maeqtt/mqtt/packets/ControlPacket.go

package packets

import (
	"bytes"
	"io"

	"badat.dev/maeqtt/v2/mqtt/types"
)

type controlPacket struct {
	packetType PacketType
	flags      uint
	reader     io.Reader
}

func (c controlPacket) write(w io.Writer) error {
	buf := bytes.NewBuffer([]byte{})

	var fixedHeader byte = (byte(c.packetType) << 4 & 0b11110000) + (byte(c.flags) & 0b1111)
	_, err := buf.Write([]byte{fixedHeader})
	if err != nil {
		return err
	}
	data, err := io.ReadAll(c.reader)
	if err != nil {
		return err
	}

	err = types.WriteDataWithVarIntLen(buf, data)
	if err != nil {
		return err
	}
	_, err = w.Write(buf.Bytes())
	if err != nil {
		return err
	}
	return nil
}