diff options
Diffstat (limited to 'klm')
| -rw-r--r-- | klm/util/murmur_hash.cc | 258 |
1 files changed, 129 insertions, 129 deletions
diff --git a/klm/util/murmur_hash.cc b/klm/util/murmur_hash.cc index d58a0727..fec47fd9 100644 --- a/klm/util/murmur_hash.cc +++ b/klm/util/murmur_hash.cc @@ -1,129 +1,129 @@ -/* Downloaded from http://sites.google.com/site/murmurhash/ which says "All
- * code is released to the public domain. For business purposes, Murmurhash is
- * under the MIT license."
- * This is modified from the original:
- * ULL tag on 0xc6a4a7935bd1e995 so this will compile on 32-bit.
- * length changed to unsigned int.
- * placed in namespace util
- * add MurmurHashNative
- * default option = 0 for seed
- */
-
-#include "util/murmur_hash.hh"
-
-namespace util {
-
-//-----------------------------------------------------------------------------
-// MurmurHash2, 64-bit versions, by Austin Appleby
-
-// The same caveats as 32-bit MurmurHash2 apply here - beware of alignment
-// and endian-ness issues if used across multiple platforms.
-
-// 64-bit hash for 64-bit platforms
-
-uint64_t MurmurHash64A ( const void * key, std::size_t len, unsigned int seed )
-{
- const uint64_t m = 0xc6a4a7935bd1e995ULL;
- const int r = 47;
-
- uint64_t h = seed ^ (len * m);
-
- const uint64_t * data = (const uint64_t *)key;
- const uint64_t * end = data + (len/8);
-
- while(data != end)
- {
- uint64_t k = *data++;
-
- k *= m;
- k ^= k >> r;
- k *= m;
-
- h ^= k;
- h *= m;
- }
-
- const unsigned char * data2 = (const unsigned char*)data;
-
- switch(len & 7)
- {
- case 7: h ^= uint64_t(data2[6]) << 48;
- case 6: h ^= uint64_t(data2[5]) << 40;
- case 5: h ^= uint64_t(data2[4]) << 32;
- case 4: h ^= uint64_t(data2[3]) << 24;
- case 3: h ^= uint64_t(data2[2]) << 16;
- case 2: h ^= uint64_t(data2[1]) << 8;
- case 1: h ^= uint64_t(data2[0]);
- h *= m;
- };
-
- h ^= h >> r;
- h *= m;
- h ^= h >> r;
-
- return h;
-}
-
-
-// 64-bit hash for 32-bit platforms
-
-uint64_t MurmurHash64B ( const void * key, std::size_t len, unsigned int seed )
-{
- const unsigned int m = 0x5bd1e995;
- const int r = 24;
-
- unsigned int h1 = seed ^ len;
- unsigned int h2 = 0;
-
- const unsigned int * data = (const unsigned int *)key;
-
- while(len >= 8)
- {
- unsigned int k1 = *data++;
- k1 *= m; k1 ^= k1 >> r; k1 *= m;
- h1 *= m; h1 ^= k1;
- len -= 4;
-
- unsigned int k2 = *data++;
- k2 *= m; k2 ^= k2 >> r; k2 *= m;
- h2 *= m; h2 ^= k2;
- len -= 4;
- }
-
- if(len >= 4)
- {
- unsigned int k1 = *data++;
- k1 *= m; k1 ^= k1 >> r; k1 *= m;
- h1 *= m; h1 ^= k1;
- len -= 4;
- }
-
- switch(len)
- {
- case 3: h2 ^= ((unsigned char*)data)[2] << 16;
- case 2: h2 ^= ((unsigned char*)data)[1] << 8;
- case 1: h2 ^= ((unsigned char*)data)[0];
- h2 *= m;
- };
-
- h1 ^= h2 >> 18; h1 *= m;
- h2 ^= h1 >> 22; h2 *= m;
- h1 ^= h2 >> 17; h1 *= m;
- h2 ^= h1 >> 19; h2 *= m;
-
- uint64_t h = h1;
-
- h = (h << 32) | h2;
-
- return h;
-}
-
-uint64_t MurmurHashNative(const void * key, std::size_t len, unsigned int seed) {
- if (sizeof(int) == 4) {
- return MurmurHash64B(key, len, seed);
- } else {
- return MurmurHash64A(key, len, seed);
- }
-}
-
-} // namespace util
+/* Downloaded from http://sites.google.com/site/murmurhash/ which says "All + * code is released to the public domain. For business purposes, Murmurhash is + * under the MIT license." + * This is modified from the original: + * ULL tag on 0xc6a4a7935bd1e995 so this will compile on 32-bit. + * length changed to unsigned int. + * placed in namespace util + * add MurmurHashNative + * default option = 0 for seed + */ + +#include "util/murmur_hash.hh" + +namespace util { + +//----------------------------------------------------------------------------- +// MurmurHash2, 64-bit versions, by Austin Appleby + +// The same caveats as 32-bit MurmurHash2 apply here - beware of alignment +// and endian-ness issues if used across multiple platforms. + +// 64-bit hash for 64-bit platforms + +uint64_t MurmurHash64A ( const void * key, std::size_t len, unsigned int seed ) +{ + const uint64_t m = 0xc6a4a7935bd1e995ULL; + const int r = 47; + + uint64_t h = seed ^ (len * m); + + const uint64_t * data = (const uint64_t *)key; + const uint64_t * end = data + (len/8); + + while(data != end) + { + uint64_t k = *data++; + + k *= m; + k ^= k >> r; + k *= m; + + h ^= k; + h *= m; + } + + const unsigned char * data2 = (const unsigned char*)data; + + switch(len & 7) + { + case 7: h ^= uint64_t(data2[6]) << 48; + case 6: h ^= uint64_t(data2[5]) << 40; + case 5: h ^= uint64_t(data2[4]) << 32; + case 4: h ^= uint64_t(data2[3]) << 24; + case 3: h ^= uint64_t(data2[2]) << 16; + case 2: h ^= uint64_t(data2[1]) << 8; + case 1: h ^= uint64_t(data2[0]); + h *= m; + }; + + h ^= h >> r; + h *= m; + h ^= h >> r; + + return h; +} + + +// 64-bit hash for 32-bit platforms + +uint64_t MurmurHash64B ( const void * key, std::size_t len, unsigned int seed ) +{ + const unsigned int m = 0x5bd1e995; + const int r = 24; + + unsigned int h1 = seed ^ len; + unsigned int h2 = 0; + + const unsigned int * data = (const unsigned int *)key; + + while(len >= 8) + { + unsigned int k1 = *data++; + k1 *= m; k1 ^= k1 >> r; k1 *= m; + h1 *= m; h1 ^= k1; + len -= 4; + + unsigned int k2 = *data++; + k2 *= m; k2 ^= k2 >> r; k2 *= m; + h2 *= m; h2 ^= k2; + len -= 4; + } + + if(len >= 4) + { + unsigned int k1 = *data++; + k1 *= m; k1 ^= k1 >> r; k1 *= m; + h1 *= m; h1 ^= k1; + len -= 4; + } + + switch(len) + { + case 3: h2 ^= ((unsigned char*)data)[2] << 16; + case 2: h2 ^= ((unsigned char*)data)[1] << 8; + case 1: h2 ^= ((unsigned char*)data)[0]; + h2 *= m; + }; + + h1 ^= h2 >> 18; h1 *= m; + h2 ^= h1 >> 22; h2 *= m; + h1 ^= h2 >> 17; h1 *= m; + h2 ^= h1 >> 19; h2 *= m; + + uint64_t h = h1; + + h = (h << 32) | h2; + + return h; +} + +uint64_t MurmurHashNative(const void * key, std::size_t len, unsigned int seed) { + if (sizeof(int) == 4) { + return MurmurHash64B(key, len, seed); + } else { + return MurmurHash64A(key, len, seed); + } +} + +} // namespace util |