Method Encode

eventstream/encode.go:47–94

Encode encodes a single EventStream message to the io.Writer the Encoder was created with. An error is returned if writing the message fails.

(w io.Writer, msg Message)

// Encode encodes a single EventStream message to the io.Writer the Encoder
// was created with. An error is returned if writing the message fails.
func (e *Encoder) Encode(w io.Writer, msg Message) (err error) {
	e.headersBuf.Reset()
	e.messageBuf.Reset()

	var writer io.Writer = e.messageBuf
	if e.options.Logger != nil && e.options.LogMessages {
		encodeMsgBuf := bytes.NewBuffer(nil)
		writer = io.MultiWriter(writer, encodeMsgBuf)
		defer func() {
			logMessageEncode(e.options.Logger, encodeMsgBuf, msg, err)
		}()
	}

	if err = EncodeHeaders(e.headersBuf, msg.Headers); err != nil {
		return err
	}

	crc := crc32.New(crc32IEEETable)
	hashWriter := io.MultiWriter(writer, crc)

	headersLen := uint32(e.headersBuf.Len())
	payloadLen := uint32(len(msg.Payload))

	if err = encodePrelude(hashWriter, crc, headersLen, payloadLen); err != nil {
		return err
	}

	if headersLen > 0 {
		if _, err = io.Copy(hashWriter, e.headersBuf); err != nil {
			return err
		}
	}

	if payloadLen > 0 {
		if _, err = hashWriter.Write(msg.Payload); err != nil {
			return err
		}
	}

	msgCRC := crc.Sum32()
	if err := binary.Write(writer, binary.BigEndian, msgCRC); err != nil {
		return err
	}

	_, err = io.Copy(w, e.messageBuf)

	return err
}

func logMessageEncode(logger logging.Logger, msgBuf *bytes.Buffer, msg Message, encodeErr error) {
	w := bytes.NewBuffer(nil)