AsyncDNS-cr  Check-in [af207d1100]

      getter raw_data : Bytes

      def initialize(@query : Query, @id : UInt16, @settings : Settings,
                     @block : Response | Error ->)
        @ns_index = 0
        @attempt = 0
        @used_ns = nil
        @raw_data = Bytes.new(512)

        # Header

        i = 0
        @raw_data[i] = (@id >> 8).to_u8; i += 1
        io = IO::Memory.new(512)
        io.write_bytes(@id, IO::ByteFormat::BigEndian)
        @raw_data[i] = (@id & 0xFF).to_u8; i += 1
        # RD
        @raw_data[i] = 1; i += 1
        i += 1
        io.write_bytes(0x100_u16, IO::ByteFormat::BigEndian)
        # QDCOUNT
        i += 1
        @raw_data[i] = 1; i += 1
        io.write_bytes(1_u16, IO::ByteFormat::BigEndian)
        # ANCOUNT, NSCOUNT and ARCOUNT
        i += 6
        3.times { io.write_bytes(0_u16) }

        # Question

        # QNAME
        @query.domain.split('.').each do |component|
          if component.bytesize > 63 || i + component.bytesize > 512
          if component.bytesize > 63 || io.size + component.bytesize > 512
            raise ArgumentError.new("Domain component too long")
          end

          raw_component = component.to_slice
          @raw_data[i] = raw_component.bytesize.to_u8; i += 1
          @raw_data[i, raw_component.bytesize].copy_from(raw_component)
          i += raw_component.bytesize
          io << component
        end

        # QTYPE
        qtype = @query.rr_type.to_i
        io.write_bytes(@query.rr_type.to_u16, IO::ByteFormat::BigEndian)
        @raw_data[i] = (qtype >> 8).to_u8; i += 1
        @raw_data[i] = (qtype & 0xFF).to_u8; i+= 1

        # QCLASS
        qclass = @query.dns_class.to_i
        @raw_data[i] = (qclass >> 8).to_u8; i += 1
        @raw_data[i] = (qclass & 0xFF).to_u8; i += 1
        io.write_bytes(@query.dns_class.to_u16, IO::ByteFormat::BigEndian)

        @raw_data = io.to_slice
      end
    end

    def initialize
      @settings = Settings.new
      @queries = Hash(UInt16, Context).new
      @tcp_queries = Hash(Socket, Context).new