class Zip::ExtraField::Generic

def self.name
  @name ||= to_s.split('::')[-1]
end

def self.register_map
  return unless const_defined?(:HEADER_ID)
  ::Zip::ExtraField::ID_MAP[const_get(:HEADER_ID)] = self
end

def ==(other)
  return false if self.class != other.class
  each do |k, v|
    return false if v != other[k]
  end
  true
end

def initial_parse(binstr)
  return false unless binstr
  if binstr[0, 2] != self.class.const_get(:HEADER_ID)
    warn 'WARNING: weird extra field header ID. Skip parsing it.'
    return false
  end
  [binstr[2, 2].unpack1('v'), binstr[4..-1]]
end

def to_c_dir_bin
  s = pack_for_c_dir
  self.class.const_get(:HEADER_ID) + [s.bytesize].pack('v') << s
end

def to_local_bin
  s = pack_for_local
  self.class.const_get(:HEADER_ID) + [s.bytesize].pack('v') << s
end