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    package org.apache.directory.shared.ldap.codec.search.controls.subEntry;
021    
022    
023    import org.apache.directory.shared.asn1.ber.IAsn1Container;
024    import org.apache.directory.shared.asn1.ber.grammar.AbstractGrammar;
025    import org.apache.directory.shared.asn1.ber.grammar.GrammarAction;
026    import org.apache.directory.shared.asn1.ber.grammar.GrammarTransition;
027    import org.apache.directory.shared.asn1.ber.grammar.IGrammar;
028    import org.apache.directory.shared.asn1.ber.tlv.TLV;
029    import org.apache.directory.shared.asn1.ber.tlv.UniversalTag;
030    import org.apache.directory.shared.asn1.ber.tlv.Value;
031    import org.apache.directory.shared.asn1.codec.DecoderException;
032    import org.apache.directory.shared.asn1.util.BooleanDecoder;
033    import org.apache.directory.shared.asn1.util.BooleanDecoderException;
034    import org.apache.directory.shared.ldap.util.StringTools;
035    import org.slf4j.Logger;
036    import 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     * @version $Rev: 764131 $, $Date: 2009-04-11 03:03:00 +0200 (Sam, 11 avr 2009) $, 
045     */
046    public class SubEntryControlGrammar extends AbstractGrammar
047    {
048        /** The logger */
049        static final Logger log = LoggerFactory.getLogger( SubEntryControlGrammar.class );
050    
051        /** The instance of grammar. SubEntryControlGrammar is a singleton */
052        private static IGrammar instance = new SubEntryControlGrammar();
053    
054    
055        /**
056         * Creates a new SubEntryGrammar object.
057         */
058        private SubEntryControlGrammar()
059        {
060            name = SubEntryControlGrammar.class.getName();
061            statesEnum = SubEntryControlStatesEnum.getInstance();
062    
063            // Create the transitions table
064            super.transitions = new GrammarTransition[SubEntryControlStatesEnum.LAST_SUB_ENTRY_STATE][256];
065    
066            super.transitions[SubEntryControlStatesEnum.START_STATE][UniversalTag.BOOLEAN_TAG] = 
067                new GrammarTransition( SubEntryControlStatesEnum.START_STATE, 
068                                        SubEntryControlStatesEnum.SUB_ENTRY_VISIBILITY_STATE, UniversalTag.BOOLEAN_TAG, 
069                    new GrammarAction( "SubEntryControl visibility" )
070                {
071                    public void action( IAsn1Container container ) throws DecoderException
072                    {
073                        SubEntryControlContainer subEntryContainer = ( SubEntryControlContainer ) container;
074                        SubEntryControlCodec control = new SubEntryControlCodec();
075                        subEntryContainer.setSubEntryControl( control );
076    
077                        TLV tlv = subEntryContainer.getCurrentTLV();
078    
079                        // We get the value. If it's a 0, it's a FALSE. If it's
080                        // a FF, it's a TRUE. Any other value should be an error,
081                        // but we could relax this constraint. So if we have
082                        // something
083                        // which is not 0, it will be interpreted as TRUE, but we
084                        // will generate a warning.
085                        Value value = tlv.getValue();
086    
087                        try
088                        {
089                            control.setVisibility( BooleanDecoder.parse( value ) );
090    
091                            // We can have an END transition
092                            container.grammarEndAllowed( true );
093                        }
094                        catch ( BooleanDecoderException bde )
095                        {
096                            log.error( "The visibility flag {} is invalid : {}. It should be 0 or 255", StringTools
097                                .dumpBytes( value.getData() ), bde.getMessage() );
098    
099                            // This will generate a PROTOCOL_ERROR
100                            throw new DecoderException( bde.getMessage() );
101                        }
102                    }
103                } );
104        }
105    
106    
107        /**
108         * This class is a singleton.
109         * 
110         * @return An instance on this grammar
111         */
112        public static IGrammar getInstance()
113        {
114            return instance;
115        }
116    }