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.api.ldap.codec.controls.search.pagedSearch; 021 022 023import org.apache.directory.api.asn1.DecoderException; 024import org.apache.directory.api.asn1.ber.grammar.AbstractGrammar; 025import org.apache.directory.api.asn1.ber.grammar.Grammar; 026import org.apache.directory.api.asn1.ber.grammar.GrammarAction; 027import org.apache.directory.api.asn1.ber.grammar.GrammarTransition; 028import org.apache.directory.api.asn1.ber.tlv.BerValue; 029import org.apache.directory.api.asn1.ber.tlv.IntegerDecoder; 030import org.apache.directory.api.asn1.ber.tlv.IntegerDecoderException; 031import org.apache.directory.api.asn1.ber.tlv.UniversalTag; 032import org.apache.directory.api.i18n.I18n; 033import org.apache.directory.api.util.Strings; 034import org.slf4j.Logger; 035import org.slf4j.LoggerFactory; 036 037 038/** 039 * This class implements the PagedSearchControl. All the actions are declared in 040 * this class. As it is a singleton, these declaration are only done once. 041 * 042 * The decoded grammar is the following : 043 * 044 * realSearchControlValue ::= SEQUENCE { 045 * size INTEGER, 046 * cookie OCTET STRING, 047 * } 048 * 049 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 050 */ 051public final class PagedResultsGrammar extends AbstractGrammar<PagedResultsContainer> 052{ 053 /** The logger */ 054 static final Logger LOG = LoggerFactory.getLogger( PagedResultsGrammar.class ); 055 056 /** The instance of grammar. PagedSearchControlGrammar is a singleton */ 057 private static Grammar<?> instance = new PagedResultsGrammar(); 058 059 060 /** 061 * Creates a new PagedSearchControlGrammar object. 062 */ 063 @SuppressWarnings("unchecked") 064 private PagedResultsGrammar() 065 { 066 setName( PagedResultsGrammar.class.getName() ); 067 068 // Create the transitions table 069 super.transitions = new GrammarTransition[PagedResultsStates.LAST_PAGED_SEARCH_STATE.ordinal()][256]; 070 071 /** 072 * Transition from initial state to PagedSearch sequence 073 * realSearchControlValue ::= SEQUENCE OF { 074 * ... 075 * 076 * Nothing to do 077 */ 078 super.transitions[PagedResultsStates.START_STATE.ordinal()][UniversalTag.SEQUENCE.getValue()] = 079 new GrammarTransition<PagedResultsContainer>( PagedResultsStates.START_STATE, 080 PagedResultsStates.PAGED_SEARCH_SEQUENCE_STATE, 081 UniversalTag.SEQUENCE.getValue(), null ); 082 083 /** 084 * Transition from PagedSearch sequence to size 085 * 086 * realSearchControlValue ::= SEQUENCE OF { 087 * size INTEGER, -- INTEGER (0..maxInt), 088 * ... 089 * 090 * Stores the size value 091 */ 092 super.transitions[PagedResultsStates.PAGED_SEARCH_SEQUENCE_STATE.ordinal()][UniversalTag.INTEGER.getValue()] = 093 new GrammarTransition<PagedResultsContainer>( PagedResultsStates.PAGED_SEARCH_SEQUENCE_STATE, 094 PagedResultsStates.SIZE_STATE, 095 UniversalTag.INTEGER.getValue(), 096 new GrammarAction<PagedResultsContainer>( "Set PagedSearchControl size" ) 097 { 098 public void action( PagedResultsContainer container ) throws DecoderException 099 { 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}