52 lines
1.3 KiB
C
52 lines
1.3 KiB
C
/*
|
|
* Copyright (c) 2020 Huawei Technologies Co.,Ltd.
|
|
*
|
|
* openGauss is licensed under Mulan PSL v2.
|
|
* You can use this software according to the terms and conditions of the Mulan PSL v2.
|
|
* You may obtain a copy of Mulan PSL v2 at:
|
|
*
|
|
* http://license.coscl.org.cn/MulanPSL2
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
|
|
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
|
|
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
|
|
* See the Mulan PSL v2 for more details.
|
|
* ---------------------------------------------------------------------------------------
|
|
*
|
|
* hashutils.h
|
|
* Utilities for working with hash values.
|
|
*
|
|
*
|
|
* IDENTIFICATION
|
|
* src/include/utils/hashutils.h
|
|
*
|
|
* ---------------------------------------------------------------------------------------
|
|
*/
|
|
|
|
#ifndef HASHUTILS_H
|
|
#define HASHUTILS_H
|
|
|
|
/*
|
|
* Simple inline murmur hash implementation hashing a 32 bit integer, for
|
|
* performance.
|
|
*/
|
|
static inline uint32 murmurhash32(uint32 data)
|
|
{
|
|
uint32 h = data;
|
|
|
|
h ^= h >> 16;
|
|
h *= 0x85ebca6b;
|
|
h ^= h >> 13;
|
|
h *= 0xc2b2ae35;
|
|
h ^= h >> 16;
|
|
return h;
|
|
}
|
|
|
|
static inline uint32 hash_combine(uint32 a, uint32 b)
|
|
{
|
|
a ^= b + 0x9e3779b9 + (a << 6) + (a >> 2);
|
|
return a;
|
|
}
|
|
|
|
#endif /* HASHUTILS_H */
|