use a uint8 to represent the key phase bit

internal/protocol/key_phase.go

@@ -3,23 +3,34 @@ package protocol
 // KeyPhase is the key phase
 type KeyPhase uint64
 
+// Bit determines the key phase bit
 func (p KeyPhase) Bit() KeyPhaseBit {
-	return p%2 == 1
+	if p%2 == 0 {
+		return KeyPhaseZero
+	}
+	return KeyPhaseOne
 }
 
 // KeyPhaseBit is the key phase bit
-type KeyPhaseBit bool
+type KeyPhaseBit uint8
 
 const (
+	// KeyPhaseUndefined is an undefined key phase
+	KeyPhaseUndefined KeyPhaseBit = iota
 	// KeyPhaseZero is key phase 0
-	KeyPhaseZero KeyPhaseBit = false
+	KeyPhaseZero
 	// KeyPhaseOne is key phase 1
-	KeyPhaseOne KeyPhaseBit = true
+	KeyPhaseOne
 )
 
 func (p KeyPhaseBit) String() string {
-	if p == KeyPhaseZero {
+	//nolint:exhaustive
+	switch p {
+	case KeyPhaseZero:
 		return "0"
+	case KeyPhaseOne:
+		return "1"
+	default:
+		return "undefined"
 	}
-	return "1"
 }

internal/protocol/key_phase_test.go

@@ -6,6 +6,11 @@ import (
 )
 
 var _ = Describe("Key Phases", func() {
+	It("has undefined as its default value", func() {
+		var k KeyPhaseBit
+		Expect(k).To(Equal(KeyPhaseUndefined))
+	})
+
 	It("has the correct string representation", func() {
 		Expect(KeyPhaseZero.String()).To(Equal("0"))
 		Expect(KeyPhaseOne.String()).To(Equal("1"))

qlog/packet_header.go

@@ -38,7 +38,6 @@ type packetHeader struct {
 	SrcConnectionID  logging.ConnectionID
 	DestConnectionID logging.ConnectionID
 
-	hasKeyPhase bool
 	KeyPhaseBit logging.KeyPhaseBit
 }
 
@@ -55,10 +54,7 @@ func transformHeader(hdr *wire.Header) *packetHeader {
 func transformExtendedHeader(hdr *wire.ExtendedHeader) *packetHeader {
 	h := transformHeader(&hdr.Header)
 	h.PacketNumber = hdr.PacketNumber
-	if !hdr.IsLongHeader {
+	h.KeyPhaseBit = hdr.KeyPhase
-		h.hasKeyPhase = true
-		h.KeyPhaseBit = hdr.KeyPhase
-	}
 	return h
 }
 
@@ -81,12 +77,7 @@ func (h packetHeader) MarshalJSONObject(enc *gojay.Encoder) {
 	if h.DestConnectionID.Len() > 0 {
 		enc.StringKey("dcid", connectionID(h.DestConnectionID).String())
 	}
-	if h.hasKeyPhase {
+	if h.KeyPhaseBit == logging.KeyPhaseZero || h.KeyPhaseBit == logging.KeyPhaseOne {
-		switch h.KeyPhaseBit {
+		enc.StringKey("key_phase_bit", h.KeyPhaseBit.String())
-		case logging.KeyPhaseZero:
-			enc.StringKey("key_phase_bit", "0")
-		case logging.KeyPhaseOne:
-			enc.StringKey("key_phase_bit", "1")
-		}
 	}
 }

qlog/packet_header_test.go

@@ -34,7 +34,10 @@ var _ = Describe("Packet Header", func() {
 
 		It("marshals a header for a 1-RTT packet", func() {
 			check(
-				&wire.ExtendedHeader{PacketNumber: 42},
+				&wire.ExtendedHeader{
+					PacketNumber: 42,
+					KeyPhase:     protocol.KeyPhaseZero,
+				},
 				map[string]interface{}{
 					"packet_number": 42,
 					"dcil":          0,