Merge pull request #183 from dumganhar/v3.3.0-native
Add MurmurHash2.h/.cpp
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//-----------------------------------------------------------------------------
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// MurmurHash2, by Austin Appleby
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// Note - This code makes a few assumptions about how your machine behaves -
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// 1. We can read a 4-byte value from any address without crashing
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// 2. sizeof(int) == 4
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// And it has a few limitations -
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// 1. It will not work incrementally.
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// 2. It will not produce the same results on little-endian and big-endian
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// machines.
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#include "MurmurHash2.h"
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namespace murmurhash2 {
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unsigned int MurmurHash2 ( const void * key, int len, unsigned int seed )
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{
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// 'm' and 'r' are mixing constants generated offline.
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// They're not really 'magic', they just happen to work well.
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const unsigned int m = 0x5bd1e995;
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const int r = 24;
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// Initialize the hash to a 'random' value
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unsigned int h = seed ^ len;
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// Mix 4 bytes at a time into the hash
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const unsigned char * data = (const unsigned char *)key;
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while(len >= 4)
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{
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unsigned int k = *(unsigned int *)data;
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k *= m;
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k ^= k >> r;
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k *= m;
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h *= m;
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h ^= k;
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data += 4;
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len -= 4;
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}
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// Handle the last few bytes of the input array
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switch(len)
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{
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case 3: h ^= data[2] << 16;
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case 2: h ^= data[1] << 8;
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case 1: h ^= data[0];
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h *= m;
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};
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// Do a few final mixes of the hash to ensure the last few
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// bytes are well-incorporated.
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h ^= h >> 13;
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h *= m;
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h ^= h >> 15;
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return h;
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}
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} // namespace murmurhash2 {
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@ -0,0 +1,7 @@
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#pragma once
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namespace murmurhash2 {
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unsigned int MurmurHash2( const void * key, int len, unsigned int seed );
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}
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@ -114,3 +114,7 @@ glslang (Built using https://github.com/YunHsiao/glslang/tree/build)
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android: 11.5.0 (commit: 1978c76)
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mac: 11.5.0 (commit: 1978c76)
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ios: 11.5.0 (commit: 1978c76)
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MurmurHash2
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all-platforms: (no version informantion): https://sites.google.com/site/murmurhash
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