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.message.control;
021    
022    
023    import org.apache.directory.shared.asn1.codec.EncoderException;
024    import org.apache.directory.shared.ldap.codec.search.controls.pagedSearch.PagedSearchControlCodec;
025    import org.slf4j.Logger;
026    import org.slf4j.LoggerFactory;
027    
028    
029    /**
030     * A request/response control used to implement a simple paging of search
031     * results. This is an implementation of RFC 2696 :
032     * <a href="http://www.faqs.org/rfcs/rfc2696.html">LDAP Control Extension for Simple Paged Results Manipulation</a>
033     * <br/>
034     * <pre>
035     *    This control is included in the searchRequest and searchResultDone
036     *    messages as part of the controls field of the LDAPMessage, as defined
037     *    in Section 4.1.12 of [LDAPv3]. The structure of this control is as
038     *    follows:
039     *
040     * pagedResultsControl ::= SEQUENCE {
041     *         controlType     1.2.840.113556.1.4.319,
042     *         criticality     BOOLEAN DEFAULT FALSE,
043     *         controlValue    searchControlValue
044     * }
045     * 
046     * The searchControlValue is an OCTET STRING wrapping the BER-encoded
047     * version of the following SEQUENCE:
048     * 
049     * realSearchControlValue ::= SEQUENCE {
050     *         size            INTEGER (0..maxInt),
051     *                                 -- requested page size from client
052     *                                 -- result set size estimate from server
053     *         cookie          OCTET STRING
054     * }
055     * 
056     * </pre>
057     * 
058     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
059     * @version $Rev: 678621 $
060     */
061    public class PagedSearchControl extends InternalAbstractControl
062    {
063        private static final long serialVersionUID = -2356861450876343999L;
064    
065        /** This class logger */
066        private static final Logger log = LoggerFactory.getLogger( PagedSearchControl.class );
067    
068        /** The Paged Search Control OID */
069        public static final String CONTROL_OID = "1.2.840.113556.1.4.319";
070        
071        /** The number of entries to return, or returned */
072        private int size;
073        
074        /** The exchanged cookie */
075        private byte[] cookie;
076    
077        /**
078         * 
079         * Creates a new instance of PagedSearchControl.
080         *
081         */
082        public PagedSearchControl()
083        {
084            super();
085            setID( CONTROL_OID );
086        }
087    
088    
089        /**
090         * @return The requested or returned number of entries
091         */
092        public int getSize()
093        {
094            return size;
095        }
096    
097    
098        /**
099         * Set the number of entry requested or returned
100         *
101         * @param size The number of entries 
102         */
103        public void setSize( int size )
104        {
105            this.size = size;
106        }
107    
108    
109        /**
110         * @return The stored cookie
111         */
112        public byte[] getCookie()
113        {
114            return cookie;
115        }
116    
117    
118        /**
119         * @return The integer value for the current cookie
120         */
121        public int getCookieValue()
122        {
123            int value = ((cookie[0]&0x00FF)<<24) + ((cookie[1]&0x00FF)<<16) + ((cookie[2]&0x00FF)<<8) + (cookie[3]&0x00FF);
124            
125            return value;
126        }
127        
128        
129        /**
130         * Set the cookie
131         *
132         * @param cookie The cookie to store in this control
133         */
134        public void setCookie( byte[] cookie )
135        {
136            this.cookie = cookie;
137        }
138    
139    
140        /**
141         * Encode the control.
142         */
143        public byte[] getEncodedValue() 
144        {
145            // should call this codec or something
146            PagedSearchControlCodec pscc = new PagedSearchControlCodec();
147            pscc.setSize( size );
148            pscc.setCookie( cookie );
149    
150            try
151            {
152                return pscc.encode( null ).array();
153            }
154            catch ( EncoderException e )
155            {
156                log.error( "Failed to encode paged search control", e );
157                throw new IllegalStateException( "Failed to encode control with encoder.", e );
158            }
159        }
160    }