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 */
020package org.apache.directory.api.ldap.codec.controls.search.entryChange;
021
022
023import java.nio.ByteBuffer;
024
025import org.apache.directory.api.asn1.Asn1Object;
026import org.apache.directory.api.asn1.DecoderException;
027import org.apache.directory.api.asn1.EncoderException;
028import org.apache.directory.api.asn1.ber.Asn1Decoder;
029import org.apache.directory.api.asn1.ber.tlv.BerValue;
030import org.apache.directory.api.asn1.ber.tlv.TLV;
031import org.apache.directory.api.asn1.ber.tlv.UniversalTag;
032import org.apache.directory.api.i18n.I18n;
033import org.apache.directory.api.ldap.codec.api.ControlDecorator;
034import org.apache.directory.api.ldap.codec.api.LdapApiService;
035import org.apache.directory.api.ldap.model.message.controls.ChangeType;
036import org.apache.directory.api.ldap.model.message.controls.EntryChange;
037import org.apache.directory.api.ldap.model.message.controls.EntryChangeImpl;
038import org.apache.directory.api.ldap.model.name.Dn;
039import org.apache.directory.api.util.Strings;
040
041
042/**
043 * An EntryChange implementation, that wraps and decorates the Control with codec
044 * specific functionality.
045 *
046 *
047 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
048 */
049public class EntryChangeDecorator extends ControlDecorator<EntryChange> implements EntryChange
050{
051
052    public static final int UNDEFINED_CHANGE_NUMBER = -1;
053
054    /** A temporary storage for the previous Dn */
055    private byte[] previousDnBytes = null;
056
057    /** The entry change global length */
058    private int eccSeqLength;
059
060    /** An instance of this decoder */
061    private static final Asn1Decoder DECODER = new Asn1Decoder();
062
063
064    /**
065     * Creates a new instance of EntryChangeDecoder wrapping a newly created
066     * EntryChange Control object.
067     */
068    public EntryChangeDecorator( LdapApiService codec )
069    {
070        super( codec, new EntryChangeImpl() );
071    }
072
073
074    /**
075     * Creates a new instance of EntryChangeDecorator wrapping the supplied
076     * EntryChange Control.
077     *
078     * @param control The EntryChange Control to be decorated.
079     */
080    public EntryChangeDecorator( LdapApiService codec, EntryChange control )
081    {
082        super( codec, control );
083    }
084
085
086    /**
087     * Internally used to not have to cast the decorated Control.
088     *
089     * @return the decorated Control.
090     */
091    private EntryChange getEntryChange()
092    {
093        return ( EntryChange ) getDecorated();
094    }
095
096
097    /**
098     * Compute the EntryChangeControl length 
099     * 
100     * 0x30 L1 
101     *   | 
102     *   +--> 0x0A 0x0(1-4) [1|2|4|8] (changeType) 
103     *  [+--> 0x04 L2 previousDN] 
104     *  [+--> 0x02 0x0(1-4) [0..2^63-1] (changeNumber)]
105     */
106    public int computeLength()
107    {
108        int changeTypesLength = 1 + 1 + 1;
109
110        int previousDnLength = 0;
111        int changeNumberLength = 0;
112
113        if ( getPreviousDn() != null )
114        {
115            previousDnBytes = Strings.getBytesUtf8( getPreviousDn().getName() );
116            previousDnLength = 1 + TLV.getNbBytes( previousDnBytes.length ) + previousDnBytes.length;
117        }
118
119        if ( getChangeNumber() != UNDEFINED_CHANGE_NUMBER )
120        {
121            changeNumberLength = 1 + 1 + BerValue.getNbBytes( getChangeNumber() );
122        }
123
124        eccSeqLength = changeTypesLength + previousDnLength + changeNumberLength;
125        valueLength = 1 + TLV.getNbBytes( eccSeqLength ) + eccSeqLength;
126
127        return valueLength;
128    }
129
130
131    /**
132     * Encodes the entry change control.
133     * 
134     * @param buffer The encoded sink
135     * @return A ByteBuffer that contains the encoded PDU
136     * @throws EncoderException If anything goes wrong.
137     */
138    public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
139    {
140        if ( buffer == null )
141        {
142            throw new EncoderException( I18n.err( I18n.ERR_04023 ) );
143        }
144
145        buffer.put( UniversalTag.SEQUENCE.getValue() );
146        buffer.put( TLV.getBytes( eccSeqLength ) );
147
148        buffer.put( UniversalTag.ENUMERATED.getValue() );
149        buffer.put( ( byte ) 1 );
150        buffer.put( BerValue.getBytes( getChangeType().getValue() ) );
151
152        if ( getPreviousDn() != null )
153        {
154            BerValue.encode( buffer, previousDnBytes );
155        }
156
157        if ( getChangeNumber() != UNDEFINED_CHANGE_NUMBER )
158        {
159            BerValue.encode( buffer, getChangeNumber() );
160        }
161
162        return buffer;
163    }
164
165
166    /**
167     * {@inheritDoc}
168     */
169    public byte[] getValue()
170    {
171        if ( value == null )
172        {
173            try
174            {
175                computeLength();
176                ByteBuffer buffer = ByteBuffer.allocate( valueLength );
177
178                buffer.put( UniversalTag.SEQUENCE.getValue() );
179                buffer.put( TLV.getBytes( eccSeqLength ) );
180
181                buffer.put( UniversalTag.ENUMERATED.getValue() );
182                buffer.put( ( byte ) 1 );
183                buffer.put( BerValue.getBytes( getChangeType().getValue() ) );
184
185                if ( getPreviousDn() != null )
186                {
187                    BerValue.encode( buffer, previousDnBytes );
188                }
189
190                if ( getChangeNumber() != UNDEFINED_CHANGE_NUMBER )
191                {
192                    BerValue.encode( buffer, getChangeNumber() );
193                }
194
195                value = buffer.array();
196            }
197            catch ( Exception e )
198            {
199                return null;
200            }
201        }
202
203        return value;
204    }
205
206
207    /**
208     * {@inheritDoc}
209     */
210    public ChangeType getChangeType()
211    {
212        return getEntryChange().getChangeType();
213    }
214
215
216    /**
217     * {@inheritDoc}
218     */
219    public void setChangeType( ChangeType changeType )
220    {
221        getEntryChange().setChangeType( changeType );
222    }
223
224
225    /**
226     * {@inheritDoc}
227     */
228    public Dn getPreviousDn()
229    {
230        return getEntryChange().getPreviousDn();
231    }
232
233
234    /**
235     * {@inheritDoc}
236     */
237    public void setPreviousDn( Dn previousDn )
238    {
239        getEntryChange().setPreviousDn( previousDn );
240    }
241
242
243    /**
244     * {@inheritDoc}
245     */
246    public long getChangeNumber()
247    {
248        return getEntryChange().getChangeNumber();
249    }
250
251
252    /**
253     * {@inheritDoc}
254     */
255    public void setChangeNumber( long changeNumber )
256    {
257        getEntryChange().setChangeNumber( changeNumber );
258    }
259
260
261    /**
262     * {@inheritDoc}
263     */
264    public Asn1Object decode( byte[] controlBytes ) throws DecoderException
265    {
266        ByteBuffer bb = ByteBuffer.wrap( controlBytes );
267        EntryChangeContainer container = new EntryChangeContainer( getCodecService(), this );
268        DECODER.decode( bb, container );
269        return this;
270    }
271}