uquic/ackhandler/received_packet_handler_test.go
2016-06-11 13:57:54 +07:00

369 lines
14 KiB
Go

package ackhandler
import (
"time"
"github.com/lucas-clemente/quic-go/frames"
"github.com/lucas-clemente/quic-go/protocol"
. "github.com/onsi/ginkgo"
. "github.com/onsi/gomega"
)
var _ = Describe("receivedPacketHandler", func() {
var (
handler *receivedPacketHandler
expectedEntropy EntropyAccumulator
)
BeforeEach(func() {
handler = NewReceivedPacketHandler().(*receivedPacketHandler)
expectedEntropy = EntropyAccumulator(0)
})
Context("accepting packets", func() {
It("handles a packet that arrives late", func() {
err := handler.ReceivedPacket(protocol.PacketNumber(1), false)
Expect(err).ToNot(HaveOccurred())
Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(1)))
err = handler.ReceivedPacket(protocol.PacketNumber(3), false)
Expect(err).ToNot(HaveOccurred())
Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(3)))
err = handler.ReceivedPacket(protocol.PacketNumber(2), false)
Expect(err).ToNot(HaveOccurred())
Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(2)))
})
It("rejects packets with packet number 0", func() {
err := handler.ReceivedPacket(protocol.PacketNumber(0), false)
Expect(err).To(MatchError(errInvalidPacketNumber))
})
It("rejects a duplicate package with PacketNumber equal to LargestObserved", func() {
for i := 1; i < 5; i++ {
err := handler.ReceivedPacket(protocol.PacketNumber(i), false)
Expect(err).ToNot(HaveOccurred())
}
err := handler.ReceivedPacket(4, false)
Expect(err).To(MatchError(ErrDuplicatePacket))
})
It("rejects a duplicate package with PacketNumber less than the LargestObserved", func() {
for i := 1; i < 5; i++ {
err := handler.ReceivedPacket(protocol.PacketNumber(i), false)
Expect(err).ToNot(HaveOccurred())
}
err := handler.ReceivedPacket(2, false)
Expect(err).To(MatchError(ErrDuplicatePacket))
})
It("saves the time when each packet arrived", func() {
err := handler.ReceivedPacket(protocol.PacketNumber(3), false)
Expect(err).ToNot(HaveOccurred())
Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(3)))
Expect(handler.packetHistory[3].TimeReceived).To(BeTemporally("~", time.Now(), 10*time.Millisecond))
})
It("doesn't store more than MaxTrackedReceivedPackets packets", func() {
for i := uint32(0); i < protocol.MaxTrackedReceivedPackets; i++ {
packetNumber := protocol.PacketNumber(1 + 2*i)
err := handler.ReceivedPacket(packetNumber, true)
Expect(err).ToNot(HaveOccurred())
}
err := handler.ReceivedPacket(protocol.PacketNumber(3*protocol.MaxTrackedReceivedPackets), true)
Expect(err).To(MatchError(errTooManyOutstandingReceivedPackets))
})
})
Context("Entropy calculation", func() {
It("calculates the entropy for continously received packets", func() {
for i := 1; i < 100; i++ {
entropyBit := false
if i%3 == 0 || i%5 == 0 {
entropyBit = true
}
expectedEntropy.Add(protocol.PacketNumber(i), entropyBit)
err := handler.ReceivedPacket(protocol.PacketNumber(i), entropyBit)
Expect(err).ToNot(HaveOccurred())
}
Expect(handler.highestInOrderObservedEntropy).To(Equal(expectedEntropy))
})
It("calculates the entropy if there is a NACK range", func() {
for i := 1; i < 100; i++ {
entropyBit := false
if i%3 == 0 || i%5 == 0 {
entropyBit = true
}
if i == 10 || i == 11 || i == 12 {
continue
}
if i < 10 {
expectedEntropy.Add(protocol.PacketNumber(i), entropyBit)
}
err := handler.ReceivedPacket(protocol.PacketNumber(i), entropyBit)
Expect(err).ToNot(HaveOccurred())
}
Expect(handler.highestInOrderObservedEntropy).To(Equal(expectedEntropy))
})
})
Context("NACK range calculation", func() {
It("Returns no NACK ranges for continously received packets", func() {
for i := 1; i < 100; i++ {
entropyBit := false
if i%2 == 0 {
entropyBit = true
}
expectedEntropy.Add(protocol.PacketNumber(i), entropyBit)
err := handler.ReceivedPacket(protocol.PacketNumber(i), entropyBit)
Expect(err).ToNot(HaveOccurred())
}
Expect(handler.largestObserved).To(Equal(protocol.PacketNumber(99)))
Expect(handler.highestInOrderObserved).To(Equal(protocol.PacketNumber(99)))
nackRanges, entropy := handler.getNackRanges()
Expect(nackRanges).To(BeEmpty())
Expect(entropy).To(Equal(expectedEntropy))
})
It("handles a single lost package", func() {
for i := 1; i < 10; i++ {
entropyBit := true
if i == 5 {
continue
}
expectedEntropy.Add(protocol.PacketNumber(i), entropyBit)
err := handler.ReceivedPacket(protocol.PacketNumber(i), entropyBit)
Expect(err).ToNot(HaveOccurred())
}
Expect(handler.largestObserved).To(Equal(protocol.PacketNumber(9)))
nackRanges, entropy := handler.getNackRanges()
Expect(nackRanges).To(HaveLen(1))
Expect(nackRanges[0]).To(Equal(frames.NackRange{FirstPacketNumber: 5, LastPacketNumber: 5}))
Expect(handler.highestInOrderObserved).To(Equal(protocol.PacketNumber(4)))
Expect(entropy).To(Equal(expectedEntropy))
})
It("handles two consecutive lost packages", func() {
for i := 1; i < 12; i++ {
entropyBit := false
if i%2 == 0 || i == 5 {
entropyBit = true
}
if i == 5 || i == 6 {
continue
}
expectedEntropy.Add(protocol.PacketNumber(i), entropyBit)
err := handler.ReceivedPacket(protocol.PacketNumber(i), entropyBit)
Expect(err).ToNot(HaveOccurred())
}
Expect(handler.largestObserved).To(Equal(protocol.PacketNumber(11)))
nackRanges, entropy := handler.getNackRanges()
Expect(nackRanges).To(HaveLen(1))
Expect(nackRanges[0]).To(Equal(frames.NackRange{FirstPacketNumber: 5, LastPacketNumber: 6}))
Expect(handler.highestInOrderObserved).To(Equal(protocol.PacketNumber(4)))
Expect(entropy).To(Equal(expectedEntropy))
})
It("handles two non-consecutively lost packages", func() {
for i := 1; i < 10; i++ {
entropyBit := false
if i%2 != 0 {
entropyBit = true
}
if i == 3 || i == 7 {
continue
}
expectedEntropy.Add(protocol.PacketNumber(i), entropyBit)
err := handler.ReceivedPacket(protocol.PacketNumber(i), entropyBit)
Expect(err).ToNot(HaveOccurred())
}
Expect(handler.largestObserved).To(Equal(protocol.PacketNumber(9)))
nackRanges, entropy := handler.getNackRanges()
Expect(nackRanges).To(HaveLen(2))
Expect(nackRanges[0]).To(Equal(frames.NackRange{FirstPacketNumber: 7, LastPacketNumber: 7}))
Expect(nackRanges[1]).To(Equal(frames.NackRange{FirstPacketNumber: 3, LastPacketNumber: 3}))
Expect(handler.highestInOrderObserved).To(Equal(protocol.PacketNumber(2)))
Expect(entropy).To(Equal(expectedEntropy))
})
It("handles two sequences of lost packages", func() {
for i := 1; i < 10; i++ {
entropyBit := true
if i == 2 || i == 3 || i == 4 || i == 7 || i == 8 {
continue
}
expectedEntropy.Add(protocol.PacketNumber(i), entropyBit)
err := handler.ReceivedPacket(protocol.PacketNumber(i), entropyBit)
Expect(err).ToNot(HaveOccurred())
}
Expect(handler.largestObserved).To(Equal(protocol.PacketNumber(9)))
nackRanges, entropy := handler.getNackRanges()
Expect(nackRanges).To(HaveLen(2))
Expect(nackRanges[0]).To(Equal(frames.NackRange{FirstPacketNumber: 7, LastPacketNumber: 8}))
Expect(nackRanges[1]).To(Equal(frames.NackRange{FirstPacketNumber: 2, LastPacketNumber: 4}))
Expect(handler.highestInOrderObserved).To(Equal(protocol.PacketNumber(1)))
Expect(entropy).To(Equal(expectedEntropy))
})
})
Context("handling STOP_WAITING frames", func() {
It("resets the entropy", func() {
// We simulate 20 packets, numbers 10, 11 and 12 lost
expectedAfterStopWaiting := EntropyAccumulator(0)
for i := 1; i < 20; i++ {
entropyBit := false
if i%3 == 0 || i%5 == 0 {
entropyBit = true
}
if i == 10 || i == 11 || i == 12 {
continue
}
if i > 12 {
expectedAfterStopWaiting.Add(protocol.PacketNumber(i), entropyBit)
}
err := handler.ReceivedPacket(protocol.PacketNumber(i), entropyBit)
Expect(err).ToNot(HaveOccurred())
}
err := handler.ReceivedStopWaiting(&frames.StopWaitingFrame{Entropy: 42, LeastUnacked: protocol.PacketNumber(12)})
Expect(err).ToNot(HaveOccurred())
_, e := handler.getNackRanges()
Expect(e).To(Equal(42 ^ expectedAfterStopWaiting))
Expect(handler.highestInOrderObserved).To(Equal(protocol.PacketNumber(11)))
Expect(handler.highestInOrderObservedEntropy).To(Equal(EntropyAccumulator(42)))
})
It("does not emit NACK ranges after STOP_WAITING", func() {
err := handler.ReceivedPacket(10, false)
Expect(err).ToNot(HaveOccurred())
ranges, _ := handler.getNackRanges()
Expect(ranges).To(HaveLen(1))
err = handler.ReceivedStopWaiting(&frames.StopWaitingFrame{Entropy: 0, LeastUnacked: protocol.PacketNumber(10)})
Expect(err).ToNot(HaveOccurred())
ranges, _ = handler.getNackRanges()
Expect(ranges).To(BeEmpty())
})
})
Context("ACK package generation", func() {
It("generates a simple ACK frame", func() {
entropy := EntropyAccumulator(0)
entropy.Add(1, true)
entropy.Add(2, true)
err := handler.ReceivedPacket(protocol.PacketNumber(1), true)
Expect(err).ToNot(HaveOccurred())
err = handler.ReceivedPacket(protocol.PacketNumber(2), true)
Expect(err).ToNot(HaveOccurred())
ack, err := handler.GetAckFrame(true)
Expect(err).ToNot(HaveOccurred())
Expect(ack.LargestObserved).To(Equal(protocol.PacketNumber(2)))
Expect(ack.Entropy).To(Equal(byte(entropy)))
})
It("generates an ACK frame with a NACK range", func() {
entropy := EntropyAccumulator(0)
entropy.Add(1, true)
entropy.Add(4, true)
err := handler.ReceivedPacket(protocol.PacketNumber(1), true)
Expect(err).ToNot(HaveOccurred())
err = handler.ReceivedPacket(protocol.PacketNumber(4), true)
Expect(err).ToNot(HaveOccurred())
ack, err := handler.GetAckFrame(true)
Expect(err).ToNot(HaveOccurred())
Expect(ack.LargestObserved).To(Equal(protocol.PacketNumber(4)))
Expect(ack.Entropy).To(Equal(byte(entropy)))
Expect(ack.NackRanges).To(Equal([]frames.NackRange{{FirstPacketNumber: 2, LastPacketNumber: 3}}))
})
It("does not generate an ACK if an ACK has already been sent for the largest Packet", func() {
err := handler.ReceivedPacket(protocol.PacketNumber(1), false)
Expect(err).ToNot(HaveOccurred())
err = handler.ReceivedPacket(protocol.PacketNumber(2), false)
Expect(err).ToNot(HaveOccurred())
ack, err := handler.GetAckFrame(true)
Expect(err).ToNot(HaveOccurred())
Expect(ack).ToNot(BeNil())
ack, err = handler.GetAckFrame(true)
Expect(err).ToNot(HaveOccurred())
Expect(ack).To(BeNil())
})
It("does not dequeue an ACK frame if told so", func() {
err := handler.ReceivedPacket(protocol.PacketNumber(2), false)
Expect(err).ToNot(HaveOccurred())
ack, err := handler.GetAckFrame(false)
Expect(err).ToNot(HaveOccurred())
Expect(ack).ToNot(BeNil())
ack, err = handler.GetAckFrame(false)
Expect(err).ToNot(HaveOccurred())
Expect(ack).ToNot(BeNil())
ack, err = handler.GetAckFrame(false)
Expect(err).ToNot(HaveOccurred())
Expect(ack).ToNot(BeNil())
})
It("returns a cached ACK frame if the ACK was not dequeued", func() {
err := handler.ReceivedPacket(protocol.PacketNumber(2), false)
Expect(err).ToNot(HaveOccurred())
ack, err := handler.GetAckFrame(false)
Expect(err).ToNot(HaveOccurred())
Expect(ack).ToNot(BeNil())
ack2, err := handler.GetAckFrame(false)
Expect(err).ToNot(HaveOccurred())
Expect(ack2).ToNot(BeNil())
Expect(&ack).To(Equal(&ack2))
})
It("generates a new ACK (and deletes the cached one) when a new packet arrives", func() {
err := handler.ReceivedPacket(protocol.PacketNumber(1), false)
Expect(err).ToNot(HaveOccurred())
ack, _ := handler.GetAckFrame(true)
Expect(ack).ToNot(BeNil())
Expect(ack.LargestObserved).To(Equal(protocol.PacketNumber(1)))
err = handler.ReceivedPacket(protocol.PacketNumber(3), false)
Expect(err).ToNot(HaveOccurred())
ack, _ = handler.GetAckFrame(true)
Expect(ack).ToNot(BeNil())
Expect(ack.LargestObserved).To(Equal(protocol.PacketNumber(3)))
})
It("generates a new ACK when an out-of-order packet arrives", func() {
err := handler.ReceivedPacket(protocol.PacketNumber(1), false)
Expect(err).ToNot(HaveOccurred())
err = handler.ReceivedPacket(protocol.PacketNumber(3), false)
Expect(err).ToNot(HaveOccurred())
ack, _ := handler.GetAckFrame(true)
Expect(ack).ToNot(BeNil())
Expect(ack.NackRanges).To(HaveLen(1))
err = handler.ReceivedPacket(protocol.PacketNumber(2), false)
Expect(err).ToNot(HaveOccurred())
ack, _ = handler.GetAckFrame(true)
Expect(ack).ToNot(BeNil())
Expect(ack.NackRanges).To(BeEmpty())
})
})
Context("Garbage Collector", func() {
It("only keeps packets with packet numbers higher than the highestInOrderObserved in packetHistory", func() {
handler.ReceivedPacket(1, true)
handler.ReceivedPacket(2, true)
handler.ReceivedPacket(4, true)
Expect(handler.packetHistory).ToNot(HaveKey(protocol.PacketNumber(1)))
Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(2)))
Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(4)))
})
It("garbage collects packetHistory after receiving a StopWaiting", func() {
handler.ReceivedPacket(1, true)
handler.ReceivedPacket(2, true)
handler.ReceivedPacket(4, true)
swf := frames.StopWaitingFrame{LeastUnacked: 4}
handler.ReceivedStopWaiting(&swf)
Expect(handler.packetHistory).ToNot(HaveKey(protocol.PacketNumber(1)))
Expect(handler.packetHistory).ToNot(HaveKey(protocol.PacketNumber(2)))
Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(4)))
})
})
})