func putBufioWriter(bw *bufio.Writer) {
bw.Reset(nil)
if pool := bufioWriterPool(bw.Available()); pool != nil {
pool.Put(bw)
}
}
func WritePacket(writer *bufio.Writer, pk *Packet) error {
if writer == nil {
return errors.New("No writer")
}
if writer.Available() == 0 {
return errors.New("Writer not available")
}
if pk.LengthPayload == 0 {
pk.LengthPayload = uint32(len(pk.Payload))
}
if pk.LengthText == 0 {
pk.LengthText = uint32(len([]byte(pk.Text)))
}
// write Header
pk.Flag = pk.Flag | lengthToPow(pk.LengthPayload) | (lengthToPow(pk.LengthText) << 2)
// write Flag
if err := binary.Write(writer, binary.BigEndian, pk.Flag); err != nil {
return err
}
// write text length
if err := writeLength(writer, pk.LengthText); err != nil {
return err
}
// write payload length
if err := writeLength(writer, pk.LengthPayload); err != nil {
return err
}
// TODO calc CRC16
var crc16 uint16
// write Seq
if err := binary.Write(writer, binary.BigEndian, crc16); err != nil {
return err
}
// write Seq
if err := binary.Write(writer, binary.BigEndian, pk.Seq); err != nil {
return err
}
// write Text
if _, err := writer.WriteString(pk.Text); err != nil {
return err
}
// flush first
// MTU = 576
// IP = 20
// TCP = 20
// XBP = 5 - 13
// 576-20-20-13
if pk.LengthPayload+pk.LengthText > 523 {
// flush header first
if err := writer.Flush(); err != nil {
return err
}
}
// TODO make Big payload write more effecient
// write Payload
if _, err := writer.Write(pk.Payload); err != nil {
return err
}
return writer.Flush()
}