expose packets library

server/internal/packets/fixedheader.go

@@ -1,59 +0,0 @@
-package packets
-
-import (
-	"bytes"
-)
-
-// FixedHeader contains the values of the fixed header portion of the MQTT packet.
-type FixedHeader struct {
-	Type      byte // the type of the packet (PUBLISH, SUBSCRIBE, etc) from bits 7 - 4 (byte 1).
-	Dup       bool // indicates if the packet was already sent at an earlier time.
-	Qos       byte // indicates the quality of service expected.
-	Retain    bool // whether the message should be retained.
-	Remaining int  // the number of remaining bytes in the payload.
-}
-
-// Encode encodes the FixedHeader and returns a bytes buffer.
-func (fh *FixedHeader) Encode(buf *bytes.Buffer) {
-	buf.WriteByte(fh.Type<<4 | encodeBool(fh.Dup)<<3 | fh.Qos<<1 | encodeBool(fh.Retain))
-	encodeLength(buf, fh.Remaining)
-}
-
-// decode extracts the specification bits from the header byte.
-func (fh *FixedHeader) Decode(headerByte byte) error {
-	fh.Type = headerByte >> 4 // Get the message type from the first 4 bytes.
-
-	switch fh.Type {
-	case Publish:
-		fh.Dup = (headerByte>>3)&0x01 > 0 // Extract flags. Check if message is duplicate.
-		fh.Qos = (headerByte >> 1) & 0x03 // Extract QoS flag.
-		fh.Retain = headerByte&0x01 > 0   // Extract retain flag.
-	case Pubrel:
-		fh.Qos = (headerByte >> 1) & 0x03
-	case Subscribe:
-		fh.Qos = (headerByte >> 1) & 0x03
-	case Unsubscribe:
-		fh.Qos = (headerByte >> 1) & 0x03
-	default:
-		if (headerByte>>3)&0x01 > 0 || (headerByte>>1)&0x03 > 0 || headerByte&0x01 > 0 {
-			return ErrInvalidFlags
-		}
-	}
-
-	return nil
-}
-
-// encodeLength writes length bits for the header.
-func encodeLength(buf *bytes.Buffer, length int) {
-	for {
-		digit := byte(length % 128)
-		length /= 128
-		if length > 0 {
-			digit |= 0x80
-		}
-		buf.WriteByte(digit)
-		if length == 0 {
-			break
-		}
-	}
-}