a4851ed835
fixed a couple actual real bugs (missing returns in operator=, wrong implicit bool conversion). mostly added a bunch of explicit ctor.
59 lines
1.5 KiB
C++
59 lines
1.5 KiB
C++
/*
|
|
* Copyright (C) 2018 The Android Open Source Project
|
|
*
|
|
* 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 TNT_UTILS_HASH_H
|
|
#define TNT_UTILS_HASH_H
|
|
|
|
#include <stdint.h>
|
|
#include <stddef.h>
|
|
|
|
namespace utils {
|
|
namespace hash {
|
|
|
|
inline uint32_t murmur3(const uint32_t* key, size_t wordCount, uint32_t seed) {
|
|
uint32_t h = seed;
|
|
size_t i = wordCount;
|
|
do {
|
|
uint32_t k = *key++;
|
|
k *= 0xcc9e2d51;
|
|
k = (k << 15) | (k >> 17);
|
|
k *= 0x1b873593;
|
|
h ^= k;
|
|
h = (h << 13) | (h >> 19);
|
|
h = (h * 5) + 0xe6546b64;
|
|
} while (--i);
|
|
h ^= wordCount;
|
|
h ^= h >> 16;
|
|
h *= 0x85ebca6b;
|
|
h ^= h >> 13;
|
|
h *= 0xc2b2ae35;
|
|
h ^= h >> 16;
|
|
return h;
|
|
}
|
|
|
|
template<typename T>
|
|
struct MurmurHashFn {
|
|
uint32_t operator()(const T& key) const {
|
|
static_assert(0 == (sizeof(key) & 3), "Hashing requires a size that is a multiple of 4.");
|
|
return murmur3((const uint32_t*) &key, sizeof(key) / 4, 0);
|
|
}
|
|
};
|
|
|
|
} // namespace hash
|
|
} // namespace utils
|
|
|
|
#endif // TNT_UTILS_HASH_H
|