nyks/buffer/readUInt.js

nodejs exupery style

"use strict";

var pow2 = [];
for(var i = 0; i < 32; i++)
  pow2[i] = Math.pow(2, i);


function unsigned(buffer, offset, length) {
  var result = 0;
  var blen = buffer.length * 8;

  offset = offset || 0;

  if(offset < 0)
    offset = blen + offset;

  if(length === undefined)
    length = blen - offset;

  if(!length)
    return 0;

  for(var i = 0, j = offset + length - 1; i < length; i++, j--)
    result += buffer[j >> 3] & pow2[7 - j % 8] ? pow2[i] : 0;

  return result;
}

module.exports = unsigned;