1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.directory.api.ldap.codec.controls.search.pagedSearch;
21
22
23 import org.apache.directory.api.asn1.DecoderException;
24 import org.apache.directory.api.asn1.ber.grammar.AbstractGrammar;
25 import org.apache.directory.api.asn1.ber.grammar.Grammar;
26 import org.apache.directory.api.asn1.ber.grammar.GrammarAction;
27 import org.apache.directory.api.asn1.ber.grammar.GrammarTransition;
28 import org.apache.directory.api.asn1.ber.tlv.BerValue;
29 import org.apache.directory.api.asn1.ber.tlv.IntegerDecoder;
30 import org.apache.directory.api.asn1.ber.tlv.IntegerDecoderException;
31 import org.apache.directory.api.asn1.ber.tlv.UniversalTag;
32 import org.apache.directory.api.i18n.I18n;
33 import org.apache.directory.api.util.Strings;
34 import org.slf4j.Logger;
35 import org.slf4j.LoggerFactory;
36
37
38 /**
39 * This class implements the PagedSearchControl. All the actions are declared in
40 * this class. As it is a singleton, these declaration are only done once.
41 *
42 * The decoded grammar is the following :
43 *
44 * realSearchControlValue ::= SEQUENCE {
45 * size INTEGER,
46 * cookie OCTET STRING,
47 * }
48 *
49 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
50 */
51 public final class PagedResultsGrammar extends AbstractGrammar<PagedResultsContainer>
52 {
53 /** The logger */
54 static final Logger LOG = LoggerFactory.getLogger( PagedResultsGrammar.class );
55
56 /** Speedup for logs */
57 static final boolean IS_DEBUG = LOG.isDebugEnabled();
58
59 /** The instance of grammar. PagedSearchControlGrammar is a singleton */
60 private static Grammar<?> instance = new PagedResultsGrammar();
61
62
63 /**
64 * Creates a new PagedSearchControlGrammar object.
65 */
66 @SuppressWarnings("unchecked")
67 private PagedResultsGrammar()
68 {
69 setName( PagedResultsGrammar.class.getName() );
70
71 // Create the transitions table
72 super.transitions = new GrammarTransition[PagedResultsStates.LAST_PAGED_SEARCH_STATE.ordinal()][256];
73
74 /**
75 * Transition from initial state to PagedSearch sequence
76 * realSearchControlValue ::= SEQUENCE OF {
77 * ...
78 *
79 * Nothing to do
80 */
81 super.transitions[PagedResultsStates.START_STATE.ordinal()][UniversalTag.SEQUENCE.getValue()] =
82 new GrammarTransition<PagedResultsContainer>( PagedResultsStates.START_STATE,
83 PagedResultsStates.PAGED_SEARCH_SEQUENCE_STATE,
84 UniversalTag.SEQUENCE.getValue(), null );
85
86 /**
87 * Transition from PagedSearch sequence to size
88 *
89 * realSearchControlValue ::= SEQUENCE OF {
90 * size INTEGER, -- INTEGER (0..maxInt),
91 * ...
92 *
93 * Stores the size value
94 */
95 super.transitions[PagedResultsStates.PAGED_SEARCH_SEQUENCE_STATE.ordinal()][UniversalTag.INTEGER.getValue()] =
96 new GrammarTransition<PagedResultsContainer>( PagedResultsStates.PAGED_SEARCH_SEQUENCE_STATE,
97 PagedResultsStates.SIZE_STATE,
98 UniversalTag.INTEGER.getValue(),
99 new GrammarAction<PagedResultsContainer>( "Set PagedSearchControl size" )
100 {
101 public void action( PagedResultsContainer container ) throws DecoderException
102 {
103 BerValue value = container.getCurrentTLV().getValue();
104
105 try
106 {
107 // Check that the value is into the allowed interval
108 int size = IntegerDecoder.parse( value, Integer.MIN_VALUE, Integer.MAX_VALUE );
109
110 // We allow negative value to absorb a bug in some M$ client.
111 // Those negative values will be transformed to Integer.MAX_VALUE.
112 if ( size < 0 )
113 {
114 size = Integer.MAX_VALUE;
115 }
116
117 if ( IS_DEBUG )
118 {
119 LOG.debug( "size = " + size );
120 }
121
122 container.getDecorator().setSize( size );
123 }
124 catch ( IntegerDecoderException ide )
125 {
126 String msg = I18n.err( I18n.ERR_04050 );
127 LOG.error( msg, ide );
128 throw new DecoderException( msg, ide );
129 }
130 }
131 } );
132
133 /**
134 * Transition from size to cookie
135 * realSearchControlValue ::= SEQUENCE OF {
136 * ...
137 * cookie OCTET STRING
138 * }
139 *
140 * Stores the cookie flag
141 */
142 super.transitions[PagedResultsStates.SIZE_STATE.ordinal()][UniversalTag.OCTET_STRING.getValue()] =
143 new GrammarTransition<PagedResultsContainer>( PagedResultsStates.SIZE_STATE,
144 PagedResultsStates.COOKIE_STATE, UniversalTag.OCTET_STRING.getValue(),
145 new GrammarAction<PagedResultsContainer>( "Set PagedSearchControl cookie" )
146 {
147 public void action( PagedResultsContainer container ) throws DecoderException
148 {
149 BerValue value = container.getCurrentTLV().getValue();
150
151 if ( container.getCurrentTLV().getLength() == 0 )
152 {
153 container.getDecorator().setCookie( Strings.EMPTY_BYTES );
154 }
155 else
156 {
157 container.getDecorator().setCookie( value.getData() );
158 }
159
160 // We can have an END transition
161 container.setGrammarEndAllowed( true );
162 }
163 } );
164 }
165
166
167 /**
168 * This class is a singleton.
169 *
170 * @return An instance on this grammar
171 */
172 public static Grammar<?> getInstance()
173 {
174 return instance;
175 }
176 }