Class: Multibases::Base64

Inherits:
Object
  • Object
show all
Defined in:
lib/multibases/base64.rb

Defined Under Namespace

Classes: Table

Constant Summary collapse

Default =

rubocop:disable Metrics/LineLength

Base64.new('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=')
UrlSafe = 
Base64.new('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_=')

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(alphabet, strict: false, encoding: nil) ⇒ Base64

Returns a new instance of Base64.



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# File 'lib/multibases/base64.rb', line 58

def initialize(alphabet, strict: false, encoding: nil)
  @table = Table.from(alphabet, strict: strict, encoding: encoding)
end

Class Method Details

.decode(packed) ⇒ Object 



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# File 'lib/multibases/base64.rb', line 27

def self.decode(packed)
  packed = packed.pack('C*') if packed.is_a?(Array)
  # Base64.strict_decode64("m").first
  # Don't use m0, as that requires padderding _always_
  DecodedByteArray.new(packed.unpack1('m').bytes)
end

.encode(plain) ⇒ Object

RFC 4648 implementation



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# File 'lib/multibases/base64.rb', line 17

def self.encode(plain)
  plain = plain.pack('C*') if plain.is_a?(Array)

  # Base64.strict_encode(plain)
  EncodedByteArray.new(
    Array(String(plain)).pack('m0').bytes,
    encoding: Encoding::US_ASCII
  )
end

Instance Method Details

#decodable?(encoded) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/multibases/base64.rb', line 108

def decodable?(encoded)
  (encoded.uniq - table_ords).length.zero?
end

#decode(encoded) ⇒ Object 



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# File 'lib/multibases/base64.rb', line 76

def decode(encoded)
  return DecodedByteArray::EMPTY if encoded.empty?

  unless encoded.is_a?(Array)
    encoded = encoded.force_encoding(@table.encoding).bytes
  end

  unless decodable?(encoded)
    raise ArgumentError, "'#{encoded}' contains unknown characters'"
  end

  unless default?
    encoded = ByteArray.new(encoded).transcode(
      table_ords,
      Default.table_ords(force_strict: @table.strict?),
      encoding: Encoding::US_ASCII
    )
  end

  Multibases::Base64.decode(encoded)
end

#default? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/multibases/base64.rb', line 98

def default?
  eql?(Default)
end

#encode(plain) ⇒ Object 



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# File 'lib/multibases/base64.rb', line 62

def encode(plain)
  return EncodedByteArray::EMPTY if plain.empty?

  encoded = Multibases::Base64.encode(plain)
  encoded.chomp!(Default.table_padder) unless @table.padder
  return encoded if default?

  encoded.transcode(
    Default.table_ords(force_strict: @table.strict?),
    table_ords,
    encoding: @table.encoding
  )
end

#eql?(other) ⇒ Boolean Also known as: ==

Returns:

  • (Boolean) 


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# File 'lib/multibases/base64.rb', line 102

def eql?(other)
  other.is_a?(Base64) && other.instance_variable_get(:@table) == @table
end

#inspect ⇒ Object 



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# File 'lib/multibases/base64.rb', line 9

def inspect
  '[Multibases::Base64 ' \
    "alphabet=\"#{@table.alphabet}\"" \
    "#{@table.padder.nil? ? '' : ' pad="' + @table.padder.chr + '"'}" \
  ']'
end

#table_ords(force_strict: nil) ⇒ Object 



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# File 'lib/multibases/base64.rb', line 112

def table_ords(force_strict: nil)
  @table.tr_ords(force_strict: force_strict)
end

#table_padder ⇒ Object 



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# File 'lib/multibases/base64.rb', line 116

def table_padder
  @table.padder
end