59 lines
1.5 KiB
C++
59 lines
1.5 KiB
C++
/*
|
|
* 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.
|
|
*
|
|
* Copyright 2010-2016 Danny Robson <danny@nerdcruft.net>
|
|
*/
|
|
|
|
#ifndef __UTIL_HASH_FLETCHER_HPP
|
|
#define __UTIL_HASH_FLETCHER_HPP
|
|
|
|
#include "../types/bits.hpp"
|
|
|
|
#include <cstdint>
|
|
#include <cstdlib>
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
namespace util { namespace hash {
|
|
template <typename DIGEST>
|
|
class fletcher {
|
|
public:
|
|
using digest_t = DIGEST;
|
|
using part_t = typename bytes_type<sizeof (digest_t) / 2>::uint;
|
|
|
|
fletcher (part_t modulus, part_t a, part_t b);
|
|
|
|
void update (const void *restrict, size_t) noexcept;
|
|
void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
|
|
|
|
void finish (void);
|
|
digest_t digest (void) const;
|
|
|
|
void reset (void);
|
|
|
|
private:
|
|
const digest_t m_modulus;
|
|
|
|
struct state_t {
|
|
part_t a, b;
|
|
};
|
|
|
|
const state_t m_initial;
|
|
state_t m_state;
|
|
};
|
|
} }
|
|
|
|
|
|
#endif
|
|
|