func()

in dialer.go [510:579]

• 59 lines of code
• 11 McCabe index (conditional complexity)

func (d *Dialer) metadataExchange(conn net.Conn) error {
	tok, err := d.iamTokenSource.Token()
	if err != nil {
		return err
	}
	authType := connectorspb.MetadataExchangeRequest_DB_NATIVE
	if d.useIAMAuthN {
		authType = connectorspb.MetadataExchangeRequest_AUTO_IAM
	}
	req := &connectorspb.MetadataExchangeRequest{
		UserAgent:   d.userAgent,
		AuthType:    authType,
		Oauth2Token: tok.AccessToken,
	}
	m, err := proto.Marshal(req)
	if err != nil {
		return err
	}
	b := d.buffer.get()
	defer d.buffer.put(b)

	buf := *b
	reqSize := proto.Size(req)
	binary.BigEndian.PutUint32(buf, uint32(reqSize))
	buf = append(buf[:4], m...)

	// Set IO deadline before write
	err = conn.SetDeadline(time.Now().Add(ioTimeout))
	if err != nil {
		return err
	}
	defer conn.SetDeadline(time.Time{})

	_, err = conn.Write(buf)
	if err != nil {
		return err
	}

	// Reset IO deadline before read
	err = conn.SetDeadline(time.Now().Add(ioTimeout))
	if err != nil {
		return err
	}
	defer conn.SetDeadline(time.Time{})

	buf = buf[:4]
	_, err = conn.Read(buf)
	if err != nil {
		return err
	}

	respSize := binary.BigEndian.Uint32(buf)
	resp := buf[:respSize]
	_, err = conn.Read(resp)
	if err != nil {
		return err
	}

	var mdxResp connectorspb.MetadataExchangeResponse
	err = proto.Unmarshal(resp, &mdxResp)
	if err != nil {
		return err
	}

	if mdxResp.GetResponseCode() != connectorspb.MetadataExchangeResponse_OK {
		return errors.New(mdxResp.GetError())
	}

	return nil
}