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added Murmurhash

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1 parent a051a5e commit 7b634b5ef5f6a52e7d063f705951e4c123c55ebf @andersjo andersjo committed May 5, 2014
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  1. +335 −0 rungsted/MurmurHash3.cpp
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+//-----------------------------------------------------------------------------
+// MurmurHash3 was written by Austin Appleby, and is placed in the public
+// domain. The author hereby disclaims copyright to this source code.
+
+// Note - The x86 and x64 versions do _not_ produce the same results, as the
+// algorithms are optimized for their respective platforms. You can still
+// compile and run any of them on any platform, but your performance with the
+// non-native version will be less than optimal.
+
+#include "MurmurHash3.h"
+
+//-----------------------------------------------------------------------------
+// Platform-specific functions and macros
+
+// Microsoft Visual Studio
+
+#if defined(_MSC_VER)
+
+#define FORCE_INLINE __forceinline
+
+#include <stdlib.h>
+
+#define ROTL32(x,y) _rotl(x,y)
+#define ROTL64(x,y) _rotl64(x,y)
+
+#define BIG_CONSTANT(x) (x)
+
+// Other compilers
+
+#else // defined(_MSC_VER)
+
+#define FORCE_INLINE inline __attribute__((always_inline))
+
+inline uint32_t rotl32 ( uint32_t x, int8_t r )
+{
+ return (x << r) | (x >> (32 - r));
+}
+
+inline uint64_t rotl64 ( uint64_t x, int8_t r )
+{
+ return (x << r) | (x >> (64 - r));
+}
+
+#define ROTL32(x,y) rotl32(x,y)
+#define ROTL64(x,y) rotl64(x,y)
+
+#define BIG_CONSTANT(x) (x##LLU)
+
+#endif // !defined(_MSC_VER)
+
+//-----------------------------------------------------------------------------
+// Block read - if your platform needs to do endian-swapping or can only
+// handle aligned reads, do the conversion here
+
+FORCE_INLINE uint32_t getblock32 ( const uint32_t * p, int i )
+{
+ return p[i];
+}
+
+FORCE_INLINE uint64_t getblock64 ( const uint64_t * p, int i )
+{
+ return p[i];
+}
+
+//-----------------------------------------------------------------------------
+// Finalization mix - force all bits of a hash block to avalanche
+
+FORCE_INLINE uint32_t fmix32 ( uint32_t h )
+{
+ h ^= h >> 16;
+ h *= 0x85ebca6b;
+ h ^= h >> 13;
+ h *= 0xc2b2ae35;
+ h ^= h >> 16;
+
+ return h;
+}
+
+//----------
+
+FORCE_INLINE uint64_t fmix64 ( uint64_t k )
+{
+ k ^= k >> 33;
+ k *= BIG_CONSTANT(0xff51afd7ed558ccd);
+ k ^= k >> 33;
+ k *= BIG_CONSTANT(0xc4ceb9fe1a85ec53);
+ k ^= k >> 33;
+
+ return k;
+}
+
+//-----------------------------------------------------------------------------
+
+void MurmurHash3_x86_32 ( const void * key, int len,
+ uint32_t seed, void * out )
+{
+ const uint8_t * data = (const uint8_t*)key;
+ const int nblocks = len / 4;
+
+ uint32_t h1 = seed;
+
+ const uint32_t c1 = 0xcc9e2d51;
+ const uint32_t c2 = 0x1b873593;
+
+ //----------
+ // body
+
+ const uint32_t * blocks = (const uint32_t *)(data + nblocks*4);
+
+ for(int i = -nblocks; i; i++)
+ {
+ uint32_t k1 = getblock32(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 = fmix32(h1);
+
+ *(uint32_t*)out = h1;
+}
+
+//-----------------------------------------------------------------------------
+
+void MurmurHash3_x86_128 ( const void * key, const int len,
+ uint32_t seed, void * out )
+{
+ const uint8_t * data = (const uint8_t*)key;
+ const int nblocks = len / 16;
+
+ uint32_t h1 = seed;
+ uint32_t h2 = seed;
+ uint32_t h3 = seed;
+ uint32_t h4 = seed;
+
+ const uint32_t c1 = 0x239b961b;
+ const uint32_t c2 = 0xab0e9789;
+ const uint32_t c3 = 0x38b34ae5;
+ const uint32_t c4 = 0xa1e38b93;
+
+ //----------
+ // body
+
+ const uint32_t * blocks = (const uint32_t *)(data + nblocks*16);
+
+ for(int i = -nblocks; i; i++)
+ {
+ uint32_t k1 = getblock32(blocks,i*4+0);
+ uint32_t k2 = getblock32(blocks,i*4+1);
+ uint32_t k3 = getblock32(blocks,i*4+2);
+ uint32_t k4 = getblock32(blocks,i*4+3);
+
+ k1 *= c1; k1 = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
+
+ h1 = ROTL32(h1,19); h1 += h2; h1 = h1*5+0x561ccd1b;
+
+ k2 *= c2; k2 = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
+
+ h2 = ROTL32(h2,17); h2 += h3; h2 = h2*5+0x0bcaa747;
+
+ k3 *= c3; k3 = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
+
+ h3 = ROTL32(h3,15); h3 += h4; h3 = h3*5+0x96cd1c35;
+
+ k4 *= c4; k4 = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
+
+ h4 = ROTL32(h4,13); h4 += h1; h4 = h4*5+0x32ac3b17;
+ }
+
+ //----------
+ // tail
+
+ const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
+
+ uint32_t k1 = 0;
+ uint32_t k2 = 0;
+ uint32_t k3 = 0;
+ uint32_t k4 = 0;
+
+ switch(len & 15)
+ {
+ case 15: k4 ^= tail[14] << 16;
+ case 14: k4 ^= tail[13] << 8;
+ case 13: k4 ^= tail[12] << 0;
+ k4 *= c4; k4 = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
+
+ case 12: k3 ^= tail[11] << 24;
+ case 11: k3 ^= tail[10] << 16;
+ case 10: k3 ^= tail[ 9] << 8;
+ case 9: k3 ^= tail[ 8] << 0;
+ k3 *= c3; k3 = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
+
+ case 8: k2 ^= tail[ 7] << 24;
+ case 7: k2 ^= tail[ 6] << 16;
+ case 6: k2 ^= tail[ 5] << 8;
+ case 5: k2 ^= tail[ 4] << 0;
+ k2 *= c2; k2 = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
+
+ case 4: k1 ^= tail[ 3] << 24;
+ case 3: k1 ^= tail[ 2] << 16;
+ case 2: k1 ^= tail[ 1] << 8;
+ case 1: k1 ^= tail[ 0] << 0;
+ k1 *= c1; k1 = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
+ };
+
+ //----------
+ // finalization
+
+ h1 ^= len; h2 ^= len; h3 ^= len; h4 ^= len;
+
+ h1 += h2; h1 += h3; h1 += h4;
+ h2 += h1; h3 += h1; h4 += h1;
+
+ h1 = fmix32(h1);
+ h2 = fmix32(h2);
+ h3 = fmix32(h3);
+ h4 = fmix32(h4);
+
+ h1 += h2; h1 += h3; h1 += h4;
+ h2 += h1; h3 += h1; h4 += h1;
+
+ ((uint32_t*)out)[0] = h1;
+ ((uint32_t*)out)[1] = h2;
+ ((uint32_t*)out)[2] = h3;
+ ((uint32_t*)out)[3] = h4;
+}
+
+//-----------------------------------------------------------------------------
+
+void MurmurHash3_x64_128 ( const void * key, const int len,
+ const uint32_t seed, void * out )
+{
+ const uint8_t * data = (const uint8_t*)key;
+ const int nblocks = len / 16;
+
+ uint64_t h1 = seed;
+ uint64_t h2 = seed;
+
+ const uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
+ const uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);
+
+ //----------
+ // body
+
+ const uint64_t * blocks = (const uint64_t *)(data);
+
+ for(int i = 0; i < nblocks; i++)
+ {
+ uint64_t k1 = getblock64(blocks,i*2+0);
+ uint64_t k2 = getblock64(blocks,i*2+1);
+
+ k1 *= c1; k1 = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
+
+ h1 = ROTL64(h1,27); h1 += h2; h1 = h1*5+0x52dce729;
+
+ k2 *= c2; k2 = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
+
+ h2 = ROTL64(h2,31); h2 += h1; h2 = h2*5+0x38495ab5;
+ }
+
+ //----------
+ // tail
+
+ const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
+
+ uint64_t k1 = 0;
+ uint64_t k2 = 0;
+
+ switch(len & 15)
+ {
+ case 15: k2 ^= ((uint64_t)tail[14]) << 48;
+ case 14: k2 ^= ((uint64_t)tail[13]) << 40;
+ case 13: k2 ^= ((uint64_t)tail[12]) << 32;
+ case 12: k2 ^= ((uint64_t)tail[11]) << 24;
+ case 11: k2 ^= ((uint64_t)tail[10]) << 16;
+ case 10: k2 ^= ((uint64_t)tail[ 9]) << 8;
+ case 9: k2 ^= ((uint64_t)tail[ 8]) << 0;
+ k2 *= c2; k2 = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
+
+ case 8: k1 ^= ((uint64_t)tail[ 7]) << 56;
+ case 7: k1 ^= ((uint64_t)tail[ 6]) << 48;
+ case 6: k1 ^= ((uint64_t)tail[ 5]) << 40;
+ case 5: k1 ^= ((uint64_t)tail[ 4]) << 32;
+ case 4: k1 ^= ((uint64_t)tail[ 3]) << 24;
+ case 3: k1 ^= ((uint64_t)tail[ 2]) << 16;
+ case 2: k1 ^= ((uint64_t)tail[ 1]) << 8;
+ case 1: k1 ^= ((uint64_t)tail[ 0]) << 0;
+ k1 *= c1; k1 = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
+ };
+
+ //----------
+ // finalization
+
+ h1 ^= len; h2 ^= len;
+
+ h1 += h2;
+ h2 += h1;
+
+ h1 = fmix64(h1);
+ h2 = fmix64(h2);
+
+ h1 += h2;
+ h2 += h1;
+
+ ((uint64_t*)out)[0] = h1;
+ ((uint64_t*)out)[1] = h2;
+}
+
+//-----------------------------------------------------------------------------
+

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