move the RTTStats to the utils package

The RTTStats are used by the logging package. In order to instrument the
congestion package, the RTTStats can't be part of that package any more
(to avoid an import loop).

internal/ackhandler/ackhandler.go

@@ -1,7 +1,6 @@
 package ackhandler
 
 import (
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/lucas-clemente/quic-go/logging"
@@ -11,7 +10,7 @@ import (
 // NewAckHandler creates a new SentPacketHandler and a new ReceivedPacketHandler
 func NewAckHandler(
 	initialPacketNumber protocol.PacketNumber,
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	pers protocol.Perspective,
 	traceCallback func(quictrace.Event),
 	tracer logging.ConnectionTracer,

internal/ackhandler/received_packet_handler.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/lucas-clemente/quic-go/internal/wire"
@@ -45,7 +44,7 @@ var _ ReceivedPacketHandler = &receivedPacketHandler{}
 
 func newReceivedPacketHandler(
 	sentPackets sentPacketTracker,
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	logger utils.Logger,
 	version protocol.VersionNumber,
 ) ReceivedPacketHandler {

internal/ackhandler/received_packet_handler_test.go

@@ -5,7 +5,6 @@ import (
 
 	"github.com/golang/mock/gomock"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/lucas-clemente/quic-go/internal/wire"
@@ -22,7 +21,7 @@ var _ = Describe("Received Packet Handler", func() {
 		sentPackets = NewMockSentPacketTracker(mockCtrl)
 		handler = newReceivedPacketHandler(
 			sentPackets,
-			&congestion.RTTStats{},
+			&utils.RTTStats{},
 			utils.DefaultLogger,
 			protocol.VersionWhatever,
 		)

internal/ackhandler/received_packet_tracker.go

@@ -3,7 +3,6 @@ package ackhandler
 import (
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/lucas-clemente/quic-go/internal/wire"
@@ -17,7 +16,7 @@ type receivedPacketTracker struct {
 	packetHistory *receivedPacketHistory
 
 	maxAckDelay time.Duration
-	rttStats    *congestion.RTTStats
+	rttStats    *utils.RTTStats
 
 	hasNewAck bool // true as soon as we received an ack-eliciting new packet
 	ackQueued bool // true once we received more than 2 (or later in the connection 10) ack-eliciting packets
@@ -32,7 +31,7 @@ type receivedPacketTracker struct {
 }
 
 func newReceivedPacketTracker(
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	logger utils.Logger,
 	version protocol.VersionNumber,
 ) *receivedPacketTracker {

internal/ackhandler/received_packet_tracker_test.go

@@ -3,7 +3,6 @@ package ackhandler
 import (
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/lucas-clemente/quic-go/internal/wire"
@@ -15,11 +14,11 @@ import (
 var _ = Describe("Received Packet Tracker", func() {
 	var (
 		tracker  *receivedPacketTracker
-		rttStats *congestion.RTTStats
+		rttStats *utils.RTTStats
 	)
 
 	BeforeEach(func() {
-		rttStats = &congestion.RTTStats{}
+		rttStats = &utils.RTTStats{}
 		tracker = newReceivedPacketTracker(rttStats, utils.DefaultLogger, protocol.VersionWhatever)
 	})
 

internal/ackhandler/sent_packet_handler.go

@@ -69,7 +69,7 @@ type sentPacketHandler struct {
 	bytesInFlight protocol.ByteCount
 
 	congestion congestion.SendAlgorithmWithDebugInfos
-	rttStats   *congestion.RTTStats
+	rttStats   *utils.RTTStats
 
 	// The number of times a PTO has been sent without receiving an ack.
 	ptoCount uint32
@@ -93,7 +93,7 @@ var _ sentPacketTracker = &sentPacketHandler{}
 
 func newSentPacketHandler(
 	initialPacketNumber protocol.PacketNumber,
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	pers protocol.Perspective,
 	traceCallback func(quictrace.Event),
 	tracer logging.ConnectionTracer,

internal/ackhandler/sent_packet_handler_test.go

@@ -5,7 +5,6 @@ import (
 	"time"
 
 	"github.com/golang/mock/gomock"
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/mocks"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
@@ -27,7 +26,7 @@ var _ = Describe("SentPacketHandler", func() {
 
 	JustBeforeEach(func() {
 		lostPackets = nil
-		rttStats := &congestion.RTTStats{}
+		rttStats := &utils.RTTStats{}
 		handler = newSentPacketHandler(42, rttStats, perspective, nil, nil, utils.DefaultLogger)
 		streamFrame = wire.StreamFrame{
 			StreamID: 5,

internal/congestion/cubic_sender.go

@@ -20,7 +20,7 @@ const (
 
 type cubicSender struct {
 	hybridSlowStart HybridSlowStart
-	rttStats        *RTTStats
+	rttStats        *utils.RTTStats
 	cubic           *Cubic
 	pacer           *pacer
 	clock           Clock
@@ -63,11 +63,11 @@ var _ SendAlgorithm = &cubicSender{}
 var _ SendAlgorithmWithDebugInfos = &cubicSender{}
 
 // NewCubicSender makes a new cubic sender
-func NewCubicSender(clock Clock, rttStats *RTTStats, reno bool) *cubicSender {
+func NewCubicSender(clock Clock, rttStats *utils.RTTStats, reno bool) *cubicSender {
 	return newCubicSender(clock, rttStats, reno, initialCongestionWindow, maxCongestionWindow)
 }
 
-func newCubicSender(clock Clock, rttStats *RTTStats, reno bool, initialCongestionWindow, initialMaxCongestionWindow protocol.ByteCount) *cubicSender {
+func newCubicSender(clock Clock, rttStats *utils.RTTStats, reno bool, initialCongestionWindow, initialMaxCongestionWindow protocol.ByteCount) *cubicSender {
 	c := &cubicSender{
 		rttStats:                   rttStats,
 		largestSentPacketNumber:    protocol.InvalidPacketNumber,

internal/congestion/cubic_sender_test.go

@@ -31,7 +31,7 @@ var _ = Describe("Cubic Sender", func() {
 		bytesInFlight     protocol.ByteCount
 		packetNumber      protocol.PacketNumber
 		ackedPacketNumber protocol.PacketNumber
-		rttStats          *RTTStats
+		rttStats          *utils.RTTStats
 	)
 
 	BeforeEach(func() {
@@ -39,7 +39,7 @@ var _ = Describe("Cubic Sender", func() {
 		packetNumber = 1
 		ackedPacketNumber = 0
 		clock = mockClock{}
-		rttStats = NewRTTStats()
+		rttStats = utils.NewRTTStats()
 		sender = newCubicSender(&clock, rttStats, true /*reno*/, initialCongestionWindowPackets*maxDatagramSize, MaxCongestionWindow)
 	})
 

internal/flowcontrol/base_flow_controller.go

@@ -4,7 +4,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 )
@@ -25,7 +24,7 @@ type baseFlowController struct {
 
 	epochStartTime   time.Time
 	epochStartOffset protocol.ByteCount
-	rttStats         *congestion.RTTStats
+	rttStats         *utils.RTTStats
 
 	logger utils.Logger
 }

internal/flowcontrol/base_flow_controller_test.go

@@ -5,7 +5,8 @@ import (
 	"strconv"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -27,7 +28,7 @@ var _ = Describe("Base Flow controller", func() {
 
 	BeforeEach(func() {
 		controller = &baseFlowController{}
-		controller.rttStats = &congestion.RTTStats{}
+		controller.rttStats = &utils.RTTStats{}
 	})
 
 	Context("send flow control", func() {

internal/flowcontrol/connection_flow_controller.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/utils"
@@ -24,7 +23,7 @@ func NewConnectionFlowController(
 	receiveWindow protocol.ByteCount,
 	maxReceiveWindow protocol.ByteCount,
 	queueWindowUpdate func(),
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	logger utils.Logger,
 ) ConnectionFlowController {
 	return &connectionFlowController{

internal/flowcontrol/connection_flow_controller_test.go

@@ -3,7 +3,6 @@ package flowcontrol
 import (
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	. "github.com/onsi/ginkgo"
@@ -25,13 +24,13 @@ var _ = Describe("Connection Flow controller", func() {
 	BeforeEach(func() {
 		queuedWindowUpdate = false
 		controller = &connectionFlowController{}
-		controller.rttStats = &congestion.RTTStats{}
+		controller.rttStats = &utils.RTTStats{}
 		controller.logger = utils.DefaultLogger
 		controller.queueWindowUpdate = func() { queuedWindowUpdate = true }
 	})
 
 	Context("Constructor", func() {
-		rttStats := &congestion.RTTStats{}
+		rttStats := &utils.RTTStats{}
 
 		It("sets the send and receive windows", func() {
 			receiveWindow := protocol.ByteCount(2000)

internal/flowcontrol/stream_flow_controller.go

@@ -3,7 +3,6 @@ package flowcontrol
 import (
 	"fmt"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/utils"
@@ -31,7 +30,7 @@ func NewStreamFlowController(
 	maxReceiveWindow protocol.ByteCount,
 	initialSendWindow protocol.ByteCount,
 	queueWindowUpdate func(protocol.StreamID),
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	logger utils.Logger,
 ) StreamFlowController {
 	return &streamFlowController{

internal/flowcontrol/stream_flow_controller_test.go

@@ -3,7 +3,6 @@ package flowcontrol
 import (
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	. "github.com/onsi/ginkgo"
@@ -18,7 +17,7 @@ var _ = Describe("Stream Flow controller", func() {
 
 	BeforeEach(func() {
 		queuedWindowUpdate = false
-		rttStats := &congestion.RTTStats{}
+		rttStats := &utils.RTTStats{}
 		controller = &streamFlowController{
 			streamID:   10,
 			connection: NewConnectionFlowController(1000, 1000, func() {}, rttStats, utils.DefaultLogger).(*connectionFlowController),
@@ -30,7 +29,7 @@ var _ = Describe("Stream Flow controller", func() {
 	})
 
 	Context("Constructor", func() {
-		rttStats := &congestion.RTTStats{}
+		rttStats := &utils.RTTStats{}
 		receiveWindow := protocol.ByteCount(2000)
 		maxReceiveWindow := protocol.ByteCount(3000)
 		sendWindow := protocol.ByteCount(4000)

internal/handshake/crypto_setup.go

@@ -10,7 +10,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/utils"
@@ -92,7 +91,7 @@ type cryptoSetup struct {
 	// for clients: to see if a ServerHello is a HelloRetryRequest
 	writeRecord chan struct{}
 
-	rttStats *congestion.RTTStats
+	rttStats *utils.RTTStats
 
 	tracer logging.ConnectionTracer
 	logger utils.Logger
@@ -136,7 +135,7 @@ func NewCryptoSetupClient(
 	runner handshakeRunner,
 	tlsConf *tls.Config,
 	enable0RTT bool,
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	tracer logging.ConnectionTracer,
 	logger utils.Logger,
 ) (CryptoSetup, <-chan *wire.TransportParameters /* ClientHello written. Receive nil for non-0-RTT */) {
@@ -168,7 +167,7 @@ func NewCryptoSetupServer(
 	runner handshakeRunner,
 	tlsConf *tls.Config,
 	enable0RTT bool,
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	tracer logging.ConnectionTracer,
 	logger utils.Logger,
 ) CryptoSetup {
@@ -197,7 +196,7 @@ func newCryptoSetup(
 	runner handshakeRunner,
 	tlsConf *tls.Config,
 	enable0RTT bool,
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	tracer logging.ConnectionTracer,
 	logger utils.Logger,
 	perspective protocol.Perspective,

internal/handshake/crypto_setup_test.go

@@ -11,7 +11,6 @@ import (
 	"math/big"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/testdata"
@@ -99,7 +98,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 			NewMockHandshakeRunner(mockCtrl),
 			tlsConf,
 			false,
-			&congestion.RTTStats{},
+			&utils.RTTStats{},
 			nil,
 			utils.DefaultLogger.WithPrefix("server"),
 		)
@@ -133,7 +132,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 			runner,
 			testdata.GetTLSConfig(),
 			false,
-			&congestion.RTTStats{},
+			&utils.RTTStats{},
 			nil,
 			utils.DefaultLogger.WithPrefix("server"),
 		)
@@ -173,7 +172,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 			runner,
 			testdata.GetTLSConfig(),
 			false,
-			&congestion.RTTStats{},
+			&utils.RTTStats{},
 			nil,
 			utils.DefaultLogger.WithPrefix("server"),
 		)
@@ -216,7 +215,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 			runner,
 			serverConf,
 			false,
-			&congestion.RTTStats{},
+			&utils.RTTStats{},
 			nil,
 			utils.DefaultLogger.WithPrefix("server"),
 		)
@@ -252,7 +251,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 			NewMockHandshakeRunner(mockCtrl),
 			serverConf,
 			false,
-			&congestion.RTTStats{},
+			&utils.RTTStats{},
 			nil,
 			utils.DefaultLogger.WithPrefix("server"),
 		)
@@ -287,8 +286,8 @@ var _ = Describe("Crypto Setup TLS", func() {
 			}
 		}
 
-		newRTTStatsWithRTT := func(rtt time.Duration) *congestion.RTTStats {
+		newRTTStatsWithRTT := func(rtt time.Duration) *utils.RTTStats {
-			rttStats := &congestion.RTTStats{}
+			rttStats := &utils.RTTStats{}
 			rttStats.UpdateRTT(rtt, 0, time.Now())
 			ExpectWithOffset(1, rttStats.SmoothedRTT()).To(Equal(rtt))
 			return rttStats
@@ -328,7 +327,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 
 		handshakeWithTLSConf := func(
 			clientConf, serverConf *tls.Config,
-			clientRTTStats, serverRTTStats *congestion.RTTStats,
+			clientRTTStats, serverRTTStats *utils.RTTStats,
 			clientTransportParameters, serverTransportParameters *wire.TransportParameters,
 			enable0RTT bool,
 		) (<-chan *wire.TransportParameters /* clientHelloWrittenChan */, CryptoSetup /* client */, error /* client error */, CryptoSetup /* server */, error /* server error */) {
@@ -399,7 +398,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 		It("handshakes", func() {
 			_, _, clientErr, _, serverErr := handshakeWithTLSConf(
 				clientConf, serverConf,
-				&congestion.RTTStats{}, &congestion.RTTStats{},
+				&utils.RTTStats{}, &utils.RTTStats{},
 				&wire.TransportParameters{}, &wire.TransportParameters{},
 				false,
 			)
@@ -411,7 +410,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 			serverConf.CurvePreferences = []tls.CurveID{tls.CurveP384}
 			_, _, clientErr, _, serverErr := handshakeWithTLSConf(
 				clientConf, serverConf,
-				&congestion.RTTStats{}, &congestion.RTTStats{},
+				&utils.RTTStats{}, &utils.RTTStats{},
 				&wire.TransportParameters{}, &wire.TransportParameters{},
 				false,
 			)
@@ -424,7 +423,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 			serverConf.ClientAuth = qtls.RequireAnyClientCert
 			_, _, clientErr, _, serverErr := handshakeWithTLSConf(
 				clientConf, serverConf,
-				&congestion.RTTStats{}, &congestion.RTTStats{},
+				&utils.RTTStats{}, &utils.RTTStats{},
 				&wire.TransportParameters{}, &wire.TransportParameters{},
 				false,
 			)
@@ -445,7 +444,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 				runner,
 				&tls.Config{InsecureSkipVerify: true},
 				false,
-				&congestion.RTTStats{},
+				&utils.RTTStats{},
 				nil,
 				utils.DefaultLogger.WithPrefix("client"),
 			)
@@ -487,7 +486,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 				cRunner,
 				clientConf,
 				false,
-				&congestion.RTTStats{},
+				&utils.RTTStats{},
 				nil,
 				utils.DefaultLogger.WithPrefix("client"),
 			)
@@ -511,7 +510,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 				sRunner,
 				serverConf,
 				false,
-				&congestion.RTTStats{},
+				&utils.RTTStats{},
 				nil,
 				utils.DefaultLogger.WithPrefix("server"),
 			)
@@ -544,7 +543,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 					cRunner,
 					clientConf,
 					false,
-					&congestion.RTTStats{},
+					&utils.RTTStats{},
 					nil,
 					utils.DefaultLogger.WithPrefix("client"),
 				)
@@ -564,7 +563,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 					sRunner,
 					serverConf,
 					false,
-					&congestion.RTTStats{},
+					&utils.RTTStats{},
 					nil,
 					utils.DefaultLogger.WithPrefix("server"),
 				)
@@ -604,7 +603,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 					cRunner,
 					clientConf,
 					false,
-					&congestion.RTTStats{},
+					&utils.RTTStats{},
 					nil,
 					utils.DefaultLogger.WithPrefix("client"),
 				)
@@ -624,7 +623,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 					sRunner,
 					serverConf,
 					false,
-					&congestion.RTTStats{},
+					&utils.RTTStats{},
 					nil,
 					utils.DefaultLogger.WithPrefix("server"),
 				)
@@ -661,7 +660,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 				clientOrigRTTStats := newRTTStatsWithRTT(clientRTT)
 				clientHelloWrittenChan, client, clientErr, server, serverErr := handshakeWithTLSConf(
 					clientConf, serverConf,
-					clientOrigRTTStats, &congestion.RTTStats{},
+					clientOrigRTTStats, &utils.RTTStats{},
 					&wire.TransportParameters{}, &wire.TransportParameters{},
 					false,
 				)
@@ -674,10 +673,10 @@ var _ = Describe("Crypto Setup TLS", func() {
 
 				csc.EXPECT().Get(gomock.Any()).Return(state, true)
 				csc.EXPECT().Put(gomock.Any(), gomock.Any()).MaxTimes(1)
-				clientRTTStats := &congestion.RTTStats{}
+				clientRTTStats := &utils.RTTStats{}
 				clientHelloWrittenChan, client, clientErr, server, serverErr = handshakeWithTLSConf(
 					clientConf, serverConf,
-					clientRTTStats, &congestion.RTTStats{},
+					clientRTTStats, &utils.RTTStats{},
 					&wire.TransportParameters{}, &wire.TransportParameters{},
 					false,
 				)
@@ -702,7 +701,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 				clientConf.ClientSessionCache = csc
 				_, client, clientErr, server, serverErr := handshakeWithTLSConf(
 					clientConf, serverConf,
-					&congestion.RTTStats{}, &congestion.RTTStats{},
+					&utils.RTTStats{}, &utils.RTTStats{},
 					&wire.TransportParameters{}, &wire.TransportParameters{},
 					false,
 				)
@@ -716,7 +715,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 				csc.EXPECT().Get(gomock.Any()).Return(state, true)
 				_, client, clientErr, server, serverErr = handshakeWithTLSConf(
 					clientConf, serverConf,
-					&congestion.RTTStats{}, &congestion.RTTStats{},
+					&utils.RTTStats{}, &utils.RTTStats{},
 					&wire.TransportParameters{}, &wire.TransportParameters{},
 					false,
 				)
@@ -759,8 +758,8 @@ var _ = Describe("Crypto Setup TLS", func() {
 				csc.EXPECT().Put(gomock.Any(), nil)
 				csc.EXPECT().Put(gomock.Any(), gomock.Any()).MaxTimes(1)
 
-				clientRTTStats := &congestion.RTTStats{}
+				clientRTTStats := &utils.RTTStats{}
-				serverRTTStats := &congestion.RTTStats{}
+				serverRTTStats := &utils.RTTStats{}
 				clientHelloWrittenChan, client, clientErr, server, serverErr = handshakeWithTLSConf(
 					clientConf, serverConf,
 					clientRTTStats, serverRTTStats,
@@ -797,7 +796,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 				const initialMaxData protocol.ByteCount = 1337
 				clientHelloWrittenChan, client, clientErr, server, serverErr := handshakeWithTLSConf(
 					clientConf, serverConf,
-					clientOrigRTTStats, &congestion.RTTStats{},
+					clientOrigRTTStats, &utils.RTTStats{},
 					&wire.TransportParameters{}, &wire.TransportParameters{InitialMaxData: initialMaxData},
 					true,
 				)
@@ -812,10 +811,10 @@ var _ = Describe("Crypto Setup TLS", func() {
 				csc.EXPECT().Put(gomock.Any(), nil)
 				csc.EXPECT().Put(gomock.Any(), gomock.Any()).MaxTimes(1)
 
-				clientRTTStats := &congestion.RTTStats{}
+				clientRTTStats := &utils.RTTStats{}
 				clientHelloWrittenChan, client, clientErr, server, serverErr = handshakeWithTLSConf(
 					clientConf, serverConf,
-					clientRTTStats, &congestion.RTTStats{},
+					clientRTTStats, &utils.RTTStats{},
 					&wire.TransportParameters{}, &wire.TransportParameters{InitialMaxData: initialMaxData + 1},
 					true,
 				)

internal/handshake/qtls.go

@@ -6,9 +6,9 @@ import (
 	"time"
 	"unsafe"
 
-	"github.com/marten-seemann/qtls"
+	"github.com/lucas-clemente/quic-go/internal/utils"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
+	"github.com/marten-seemann/qtls"
 )
 
 func init() {
@@ -46,7 +46,7 @@ func tlsConfigToQtlsConfig(
 	c *tls.Config,
 	recordLayer qtls.RecordLayer,
 	extHandler tlsExtensionHandler,
-	rttStats *congestion.RTTStats,
+	rttStats *utils.RTTStats,
 	getDataForSessionState func() []byte,
 	setDataFromSessionState func([]byte),
 	accept0RTT func([]byte) bool,

internal/handshake/qtls_test.go

@@ -6,7 +6,8 @@ import (
 	"net"
 	"unsafe"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+
 	"github.com/marten-seemann/qtls"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -30,19 +31,19 @@ func (*mockExtensionHandler) TransportParameters() <-chan []byte { panic("not im
 var _ = Describe("qtls.Config", func() {
 	It("sets MinVersion and MaxVersion", func() {
 		tlsConf := &tls.Config{MinVersion: tls.VersionTLS11, MaxVersion: tls.VersionTLS12}
-		qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+		qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 		Expect(qtlsConf.MinVersion).To(BeEquivalentTo(tls.VersionTLS13))
 		Expect(qtlsConf.MaxVersion).To(BeEquivalentTo(tls.VersionTLS13))
 	})
 
 	It("works when called with a nil config", func() {
-		qtlsConf := tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+		qtlsConf := tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 		Expect(qtlsConf).ToNot(BeNil())
 	})
 
 	It("sets the setter and getter function for TLS extensions", func() {
 		extHandler := &mockExtensionHandler{}
-		qtlsConf := tlsConfigToQtlsConfig(&tls.Config{}, nil, extHandler, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+		qtlsConf := tlsConfigToQtlsConfig(&tls.Config{}, nil, extHandler, utils.NewRTTStats(), nil, nil, nil, nil, false)
 		Expect(extHandler.get).To(BeFalse())
 		qtlsConf.GetExtensions(10)
 		Expect(extHandler.get).To(BeTrue())
@@ -53,7 +54,7 @@ var _ = Describe("qtls.Config", func() {
 
 	It("sets the Accept0RTT callback", func() {
 		accept0RTT := func([]byte) bool { return true }
-		qtlsConf := tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, accept0RTT, nil, false)
+		qtlsConf := tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, accept0RTT, nil, false)
 		Expect(qtlsConf.Accept0RTT).ToNot(BeNil())
 		Expect(qtlsConf.Accept0RTT(nil)).To(BeTrue())
 	})
@@ -61,32 +62,32 @@ var _ = Describe("qtls.Config", func() {
 	It("sets the Accept0RTT callback", func() {
 		var called bool
 		rejected0RTT := func() { called = true }
-		qtlsConf := tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, rejected0RTT, false)
+		qtlsConf := tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, rejected0RTT, false)
 		Expect(qtlsConf.Rejected0RTT).ToNot(BeNil())
 		qtlsConf.Rejected0RTT()
 		Expect(called).To(BeTrue())
 	})
 
 	It("enables 0-RTT", func() {
-		qtlsConf := tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+		qtlsConf := tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 		Expect(qtlsConf.Enable0RTT).To(BeFalse())
 		Expect(qtlsConf.MaxEarlyData).To(BeZero())
-		qtlsConf = tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, true)
+		qtlsConf = tlsConfigToQtlsConfig(nil, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, true)
 		Expect(qtlsConf.Enable0RTT).To(BeTrue())
 		Expect(qtlsConf.MaxEarlyData).To(Equal(uint32(0xffffffff)))
 	})
 
 	It("initializes such that the session ticket key remains constant", func() {
 		tlsConf := &tls.Config{}
-		qtlsConf1 := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+		qtlsConf1 := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
-		qtlsConf2 := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+		qtlsConf2 := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 		Expect(qtlsConf1.SessionTicketKey).ToNot(BeZero()) // should now contain a random value
 		Expect(qtlsConf1.SessionTicketKey).To(Equal(qtlsConf2.SessionTicketKey))
 	})
 
 	Context("GetConfigForClient callback", func() {
 		It("doesn't set it if absent", func() {
-			qtlsConf := tlsConfigToQtlsConfig(&tls.Config{}, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(&tls.Config{}, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			Expect(qtlsConf.GetConfigForClient).To(BeNil())
 		})
 
@@ -97,7 +98,7 @@ var _ = Describe("qtls.Config", func() {
 				},
 			}
 			extHandler := &mockExtensionHandler{}
-			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, extHandler, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, extHandler, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			Expect(qtlsConf.GetConfigForClient).ToNot(BeNil())
 			confForClient, err := qtlsConf.GetConfigForClient(nil)
 			Expect(err).ToNot(HaveOccurred())
@@ -117,7 +118,7 @@ var _ = Describe("qtls.Config", func() {
 					return nil, testErr
 				},
 			}
-			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			_, err := qtlsConf.GetConfigForClient(nil)
 			Expect(err).To(MatchError(testErr))
 		})
@@ -128,7 +129,7 @@ var _ = Describe("qtls.Config", func() {
 					return nil, nil
 				},
 			}
-			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			Expect(qtlsConf.GetConfigForClient(nil)).To(BeNil())
 		})
 	})
@@ -140,7 +141,7 @@ var _ = Describe("qtls.Config", func() {
 					return &tls.Certificate{Certificate: [][]byte{[]byte("foo"), []byte("bar")}}, nil
 				},
 			}
-			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			qtlsCert, err := qtlsConf.GetCertificate(nil)
 			Expect(err).ToNot(HaveOccurred())
 			Expect(qtlsCert).ToNot(BeNil())
@@ -148,7 +149,7 @@ var _ = Describe("qtls.Config", func() {
 		})
 
 		It("doesn't set it if absent", func() {
-			qtlsConf := tlsConfigToQtlsConfig(&tls.Config{}, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(&tls.Config{}, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			Expect(qtlsConf.GetCertificate).To(BeNil())
 		})
 
@@ -158,7 +159,7 @@ var _ = Describe("qtls.Config", func() {
 					return nil, errors.New("test")
 				},
 			}
-			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			_, err := qtlsConf.GetCertificate(nil)
 			Expect(err).To(MatchError("test"))
 		})
@@ -169,21 +170,21 @@ var _ = Describe("qtls.Config", func() {
 					return nil, nil
 				},
 			}
-			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			Expect(qtlsConf.GetCertificate(nil)).To(BeNil())
 		})
 	})
 
 	Context("ClientSessionCache", func() {
 		It("doesn't set if absent", func() {
-			qtlsConf := tlsConfigToQtlsConfig(&tls.Config{}, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(&tls.Config{}, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			Expect(qtlsConf.ClientSessionCache).To(BeNil())
 		})
 
 		It("puts a nil session state", func() {
 			csc := NewMockClientSessionCache(mockCtrl)
 			tlsConf := &tls.Config{ClientSessionCache: csc}
-			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, congestion.NewRTTStats(), nil, nil, nil, nil, false)
+			qtlsConf := tlsConfigToQtlsConfig(tlsConf, nil, &mockExtensionHandler{}, utils.NewRTTStats(), nil, nil, nil, nil, false)
 			// put something
 			csc.EXPECT().Put("foobar", nil)
 			qtlsConf.ClientSessionCache.Put("foobar", nil)

internal/handshake/updatable_aead.go

@@ -9,7 +9,6 @@ import (
 	"strconv"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/lucas-clemente/quic-go/logging"
@@ -72,7 +71,7 @@ type updatableAEAD struct {
 	headerDecrypter headerProtector
 	headerEncrypter headerProtector
 
-	rttStats *congestion.RTTStats
+	rttStats *utils.RTTStats
 
 	tracer logging.ConnectionTracer
 	logger utils.Logger
@@ -84,7 +83,7 @@ type updatableAEAD struct {
 var _ ShortHeaderOpener = &updatableAEAD{}
 var _ ShortHeaderSealer = &updatableAEAD{}
 
-func newUpdatableAEAD(rttStats *congestion.RTTStats, tracer logging.ConnectionTracer, logger utils.Logger) *updatableAEAD {
+func newUpdatableAEAD(rttStats *utils.RTTStats, tracer logging.ConnectionTracer, logger utils.Logger) *updatableAEAD {
 	return &updatableAEAD{
 		firstPacketNumber:       protocol.InvalidPacketNumber,
 		largestAcked:            protocol.InvalidPacketNumber,

internal/handshake/updatable_aead_test.go

@@ -6,7 +6,6 @@ import (
 	"os"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/utils"
 	"github.com/marten-seemann/qtls"
@@ -18,7 +17,7 @@ import (
 var _ = Describe("Updatable AEAD", func() {
 	It("ChaCha test vector from the draft", func() {
 		secret := splitHexString("9ac312a7f877468ebe69422748ad00a1 5443f18203a07d6060f688f30f21632b")
-		aead := newUpdatableAEAD(&congestion.RTTStats{}, nil, nil)
+		aead := newUpdatableAEAD(&utils.RTTStats{}, nil, nil)
 		chacha := cipherSuites[2]
 		Expect(chacha.ID).To(Equal(qtls.TLS_CHACHA20_POLY1305_SHA256))
 		aead.SetWriteKey(chacha, secret)
@@ -37,7 +36,7 @@ var _ = Describe("Updatable AEAD", func() {
 		cs := cipherSuites[i]
 
 		Context(fmt.Sprintf("using %s", qtls.CipherSuiteName(cs.ID)), func() {
-			getPeers := func(rttStats *congestion.RTTStats) (client, server *updatableAEAD) {
+			getPeers := func(rttStats *utils.RTTStats) (client, server *updatableAEAD) {
 				trafficSecret1 := make([]byte, 16)
 				trafficSecret2 := make([]byte, 16)
 				rand.Read(trafficSecret1)
@@ -54,7 +53,7 @@ var _ = Describe("Updatable AEAD", func() {
 
 			Context("header protection", func() {
 				It("encrypts and decrypts the header", func() {
-					server, client := getPeers(&congestion.RTTStats{})
+					server, client := getPeers(&utils.RTTStats{})
 					var lastFiveBitsDifferent int
 					for i := 0; i < 100; i++ {
 						sample := make([]byte, 16)
@@ -77,10 +76,10 @@ var _ = Describe("Updatable AEAD", func() {
 			Context("message encryption", func() {
 				var msg, ad []byte
 				var server, client *updatableAEAD
-				var rttStats *congestion.RTTStats
+				var rttStats *utils.RTTStats
 
 				BeforeEach(func() {
-					rttStats = &congestion.RTTStats{}
+					rttStats = &utils.RTTStats{}
 					server, client = getPeers(rttStats)
 					msg = []byte("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.")
 					ad = []byte("Donec in velit neque.")

internal/mocks/connection_tracer.go

@@ -5,15 +5,16 @@
 package mocks
 
 import (
-	net "net"
+	"net"
-	reflect "reflect"
+	"reflect"
-	time "time"
+	"time"
 
-	gomock "github.com/golang/mock/gomock"
+	"github.com/lucas-clemente/quic-go/internal/utils"
-	congestion "github.com/lucas-clemente/quic-go/internal/congestion"
+
-	protocol "github.com/lucas-clemente/quic-go/internal/protocol"
+	"github.com/golang/mock/gomock"
-	wire "github.com/lucas-clemente/quic-go/internal/wire"
+	"github.com/lucas-clemente/quic-go/internal/protocol"
-	logging "github.com/lucas-clemente/quic-go/logging"
+	"github.com/lucas-clemente/quic-go/internal/wire"
+	"github.com/lucas-clemente/quic-go/logging"
 )
 
 // MockConnectionTracer is a mock of ConnectionTracer interface
@@ -256,7 +257,7 @@ func (mr *MockConnectionTracerMockRecorder) UpdatedKeyFromTLS(arg0, arg1 interfa
 }
 
 // UpdatedMetrics mocks base method
-func (m *MockConnectionTracer) UpdatedMetrics(arg0 *congestion.RTTStats, arg1, arg2 protocol.ByteCount, arg3 int) {
+func (m *MockConnectionTracer) UpdatedMetrics(arg0 *utils.RTTStats, arg1, arg2 protocol.ByteCount, arg3 int) {
 	m.ctrl.T.Helper()
 	m.ctrl.Call(m, "UpdatedMetrics", arg0, arg1, arg2, arg3)
 }

internal/utils/rtt_stats.go

@@ -1,10 +1,9 @@
-package congestion
+package utils
 
 import (
 	"time"
 
 	"github.com/lucas-clemente/quic-go/internal/protocol"
-	"github.com/lucas-clemente/quic-go/internal/utils"
 )
 
 const (
@@ -56,7 +55,7 @@ func (r *RTTStats) PTO(includeMaxAckDelay bool) time.Duration {
 	if r.SmoothedRTT() == 0 {
 		return 2 * defaultInitialRTT
 	}
-	pto := r.SmoothedRTT() + utils.MaxDuration(4*r.MeanDeviation(), protocol.TimerGranularity)
+	pto := r.SmoothedRTT() + MaxDuration(4*r.MeanDeviation(), protocol.TimerGranularity)
 	if includeMaxAckDelay {
 		pto += r.MaxAckDelay()
 	}
@@ -65,7 +64,7 @@ func (r *RTTStats) PTO(includeMaxAckDelay bool) time.Duration {
 
 // UpdateRTT updates the RTT based on a new sample.
 func (r *RTTStats) UpdateRTT(sendDelta, ackDelay time.Duration, now time.Time) {
-	if sendDelta == utils.InfDuration || sendDelta <= 0 {
+	if sendDelta == InfDuration || sendDelta <= 0 {
 		return
 	}
 
@@ -91,7 +90,7 @@ func (r *RTTStats) UpdateRTT(sendDelta, ackDelay time.Duration, now time.Time) {
 		r.smoothedRTT = sample
 		r.meanDeviation = sample / 2
 	} else {
-		r.meanDeviation = time.Duration(oneMinusBeta*float32(r.meanDeviation/time.Microsecond)+rttBeta*float32(utils.AbsDuration(r.smoothedRTT-sample)/time.Microsecond)) * time.Microsecond
+		r.meanDeviation = time.Duration(oneMinusBeta*float32(r.meanDeviation/time.Microsecond)+rttBeta*float32(AbsDuration(r.smoothedRTT-sample)/time.Microsecond)) * time.Microsecond
 		r.smoothedRTT = time.Duration((float32(r.smoothedRTT/time.Microsecond)*oneMinusAlpha)+(float32(sample/time.Microsecond)*rttAlpha)) * time.Microsecond
 	}
 }
@@ -123,6 +122,6 @@ func (r *RTTStats) OnConnectionMigration() {
 // is larger. The mean deviation is increased to the most recent deviation if
 // it's larger.
 func (r *RTTStats) ExpireSmoothedMetrics() {
-	r.meanDeviation = utils.MaxDuration(r.meanDeviation, utils.AbsDuration(r.smoothedRTT-r.latestRTT))
+	r.meanDeviation = MaxDuration(r.meanDeviation, AbsDuration(r.smoothedRTT-r.latestRTT))
-	r.smoothedRTT = utils.MaxDuration(r.smoothedRTT, r.latestRTT)
+	r.smoothedRTT = MaxDuration(r.smoothedRTT, r.latestRTT)
 }

internal/utils/rtt_stats_test.go

@@ -1,10 +1,10 @@
-package congestion
+package utils
 
 import (
 	"time"
 
 	"github.com/lucas-clemente/quic-go/internal/protocol"
-	"github.com/lucas-clemente/quic-go/internal/utils"
+
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 )
@@ -113,7 +113,7 @@ var _ = Describe("RTT stats", func() {
 
 		badSendDeltas := []time.Duration{
 			0,
-			utils.InfDuration,
+			InfDuration,
 			-1000 * time.Microsecond,
 		}
 		// log.StartCapturingLogs();

logging/interface.go

@@ -6,7 +6,8 @@ import (
 	"net"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/qerr"
 	"github.com/lucas-clemente/quic-go/internal/wire"
@@ -49,7 +50,7 @@ type (
 	ApplicationError = qerr.ErrorCode
 
 	// The RTTStats contain statistics used by the congestion controller.
-	RTTStats = congestion.RTTStats
+	RTTStats = utils.RTTStats
 )
 
 const (

logging/mock_connection_tracer_test.go

@@ -5,13 +5,14 @@
 package logging
 
 import (
-	gomock "github.com/golang/mock/gomock"
+	"net"
-	congestion "github.com/lucas-clemente/quic-go/internal/congestion"
+	"reflect"
-	protocol "github.com/lucas-clemente/quic-go/internal/protocol"
+	"time"
-	wire "github.com/lucas-clemente/quic-go/internal/wire"
+
-	net "net"
+	"github.com/golang/mock/gomock"
-	reflect "reflect"
+	"github.com/lucas-clemente/quic-go/internal/protocol"
-	time "time"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+	"github.com/lucas-clemente/quic-go/internal/wire"
 )
 
 // MockConnectionTracer is a mock of ConnectionTracer interface
@@ -254,7 +255,7 @@ func (mr *MockConnectionTracerMockRecorder) UpdatedKeyFromTLS(arg0, arg1 interfa
 }
 
 // UpdatedMetrics mocks base method
-func (m *MockConnectionTracer) UpdatedMetrics(arg0 *congestion.RTTStats, arg1, arg2 protocol.ByteCount, arg3 int) {
+func (m *MockConnectionTracer) UpdatedMetrics(arg0 *utils.RTTStats, arg1, arg2 protocol.ByteCount, arg3 int) {
 	m.ctrl.T.Helper()
 	m.ctrl.Call(m, "UpdatedMetrics", arg0, arg1, arg2, arg3)
 }

qlog/qlog.go

@@ -9,7 +9,8 @@ import (
 	"sync"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/internal/wire"
 	"github.com/lucas-clemente/quic-go/logging"
@@ -286,7 +287,7 @@ func (t *connectionTracer) DroppedPacket(pt logging.PacketType, size protocol.By
 	t.mutex.Unlock()
 }
 
-func (t *connectionTracer) UpdatedMetrics(rttStats *congestion.RTTStats, cwnd, bytesInFlight protocol.ByteCount, packetsInFlight int) {
+func (t *connectionTracer) UpdatedMetrics(rttStats *utils.RTTStats, cwnd, bytesInFlight protocol.ByteCount, packetsInFlight int) {
 	m := &metrics{
 		MinRTT:           rttStats.MinRTT(),
 		SmoothedRTT:      rttStats.SmoothedRTT(),

qlog/qlog_test.go

@@ -10,7 +10,8 @@ import (
 	"os"
 	"time"
 
-	"github.com/lucas-clemente/quic-go/internal/congestion"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/lucas-clemente/quic-go/logging"
 
@@ -438,7 +439,7 @@ var _ = Describe("Tracing", func() {
 
 			It("records metrics updates", func() {
 				now := time.Now()
-				rttStats := congestion.NewRTTStats()
+				rttStats := utils.NewRTTStats()
 				rttStats.UpdateRTT(15*time.Millisecond, 0, now)
 				rttStats.UpdateRTT(20*time.Millisecond, 0, now)
 				rttStats.UpdateRTT(25*time.Millisecond, 0, now)
@@ -472,13 +473,13 @@ var _ = Describe("Tracing", func() {
 
 			It("only logs the diff between two metrics updates", func() {
 				now := time.Now()
-				rttStats := congestion.NewRTTStats()
+				rttStats := utils.NewRTTStats()
 				rttStats.UpdateRTT(15*time.Millisecond, 0, now)
 				rttStats.UpdateRTT(20*time.Millisecond, 0, now)
 				rttStats.UpdateRTT(25*time.Millisecond, 0, now)
 				Expect(rttStats.MinRTT()).To(Equal(15 * time.Millisecond))
 
-				rttStats2 := congestion.NewRTTStats()
+				rttStats2 := utils.NewRTTStats()
 				rttStats2.UpdateRTT(15*time.Millisecond, 0, now)
 				rttStats2.UpdateRTT(15*time.Millisecond, 0, now)
 				rttStats2.UpdateRTT(15*time.Millisecond, 0, now)

session.go

@@ -13,7 +13,6 @@ import (
 	"time"
 
 	"github.com/lucas-clemente/quic-go/internal/ackhandler"
-	"github.com/lucas-clemente/quic-go/internal/congestion"
 	"github.com/lucas-clemente/quic-go/internal/flowcontrol"
 	"github.com/lucas-clemente/quic-go/internal/handshake"
 	"github.com/lucas-clemente/quic-go/internal/logutils"
@@ -144,7 +143,7 @@ type session struct {
 	connIDManager   *connIDManager
 	connIDGenerator *connIDGenerator
 
-	rttStats *congestion.RTTStats
+	rttStats *utils.RTTStats
 
 	cryptoStreamManager   *cryptoStreamManager
 	sentPacketHandler     ackhandler.SentPacketHandler
@@ -472,7 +471,7 @@ func (s *session) preSetup() {
 	s.sendQueue = newSendQueue(s.conn)
 	s.retransmissionQueue = newRetransmissionQueue(s.version)
 	s.frameParser = wire.NewFrameParser(s.version)
-	s.rttStats = &congestion.RTTStats{}
+	s.rttStats = &utils.RTTStats{}
 	s.connFlowController = flowcontrol.NewConnectionFlowController(
 		protocol.InitialMaxData,
 		protocol.ByteCount(s.config.MaxReceiveConnectionFlowControlWindow),