MurmurHash2

unsigned int MurmurHash2 (char * key, unsigned int len)
{
  const unsigned int m = 0x5bd1e995;
  const unsigned int seed = 0;
  const int r = 24;

  unsigned int h = seed ^ len;

  const unsigned char * data = (const unsigned char *)key;
  unsigned int k = 0;

  while (len >= 4)
  {
      k  = data[0];
      k |= data[1] << 8;
      k |= data[2] << 16;
      k |= data[3] << 24;

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

      h *= m;
      h ^= k;

      data += 4;
      len -= 4;
  }

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

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

  return h;
}

#define mmix(h,k) { k *= m; k ^= k >> r; k *= m; h *= m; h ^= k; }

unsigned int MurmurHash2A ( const void * key, int len, unsigned int seed )
{
	const unsigned int m = 0x5bd1e995;
	const int r = 24;
	unsigned int l = len;

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

	unsigned int h = seed;
	unsigned int k;

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

		mmix(h,k);

		data += 4;
		len -= 4;
	}

	unsigned int t = 0;

	switch(len)
	{
	case 3: t ^= data[2] << 16;
	case 2: t ^= data[1] << 8;
	case 1: t ^= data[0];
	};

	mmix(h,t);
	mmix(h,l);

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

	return h;
}