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Add MurmurHash3 implementation to hash.h/add hash.cpp.
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Original file line number | Diff line number | Diff line change |
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@@ -0,0 +1,58 @@ | ||
#include "hash.h" | ||
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inline uint32_t ROTL32 ( uint32_t x, int8_t r ) | ||
{ | ||
return (x << r) | (x >> (32 - r)); | ||
} | ||
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unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash) | ||
{ | ||
// The following is MurmurHash3 (x86_32), see http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp | ||
uint32_t h1 = nHashSeed; | ||
const uint32_t c1 = 0xcc9e2d51; | ||
const uint32_t c2 = 0x1b873593; | ||
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const int nblocks = vDataToHash.size() / 4; | ||
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//---------- | ||
// body | ||
const uint32_t * blocks = (const uint32_t *)(&vDataToHash[0] + nblocks*4); | ||
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for(int i = -nblocks; i; i++) | ||
{ | ||
uint32_t k1 = blocks[i]; | ||
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k1 *= c1; | ||
k1 = ROTL32(k1,15); | ||
k1 *= c2; | ||
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h1 ^= k1; | ||
h1 = ROTL32(h1,13); | ||
h1 = h1*5+0xe6546b64; | ||
} | ||
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//---------- | ||
// tail | ||
const uint8_t * tail = (const uint8_t*)(&vDataToHash[0] + nblocks*4); | ||
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uint32_t k1 = 0; | ||
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switch(vDataToHash.size() & 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; | ||
}; | ||
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//---------- | ||
// finalization | ||
h1 ^= vDataToHash.size(); | ||
h1 ^= h1 >> 16; | ||
h1 *= 0x85ebca6b; | ||
h1 ^= h1 >> 13; | ||
h1 *= 0xc2b2ae35; | ||
h1 ^= h1 >> 16; | ||
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return h1; | ||
} |
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Original file line number | Diff line number | Diff line change |
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@@ -83,6 +83,7 @@ OBJS= \ | |
obj/wallet.o \ | ||
obj/walletdb.o \ | ||
obj/noui.o \ | ||
obj/hash.o \ | ||
obj/leveldb.o \ | ||
obj/txdb.o | ||
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