class Aws::Plugins::SQSMd5s::Handler

def md5_of_message_attributes(message_attributes)
  encoded = { }
  message_attributes.each do |name, attribute|
    name = name.to_s
    encoded[name] = String.new
    data_type_without_label = DATA_TYPE.match(attribute[:data_type])[1]
    encoded[name] << encode_length_and_bytes(name) <<
    encode_length_and_bytes(attribute[:data_type]) <<
    [TRANSPORT_TYPE_ENCODINGS[data_type_without_label]].pack('C'.freeze)
    if attribute[:string_value] != nil
      encoded[name] << encode_length_and_string(attribute[:string_value])
    elsif attribute[:binary_value] != nil
      encoded[name] << encode_length_and_bytes(attribute[:binary_value])
    end
  end
  buffer = encoded.keys.sort.reduce(String.new) do |string, name|
    string << encoded[name]
  end
  OpenSSL::Digest::MD5.hexdigest(buffer)
end