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.extended.operations.cancel;
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.grammar.IStates;
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.IntegerDecoder;
033    import org.apache.directory.shared.asn1.util.IntegerDecoderException;
034    import org.apache.directory.shared.i18n.I18n;
035    import org.apache.directory.shared.ldap.util.StringTools;
036    import org.slf4j.Logger;
037    import org.slf4j.LoggerFactory;
038    
039    
040    /**
041     * This class implements the Cancel operation. All the actions are declared
042     * in this class. As it is a singleton, these declaration are only done once.
043     * The grammar is :
044     * 
045     * <pre>
046     *  cancelRequestValue ::= SEQUENCE {
047     *      cancelId     MessageID 
048     *                   -- MessageID is as defined in [RFC2251]
049     * }
050     * </pre>
051     * 
052     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
053     * @version $Rev: 687720 $, $Date: 2008-08-21 14:05:50 +0200 (Thu, 21 Aug 2008) $, 
054     */
055    public class CancelGrammar extends AbstractGrammar
056    {
057        /** The logger */
058        static final Logger LOG = LoggerFactory.getLogger( CancelGrammar.class );
059    
060        /** Speedup for logs */
061        static final boolean IS_DEBUG = LOG.isDebugEnabled();
062    
063        /** The instance of grammar. CancelGrammar is a singleton */
064        private static IGrammar instance = new CancelGrammar();
065    
066    
067        /**
068         * Creates a new GracefulDisconnectGrammar object.
069         */
070        private CancelGrammar()
071        {
072            name = CancelGrammar.class.getName();
073            statesEnum = CancelStatesEnum.getInstance();
074    
075            // Create the transitions table
076            super.transitions = new GrammarTransition[CancelStatesEnum.LAST_CANCEL_STATE][256];
077    
078            /**
079             * Transition from init state to cancel sequence
080             * cancelRequestValue ::= SEQUENCE {
081             *     ... 
082             * 
083             * Creates the Cancel object
084             */
085            super.transitions[IStates.INIT_GRAMMAR_STATE][UniversalTag.SEQUENCE_TAG] = 
086                new GrammarTransition( IStates.INIT_GRAMMAR_STATE,
087                                        CancelStatesEnum.CANCEL_SEQUENCE_STATE, 
088                                        UniversalTag.SEQUENCE_TAG,
089                    new GrammarAction(
090                    "Init Cancel" )
091                {
092                    public void action( IAsn1Container container )
093                    {
094                        CancelContainer cancelContainer = ( CancelContainer ) container;
095                        Cancel cancel = new Cancel();
096                        cancelContainer.setCancel( cancel );
097                    }
098                } );
099    
100            /**
101             * Transition from cancel SEQ to cancelId
102             * 
103             * cancelRequestValue ::= SEQUENCE {
104             *     cancelId   MessageID 
105             * }
106             *     
107             * Set the cancelId value into the Cancel object.    
108             */
109            super.transitions[CancelStatesEnum.CANCEL_SEQUENCE_STATE][UniversalTag.INTEGER_TAG] = 
110                new GrammarTransition( CancelStatesEnum.CANCEL_SEQUENCE_STATE,
111                                        CancelStatesEnum.CANCEL_ID_STATE, 
112                                        UniversalTag.INTEGER_TAG, 
113                    new GrammarAction( "Stores CancelId" )
114                {
115                    public void action( IAsn1Container container ) throws DecoderException
116                    {
117                        CancelContainer cancelContainer = ( CancelContainer ) container;
118                        Value value = cancelContainer.getCurrentTLV().getValue();
119        
120                        try
121                        {
122                            int cancelId = IntegerDecoder.parse( value, 0, Integer.MAX_VALUE );
123            
124                            if ( IS_DEBUG )
125                            {
126                                LOG.debug( "CancelId = " + cancelId );
127                            }
128            
129                            cancelContainer.getCancel().setCancelId( cancelId );
130                            cancelContainer.grammarEndAllowed( true );
131                        }
132                        catch ( IntegerDecoderException e )
133                        {
134                            String msg = I18n.err( I18n.ERR_04031, StringTools.dumpBytes( value.getData() ) );
135                            LOG.error( msg );
136                            throw new DecoderException( msg );
137                        }
138                    }
139                });
140        }
141    
142    
143        /**
144         * This class is a singleton.
145         * 
146         * @return An instance on this grammar
147         */
148        public static IGrammar getInstance()
149        {
150            return instance;
151        }
152    }