Class: Base32::Crockford

Inherits:
Object
  • Object
show all
Defined in:
lib/base32/crockford.rb

Constant Summary collapse

ENCODE = 
"0123456789ABCDEFGHJKMNPQRSTVWXYZ"
DECODE = 
{
  '0' => 0,
  '1' => 1,
  '2' => 2,
  '3' => 3,
  '4' => 4,
  '5' => 5,
  '6' => 6,
  '7' => 7,
  '8' => 8,
  '9' => 9,
  'A' => 10,
  'B' => 11,
  'C' => 12,
  'D' => 13,
  'E' => 14,
  'F' => 15,
  'G' => 16,
  'H' => 17,
  'J' => 18,
  'K' => 19,
  'M' => 20,
  'N' => 21,
  'P' => 22,
  'Q' => 23,
  'R' => 24,
  'S' => 25,
  'T' => 26,
  'V' => 27,
  'W' => 28,
  'X' => 29,
  'Y' => 30,
  'Z' => 31,
}

Class Method Summary collapse

Class Method Details

.decode(v, to = :binary_string) ⇒ Object 



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# File 'lib/base32/crockford.rb', line 89

def self.decode v, to = :binary_string
  normalized = v.upcase.tr("OILU", "011").tr("-", "").reverse

  n = 0
  bits = 0
  res = ""
  res.force_encoding("binary") if res.respond_to?(:force_encoding)
  normalized.each_byte do |b|
    n += (DECODE[ b.chr ] << bits)
    bits += 5

    while bits >= 8 do
      res << (n & 255).chr
      n >>= 8
      bits -= 8
    end
  end
  res << n if n != 0
  res << 0 if res.empty?
  res = res.reverse

  case to
  when :integer
    v = 0
    res.each_byte do |byte|
      v <<= 8
      v |= byte
    end
    v
  else
    res
  end
end

.encode(v) ⇒ Object 



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# File 'lib/base32/crockford.rb', line 59

def self.encode v
  if v.respond_to?(:integer?) && v.integer?
    normalized = NormalizedInteger.new(v)
  else
    normalized = v.reverse
  end
 
  n = 0
  bits = 0
  res = ""
  normalized.each_byte do |b|
    n += b << bits
    bits += 8

    while bits >= 5 do
      res << ENCODE[ n & 31 ]
      n >>= 5
      bits -= 5
    end
  end
  res << ENCODE[ n & 31 ] if n != 0
  res << 0 if res.empty?

  res.reverse
end

.hypenate(v) ⇒ Object 



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# File 'lib/base32/crockford.rb', line 85

def self.hypenate v
  v.reverse.gsub(/(\w\w\w\w\w)/, "\\1-").gsub(/-$/, "").downcase.reverse
end