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 * https://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 /** The instance of grammar. PagedSearchControlGrammar is a singleton */
57 private static Grammar<?> instance = new PagedResultsGrammar();
58
59
60 /**
61 * Creates a new PagedSearchControlGrammar object.
62 */
63 @SuppressWarnings("unchecked")
64 private PagedResultsGrammar()
65 {
66 setName( PagedResultsGrammar.class.getName() );
67
68 // Create the transitions table
69 super.transitions = new GrammarTransition[PagedResultsStates.LAST_PAGED_SEARCH_STATE.ordinal()][256];
70
71 /**
72 * Transition from initial state to PagedSearch sequence
73 * realSearchControlValue ::= SEQUENCE OF {
74 * ...
75 *
76 * Nothing to do
77 */
78 super.transitions[PagedResultsStates.START_STATE.ordinal()][UniversalTag.SEQUENCE.getValue()] =
79 new GrammarTransition<PagedResultsContainer>( PagedResultsStates.START_STATE,
80 PagedResultsStates.PAGED_SEARCH_SEQUENCE_STATE,
81 UniversalTag.SEQUENCE.getValue(), null );
82
83 /**
84 * Transition from PagedSearch sequence to size
85 *
86 * realSearchControlValue ::= SEQUENCE OF {
87 * size INTEGER, -- INTEGER (0..maxInt),
88 * ...
89 *
90 * Stores the size value
91 */
92 super.transitions[PagedResultsStates.PAGED_SEARCH_SEQUENCE_STATE.ordinal()][UniversalTag.INTEGER.getValue()] =
93 new GrammarTransition<PagedResultsContainer>( PagedResultsStates.PAGED_SEARCH_SEQUENCE_STATE,
94 PagedResultsStates.SIZE_STATE,
95 UniversalTag.INTEGER.getValue(),
96 new GrammarAction<PagedResultsContainer>( "Set PagedSearchControl size" )
97 {
98 public void action( PagedResultsContainer container ) throws DecoderException
99 {
100 BerValue value = container.getCurrentTLV().getValue();
101
102 try
103 {
104 // Check that the value is into the allowed interval
105 int size = IntegerDecoder.parse( value, Integer.MIN_VALUE, Integer.MAX_VALUE );
106
107 // We allow negative value to absorb a bug in some M$ client.
108 // Those negative values will be transformed to Integer.MAX_VALUE.
109 if ( size < 0 )
110 {
111 size = Integer.MAX_VALUE;
112 }
113
114 if ( LOG.isDebugEnabled() )
115 {
116 LOG.debug( I18n.msg( I18n.MSG_05303_SIZE, size ) );
117 }
118
119 container.getPagedResults().setSize( size );
120 }
121 catch ( IntegerDecoderException ide )
122 {
123 String msg = I18n.err( I18n.ERR_05306_PAGED_SEARCH_SIZE_DECODING_ERROR );
124 LOG.error( msg, ide );
125 throw new DecoderException( msg, ide );
126 }
127 }
128 } );
129
130 /**
131 * Transition from size to cookie
132 * realSearchControlValue ::= SEQUENCE OF {
133 * ...
134 * cookie OCTET STRING
135 * }
136 *
137 * Stores the cookie flag
138 */
139 super.transitions[PagedResultsStates.SIZE_STATE.ordinal()][UniversalTag.OCTET_STRING.getValue()] =
140 new GrammarTransition<PagedResultsContainer>( PagedResultsStates.SIZE_STATE,
141 PagedResultsStates.COOKIE_STATE, UniversalTag.OCTET_STRING.getValue(),
142 new GrammarAction<PagedResultsContainer>( "Set PagedSearchControl cookie" )
143 {
144 public void action( PagedResultsContainer container )
145 {
146 BerValue value = container.getCurrentTLV().getValue();
147
148 if ( container.getCurrentTLV().getLength() == 0 )
149 {
150 container.getPagedResults().setCookie( Strings.EMPTY_BYTES );
151 }
152 else
153 {
154 container.getPagedResults().setCookie( value.getData() );
155 }
156
157 // We can have an END transition
158 container.setGrammarEndAllowed( true );
159 }
160 } );
161 }
162
163
164 /**
165 * This class is a singleton.
166 *
167 * @return An instance on this grammar
168 */
169 public static Grammar<?> getInstance()
170 {
171 return instance;
172 }
173 }