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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:55:53 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:55:53 +0000 |
commit | 3d0386f27ca66379acf50199e1d1298386eeeeb8 (patch) | |
tree | f87bd4a126b3a843858eb447e8fd5893c3ee3882 /contrib/murmurhash3/murmurhash3.c | |
parent | Initial commit. (diff) | |
download | knot-resolver-3d0386f27ca66379acf50199e1d1298386eeeeb8.tar.xz knot-resolver-3d0386f27ca66379acf50199e1d1298386eeeeb8.zip |
Adding upstream version 3.2.1.upstream/3.2.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'contrib/murmurhash3/murmurhash3.c')
-rw-r--r-- | contrib/murmurhash3/murmurhash3.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/contrib/murmurhash3/murmurhash3.c b/contrib/murmurhash3/murmurhash3.c new file mode 100644 index 0000000..06ed7d8 --- /dev/null +++ b/contrib/murmurhash3/murmurhash3.c @@ -0,0 +1,74 @@ +/* This is MurmurHash3. The original C++ code was placed in the public domain + * by its author, Austin Appleby. */ + +#include "murmurhash3.h" + +static inline uint32_t fmix(uint32_t h) +{ + h ^= h >> 16; + h *= 0x85ebca6b; + h ^= h >> 13; + h *= 0xc2b2ae35; + h ^= h >> 16; + + return h; +} + +static inline uint32_t rotl32(uint32_t x, int8_t r) +{ + return (x << r) | (x >> (32 - r)); +} + +uint32_t hash(const char* data, size_t len_) +{ + const int len = (int) len_; + const int nblocks = len / 4; + + uint32_t h1 = 0xc062fb4a; + + uint32_t c1 = 0xcc9e2d51; + uint32_t c2 = 0x1b873593; + + //---------- + // body + + const uint32_t * blocks = (const uint32_t*) (data + nblocks * 4); + + int i; + for(i = -nblocks; i; i++) + { + uint32_t k1 = blocks[i]; + + k1 *= c1; + k1 = rotl32(k1, 15); + k1 *= c2; + + h1 ^= k1; + h1 = rotl32(h1, 13); + h1 = h1*5+0xe6546b64; + } + + //---------- + // tail + + const uint8_t * tail = (const uint8_t*)(data + nblocks*4); + + uint32_t k1 = 0; + + switch(len & 3) + { + case 3: k1 ^= tail[2] << 16; + case 2: k1 ^= tail[1] << 8; + case 1: k1 ^= tail[0]; + k1 *= c1; k1 = rotl32(k1,15); k1 *= c2; h1 ^= k1; + } + + //---------- + // finalization + + h1 ^= len; + + h1 = fmix(h1); + + return h1; +} |