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algorithm CRC32 added

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lganzzzo 2018-08-05 02:28:31 +03:00
parent 3fd6a2cf0c
commit ca16919063
2 changed files with 129 additions and 0 deletions
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77
algorithm/CRC32.cpp Normal file
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/***************************************************************************
*
* Project _____ __ ____ _ _
* ( _ ) /__\ (_ _)_| |_ _| |_
* )(_)( /(__)\ )( (_ _)(_ _)
* (_____)(__)(__)(__) |_| |_|
*
*
* Copyright 2018-present, Leonid Stryzhevskyi, <lganzzzo@gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
***************************************************************************/
#include "CRC32.hpp"
namespace oatpp { namespace algorithm {
const p_word32 CRC32::TABLE_04C11DB7 = generateTable(0x04C11DB7);
v_word32 CRC32::bitReverse(v_word32 poly) {
v_word32 result = 0;
for(v_int32 i = 0; i < 32; i ++) {
if((poly & (1 << i)) > 0) {
result |= 1 << (31 - i);
}
}
return result;
}
p_word32 CRC32::generateTable(v_word32 poly) {
p_word32 result = new v_word32[256];
v_word32 polyReverse = bitReverse(poly);
v_word32 value;
for(v_int32 i = 0; i < 256; i++) {
value = i;
for (v_int32 bit = 0; bit < 8; bit++) {
if (value & 1) {
value = (value >> 1) ^ polyReverse;
} else {
value = (value >> 1);
}
}
result[i] = value;
}
return result;
}
v_word32 CRC32::calc(const void *buffer, v_int32 size, v_word32 crc, v_word32 initValue, v_word32 xorOut, p_word32 table) {
p_word8 data = (p_word8) buffer;
crc = crc ^ initValue;
for(v_int32 i = 0; i < size; i++) {
crc = table[(crc & 0xFF) ^ data[i]] ^ (crc >> 8);
}
return crc ^ xorOut;
}
}}

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/***************************************************************************
*
* Project _____ __ ____ _ _
* ( _ ) /__\ (_ _)_| |_ _| |_
* )(_)( /(__)\ )( (_ _)(_ _)
* (_____)(__)(__)(__) |_| |_|
*
*
* Copyright 2018-present, Leonid Stryzhevskyi, <lganzzzo@gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
***************************************************************************/
#ifndef oatpp_algorithm_CRC32_hpp
#define oatpp_algorithm_CRC32_hpp
#include "oatpp/core/base/Environment.hpp"
#include "oatpp/encoding/Hex.hpp"
namespace oatpp { namespace algorithm {
class CRC32 {
public:
static const p_word32 TABLE_04C11DB7;
public:
static v_word32 bitReverse(v_word32 poly);
/**
* Generates v_word32 table[256] for polynomial
*/
static p_word32 generateTable(v_word32 poly);
static v_word32 calc(const void *buffer, v_int32 size, v_word32 crc = 0, v_word32 initValue = 0xFFFFFFFF, v_word32 xorOut = 0xFFFFFFFF, p_word32 table = TABLE_04C11DB7);
};
}}
#endif /* oatpp_algorithm_CRC32_hpp */