diff options
Diffstat (limited to 'klm/util/murmur_hash.cc')
-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 fec47fd9..d58a0727 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
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