net/quic/quic_unacked_packet_map_test.cc - platform/external/chromium_org - Git at Google

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "net/quic/quic_unacked_packet_map.h"

 #include "net/quic/test_tools/quic_test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"

 using std::min;

 namespace net {
 namespace test {
 namespace {

 // Default packet length.
 const uint32 kDefaultAckLength = 50;
 const uint32 kDefaultLength = 1000;

 class QuicUnackedPacketMapTest : public ::testing::Test {
  protected:
   QuicUnackedPacketMapTest()
       : now_(QuicTime::Zero().Add(QuicTime::Delta::FromMilliseconds(1000))) {
   }

   SerializedPacket CreateRetransmittablePacket(
       QuicPacketSequenceNumber sequence_number) {
     return SerializedPacket(sequence_number, PACKET_1BYTE_SEQUENCE_NUMBER,
                             nullptr, 0, new RetransmittableFrames());
   }

   SerializedPacket CreateNonRetransmittablePacket(
       QuicPacketSequenceNumber sequence_number) {
     return SerializedPacket(sequence_number, PACKET_1BYTE_SEQUENCE_NUMBER,
                             nullptr, 0, nullptr);
   }

   void VerifyInFlightPackets(QuicPacketSequenceNumber* packets,
                              size_t num_packets) {
     unacked_packets_.RemoveObsoletePackets();
     if (num_packets == 0) {
       EXPECT_FALSE(unacked_packets_.HasInFlightPackets());
       EXPECT_FALSE(unacked_packets_.HasMultipleInFlightPackets());
       return;
     }
     if (num_packets == 1) {
       EXPECT_TRUE(unacked_packets_.HasInFlightPackets());
       EXPECT_FALSE(unacked_packets_.HasMultipleInFlightPackets());
       ASSERT_TRUE(unacked_packets_.IsUnacked(packets[0]));
       EXPECT_TRUE(unacked_packets_.GetTransmissionInfo(packets[0]).in_flight);
     }
     for (size_t i = 0; i < num_packets; ++i) {
       ASSERT_TRUE(unacked_packets_.IsUnacked(packets[i]));
       EXPECT_TRUE(unacked_packets_.GetTransmissionInfo(packets[i]).in_flight);
     }
     size_t in_flight_count = 0;
     for (QuicUnackedPacketMap::const_iterator it = unacked_packets_.begin();
          it != unacked_packets_.end(); ++it) {
       if (it->in_flight) {
         ++in_flight_count;
       }
     }
     EXPECT_EQ(num_packets, in_flight_count);
   }

   void VerifyUnackedPackets(QuicPacketSequenceNumber* packets,
                             size_t num_packets) {
     unacked_packets_.RemoveObsoletePackets();
     if (num_packets == 0) {
       EXPECT_FALSE(unacked_packets_.HasUnackedPackets());
       EXPECT_FALSE(unacked_packets_.HasUnackedRetransmittableFrames());
       return;
     }
     EXPECT_TRUE(unacked_packets_.HasUnackedPackets());
     for (size_t i = 0; i < num_packets; ++i) {
       EXPECT_TRUE(unacked_packets_.IsUnacked(packets[i])) << packets[i];
     }
     EXPECT_EQ(num_packets, unacked_packets_.GetNumUnackedPacketsDebugOnly());
   }

   void VerifyRetransmittablePackets(QuicPacketSequenceNumber* packets,
                                     size_t num_packets) {
     unacked_packets_.RemoveObsoletePackets();
     size_t num_retransmittable_packets = 0;
     for (QuicUnackedPacketMap::const_iterator it = unacked_packets_.begin();
          it != unacked_packets_.end(); ++it) {
       if (it->retransmittable_frames != nullptr) {
         ++num_retransmittable_packets;
       }
     }
     EXPECT_EQ(num_packets, num_retransmittable_packets);
     for (size_t i = 0; i < num_packets; ++i) {
       EXPECT_TRUE(unacked_packets_.HasRetransmittableFrames(packets[i]))
           << " packets[" << i << "]:" << packets[i];
     }
   }

   QuicUnackedPacketMap unacked_packets_;
   QuicTime now_;
 };

 TEST_F(QuicUnackedPacketMapTest, RttOnly) {
   // Acks are only tracked for RTT measurement purposes.
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(1), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultAckLength,
                                  false);

   QuicPacketSequenceNumber unacked[] = { 1 };
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(nullptr, 0);
   VerifyRetransmittablePackets(nullptr, 0);

   unacked_packets_.IncreaseLargestObserved(1);
   VerifyUnackedPackets(nullptr, 0);
   VerifyInFlightPackets(nullptr, 0);
   VerifyRetransmittablePackets(nullptr, 0);
 }

 TEST_F(QuicUnackedPacketMapTest, DiscardOldRttOnly) {
   // Acks are only tracked for RTT measurement purposes, and are discarded
   // when more than 200 accumulate.
   const size_t kNumUnackedPackets = 200;
   for (size_t i = 1; i < 400; ++i) {
     unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(i), 0,
                                    NOT_RETRANSMISSION, now_, kDefaultAckLength,
                                    false);
     unacked_packets_.RemoveObsoletePackets();
     EXPECT_EQ(min(i, kNumUnackedPackets),
               unacked_packets_.GetNumUnackedPacketsDebugOnly());
   }
 }

 TEST_F(QuicUnackedPacketMapTest, RetransmittableInflightAndRtt) {
   // Simulate a retransmittable packet being sent and acked.
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked[] = { 1 };
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   VerifyRetransmittablePackets(unacked, arraysize(unacked));

   unacked_packets_.RemoveRetransmittability(1);
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   VerifyRetransmittablePackets(nullptr, 0);

   unacked_packets_.IncreaseLargestObserved(1);
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   VerifyRetransmittablePackets(nullptr, 0);

   unacked_packets_.RemoveFromInFlight(1);
   VerifyUnackedPackets(nullptr, 0);
   VerifyInFlightPackets(nullptr, 0);
   VerifyRetransmittablePackets(nullptr, 0);
 }

 TEST_F(QuicUnackedPacketMapTest, RetransmittedPacket) {
   // Simulate a retransmittable packet being sent, retransmitted, and the first
   // transmission being acked.
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(2), 1,
                                  LOSS_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked[] = { 1, 2 };
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   QuicPacketSequenceNumber retransmittable[] = { 2 };
   VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));

   unacked_packets_.RemoveRetransmittability(1);
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   VerifyRetransmittablePackets(nullptr, 0);

   unacked_packets_.IncreaseLargestObserved(2);
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   VerifyRetransmittablePackets(nullptr, 0);

   unacked_packets_.RemoveFromInFlight(2);
   QuicPacketSequenceNumber unacked2[] = { 1 };
   VerifyUnackedPackets(unacked, arraysize(unacked2));
   VerifyInFlightPackets(unacked, arraysize(unacked2));
   VerifyRetransmittablePackets(nullptr, 0);

   unacked_packets_.RemoveFromInFlight(1);
   VerifyUnackedPackets(nullptr, 0);
   VerifyInFlightPackets(nullptr, 0);
   VerifyRetransmittablePackets(nullptr, 0);
 }

 TEST_F(QuicUnackedPacketMapTest, RetransmitThreeTimes) {
   // Simulate a retransmittable packet being sent and retransmitted twice.
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(2), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked[] = { 1, 2 };
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   QuicPacketSequenceNumber retransmittable[] = { 1, 2 };
   VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));

   // Early retransmit 1 as 3 and send new data as 4.
   unacked_packets_.IncreaseLargestObserved(2);
   unacked_packets_.RemoveFromInFlight(2);
   unacked_packets_.RemoveRetransmittability(2);
   unacked_packets_.RemoveFromInFlight(1);
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(3), 1,
                                  LOSS_RETRANSMISSION, now_, kDefaultLength,
                                  true);
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(4), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked2[] = { 1, 3, 4 };
   VerifyUnackedPackets(unacked2, arraysize(unacked2));
   QuicPacketSequenceNumber pending2[] = { 3, 4, };
   VerifyInFlightPackets(pending2, arraysize(pending2));
   QuicPacketSequenceNumber retransmittable2[] = { 3, 4 };
   VerifyRetransmittablePackets(retransmittable2, arraysize(retransmittable2));

   // Early retransmit 3 (formerly 1) as 5, and remove 1 from unacked.
   unacked_packets_.IncreaseLargestObserved(4);
   unacked_packets_.RemoveFromInFlight(4);
   unacked_packets_.RemoveRetransmittability(4);
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(5), 3,
                                  LOSS_RETRANSMISSION, now_, kDefaultLength,
                                  true);
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(6), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked3[] = { 3, 5, 6 };
   VerifyUnackedPackets(unacked3, arraysize(unacked3));
   QuicPacketSequenceNumber pending3[] = { 3, 5, 6 };
   VerifyInFlightPackets(pending3, arraysize(pending3));
   QuicPacketSequenceNumber retransmittable3[] = { 5, 6 };
   VerifyRetransmittablePackets(retransmittable3, arraysize(retransmittable3));

   // Early retransmit 5 as 7 and ensure in flight packet 3 is not removed.
   unacked_packets_.IncreaseLargestObserved(6);
   unacked_packets_.RemoveFromInFlight(6);
   unacked_packets_.RemoveRetransmittability(6);
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(7), 5,
                                  LOSS_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked4[] = { 3, 5, 7 };
   VerifyUnackedPackets(unacked4, arraysize(unacked4));
   QuicPacketSequenceNumber pending4[] = { 3, 5, 7 };
   VerifyInFlightPackets(pending4, arraysize(pending4));
   QuicPacketSequenceNumber retransmittable4[] = { 7 };
   VerifyRetransmittablePackets(retransmittable4, arraysize(retransmittable4));

   // Remove the older two transmissions from in flight.
   unacked_packets_.RemoveFromInFlight(3);
   unacked_packets_.RemoveFromInFlight(5);
   QuicPacketSequenceNumber pending5[] = { 7 };
   VerifyInFlightPackets(pending5, arraysize(pending5));

   // Now test ClearAllPreviousTransmissions, leaving one packet.
   unacked_packets_.ClearAllPreviousRetransmissions();
   QuicPacketSequenceNumber unacked5[] = { 7 };
   VerifyUnackedPackets(unacked5, arraysize(unacked5));
   QuicPacketSequenceNumber retransmittable5[] = { 7 };
   VerifyRetransmittablePackets(retransmittable5, arraysize(retransmittable5));
 }

 TEST_F(QuicUnackedPacketMapTest, RetransmitFourTimes) {
   // Simulate a retransmittable packet being sent and retransmitted twice.
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(2), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked[] = { 1, 2 };
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   QuicPacketSequenceNumber retransmittable[] = { 1, 2 };
   VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));

   // Early retransmit 1 as 3.
   unacked_packets_.IncreaseLargestObserved(2);
   unacked_packets_.RemoveFromInFlight(2);
   unacked_packets_.RemoveRetransmittability(2);
   unacked_packets_.RemoveFromInFlight(1);
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(3), 1,
                                  LOSS_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked2[] = { 1, 3 };
   VerifyUnackedPackets(unacked2, arraysize(unacked2));
   QuicPacketSequenceNumber pending2[] = { 3 };
   VerifyInFlightPackets(pending2, arraysize(pending2));
   QuicPacketSequenceNumber retransmittable2[] = { 3 };
   VerifyRetransmittablePackets(retransmittable2, arraysize(retransmittable2));

   // TLP 3 (formerly 1) as 4, and don't remove 1 from unacked.
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(4), 3,
                                  TLP_RETRANSMISSION, now_, kDefaultLength,
                                  true);
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(5), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked3[] = { 1, 3, 4, 5 };
   VerifyUnackedPackets(unacked3, arraysize(unacked3));
   QuicPacketSequenceNumber pending3[] = { 3, 4, 5 };
   VerifyInFlightPackets(pending3, arraysize(pending3));
   QuicPacketSequenceNumber retransmittable3[] = { 4, 5 };
   VerifyRetransmittablePackets(retransmittable3, arraysize(retransmittable3));

   // Early retransmit 4 as 6 and ensure in flight packet 3 is removed.
   unacked_packets_.IncreaseLargestObserved(5);
   unacked_packets_.RemoveFromInFlight(5);
   unacked_packets_.RemoveRetransmittability(5);
   unacked_packets_.RemoveFromInFlight(3);
   unacked_packets_.RemoveFromInFlight(4);
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(6), 4,
                                  LOSS_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked4[] = { 4, 6 };
   VerifyUnackedPackets(unacked4, arraysize(unacked4));
   QuicPacketSequenceNumber pending4[] = { 6 };
   VerifyInFlightPackets(pending4, arraysize(pending4));
   QuicPacketSequenceNumber retransmittable4[] = { 6 };
   VerifyRetransmittablePackets(retransmittable4, arraysize(retransmittable4));
 }

 TEST_F(QuicUnackedPacketMapTest, RestoreInflight) {
   // Simulate a retransmittable packet being sent, retransmitted, and the first
   // transmission being acked.
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);
   unacked_packets_.RemoveFromInFlight(1);
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(2), 1,
                                  RTO_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   QuicPacketSequenceNumber unacked[] = { 1, 2 };
   VerifyUnackedPackets(unacked, arraysize(unacked));
   QuicPacketSequenceNumber retransmittable[] = { 2 };
   VerifyInFlightPackets(retransmittable, arraysize(retransmittable));
   VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));
   EXPECT_EQ(kDefaultLength, unacked_packets_.bytes_in_flight());

   // Simulate an F-RTO, and restore 1 to flight.
   unacked_packets_.RestoreInFlight(1);
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));
   EXPECT_EQ(2 * kDefaultLength, unacked_packets_.bytes_in_flight());
 }

 TEST_F(QuicUnackedPacketMapTest, SendWithGap) {
   // Simulate a retransmittable packet being sent, retransmitted, and the first
   // transmission being acked.
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);
   unacked_packets_.AddSentPacket(CreateRetransmittablePacket(3), 0,
                                  NOT_RETRANSMISSION, now_, kDefaultLength,
                                  true);
   unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(5), 3,
                                  LOSS_RETRANSMISSION, now_, kDefaultLength,
                                  true);

   EXPECT_EQ(1u, unacked_packets_.GetLeastUnacked());
   EXPECT_TRUE(unacked_packets_.IsUnacked(1));
   EXPECT_FALSE(unacked_packets_.IsUnacked(2));
   EXPECT_TRUE(unacked_packets_.IsUnacked(3));
   EXPECT_FALSE(unacked_packets_.IsUnacked(4));
   EXPECT_TRUE(unacked_packets_.IsUnacked(5));
   EXPECT_EQ(5u, unacked_packets_.largest_sent_packet());
 }


 }  // namespace
 }  // namespace test
 }  // namespace net
	// Copyright 2014 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "net/quic/quic_unacked_packet_map.h"

	#include "net/quic/test_tools/quic_test_utils.h"
	#include "testing/gtest/include/gtest/gtest.h"

	using std::min;

	namespace net {
	namespace test {
	namespace {

	// Default packet length.
	const uint32 kDefaultAckLength = 50;
	const uint32 kDefaultLength = 1000;

	class QuicUnackedPacketMapTest : public ::testing::Test {
	protected:
	QuicUnackedPacketMapTest()
	: now_(QuicTime::Zero().Add(QuicTime::Delta::FromMilliseconds(1000))) {
	}

	SerializedPacket CreateRetransmittablePacket(
	QuicPacketSequenceNumber sequence_number) {
	return SerializedPacket(sequence_number, PACKET_1BYTE_SEQUENCE_NUMBER,
	nullptr, 0, new RetransmittableFrames());
	}

	SerializedPacket CreateNonRetransmittablePacket(
	QuicPacketSequenceNumber sequence_number) {
	return SerializedPacket(sequence_number, PACKET_1BYTE_SEQUENCE_NUMBER,
	nullptr, 0, nullptr);
	}

	void VerifyInFlightPackets(QuicPacketSequenceNumber* packets,
	size_t num_packets) {
	unacked_packets_.RemoveObsoletePackets();
	if (num_packets == 0) {
	EXPECT_FALSE(unacked_packets_.HasInFlightPackets());
	EXPECT_FALSE(unacked_packets_.HasMultipleInFlightPackets());
	return;
	}
	if (num_packets == 1) {
	EXPECT_TRUE(unacked_packets_.HasInFlightPackets());
	EXPECT_FALSE(unacked_packets_.HasMultipleInFlightPackets());
	ASSERT_TRUE(unacked_packets_.IsUnacked(packets[0]));
	EXPECT_TRUE(unacked_packets_.GetTransmissionInfo(packets[0]).in_flight);
	}
	for (size_t i = 0; i < num_packets; ++i) {
	ASSERT_TRUE(unacked_packets_.IsUnacked(packets[i]));
	EXPECT_TRUE(unacked_packets_.GetTransmissionInfo(packets[i]).in_flight);
	}
	size_t in_flight_count = 0;
	for (QuicUnackedPacketMap::const_iterator it = unacked_packets_.begin();
	it != unacked_packets_.end(); ++it) {
	if (it->in_flight) {
	++in_flight_count;
	}
	}
	EXPECT_EQ(num_packets, in_flight_count);
	}

	void VerifyUnackedPackets(QuicPacketSequenceNumber* packets,
	size_t num_packets) {
	unacked_packets_.RemoveObsoletePackets();
	if (num_packets == 0) {
	EXPECT_FALSE(unacked_packets_.HasUnackedPackets());
	EXPECT_FALSE(unacked_packets_.HasUnackedRetransmittableFrames());
	return;
	}
	EXPECT_TRUE(unacked_packets_.HasUnackedPackets());
	for (size_t i = 0; i < num_packets; ++i) {
	EXPECT_TRUE(unacked_packets_.IsUnacked(packets[i])) << packets[i];
	}
	EXPECT_EQ(num_packets, unacked_packets_.GetNumUnackedPacketsDebugOnly());
	}

	void VerifyRetransmittablePackets(QuicPacketSequenceNumber* packets,
	size_t num_packets) {
	unacked_packets_.RemoveObsoletePackets();
	size_t num_retransmittable_packets = 0;
	for (QuicUnackedPacketMap::const_iterator it = unacked_packets_.begin();
	it != unacked_packets_.end(); ++it) {
	if (it->retransmittable_frames != nullptr) {
	++num_retransmittable_packets;
	}
	}
	EXPECT_EQ(num_packets, num_retransmittable_packets);
	for (size_t i = 0; i < num_packets; ++i) {
	EXPECT_TRUE(unacked_packets_.HasRetransmittableFrames(packets[i]))
	<< " packets[" << i << "]:" << packets[i];
	}
	}

	QuicUnackedPacketMap unacked_packets_;
	QuicTime now_;
	};

	TEST_F(QuicUnackedPacketMapTest, RttOnly) {
	// Acks are only tracked for RTT measurement purposes.
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(1), 0,
	NOT_RETRANSMISSION, now_, kDefaultAckLength,
	false);

	QuicPacketSequenceNumber unacked[] = { 1 };
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(nullptr, 0);
	VerifyRetransmittablePackets(nullptr, 0);

	unacked_packets_.IncreaseLargestObserved(1);
	VerifyUnackedPackets(nullptr, 0);
	VerifyInFlightPackets(nullptr, 0);
	VerifyRetransmittablePackets(nullptr, 0);
	}

	TEST_F(QuicUnackedPacketMapTest, DiscardOldRttOnly) {
	// Acks are only tracked for RTT measurement purposes, and are discarded
	// when more than 200 accumulate.
	const size_t kNumUnackedPackets = 200;
	for (size_t i = 1; i < 400; ++i) {
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(i), 0,
	NOT_RETRANSMISSION, now_, kDefaultAckLength,
	false);
	unacked_packets_.RemoveObsoletePackets();
	EXPECT_EQ(min(i, kNumUnackedPackets),
	unacked_packets_.GetNumUnackedPacketsDebugOnly());
	}
	}

	TEST_F(QuicUnackedPacketMapTest, RetransmittableInflightAndRtt) {
	// Simulate a retransmittable packet being sent and acked.
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked[] = { 1 };
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(unacked, arraysize(unacked));
	VerifyRetransmittablePackets(unacked, arraysize(unacked));

	unacked_packets_.RemoveRetransmittability(1);
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(unacked, arraysize(unacked));
	VerifyRetransmittablePackets(nullptr, 0);

	unacked_packets_.IncreaseLargestObserved(1);
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(unacked, arraysize(unacked));
	VerifyRetransmittablePackets(nullptr, 0);

	unacked_packets_.RemoveFromInFlight(1);
	VerifyUnackedPackets(nullptr, 0);
	VerifyInFlightPackets(nullptr, 0);
	VerifyRetransmittablePackets(nullptr, 0);
	}

	TEST_F(QuicUnackedPacketMapTest, RetransmittedPacket) {
	// Simulate a retransmittable packet being sent, retransmitted, and the first
	// transmission being acked.
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(2), 1,
	LOSS_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked[] = { 1, 2 };
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(unacked, arraysize(unacked));
	QuicPacketSequenceNumber retransmittable[] = { 2 };
	VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));

	unacked_packets_.RemoveRetransmittability(1);
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(unacked, arraysize(unacked));
	VerifyRetransmittablePackets(nullptr, 0);

	unacked_packets_.IncreaseLargestObserved(2);
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(unacked, arraysize(unacked));
	VerifyRetransmittablePackets(nullptr, 0);

	unacked_packets_.RemoveFromInFlight(2);
	QuicPacketSequenceNumber unacked2[] = { 1 };
	VerifyUnackedPackets(unacked, arraysize(unacked2));
	VerifyInFlightPackets(unacked, arraysize(unacked2));
	VerifyRetransmittablePackets(nullptr, 0);

	unacked_packets_.RemoveFromInFlight(1);
	VerifyUnackedPackets(nullptr, 0);
	VerifyInFlightPackets(nullptr, 0);
	VerifyRetransmittablePackets(nullptr, 0);
	}

	TEST_F(QuicUnackedPacketMapTest, RetransmitThreeTimes) {
	// Simulate a retransmittable packet being sent and retransmitted twice.
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(2), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked[] = { 1, 2 };
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(unacked, arraysize(unacked));
	QuicPacketSequenceNumber retransmittable[] = { 1, 2 };
	VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));

	// Early retransmit 1 as 3 and send new data as 4.
	unacked_packets_.IncreaseLargestObserved(2);
	unacked_packets_.RemoveFromInFlight(2);
	unacked_packets_.RemoveRetransmittability(2);
	unacked_packets_.RemoveFromInFlight(1);
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(3), 1,
	LOSS_RETRANSMISSION, now_, kDefaultLength,
	true);
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(4), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked2[] = { 1, 3, 4 };
	VerifyUnackedPackets(unacked2, arraysize(unacked2));
	QuicPacketSequenceNumber pending2[] = { 3, 4, };
	VerifyInFlightPackets(pending2, arraysize(pending2));
	QuicPacketSequenceNumber retransmittable2[] = { 3, 4 };
	VerifyRetransmittablePackets(retransmittable2, arraysize(retransmittable2));

	// Early retransmit 3 (formerly 1) as 5, and remove 1 from unacked.
	unacked_packets_.IncreaseLargestObserved(4);
	unacked_packets_.RemoveFromInFlight(4);
	unacked_packets_.RemoveRetransmittability(4);
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(5), 3,
	LOSS_RETRANSMISSION, now_, kDefaultLength,
	true);
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(6), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked3[] = { 3, 5, 6 };
	VerifyUnackedPackets(unacked3, arraysize(unacked3));
	QuicPacketSequenceNumber pending3[] = { 3, 5, 6 };
	VerifyInFlightPackets(pending3, arraysize(pending3));
	QuicPacketSequenceNumber retransmittable3[] = { 5, 6 };
	VerifyRetransmittablePackets(retransmittable3, arraysize(retransmittable3));

	// Early retransmit 5 as 7 and ensure in flight packet 3 is not removed.
	unacked_packets_.IncreaseLargestObserved(6);
	unacked_packets_.RemoveFromInFlight(6);
	unacked_packets_.RemoveRetransmittability(6);
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(7), 5,
	LOSS_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked4[] = { 3, 5, 7 };
	VerifyUnackedPackets(unacked4, arraysize(unacked4));
	QuicPacketSequenceNumber pending4[] = { 3, 5, 7 };
	VerifyInFlightPackets(pending4, arraysize(pending4));
	QuicPacketSequenceNumber retransmittable4[] = { 7 };
	VerifyRetransmittablePackets(retransmittable4, arraysize(retransmittable4));

	// Remove the older two transmissions from in flight.
	unacked_packets_.RemoveFromInFlight(3);
	unacked_packets_.RemoveFromInFlight(5);
	QuicPacketSequenceNumber pending5[] = { 7 };
	VerifyInFlightPackets(pending5, arraysize(pending5));

	// Now test ClearAllPreviousTransmissions, leaving one packet.
	unacked_packets_.ClearAllPreviousRetransmissions();
	QuicPacketSequenceNumber unacked5[] = { 7 };
	VerifyUnackedPackets(unacked5, arraysize(unacked5));
	QuicPacketSequenceNumber retransmittable5[] = { 7 };
	VerifyRetransmittablePackets(retransmittable5, arraysize(retransmittable5));
	}

	TEST_F(QuicUnackedPacketMapTest, RetransmitFourTimes) {
	// Simulate a retransmittable packet being sent and retransmitted twice.
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(2), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked[] = { 1, 2 };
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(unacked, arraysize(unacked));
	QuicPacketSequenceNumber retransmittable[] = { 1, 2 };
	VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));

	// Early retransmit 1 as 3.
	unacked_packets_.IncreaseLargestObserved(2);
	unacked_packets_.RemoveFromInFlight(2);
	unacked_packets_.RemoveRetransmittability(2);
	unacked_packets_.RemoveFromInFlight(1);
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(3), 1,
	LOSS_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked2[] = { 1, 3 };
	VerifyUnackedPackets(unacked2, arraysize(unacked2));
	QuicPacketSequenceNumber pending2[] = { 3 };
	VerifyInFlightPackets(pending2, arraysize(pending2));
	QuicPacketSequenceNumber retransmittable2[] = { 3 };
	VerifyRetransmittablePackets(retransmittable2, arraysize(retransmittable2));

	// TLP 3 (formerly 1) as 4, and don't remove 1 from unacked.
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(4), 3,
	TLP_RETRANSMISSION, now_, kDefaultLength,
	true);
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(5), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked3[] = { 1, 3, 4, 5 };
	VerifyUnackedPackets(unacked3, arraysize(unacked3));
	QuicPacketSequenceNumber pending3[] = { 3, 4, 5 };
	VerifyInFlightPackets(pending3, arraysize(pending3));
	QuicPacketSequenceNumber retransmittable3[] = { 4, 5 };
	VerifyRetransmittablePackets(retransmittable3, arraysize(retransmittable3));

	// Early retransmit 4 as 6 and ensure in flight packet 3 is removed.
	unacked_packets_.IncreaseLargestObserved(5);
	unacked_packets_.RemoveFromInFlight(5);
	unacked_packets_.RemoveRetransmittability(5);
	unacked_packets_.RemoveFromInFlight(3);
	unacked_packets_.RemoveFromInFlight(4);
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(6), 4,
	LOSS_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked4[] = { 4, 6 };
	VerifyUnackedPackets(unacked4, arraysize(unacked4));
	QuicPacketSequenceNumber pending4[] = { 6 };
	VerifyInFlightPackets(pending4, arraysize(pending4));
	QuicPacketSequenceNumber retransmittable4[] = { 6 };
	VerifyRetransmittablePackets(retransmittable4, arraysize(retransmittable4));
	}

	TEST_F(QuicUnackedPacketMapTest, RestoreInflight) {
	// Simulate a retransmittable packet being sent, retransmitted, and the first
	// transmission being acked.
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);
	unacked_packets_.RemoveFromInFlight(1);
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(2), 1,
	RTO_RETRANSMISSION, now_, kDefaultLength,
	true);

	QuicPacketSequenceNumber unacked[] = { 1, 2 };
	VerifyUnackedPackets(unacked, arraysize(unacked));
	QuicPacketSequenceNumber retransmittable[] = { 2 };
	VerifyInFlightPackets(retransmittable, arraysize(retransmittable));
	VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));
	EXPECT_EQ(kDefaultLength, unacked_packets_.bytes_in_flight());

	// Simulate an F-RTO, and restore 1 to flight.
	unacked_packets_.RestoreInFlight(1);
	VerifyUnackedPackets(unacked, arraysize(unacked));
	VerifyInFlightPackets(unacked, arraysize(unacked));
	VerifyRetransmittablePackets(retransmittable, arraysize(retransmittable));
	EXPECT_EQ(2 * kDefaultLength, unacked_packets_.bytes_in_flight());
	}

	TEST_F(QuicUnackedPacketMapTest, SendWithGap) {
	// Simulate a retransmittable packet being sent, retransmitted, and the first
	// transmission being acked.
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(1), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);
	unacked_packets_.AddSentPacket(CreateRetransmittablePacket(3), 0,
	NOT_RETRANSMISSION, now_, kDefaultLength,
	true);
	unacked_packets_.AddSentPacket(CreateNonRetransmittablePacket(5), 3,
	LOSS_RETRANSMISSION, now_, kDefaultLength,
	true);

	EXPECT_EQ(1u, unacked_packets_.GetLeastUnacked());
	EXPECT_TRUE(unacked_packets_.IsUnacked(1));
	EXPECT_FALSE(unacked_packets_.IsUnacked(2));
	EXPECT_TRUE(unacked_packets_.IsUnacked(3));
	EXPECT_FALSE(unacked_packets_.IsUnacked(4));
	EXPECT_TRUE(unacked_packets_.IsUnacked(5));
	EXPECT_EQ(5u, unacked_packets_.largest_sent_packet());
	}


	} // namespace
	} // namespace test
	} // namespace net