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.asn1.ber.tlv; 021 022 023import org.apache.directory.api.i18n.I18n; 024 025 026/** 027 * Parse and decode a Long value. 028 * 029 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 030 */ 031public final class LongDecoder 032{ 033 /** A mask used to get only the necessary bytes */ 034 private static final long[] MASK = new long[] 035 { 0x00000000000000FFL, 0x000000000000FFFFL, 0x0000000000FFFFFFL, 0x00000000FFFFFFFFL, 0x000000FFFFFFFFFFL, 036 0x0000FFFFFFFFFFFFL, 0x00FFFFFFFFFFFFFFL, 0xFFFFFFFFFFFFFFFFL }; 037 038 039 private LongDecoder() 040 { 041 } 042 043 044 /** 045 * Parse a byte buffer and send back an long, controlling that this number 046 * is in a specified interval. 047 * 048 * @param value The byte buffer to parse 049 * @param min Lowest value allowed, included 050 * @param max Highest value allowed, included 051 * @return An integer 052 * @throws LongDecoderException Thrown if the byte stream does not contains an integer 053 */ 054 public static long parse( BerValue value, long min, long max ) throws LongDecoderException 055 { 056 long result = parseLong( value ); 057 058 if ( ( result >= min ) && ( result <= max ) ) 059 { 060 return result; 061 } 062 else 063 { 064 throw new LongDecoderException( I18n.err( I18n.ERR_00038_VALUE_NOT_IN_RANGE, min, max ) ); 065 } 066 } 067 068 069 /** 070 * Parse a byte buffer and send back an integer 071 * 072 * @param value The byte buffer to parse 073 * @return An integer 074 * @throws LongDecoderException Thrown if the byte stream does not contains an integer 075 */ 076 public static long parse( BerValue value ) throws LongDecoderException 077 { 078 return parseLong( value ); 079 } 080 081 082 /** 083 * Helper method used to parse the long. We don't check any minimal or maximal 084 * bound. 085 * 086 * @param value The value to parse to a long 087 * @return The decoded long 088 * @throws LongDecoderException If we failed to decode a long 089 */ 090 public static long parseLong( BerValue value ) throws LongDecoderException 091 { 092 long result = 0; 093 094 byte[] bytes = value.getData(); 095 096 if ( ( bytes == null ) || ( bytes.length == 0 ) ) 097 { 098 throw new LongDecoderException( I18n.err( I18n.ERR_00039_0_BYTES_LONG_LONG ) ); 099 } 100 101 if ( bytes.length > 8 ) 102 { 103 throw new LongDecoderException( I18n.err( I18n.ERR_00039_0_BYTES_LONG_LONG ) ); 104 } 105 106 for ( int i = 0; ( i < bytes.length ) && ( i < 9 ); i++ ) 107 { 108 result = ( result << 8 ) | ( bytes[i] & 0x00FF ); 109 } 110 111 if ( ( bytes[0] & 0x80 ) == 0x80 ) 112 { 113 result = -( ( ( ~result ) + 1 ) & MASK[bytes.length - 1] ); 114 } 115 116 return result; 117 } 118}