//—————————————————————————– // MurmurHash2 was written by Austin Appleby, and is placed in the public // domain. The author hereby disclaims copyright to this source code. //—————————————————————————– // LibSass only needs MurmurHash2, so we made this header only //—————————————————————————–

ifndef MURMURHASH2_H define MURMURHASH2_H

//—————————————————————————– // Platform-specific functions and macros

// Microsoft Visual Studio

if defined(_MSC_VER) && (_MSC_VER < 1600)

typedef unsigned char uint8_t; typedef unsigned int uint32_t; typedef unsigned __int64 uint64_t;

// Other compilers

else // defined(_MSC_VER)

include <stdint.h>

endif // !defined(_MSC_VER)

//—————————————————————————–

inline uint32_t MurmurHash2 ( const void * key, int len, uint32_t seed ) {

// 'm' and 'r' are mixing constants generated offline.
// They're not really 'magic', they just happen to work well.

const uint32_t m = 0x5bd1e995;
const int r = 24;

// Initialize the hash to a 'random' value

uint32_t h = seed ^ len;

// Mix 4 bytes at a time into the hash

const unsigned char * data = (const unsigned char *)key;

while(len >= 4)
{
  uint32_t k = *(uint32_t*)data;

  k *= m;
  k ^= k >> r;
  k *= m;

  h *= m;
  h ^= k;

  data += 4;
  len -= 4;
}

// Handle the last few bytes of the input array

switch(len)
{
case 3:
  h ^= data[2] << 16;
  /* fall through */
case 2:
  h ^= data[1] << 8;
  /* fall through */
case 1:
  h ^= data[0];
  h *= m;
};

// Do a few final mixes of the hash to ensure the last few
// bytes are well-incorporated.

h ^= h >> 13;
h *= m;
h ^= h >> 15;

return h;

}

//—————————————————————————–

endif // MURMURHASH2_H