libcruft-util/hash/xxhash.hpp

49 lines
1.3 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 2016-2018 Danny Robson <danny@nerdcruft.net>
*/
#ifndef CRUFT_UTIL_HASH_XXHASH_HPP
#define CRUFT_UTIL_HASH_XXHASH_HPP
#include "../view.hpp"
#include <cstdint>
#include <type_traits>
namespace util::hash {
template <typename WordT>
class xxhash {
public:
static_assert (std::is_same<WordT,std::uint32_t>::value || std::is_same<WordT,std::uint64_t>::value);
using digest_t = WordT;
using word_t = WordT;
static constexpr int block_bytes = 4 * sizeof (word_t);
static constexpr word_t DEFAULT_SEED = 0;
xxhash (word_t seed = DEFAULT_SEED);
digest_t operator() (const util::view<const uint8_t*> data);
private:
word_t m_seed;
};
using xxhash32 = xxhash<uint32_t>;
using xxhash64 = xxhash<uint64_t>;
}
#endif