pearson.js
var table = [

     98,   6,  85, 150,  36,  23, 112, 164, 135, 207, 169,   5,  26,  64, 165, 219,
     61,  20,  68,  89, 130,  63,  52, 102,  24, 229, 132, 245,  80, 216, 195, 115,
     90, 168, 156, 203, 177, 120,   2, 190, 188,   7, 100, 185, 174, 243, 162,  10,
    237,  18, 253, 225,   8, 208, 172, 244, 255, 126, 101,  79, 145, 235, 228, 121,
    123, 251,  67, 250, 161,   0, 107,  97, 241, 111, 181,  82, 249,  33,  69,  55,
     59, 153,  29,   9, 213, 167,  84,  93,  30,  46,  94,  75, 151, 114,  73, 222,
    197,  96, 210,  45,  16, 227, 248, 202,  51, 152, 252, 125,  81, 206, 215, 186,
     39, 158, 178, 187, 131, 136,   1,  49,  50,  17, 141,  91,  47, 129,  60,  99,
    154,  35,  86, 171, 105,  34,  38, 200, 147,  58,  77, 118, 173, 246,  76, 254,
    133, 232, 196, 144, 198, 124,  53,   4, 108,  74, 223, 234, 134, 230, 157, 139,
    189, 205, 199, 128, 176,  19, 211, 236, 127, 192, 231,  70, 233,  88, 146,  44,
    183, 201,  22,  83,  13, 214, 116, 109, 159,  32,  95, 226, 140, 220,  57,  12,
    221,  31, 209, 182, 143,  92, 149, 184, 148,  62, 113,  65,  37,  27, 106, 166,
      3,  14, 204,  72,  21,  41,  56,  66,  28, 193,  40, 217,  25,  54, 179, 117,
    238,  87, 240, 155, 180, 170, 242, 212, 191, 163,  78, 218, 137, 194, 175, 110,
     43, 119, 224,  71, 122, 142,  42, 160, 104,  48, 247, 103,  15,  11, 138, 239
];

// Calculates Pearson hash on the subset of bytes in Buffer.

module.exports = function(data, start, end) {

    var sum = 0;

    for (var i = start; i < end; i++) {

        sum = table[sum ^ data.readUInt8(i)];
    }

    return sum;
};