class Multibases::Base32::Chunk

Public Class Methods

new(bytes, table) click to toggle source
# File lib/multibases/base32.rb, line 49
def initialize(bytes, table)
  @bytes = bytes
  @table = table
end

Public Instance Methods

decode() click to toggle source
# File lib/multibases/base32.rb, line 54
def decode
  bytes = @bytes.take_while { |c| c != @table.padder }

  n = (bytes.length * 5.0 / 8.0).floor
  p = bytes.length < 8 ? 5 - (n * 8) % 5 : 0

  c = bytes.inject(0) do |m, o|
    i = @table.index(o)
    raise ArgumentError, "Invalid character '#{[o].pack('C*')}'" if i.nil?

    (m << 5) + i
  end >> p

  (0..(n - 1)).to_a.reverse.collect { |i| ((c >> i * 8) & 0xff) }
end
encode() click to toggle source
# File lib/multibases/base32.rb, line 70
def encode
  n = (@bytes.length * 8.0 / 5.0).ceil
  p = n < 8 ? 5 - (@bytes.length * 8) % 5 : 0
  c = @bytes.inject(0) { |m, o| (m << 8) + o } << p

  output = (0..(n - 1)).to_a.reverse.collect do |i|
    @table.ord_at((c >> i * 5) & 0x1f)
  end
  @table.padder ? output + Array.new((8 - n), @table.padder) : output
end