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// metrohash64.h
//
// Copyright 2015-2018 J. Andrew Rogers
//
// 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 METROHASH_METROHASH_64_H
#define METROHASH_METROHASH_64_H
#include <stdint.h>
class MetroHash64
{
public:
static const uint32_t bits = 64;
// Constructor initializes the same as Initialize()
MetroHash64(const uint64_t seed=0);
// Initializes internal state for new hash with optional seed
void Initialize(const uint64_t seed=0);
// Update the hash state with a string of bytes. If the length
// is sufficiently long, the implementation switches to a bulk
// hashing algorithm directly on the argument buffer for speed.
void Update(const uint8_t * buffer, const uint64_t length);
// Constructs the final hash and writes it to the argument buffer.
// After a hash is finalized, this instance must be Initialized()-ed
// again or the behavior of Update() and Finalize() is undefined.
void Finalize(uint8_t * const hash);
// A non-incremental function implementation. This can be significantly
// faster than the incremental implementation for some usage patterns.
static void Hash(const uint8_t * buffer, const uint64_t length, uint8_t * const hash, const uint64_t seed=0);
// Does implementation correctly execute test vectors?
static bool ImplementationVerified();
// test vectors -- Hash(test_string, seed=0) => test_seed_0
static const char * test_string;
static const uint8_t test_seed_0[8];
static const uint8_t test_seed_1[8];
private:
static const uint64_t k0 = 0xD6D018F5;
static const uint64_t k1 = 0xA2AA033B;
static const uint64_t k2 = 0x62992FC1;
static const uint64_t k3 = 0x30BC5B29;
struct { uint64_t v[4]; } state;
struct { uint8_t b[32]; } input;
uint64_t bytes;
uint64_t vseed;
};
// Legacy 64-bit hash functions -- do not use
void metrohash64_1(const uint8_t * key, uint64_t len, uint32_t seed, uint8_t * out);
void metrohash64_2(const uint8_t * key, uint64_t len, uint32_t seed, uint8_t * out);
#endif // #ifndef METROHASH_METROHASH_64_H
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