Contents

//-----------------------------------------------------------------------------
// MurmurHash2, by Austin Appleby

// Note - This code makes a few assumptions about how your machine behaves -

// 1. We can read a 4-byte value from any address without crashing
// 2. sizeof(int) == 4

// And it has a few limitations -

// 1. It will not work incrementally.
// 2. It will not produce the same results on little-endian and big-endian
//    machines.

unsigned int MurmurHash2 ( const void * key, int len, unsigned int seed )
{
  // 'm' and 'r' are mixing constants generated offline.
  // They're not really 'magic', they just happen to work well.

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

  // Initialize the hash to a 'random' value

  unsigned int h = seed ^ len;

  // Mix 4 bytes at a time into the hash

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

  while(len >= 4)
  {
    unsigned int k = *(unsigned int *)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;
  case 2: h ^= data[1] << 8;
  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;
} 

Version data entries

9 entries across 9 versions & 1 rubygems

Version	Path
jaro_winkler-1.4.0-java	ext/jaro_winkler/murmur_hash2.c
jaro_winkler-1.4.0	ext/jaro_winkler/murmur_hash2.c
jaro_winkler-1.3.7	ext/jaro_winkler/murmur_hash2.c
jaro_winkler-1.3.6	ext/jaro_winkler/murmur_hash2.c
jaro_winkler-1.3.5	ext/jaro_winkler/murmur_hash2.c
jaro_winkler-1.3.4	ext/jaro_winkler/murmur_hash2.c
jaro_winkler-1.3.3	ext/jaro_winkler/murmur_hash2.c
jaro_winkler-1.3.2	ext/jaro_winkler/murmur_hash2.c
jaro_winkler-1.3.2.beta2	ext/jaro_winkler/murmur_hash2.c