1.1 --- a/MurmurHash2.c	Thu Feb 09 15:51:22 2012 +0100
     1.2 +++ b/MurmurHash2.c	Sat Feb 11 17:55:51 2012 -0800
     1.3 @@ -1,64 +1,69 @@
     1.4 -//-----------------------------------------------------------------------------
     1.5 -// MurmurHash2, by Austin Appleby
     1.6 -
     1.7 -// Note - This code makes a few assumptions about how your machine behaves -
     1.8 -
     1.9 -// 1. We can read a 4-byte value from any address without crashing
    1.10 -// 2. sizeof(int) == 4
    1.11 -
    1.12 -// And it has a few limitations -
    1.13 -
    1.14 -// 1. It will not work incrementally.
    1.15 -// 2. It will not produce the same results on little-endian and big-endian
    1.16 -//    machines.
    1.17 -
    1.18 -unsigned int MurmurHash2 ( const void * key, int len, unsigned int seed )
    1.19 -{
    1.20 -	// 'm' and 'r' are mixing constants generated offline.
    1.21 -	// They're not really 'magic', they just happen to work well.
    1.22 -
    1.23 -	const unsigned int m = 0x5bd1e995;
    1.24 -	const int r = 24;
    1.25 -
    1.26 -	// Initialize the hash to a 'random' value
    1.27 -
    1.28 -	unsigned int h = seed ^ len;
    1.29 -
    1.30 -	// Mix 4 bytes at a time into the hash
    1.31 -
    1.32 -	const unsigned char * data = (const unsigned char *)key;
    1.33 -
    1.34 -	while(len >= 4)
    1.35 -	{
    1.36 -		unsigned int k = *(unsigned int *)data;
    1.37 -
    1.38 -		k *= m; 
    1.39 -		k ^= k >> r; 
    1.40 -		k *= m; 
    1.41 -		
    1.42 -		h *= m; 
    1.43 -		h ^= k;
    1.44 -
    1.45 -		data += 4;
    1.46 -		len -= 4;
    1.47 -	}
    1.48 -	
    1.49 -	// Handle the last few bytes of the input array
    1.50 -
    1.51 -	switch(len)
    1.52 -	{
    1.53 -	case 3: h ^= data[2] << 16;
    1.54 -	case 2: h ^= data[1] << 8;
    1.55 -	case 1: h ^= data[0];
    1.56 -	        h *= m;
    1.57 -	};
    1.58 -
    1.59 -	// Do a few final mixes of the hash to ensure the last few
    1.60 -	// bytes are well-incorporated.
    1.61 -
    1.62 -	h ^= h >> 13;
    1.63 -	h *= m;
    1.64 -	h ^= h >> 15;
    1.65 -
    1.66 -	return h;
    1.67 -} 
    1.68 +
    1.69 +/*This file is sample code pulled off the web -- NOT part of the compiled code
    1.70 + * make sure it doesn't get included in makefile 'cause it doesn't compile
    1.71 + */
    1.72 +
    1.73 +//-----------------------------------------------------------------------------
    1.74 +// MurmurHash2, by Austin Appleby
    1.75 +
    1.76 +// Note - This code makes a few assumptions about how your machine behaves -
    1.77 +
    1.78 +// 1. We can read a 4-byte value from any address without crashing
    1.79 +// 2. sizeof(int) == 4
    1.80 +
    1.81 +// And it has a few limitations -
    1.82 +
    1.83 +// 1. It will not work incrementally.
    1.84 +// 2. It will not produce the same results on little-endian and big-endian
    1.85 +//    machines.
    1.86 +
    1.87 +unsigned int MurmurHash2 ( const void * key, int len, unsigned int seed )
    1.88 +{
    1.89 +	// 'm' and 'r' are mixing constants generated offline.
    1.90 +	// They're not really 'magic', they just happen to work well.
    1.91 +
    1.92 +	const unsigned int m = 0x5bd1e995;
    1.93 +	const int r = 24;
    1.94 +
    1.95 +	// Initialize the hash to a 'random' value
    1.96 +
    1.97 +	unsigned int h = seed ^ len;
    1.98 +
    1.99 +	// Mix 4 bytes at a time into the hash
   1.100 +
   1.101 +	const unsigned char * data = (const unsigned char *)key;
   1.102 +
   1.103 +	while(len >= 4)
   1.104 +	{
   1.105 +		unsigned int k = *(unsigned int *)data;
   1.106 +
   1.107 +		k *= m; 
   1.108 +		k ^= k >> r; 
   1.109 +		k *= m; 
   1.110 +		
   1.111 +		h *= m; 
   1.112 +		h ^= k;
   1.113 +
   1.114 +		data += 4;
   1.115 +		len -= 4;
   1.116 +	}
   1.117 +	
   1.118 +	// Handle the last few bytes of the input array
   1.119 +
   1.120 +	switch(len)
   1.121 +	{
   1.122 +	case 3: h ^= data[2] << 16;
   1.123 +	case 2: h ^= data[1] << 8;
   1.124 +	case 1: h ^= data[0];
   1.125 +	        h *= m;
   1.126 +	};
   1.127 +
   1.128 +	// Do a few final mixes of the hash to ensure the last few
   1.129 +	// bytes are well-incorporated.
   1.130 +
   1.131 +	h ^= h >> 13;
   1.132 +	h *= m;
   1.133 +	h ^= h >> 15;
   1.134 +
   1.135 +	return h;
   1.136 +}