simplify pruning of old ACK ranges

internal/ackhandler/ackhandler.go

@@ -17,6 +17,6 @@ func NewAckHandler(
 	logger utils.Logger,
 	version protocol.VersionNumber,
 ) (SentPacketHandler, ReceivedPacketHandler) {
-	return newSentPacketHandler(initialPacketNumber, rttStats, pers, traceCallback, qlogger, logger),
-		newReceivedPacketHandler(rttStats, logger, version)
+	sph := newSentPacketHandler(initialPacketNumber, rttStats, pers, traceCallback, qlogger, logger)
+	return sph, newReceivedPacketHandler(sph, rttStats, logger, version)
 }

internal/ackhandler/interfaces.go

@@ -42,7 +42,6 @@ type SentPacketHandler interface {
 	ShouldSendNumPackets() int
 
 	// only to be called once the handshake is complete
-	GetLowestPacketNotConfirmedAcked() protocol.PacketNumber
 	QueueProbePacket(protocol.EncryptionLevel) bool /* was a packet queued */
 
 	PeekPacketNumber(protocol.EncryptionLevel) (protocol.PacketNumber, protocol.PacketNumberLen)
@@ -55,10 +54,13 @@ type SentPacketHandler interface {
 	GetStats() *quictrace.TransportState
 }
 
+type sentPacketTracker interface {
+	GetLowestPacketNotConfirmedAcked() protocol.PacketNumber
+}
+
 // ReceivedPacketHandler handles ACKs needed to send for incoming packets
 type ReceivedPacketHandler interface {
 	ReceivedPacket(pn protocol.PacketNumber, encLevel protocol.EncryptionLevel, rcvTime time.Time, shouldInstigateAck bool) error
-	IgnoreBelow(protocol.PacketNumber)
 	DropPackets(protocol.EncryptionLevel)
 
 	GetAlarmTimeout() time.Time

internal/ackhandler/mock_sent_packet_tracker_test.go

@@ -0,0 +1,49 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: github.com/lucas-clemente/quic-go/internal/ackhandler (interfaces: SentPacketTracker)
+
+// Package ackhandler is a generated GoMock package.
+package ackhandler
+
+import (
+	reflect "reflect"
+
+	gomock "github.com/golang/mock/gomock"
+	protocol "github.com/lucas-clemente/quic-go/internal/protocol"
+)
+
+// MockSentPacketTracker is a mock of SentPacketTracker interface
+type MockSentPacketTracker struct {
+	ctrl     *gomock.Controller
+	recorder *MockSentPacketTrackerMockRecorder
+}
+
+// MockSentPacketTrackerMockRecorder is the mock recorder for MockSentPacketTracker
+type MockSentPacketTrackerMockRecorder struct {
+	mock *MockSentPacketTracker
+}
+
+// NewMockSentPacketTracker creates a new mock instance
+func NewMockSentPacketTracker(ctrl *gomock.Controller) *MockSentPacketTracker {
+	mock := &MockSentPacketTracker{ctrl: ctrl}
+	mock.recorder = &MockSentPacketTrackerMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockSentPacketTracker) EXPECT() *MockSentPacketTrackerMockRecorder {
+	return m.recorder
+}
+
+// GetLowestPacketNotConfirmedAcked mocks base method
+func (m *MockSentPacketTracker) GetLowestPacketNotConfirmedAcked() protocol.PacketNumber {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "GetLowestPacketNotConfirmedAcked")
+	ret0, _ := ret[0].(protocol.PacketNumber)
+	return ret0
+}
+
+// GetLowestPacketNotConfirmedAcked indicates an expected call of GetLowestPacketNotConfirmedAcked
+func (mr *MockSentPacketTrackerMockRecorder) GetLowestPacketNotConfirmedAcked() *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetLowestPacketNotConfirmedAcked", reflect.TypeOf((*MockSentPacketTracker)(nil).GetLowestPacketNotConfirmedAcked))
+}

internal/ackhandler/mockgen.go

@@ -0,0 +1,3 @@
+package ackhandler
+
+//go:generate sh -c "../../mockgen_private.sh ackhandler mock_sent_packet_tracker_test.go github.com/lucas-clemente/quic-go/internal/ackhandler sentPacketTracker"

internal/ackhandler/received_packet_handler.go

@@ -32,6 +32,8 @@ const (
 )
 
 type receivedPacketHandler struct {
+	sentPackets sentPacketTracker
+
 	initialPackets   *receivedPacketTracker
 	handshakePackets *receivedPacketTracker
 	appDataPackets   *receivedPacketTracker
@@ -42,11 +44,13 @@ type receivedPacketHandler struct {
 var _ ReceivedPacketHandler = &receivedPacketHandler{}
 
 func newReceivedPacketHandler(
+	sentPackets sentPacketTracker,
 	rttStats *congestion.RTTStats,
 	logger utils.Logger,
 	version protocol.VersionNumber,
 ) ReceivedPacketHandler {
 	return &receivedPacketHandler{
+		sentPackets:      sentPackets,
 		initialPackets:   newReceivedPacketTracker(rttStats, logger, version),
 		handshakePackets: newReceivedPacketTracker(rttStats, logger, version),
 		appDataPackets:   newReceivedPacketTracker(rttStats, logger, version),
@@ -74,6 +78,7 @@ func (h *receivedPacketHandler) ReceivedPacket(
 		if h.lowest1RTTPacket == protocol.InvalidPacketNumber || pn < h.lowest1RTTPacket {
 			h.lowest1RTTPacket = pn
 		}
+		h.appDataPackets.IgnoreBelow(h.sentPackets.GetLowestPacketNotConfirmedAcked())
 		h.appDataPackets.ReceivedPacket(pn, rcvTime, shouldInstigateAck)
 	default:
 		panic(fmt.Sprintf("received packet with unknown encryption level: %s", encLevel))
@@ -81,11 +86,6 @@ func (h *receivedPacketHandler) ReceivedPacket(
 	return nil
 }
 
-// only to be used with 1-RTT packets
-func (h *receivedPacketHandler) IgnoreBelow(pn protocol.PacketNumber) {
-	h.appDataPackets.IgnoreBelow(pn)
-}
-
 func (h *receivedPacketHandler) DropPackets(encLevel protocol.EncryptionLevel) {
 	switch encLevel {
 	case protocol.EncryptionInitial:

internal/ackhandler/received_packet_handler_test.go

@@ -14,9 +14,12 @@ import (
 
 var _ = Describe("Received Packet Handler", func() {
 	var handler ReceivedPacketHandler
+	var sentPackets *MockSentPacketTracker
 
 	BeforeEach(func() {
+		sentPackets = NewMockSentPacketTracker(mockCtrl)
 		handler = newReceivedPacketHandler(
+			sentPackets,
 			&congestion.RTTStats{},
 			utils.DefaultLogger,
 			protocol.VersionWhatever,
@@ -24,6 +27,7 @@ var _ = Describe("Received Packet Handler", func() {
 	})
 
 	It("generates ACKs for different packet number spaces", func() {
+		sentPackets.EXPECT().GetLowestPacketNotConfirmedAcked().AnyTimes()
 		sendTime := time.Now().Add(-time.Second)
 		Expect(handler.ReceivedPacket(2, protocol.EncryptionInitial, sendTime, true)).To(Succeed())
 		Expect(handler.ReceivedPacket(1, protocol.EncryptionHandshake, sendTime, true)).To(Succeed())
@@ -49,6 +53,7 @@ var _ = Describe("Received Packet Handler", func() {
 	})
 
 	It("uses the same packet number space for 0-RTT and 1-RTT packets", func() {
+		sentPackets.EXPECT().GetLowestPacketNotConfirmedAcked().AnyTimes()
 		sendTime := time.Now().Add(-time.Second)
 		Expect(handler.ReceivedPacket(2, protocol.Encryption0RTT, sendTime, true)).To(Succeed())
 		Expect(handler.ReceivedPacket(3, protocol.Encryption1RTT, sendTime, true)).To(Succeed())
@@ -59,6 +64,7 @@ var _ = Describe("Received Packet Handler", func() {
 	})
 
 	It("rejects 0-RTT packets with higher packet numbers than 1-RTT packets", func() {
+		sentPackets.EXPECT().GetLowestPacketNotConfirmedAcked().AnyTimes()
 		sendTime := time.Now()
 		Expect(handler.ReceivedPacket(10, protocol.Encryption0RTT, sendTime, true)).To(Succeed())
 		Expect(handler.ReceivedPacket(11, protocol.Encryption1RTT, sendTime, true)).To(Succeed())
@@ -66,6 +72,7 @@ var _ = Describe("Received Packet Handler", func() {
 	})
 
 	It("allows reordered 0-RTT packets", func() {
+		sentPackets.EXPECT().GetLowestPacketNotConfirmedAcked().AnyTimes()
 		sendTime := time.Now()
 		Expect(handler.ReceivedPacket(10, protocol.Encryption0RTT, sendTime, true)).To(Succeed())
 		Expect(handler.ReceivedPacket(12, protocol.Encryption1RTT, sendTime, true)).To(Succeed())
@@ -83,6 +90,7 @@ var _ = Describe("Received Packet Handler", func() {
 	})
 
 	It("drops Handshake packets", func() {
+		sentPackets.EXPECT().GetLowestPacketNotConfirmedAcked().AnyTimes()
 		sendTime := time.Now().Add(-time.Second)
 		Expect(handler.ReceivedPacket(1, protocol.EncryptionHandshake, sendTime, true)).To(Succeed())
 		Expect(handler.ReceivedPacket(2, protocol.Encryption1RTT, sendTime, true)).To(Succeed())
@@ -92,7 +100,26 @@ var _ = Describe("Received Packet Handler", func() {
 		Expect(handler.GetAckFrame(protocol.Encryption1RTT)).ToNot(BeNil())
 	})
 
-	It("does nothing when droping 0-RTT packets", func() {
+	It("does nothing when dropping 0-RTT packets", func() {
 		handler.DropPackets(protocol.Encryption0RTT)
 	})
+
+	It("drops old ACK ranges", func() {
+		sendTime := time.Now()
+		sentPackets.EXPECT().GetLowestPacketNotConfirmedAcked().Times(2)
+		Expect(handler.ReceivedPacket(1, protocol.Encryption1RTT, sendTime, true)).To(Succeed())
+		Expect(handler.ReceivedPacket(2, protocol.Encryption1RTT, sendTime, true)).To(Succeed())
+		ack := handler.GetAckFrame(protocol.Encryption1RTT)
+		Expect(ack).ToNot(BeNil())
+		Expect(ack.LowestAcked()).To(Equal(protocol.PacketNumber(1)))
+		Expect(ack.LargestAcked()).To(Equal(protocol.PacketNumber(2)))
+		sentPackets.EXPECT().GetLowestPacketNotConfirmedAcked()
+		Expect(handler.ReceivedPacket(3, protocol.Encryption1RTT, sendTime, true)).To(Succeed())
+		sentPackets.EXPECT().GetLowestPacketNotConfirmedAcked().Return(protocol.PacketNumber(2))
+		Expect(handler.ReceivedPacket(4, protocol.Encryption1RTT, sendTime, true)).To(Succeed())
+		ack = handler.GetAckFrame(protocol.Encryption1RTT)
+		Expect(ack).ToNot(BeNil())
+		Expect(ack.LowestAcked()).To(Equal(protocol.PacketNumber(2)))
+		Expect(ack.LargestAcked()).To(Equal(protocol.PacketNumber(4)))
+	})
 })

internal/ackhandler/sent_packet_handler.go

@@ -80,6 +80,9 @@ type sentPacketHandler struct {
 	logger        utils.Logger
 }
 
+var _ SentPacketHandler = &sentPacketHandler{}
+var _ sentPacketTracker = &sentPacketHandler{}
+
 func newSentPacketHandler(
 	initialPacketNumber protocol.PacketNumber,
 	rttStats *congestion.RTTStats,