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.subentries;
021
022
023import org.apache.directory.api.asn1.DecoderException;
024import org.apache.directory.api.asn1.ber.grammar.AbstractGrammar;
025import org.apache.directory.api.asn1.ber.grammar.Grammar;
026import org.apache.directory.api.asn1.ber.grammar.GrammarAction;
027import org.apache.directory.api.asn1.ber.grammar.GrammarTransition;
028import org.apache.directory.api.asn1.ber.tlv.BerValue;
029import org.apache.directory.api.asn1.ber.tlv.BooleanDecoder;
030import org.apache.directory.api.asn1.ber.tlv.BooleanDecoderException;
031import org.apache.directory.api.asn1.ber.tlv.TLV;
032import org.apache.directory.api.asn1.ber.tlv.UniversalTag;
033import org.apache.directory.api.i18n.I18n;
034import org.apache.directory.api.util.Strings;
035import org.slf4j.Logger;
036import org.slf4j.LoggerFactory;
037
038
039/**
040 * This class implements the SubEntryControl. All the actions are declared in
041 * this class. As it is a singleton, these declaration are only done once.
042 * 
043 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
044 */
045public final class SubentriesGrammar extends AbstractGrammar<SubentriesContainer>
046{
047    /** The logger */
048    static final Logger LOG = LoggerFactory.getLogger( SubentriesGrammar.class );
049
050    /** The instance of grammar. SubEntryControlGrammar is a singleton */
051    private static Grammar<SubentriesContainer> instance = new SubentriesGrammar();
052
053
054    /**
055     * Creates a new SubEntryGrammar object.
056     */
057    @SuppressWarnings("unchecked")
058    private SubentriesGrammar()
059    {
060        setName( SubentriesGrammar.class.getName() );
061
062        // Create the transitions table
063        super.transitions = new GrammarTransition[SubentriesStates.LAST_SUB_ENTRY_STATE.ordinal()][256];
064
065        super.transitions[SubentriesStates.START_STATE.ordinal()][UniversalTag.BOOLEAN.getValue()] =
066            new GrammarTransition<SubentriesContainer>( SubentriesStates.START_STATE,
067                SubentriesStates.SUB_ENTRY_VISIBILITY_STATE, UniversalTag.BOOLEAN.getValue(),
068                new GrammarAction<SubentriesContainer>( "SubEntryControl visibility" )
069                {
070                    public void action( SubentriesContainer container ) throws DecoderException
071                    {
072                        TLV tlv = container.getCurrentTLV();
073
074                        // We get the value. If it's a 0, it's a FALSE. If it's
075                        // a FF, it's a TRUE. Any other value should be an error,
076                        // but we could relax this constraint. So if we have
077                        // something
078                        // which is not 0, it will be interpreted as TRUE, but we
079                        // will generate a warning.
080                        BerValue value = tlv.getValue();
081
082                        try
083                        {
084                            container.getSubentriesControl().setVisibility( BooleanDecoder.parse( value ) );
085
086                            // We can have an END transition
087                            container.setGrammarEndAllowed( true );
088                        }
089                        catch ( BooleanDecoderException bde )
090                        {
091                            LOG.error( I18n.err( I18n.ERR_04054, Strings.dumpBytes( value.getData() ), bde.getMessage() ) );
092
093                            // This will generate a PROTOCOL_ERROR
094                            throw new DecoderException( bde.getMessage() );
095                        }
096                    }
097                } );
098    }
099
100
101    /**
102     * This class is a singleton.
103     * 
104     * @return An instance on this grammar
105     */
106    public static Grammar<SubentriesContainer> getInstance()
107    {
108        return instance;
109    }
110}