
025    import java.util.Iterator;
026    import java.util.Map;
027    
028    
029    /**
030     * The Dynamic Host Configuration Protocol (DHCP) provides a framework
031     * for passing configuration information to hosts on a TCP/IP network.  
032     * Configuration parameters and other control information are carried in
033     * tagged data items that are stored in the 'options' field of the DHCP
034     * message.  The data items themselves are also called "options."
035     * 
036     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
037     * @version $Rev: 642496 $, $Date: 2008-03-29 04:09:22 +0100 (Sat, 29 Mar 2008) $
038     */
039    public class OptionsField
040    {
041        /**
042         * A map of option code (Integer)->DhcpOption. FIXME: use IntHashtable from
043         * commons collections
044         */
045        private Map options = new HashMap();
046    
047    
048        public void add( DhcpOption option )
049        {
050            options.put( new Integer( option.getTag() ), option );
051        }
052    
053    
054        public boolean isEmpty()
055        {
056            return options.isEmpty();
057        }
058    
059    
060        public Iterator iterator()
061        {
062            return options.values().iterator();
063        }
064    
065    
066        /**
067         * Return the (first) DHCP option matching a given option class or
068         * <code>null</code> of the option isn't set.
069         * 
070         * @param optionClass
071         */
072        public DhcpOption get( Class optionClass )
073        {
074            Integer key = new Integer( DhcpOption.getTagByClass( optionClass ) );
075            return ( DhcpOption ) options.get( key );
076        }
077    
078    
079        /**
080         * Return the (first) DHCP option matching a given tag or <code>null</code>
081         * of the option isn't set.
082         * 
083         * @param tag
084         */
085        public DhcpOption get( int tag )
086        {
087            Integer key = new Integer( tag );
088            return ( DhcpOption ) options.get( key );
089        }
090    
091    
092        /**
093         * Merge the options from the given options field into my options. Existing
094         * options are replaced by the ones from the supplied options field.
095         * 
096         * @param options
097         */
098        public void merge( OptionsField options )
099        {
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    }