From 80c5170283dd072c76f0dfd303c09f5714536687 Mon Sep 17 00:00:00 2001 From: Kenneth Heafield Date: Tue, 11 Oct 2011 14:59:12 -0400 Subject: util/murmur_hash.cc --- klm/util/murmur_hash.cc | 258 ++++++++++++++++++++++++------------------------ 1 file changed, 129 insertions(+), 129 deletions(-) (limited to 'klm') 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 -- cgit v1.2.3