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.shared.ldap.extras.extended.ads_impl.cancel;
021
022
023import org.apache.directory.shared.asn1.ber.Asn1Container;
024import org.apache.directory.shared.asn1.ber.grammar.AbstractGrammar;
025import org.apache.directory.shared.asn1.ber.grammar.Grammar;
026import org.apache.directory.shared.asn1.ber.grammar.GrammarAction;
027import org.apache.directory.shared.asn1.ber.grammar.GrammarTransition;
028import org.apache.directory.shared.asn1.ber.tlv.UniversalTag;
029import org.apache.directory.shared.asn1.ber.tlv.Value;
030import org.apache.directory.shared.asn1.DecoderException;
031import org.apache.directory.shared.asn1.ber.tlv.IntegerDecoder;
032import org.apache.directory.shared.asn1.ber.tlv.IntegerDecoderException;
033import org.apache.directory.shared.i18n.I18n;
034import org.apache.directory.shared.util.Strings;
035import org.slf4j.Logger;
036import org.slf4j.LoggerFactory;
037
038
039/**
040 * This class implements the Cancel operation. All the actions are declared
041 * in this class. As it is a singleton, these declaration are only done once.
042 * The grammar is :
043 * 
044 * <pre>
045 *  cancelRequestValue ::= SEQUENCE {
046 *      cancelId     MessageID 
047 *                   -- MessageID is as defined in [RFC2251]
048 * }
049 * </pre>
050 * 
051 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
052 */
053public final class CancelGrammar extends AbstractGrammar<CancelContainer>
054{
055    /** The logger */
056    static final Logger LOG = LoggerFactory.getLogger( CancelGrammar.class );
057
058    /** Speedup for logs */
059    static final boolean IS_DEBUG = LOG.isDebugEnabled();
060
061    /** The instance of grammar. CancelGrammar is a singleton */
062    private static Grammar<CancelContainer> instance = new CancelGrammar();
063
064
065    /**
066     * Creates a new GracefulDisconnectGrammar object.
067     */
068    @SuppressWarnings({ "unchecked", "rawtypes" })
069    private CancelGrammar()
070    {
071        setName( CancelGrammar.class.getName() );
072
073        // Create the transitions table
074        super.transitions = new GrammarTransition[CancelStatesEnum.LAST_CANCEL_STATE.ordinal()][256];
075
076        /**
077         * Transition from init state to cancel sequence
078         * cancelRequestValue ::= SEQUENCE {
079         *     ... 
080         * 
081         * Creates the Cancel object
082         */
083        super.transitions[CancelStatesEnum.START_STATE.ordinal()][UniversalTag.SEQUENCE.getValue()] = 
084            new GrammarTransition<CancelContainer>( CancelStatesEnum.START_STATE,
085                                    CancelStatesEnum.CANCEL_SEQUENCE_STATE, 
086                                    UniversalTag.SEQUENCE.getValue(),
087                new GrammarAction( "Init Cancel" )
088            {
089                public void action( Asn1Container container )
090                {
091                    CancelContainer cancelContainer = ( CancelContainer ) container;
092                    Cancel cancel = new Cancel();
093                    cancelContainer.setCancel( cancel );
094                }
095            } );
096
097        /**
098         * Transition from cancel SEQ to cancelId
099         * 
100         * cancelRequestValue ::= SEQUENCE {
101         *     cancelId   MessageID 
102         * }
103         *     
104         * Set the cancelId value into the Cancel object.    
105         */
106        super.transitions[CancelStatesEnum.CANCEL_SEQUENCE_STATE.ordinal()][UniversalTag.INTEGER.getValue()] = 
107            new GrammarTransition<CancelContainer>( CancelStatesEnum.CANCEL_SEQUENCE_STATE,
108                                    CancelStatesEnum.CANCEL_ID_STATE, 
109                                    UniversalTag.INTEGER.getValue(), 
110                new GrammarAction( "Stores CancelId" )
111            {
112                public void action( Asn1Container container ) throws DecoderException
113                {
114                    CancelContainer cancelContainer = ( CancelContainer ) container;
115                    Value value = cancelContainer.getCurrentTLV().getValue();
116    
117                    try
118                    {
119                        int cancelId = IntegerDecoder.parse( value, 0, Integer.MAX_VALUE );
120        
121                        if ( IS_DEBUG )
122                        {
123                            LOG.debug( "CancelId = " + cancelId );
124                        }
125        
126                        cancelContainer.getCancel().setCancelId( cancelId );
127                        cancelContainer.setGrammarEndAllowed( true );
128                    }
129                    catch ( IntegerDecoderException e )
130                    {
131                        String msg = I18n.err( I18n.ERR_04031, Strings.dumpBytes(value.getData()) );
132                        LOG.error( msg );
133                        throw new DecoderException( msg );
134                    }
135                }
136            });
137    }
138
139
140    /**
141     * This class is a singleton.
142     * 
143     * @return An instance on this grammar
144     */
145    public static Grammar<CancelContainer> getInstance()
146    {
147        return instance;
148    }
149}