libcruft-util/hash/bsdsum.cpp

79 lines
1.8 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 Danny Robson <danny@nerdcruft.net>
*/
#include "bsdsum.hpp"
#include "../debug.hpp"
using util::hash::bsdsum;
///////////////////////////////////////////////////////////////////////////////
bsdsum::bsdsum ()
{
reset ();
}
//-----------------------------------------------------------------------------
void
bsdsum::reset (void)
{
m_accum = 0;
}
///////////////////////////////////////////////////////////////////////////////
void
bsdsum::update (const void *restrict data, size_t size) noexcept
{
auto first = static_cast<const uint8_t *restrict> (data);
update (first, first + size);
}
///////////////////////////////////////////////////////////////////////////////
void
bsdsum::update (
const uint8_t *const restrict first,
const uint8_t *const restrict last) noexcept
{
CHECK (first);
CHECK (last);
CHECK_LE (first, last);
for (auto cursor = first; cursor != last; ++cursor) {
m_accum = (m_accum >> 1u) | ((m_accum & 0x01u) << 15u);
m_accum += *cursor;
}
}
//-----------------------------------------------------------------------------
void
bsdsum::finish (void)
{ ; }
//-----------------------------------------------------------------------------
typename bsdsum::digest_t
bsdsum::digest (void) const
{
return m_accum;
}