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.asn1.util;
021    
022    
023    import org.apache.directory.shared.asn1.ber.tlv.Value;
024    import org.apache.directory.shared.i18n.I18n;
025    
026    
027    /**
028     * Parse and decode a Long value.
029     * 
030     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
031     * @version $Rev: 664290 $, $Date: 2008-06-07 08:28:06 +0200 (Sat, 07 Jun 2008) $
032     */
033    public class LongDecoder
034    {
035        private static final long[] MASK = new long[]
036            { 
037                0x00000000000000FFL, 
038                0x000000000000FFFFL, 
039                0x0000000000FFFFFFL, 
040                0x00000000FFFFFFFFL,
041                0x000000FFFFFFFFFFL, 
042                0x0000FFFFFFFFFFFFL, 
043                0x00FFFFFFFFFFFFFFL, 
044                0xFFFFFFFFFFFFFFFFL 
045            };
046    
047    
048        // ~ Methods
049        // ------------------------------------------------------------------------------------
050    
051        /**
052         * Parse a byte buffer and send back an long, controlling that this number
053         * is in a specified interval.
054         * 
055         * @param value The byte buffer to parse
056         * @param min Lowest value allowed, included
057         * @param max Highest value allowed, included
058         * @return An integer
059         * @throws LongDecoderException
060         *             Thrown if the byte stream does not contains an integer
061         */
062        public static long parse( Value value, long min, long max ) throws LongDecoderException
063        {
064    
065            long result = 0;
066    
067            byte[] bytes = value.getData();
068    
069            if ( ( bytes == null ) || ( bytes.length == 0 ) )
070            {
071                throw new LongDecoderException( I18n.err( I18n.ERR_00039 ) );
072            }
073    
074            if ( bytes.length > 8 )
075            {
076                throw new LongDecoderException( I18n.err( I18n.ERR_00039 ) );
077            }
078    
079            for ( int i = 0; ( i < bytes.length ) && ( i < 9 ); i++ )
080            {
081                result = ( result << 8 ) | ( bytes[i] & 0x00FF );
082            }
083    
084            if ( ( bytes[0] & 0x80 ) == 0x80 )
085            {
086                result = -( ( ( ~result ) + 1 ) & MASK[bytes.length - 1] );
087            }
088    
089            if ( ( result >= min ) && ( result <= max ) )
090            {
091                return result;
092            }
093            else
094            {
095                throw new LongDecoderException( I18n.err( I18n.ERR_00038, min, max ) );
096            }
097        }
098    
099    
100        /**
101         * Parse a byte buffer and send back an integer
102         * 
103         * @param value The byte buffer to parse
104         * @return An integer
105         * @throws IntegerDecoderException
106         *             Thrown if the byte stream does not contains an integer
107         */
108        public static long parse( Value value ) throws LongDecoderException
109        {
110            return parse( value, Long.MIN_VALUE, Long.MAX_VALUE );
111        }
112    }