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package ackhandler
import (
"math/rand/v2"
"slices"
"testing"
"github.com/quic-go/quic-go/internal/protocol"
"github.com/quic-go/quic-go/internal/wire"
"github.com/stretchr/testify/require"
)
func TestReceivedPacketHistorySingleRange(t *testing.T) {
hist := newReceivedPacketHistory()
require.True(t, hist.ReceivedPacket(4))
require.Equal(t, []wire.AckRange{{Smallest: 4, Largest: 4}}, hist.AppendAckRanges(nil))
// add a duplicate packet
require.False(t, hist.ReceivedPacket(4))
require.Equal(t, []wire.AckRange{{Smallest: 4, Largest: 4}}, hist.AppendAckRanges(nil))
// add a few more packets to extend the range
require.True(t, hist.ReceivedPacket(5))
require.True(t, hist.ReceivedPacket(6))
require.Equal(t, []wire.AckRange{{Smallest: 4, Largest: 6}}, hist.AppendAckRanges(nil))
// add a duplicate within this range
require.False(t, hist.ReceivedPacket(5))
require.Equal(t, []wire.AckRange{{Smallest: 4, Largest: 6}}, hist.AppendAckRanges(nil))
// extend the range at the front
require.True(t, hist.ReceivedPacket(3))
require.Equal(t, []wire.AckRange{{Smallest: 3, Largest: 6}}, hist.AppendAckRanges(nil))
}
func TestReceivedPacketHistoryRanges(t *testing.T) {
hist := newReceivedPacketHistory()
require.Zero(t, hist.GetHighestAckRange())
require.True(t, hist.ReceivedPacket(4))
require.True(t, hist.ReceivedPacket(10))
require.Equal(t, []wire.AckRange{
{Smallest: 10, Largest: 10},
{Smallest: 4, Largest: 4},
}, hist.AppendAckRanges(nil))
require.Equal(t, wire.AckRange{Smallest: 10, Largest: 10}, hist.GetHighestAckRange())
// create a new range in the middle
require.True(t, hist.ReceivedPacket(7))
require.Equal(t, []wire.AckRange{
{Smallest: 10, Largest: 10},
{Smallest: 7, Largest: 7},
{Smallest: 4, Largest: 4},
}, hist.AppendAckRanges(nil))
// create a new range at the front
require.True(t, hist.ReceivedPacket(1))
require.Equal(t, []wire.AckRange{
{Smallest: 10, Largest: 10},
{Smallest: 7, Largest: 7},
{Smallest: 4, Largest: 4},
{Smallest: 1, Largest: 1},
}, hist.AppendAckRanges(nil))
// extend an existing range at the end
require.True(t, hist.ReceivedPacket(8))
require.Equal(t, []wire.AckRange{
{Smallest: 10, Largest: 10},
{Smallest: 7, Largest: 8},
{Smallest: 4, Largest: 4},
{Smallest: 1, Largest: 1},
}, hist.AppendAckRanges(nil))
// extend an existing range at the front
require.True(t, hist.ReceivedPacket(6))
require.Equal(t, []wire.AckRange{
{Smallest: 10, Largest: 10},
{Smallest: 6, Largest: 8},
{Smallest: 4, Largest: 4},
{Smallest: 1, Largest: 1},
}, hist.AppendAckRanges(nil))
// close a range
require.True(t, hist.ReceivedPacket(9))
require.Equal(t, []wire.AckRange{
{Smallest: 6, Largest: 10},
{Smallest: 4, Largest: 4},
{Smallest: 1, Largest: 1},
}, hist.AppendAckRanges(nil))
}
func TestReceivedPacketHistoryMaxNumAckRanges(t *testing.T) {
hist := newReceivedPacketHistory()
for i := protocol.PacketNumber(0); i < protocol.MaxNumAckRanges; i++ {
require.True(t, hist.ReceivedPacket(2*i))
}
require.Len(t, hist.ranges, protocol.MaxNumAckRanges)
require.Equal(t, interval{Start: 0, End: 0}, hist.ranges[0])
hist.ReceivedPacket(2*protocol.MaxNumAckRanges + 1000)
// check that the oldest ACK range was deleted
require.Len(t, hist.ranges, protocol.MaxNumAckRanges)
require.Equal(t, interval{Start: 2, End: 2}, hist.ranges[0])
}
func TestReceivedPacketHistoryDeleteBelow(t *testing.T) {
hist := newReceivedPacketHistory()
hist.DeleteBelow(2)
require.Empty(t, hist.AppendAckRanges(nil))
require.True(t, hist.ReceivedPacket(2))
require.True(t, hist.ReceivedPacket(4))
require.True(t, hist.ReceivedPacket(5))
require.True(t, hist.ReceivedPacket(6))
require.True(t, hist.ReceivedPacket(10))
hist.DeleteBelow(6)
require.Equal(t, []wire.AckRange{
{Smallest: 10, Largest: 10},
{Smallest: 6, Largest: 6},
}, hist.AppendAckRanges(nil))
// deleting from an existing range
require.True(t, hist.ReceivedPacket(7))
require.True(t, hist.ReceivedPacket(8))
hist.DeleteBelow(7)
require.Equal(t, []wire.AckRange{
{Smallest: 10, Largest: 10},
{Smallest: 7, Largest: 8},
}, hist.AppendAckRanges(nil))
// keep a one-packet range
hist.DeleteBelow(10)
require.Equal(t, []wire.AckRange{{Smallest: 10, Largest: 10}}, hist.AppendAckRanges(nil))
// delayed packets below deleted ranges are ignored
require.False(t, hist.ReceivedPacket(5))
require.Equal(t, []wire.AckRange{{Smallest: 10, Largest: 10}}, hist.AppendAckRanges(nil))
}
func TestReceivedPacketHistoryDuplicateDetection(t *testing.T) {
hist := newReceivedPacketHistory()
require.False(t, hist.IsPotentiallyDuplicate(5))
require.True(t, hist.ReceivedPacket(4))
require.True(t, hist.ReceivedPacket(5))
require.True(t, hist.ReceivedPacket(6))
require.True(t, hist.ReceivedPacket(8))
require.True(t, hist.ReceivedPacket(9))
require.False(t, hist.IsPotentiallyDuplicate(3))
require.True(t, hist.IsPotentiallyDuplicate(4))
require.True(t, hist.IsPotentiallyDuplicate(5))
require.True(t, hist.IsPotentiallyDuplicate(6))
require.False(t, hist.IsPotentiallyDuplicate(7))
require.True(t, hist.IsPotentiallyDuplicate(8))
require.True(t, hist.IsPotentiallyDuplicate(9))
require.False(t, hist.IsPotentiallyDuplicate(10))
// delete and check for potential duplicates
hist.DeleteBelow(8)
require.True(t, hist.IsPotentiallyDuplicate(7))
require.True(t, hist.IsPotentiallyDuplicate(8))
require.True(t, hist.IsPotentiallyDuplicate(9))
require.False(t, hist.IsPotentiallyDuplicate(10))
}
func TestReceivedPacketHistoryRandomized(t *testing.T) {
hist := newReceivedPacketHistory()
packets := make(map[protocol.PacketNumber]int)
const num = 2 * protocol.MaxNumAckRanges
numLostPackets := rand.IntN(protocol.MaxNumAckRanges)
numRcvdPackets := num - numLostPackets
for i := 0; i < num; i++ {
packets[protocol.PacketNumber(i)] = 0
}
lostPackets := make([]protocol.PacketNumber, 0, numLostPackets)
for len(lostPackets) < numLostPackets {
p := protocol.PacketNumber(rand.IntN(num))
if _, ok := packets[p]; ok {
lostPackets = append(lostPackets, p)
delete(packets, p)
}
}
slices.Sort(lostPackets)
t.Logf("Losing packets: %v", lostPackets)
ordered := make([]protocol.PacketNumber, 0, numRcvdPackets)
for p := range packets {
ordered = append(ordered, p)
}
rand.Shuffle(len(ordered), func(i, j int) { ordered[i], ordered[j] = ordered[j], ordered[i] })
t.Logf("Receiving packets: %v", ordered)
for i, p := range ordered {
require.True(t, hist.ReceivedPacket(p))
// sometimes receive a duplicate
if i > 0 && rand.Int()%5 == 0 {
require.False(t, hist.ReceivedPacket(ordered[rand.IntN(i)]))
}
}
var counter int
ackRanges := hist.AppendAckRanges(nil)
t.Logf("ACK ranges: %v", ackRanges)
require.LessOrEqual(t, len(ackRanges), numLostPackets+1)
for _, ackRange := range ackRanges {
for p := ackRange.Smallest; p <= ackRange.Largest; p++ {
counter++
require.Contains(t, packets, p)
}
}
require.Equal(t, numRcvdPackets, counter)
}
func BenchmarkHistoryReceiveSequentialPackets(b *testing.B) {
hist := newReceivedPacketHistory()
for i := 0; i < b.N; i++ {
hist.ReceivedPacket(protocol.PacketNumber(i))
}
}
// Packets are received sequentially, with occasional gaps
func BenchmarkHistoryReceiveCommonCase(b *testing.B) {
hist := newReceivedPacketHistory()
var pn protocol.PacketNumber
for i := 0; i < b.N; i++ {
hist.ReceivedPacket(pn)
pn++
if i%2000 == 0 {
pn += 4
}
}
}
func BenchmarkHistoryReceiveSequentialPacketsWithGaps(b *testing.B) {
hist := newReceivedPacketHistory()
for i := 0; i < b.N; i++ {
hist.ReceivedPacket(protocol.PacketNumber(2 * i))
}
}
func BenchmarkHistoryReceiveReversePacketsWithGaps(b *testing.B) {
hist := newReceivedPacketHistory()
for i := 0; i < b.N; i++ {
hist.ReceivedPacket(protocol.PacketNumber(2 * (b.N - i)))
}
}
func BenchmarkHistoryIsDuplicate(b *testing.B) {
b.ReportAllocs()
hist := newReceivedPacketHistory()
var pn protocol.PacketNumber
for i := 0; i < protocol.MaxNumAckRanges; i++ {
for j := 0; j < 5; j++ {
hist.ReceivedPacket(pn)
pn++
}
pn += 5 // create a gap
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
hist.IsPotentiallyDuplicate(protocol.PacketNumber(i) % pn)
}
}
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