class Ffc16

Constants

MODX

Public Class Methods

checksum(buf) click to toggle source

# File lib/ffc16.rb, line 5
def self.checksum(buf)

  inx = 0
  end_buf = buf.length

  c0 = 0
  c1 = 0

  loop do

    end_chunk = (inx + MODX < end_buf) ?  inx + MODX : end_buf

    loop do

      c0 += 0xff & buf[inx].ord
      c1 += c0

      inx += 1
      break unless inx < end_chunk
    end

    c0 %= 255
    c1 %= 255

    break unless inx < end_buf

  end

  c1 << 8 | c0
end