Discard old packets from the QuicSentPacketManager which are only

net/quic/quic_unacked_packet_map_test.cc

 // 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:
@@ skipping 86 matching lines @@
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(NULL, 0);
   VerifyRetransmittablePackets(NULL, 0);
 
   unacked_packets_.IncreaseLargestObserved(1);
   VerifyUnackedPackets(NULL, 0);
   VerifyInFlightPackets(NULL, 0);
   VerifyRetransmittablePackets(NULL, 0);
 }
 
+TEST_F(QuicUnackedPacketMapTest, DiscardOldRttOnly) {
+  // Acks are only tracked for RTT measurement purposes, and are discarded
+  // when more than 200 accumulate.
+  for (int i = 1; i < 400; ++i) {
+    unacked_packets_.AddPacket(CreateNonRetransmittablePacket(i));
+    unacked_packets_.SetSent(i, now_, kDefaultAckLength, false);
+    unacked_packets_.RemoveObsoletePackets();
+    EXPECT_EQ(static_cast<size_t>(min(i, 200)),
+              unacked_packets_.GetNumUnackedPacketsDebugOnly());
+  }
+}
+
 TEST_F(QuicUnackedPacketMapTest, RetransmittableInflightAndRtt) {
   // Simulate a retransmittable packet being sent and acked.
   unacked_packets_.AddPacket(CreateRetransmittablePacket(1));
   unacked_packets_.SetSent(1, now_, kDefaultLength, true);
 
   QuicPacketSequenceNumber unacked[] = { 1 };
   VerifyUnackedPackets(unacked, arraysize(unacked));
   VerifyInFlightPackets(unacked, arraysize(unacked));
   VerifyRetransmittablePackets(unacked, arraysize(unacked));
 
@@ skipping 119 matching lines @@
   unacked_packets_.ClearPreviousRetransmissions(5);
   QuicPacketSequenceNumber unacked5[] = { 7 };
   VerifyUnackedPackets(unacked5, arraysize(unacked5));
   QuicPacketSequenceNumber retransmittable5[] = { 7 };
   VerifyRetransmittablePackets(retransmittable5, arraysize(retransmittable5));
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net