mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-13 01:41:59 +00:00
74 lines
2.6 KiB
C++
74 lines
2.6 KiB
C++
// 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
|