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Diffstat (limited to 'src/basic/MurmurHash2.c')
-rw-r--r-- | src/basic/MurmurHash2.c | 86 |
1 files changed, 0 insertions, 86 deletions
diff --git a/src/basic/MurmurHash2.c b/src/basic/MurmurHash2.c deleted file mode 100644 index 9020793930..0000000000 --- a/src/basic/MurmurHash2.c +++ /dev/null @@ -1,86 +0,0 @@ -//----------------------------------------------------------------------------- -// MurmurHash2 was written by Austin Appleby, and is placed in the public -// domain. The author hereby disclaims copyright to this source code. - -// Note - This code makes a few assumptions about how your machine behaves - - -// 1. We can read a 4-byte value from any address without crashing -// 2. sizeof(int) == 4 - -// And it has a few limitations - - -// 1. It will not work incrementally. -// 2. It will not produce the same results on little-endian and big-endian -// machines. - -#include "MurmurHash2.h" - -//----------------------------------------------------------------------------- -// Platform-specific functions and macros - -// Microsoft Visual Studio - -#if defined(_MSC_VER) - -#define BIG_CONSTANT(x) (x) - -// Other compilers - -#else // defined(_MSC_VER) - -#define BIG_CONSTANT(x) (x##LLU) - -#endif // !defined(_MSC_VER) - -//----------------------------------------------------------------------------- - -uint32_t MurmurHash2 ( const void * key, int len, uint32_t seed ) -{ - // 'm' and 'r' are mixing constants generated offline. - // They're not really 'magic', they just happen to work well. - - const uint32_t m = 0x5bd1e995; - const int r = 24; - - // Initialize the hash to a 'random' value - - uint32_t h = seed ^ len; - - // Mix 4 bytes at a time into the hash - - const unsigned char * data = (const unsigned char *)key; - - while (len >= 4) - { - uint32_t k = *(uint32_t*)data; - - k *= m; - k ^= k >> r; - k *= m; - - h *= m; - h ^= k; - - data += 4; - len -= 4; - } - - // Handle the last few bytes of the input array - - switch(len) - { - case 3: h ^= data[2] << 16; - case 2: h ^= data[1] << 8; - case 1: h ^= data[0]; - h *= m; - }; - - // Do a few final mixes of the hash to ensure the last few - // bytes are well-incorporated. - - h ^= h >> 13; - h *= m; - h ^= h >> 15; - - return h; -} |