Fork NackModule and RtpVideoStreamReceiver

Bug: webrtc:11595
Change-Id: I4d14c0bf9c32e09d1624099a256f2778afebd4df
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/175901
Commit-Queue: Tommi <tommi@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31337}
diff --git a/modules/video_coding/nack_module2_unittest.cc b/modules/video_coding/nack_module2_unittest.cc
new file mode 100644
index 0000000..ebc28ec
--- /dev/null
+++ b/modules/video_coding/nack_module2_unittest.cc
@@ -0,0 +1,371 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "modules/video_coding/nack_module2.h"
+
+#include <algorithm>
+#include <cstdint>
+#include <cstring>
+#include <memory>
+
+#include "system_wrappers/include/clock.h"
+#include "test/field_trial.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+class TestNackModule2 : public ::testing::TestWithParam<bool>,
+                        public NackSender,
+                        public KeyFrameRequestSender {
+ protected:
+  TestNackModule2()
+      : clock_(new SimulatedClock(0)),
+        field_trial_(GetParam()
+                         ? "WebRTC-ExponentialNackBackoff/enabled:true/"
+                         : "WebRTC-ExponentialNackBackoff/enabled:false/"),
+        nack_module_(clock_.get(), this, this),
+        keyframes_requested_(0) {}
+
+  void SetUp() override { nack_module_.UpdateRtt(kDefaultRttMs); }
+
+  void SendNack(const std::vector<uint16_t>& sequence_numbers,
+                bool buffering_allowed) override {
+    sent_nacks_.insert(sent_nacks_.end(), sequence_numbers.begin(),
+                       sequence_numbers.end());
+  }
+
+  void RequestKeyFrame() override { ++keyframes_requested_; }
+
+  static constexpr int64_t kDefaultRttMs = 20;
+  std::unique_ptr<SimulatedClock> clock_;
+  test::ScopedFieldTrials field_trial_;
+  NackModule2 nack_module_;
+  std::vector<uint16_t> sent_nacks_;
+  int keyframes_requested_;
+};
+
+TEST_P(TestNackModule2, NackOnePacket) {
+  nack_module_.OnReceivedPacket(1, false, false);
+  nack_module_.OnReceivedPacket(3, false, false);
+  EXPECT_EQ(1u, sent_nacks_.size());
+  EXPECT_EQ(2, sent_nacks_[0]);
+}
+
+TEST_P(TestNackModule2, WrappingSeqNum) {
+  nack_module_.OnReceivedPacket(0xfffe, false, false);
+  nack_module_.OnReceivedPacket(1, false, false);
+  EXPECT_EQ(2u, sent_nacks_.size());
+  EXPECT_EQ(0xffff, sent_nacks_[0]);
+  EXPECT_EQ(0, sent_nacks_[1]);
+}
+
+TEST_P(TestNackModule2, WrappingSeqNumClearToKeyframe) {
+  nack_module_.OnReceivedPacket(0xfffe, false, false);
+  nack_module_.OnReceivedPacket(1, false, false);
+  EXPECT_EQ(2u, sent_nacks_.size());
+  EXPECT_EQ(0xffff, sent_nacks_[0]);
+  EXPECT_EQ(0, sent_nacks_[1]);
+
+  sent_nacks_.clear();
+  nack_module_.OnReceivedPacket(2, true, false);
+  EXPECT_EQ(0u, sent_nacks_.size());
+
+  nack_module_.OnReceivedPacket(501, true, false);
+  EXPECT_EQ(498u, sent_nacks_.size());
+  for (int seq_num = 3; seq_num < 501; ++seq_num)
+    EXPECT_EQ(seq_num, sent_nacks_[seq_num - 3]);
+
+  sent_nacks_.clear();
+  nack_module_.OnReceivedPacket(1001, false, false);
+  EXPECT_EQ(499u, sent_nacks_.size());
+  for (int seq_num = 502; seq_num < 1001; ++seq_num)
+    EXPECT_EQ(seq_num, sent_nacks_[seq_num - 502]);
+
+  sent_nacks_.clear();
+  clock_->AdvanceTimeMilliseconds(100);
+  nack_module_.Process();
+  EXPECT_EQ(999u, sent_nacks_.size());
+  EXPECT_EQ(0xffff, sent_nacks_[0]);
+  EXPECT_EQ(0, sent_nacks_[1]);
+  for (int seq_num = 3; seq_num < 501; ++seq_num)
+    EXPECT_EQ(seq_num, sent_nacks_[seq_num - 1]);
+  for (int seq_num = 502; seq_num < 1001; ++seq_num)
+    EXPECT_EQ(seq_num, sent_nacks_[seq_num - 2]);
+
+  // Adding packet 1004 will cause the nack list to reach it's max limit.
+  // It will then clear all nacks up to the next keyframe (seq num 2),
+  // thus removing 0xffff and 0 from the nack list.
+  sent_nacks_.clear();
+  nack_module_.OnReceivedPacket(1004, false, false);
+  EXPECT_EQ(2u, sent_nacks_.size());
+  EXPECT_EQ(1002, sent_nacks_[0]);
+  EXPECT_EQ(1003, sent_nacks_[1]);
+
+  sent_nacks_.clear();
+  clock_->AdvanceTimeMilliseconds(100);
+  nack_module_.Process();
+  EXPECT_EQ(999u, sent_nacks_.size());
+  for (int seq_num = 3; seq_num < 501; ++seq_num)
+    EXPECT_EQ(seq_num, sent_nacks_[seq_num - 3]);
+  for (int seq_num = 502; seq_num < 1001; ++seq_num)
+    EXPECT_EQ(seq_num, sent_nacks_[seq_num - 4]);
+
+  // Adding packet 1007 will cause the nack module to overflow again, thus
+  // clearing everything up to 501 which is the next keyframe.
+  nack_module_.OnReceivedPacket(1007, false, false);
+  sent_nacks_.clear();
+  clock_->AdvanceTimeMilliseconds(100);
+  nack_module_.Process();
+  EXPECT_EQ(503u, sent_nacks_.size());
+  for (int seq_num = 502; seq_num < 1001; ++seq_num)
+    EXPECT_EQ(seq_num, sent_nacks_[seq_num - 502]);
+  EXPECT_EQ(1005, sent_nacks_[501]);
+  EXPECT_EQ(1006, sent_nacks_[502]);
+}
+
+TEST_P(TestNackModule2, DontBurstOnTimeSkip) {
+  nack_module_.Process();
+  clock_->AdvanceTimeMilliseconds(20);
+  EXPECT_EQ(0, nack_module_.TimeUntilNextProcess());
+  nack_module_.Process();
+
+  clock_->AdvanceTimeMilliseconds(100);
+  EXPECT_EQ(0, nack_module_.TimeUntilNextProcess());
+  nack_module_.Process();
+  EXPECT_EQ(20, nack_module_.TimeUntilNextProcess());
+
+  clock_->AdvanceTimeMilliseconds(19);
+  EXPECT_EQ(1, nack_module_.TimeUntilNextProcess());
+  clock_->AdvanceTimeMilliseconds(2);
+  nack_module_.Process();
+  EXPECT_EQ(19, nack_module_.TimeUntilNextProcess());
+
+  clock_->AdvanceTimeMilliseconds(19);
+  EXPECT_EQ(0, nack_module_.TimeUntilNextProcess());
+  nack_module_.Process();
+
+  clock_->AdvanceTimeMilliseconds(21);
+  EXPECT_EQ(0, nack_module_.TimeUntilNextProcess());
+  nack_module_.Process();
+  EXPECT_EQ(19, nack_module_.TimeUntilNextProcess());
+}
+
+TEST_P(TestNackModule2, ResendNack) {
+  nack_module_.OnReceivedPacket(1, false, false);
+  nack_module_.OnReceivedPacket(3, false, false);
+  size_t expected_nacks_sent = 1;
+  EXPECT_EQ(expected_nacks_sent, sent_nacks_.size());
+  EXPECT_EQ(2, sent_nacks_[0]);
+
+  if (GetParam()) {
+    // Retry has to wait at least 5ms by default.
+    nack_module_.UpdateRtt(1);
+    clock_->AdvanceTimeMilliseconds(4);
+    nack_module_.Process();  // Too early.
+    EXPECT_EQ(expected_nacks_sent, sent_nacks_.size());
+
+    clock_->AdvanceTimeMilliseconds(1);
+    nack_module_.Process();  // Now allowed.
+    EXPECT_EQ(++expected_nacks_sent, sent_nacks_.size());
+  } else {
+    nack_module_.UpdateRtt(1);
+    clock_->AdvanceTimeMilliseconds(1);
+    nack_module_.Process();  // Fast retransmit allowed.
+    EXPECT_EQ(++expected_nacks_sent, sent_nacks_.size());
+  }
+
+  // N:th try has to wait b^(N-1) * rtt by default.
+  const double b = GetParam() ? 1.25 : 1.0;
+  for (int i = 2; i < 10; ++i) {
+    // Change RTT, above the 40ms max for exponential backoff.
+    TimeDelta rtt = TimeDelta::Millis(160);  // + (i * 10 - 40)
+    nack_module_.UpdateRtt(rtt.ms());
+
+    // RTT gets capped at 160ms in backoff calculations.
+    TimeDelta expected_backoff_delay =
+        std::pow(b, i - 1) * std::min(rtt, TimeDelta::Millis(160));
+
+    // Move to one millisecond before next allowed NACK.
+    clock_->AdvanceTimeMilliseconds(expected_backoff_delay.ms() - 1);
+    nack_module_.Process();
+    EXPECT_EQ(expected_nacks_sent, sent_nacks_.size());
+
+    // Move to one millisecond after next allowed NACK.
+    // After rather than on to avoid rounding errors.
+    clock_->AdvanceTimeMilliseconds(2);
+    nack_module_.Process();  // Now allowed.
+    EXPECT_EQ(++expected_nacks_sent, sent_nacks_.size());
+  }
+
+  // Giving up after 10 tries.
+  clock_->AdvanceTimeMilliseconds(3000);
+  nack_module_.Process();
+  EXPECT_EQ(expected_nacks_sent, sent_nacks_.size());
+}
+
+TEST_P(TestNackModule2, ResendPacketMaxRetries) {
+  nack_module_.OnReceivedPacket(1, false, false);
+  nack_module_.OnReceivedPacket(3, false, false);
+  EXPECT_EQ(1u, sent_nacks_.size());
+  EXPECT_EQ(2, sent_nacks_[0]);
+
+  int backoff_factor = 1;
+  for (size_t retries = 1; retries < 10; ++retries) {
+    // Exponential backoff, so that we don't reject NACK because of time.
+    clock_->AdvanceTimeMilliseconds(backoff_factor * kDefaultRttMs);
+    backoff_factor *= 2;
+    nack_module_.Process();
+    EXPECT_EQ(retries + 1, sent_nacks_.size());
+  }
+
+  clock_->AdvanceTimeMilliseconds(backoff_factor * kDefaultRttMs);
+  nack_module_.Process();
+  EXPECT_EQ(10u, sent_nacks_.size());
+}
+
+TEST_P(TestNackModule2, TooLargeNackList) {
+  nack_module_.OnReceivedPacket(0, false, false);
+  nack_module_.OnReceivedPacket(1001, false, false);
+  EXPECT_EQ(1000u, sent_nacks_.size());
+  EXPECT_EQ(0, keyframes_requested_);
+  nack_module_.OnReceivedPacket(1003, false, false);
+  EXPECT_EQ(1000u, sent_nacks_.size());
+  EXPECT_EQ(1, keyframes_requested_);
+  nack_module_.OnReceivedPacket(1004, false, false);
+  EXPECT_EQ(1000u, sent_nacks_.size());
+  EXPECT_EQ(1, keyframes_requested_);
+}
+
+TEST_P(TestNackModule2, TooLargeNackListWithKeyFrame) {
+  nack_module_.OnReceivedPacket(0, false, false);
+  nack_module_.OnReceivedPacket(1, true, false);
+  nack_module_.OnReceivedPacket(1001, false, false);
+  EXPECT_EQ(999u, sent_nacks_.size());
+  EXPECT_EQ(0, keyframes_requested_);
+  nack_module_.OnReceivedPacket(1003, false, false);
+  EXPECT_EQ(1000u, sent_nacks_.size());
+  EXPECT_EQ(0, keyframes_requested_);
+  nack_module_.OnReceivedPacket(1005, false, false);
+  EXPECT_EQ(1000u, sent_nacks_.size());
+  EXPECT_EQ(1, keyframes_requested_);
+}
+
+TEST_P(TestNackModule2, ClearUpTo) {
+  nack_module_.OnReceivedPacket(0, false, false);
+  nack_module_.OnReceivedPacket(100, false, false);
+  EXPECT_EQ(99u, sent_nacks_.size());
+
+  sent_nacks_.clear();
+  clock_->AdvanceTimeMilliseconds(100);
+  nack_module_.ClearUpTo(50);
+  nack_module_.Process();
+  EXPECT_EQ(50u, sent_nacks_.size());
+  EXPECT_EQ(50, sent_nacks_[0]);
+}
+
+TEST_P(TestNackModule2, ClearUpToWrap) {
+  nack_module_.OnReceivedPacket(0xfff0, false, false);
+  nack_module_.OnReceivedPacket(0xf, false, false);
+  EXPECT_EQ(30u, sent_nacks_.size());
+
+  sent_nacks_.clear();
+  clock_->AdvanceTimeMilliseconds(100);
+  nack_module_.ClearUpTo(0);
+  nack_module_.Process();
+  EXPECT_EQ(15u, sent_nacks_.size());
+  EXPECT_EQ(0, sent_nacks_[0]);
+}
+
+TEST_P(TestNackModule2, PacketNackCount) {
+  EXPECT_EQ(0, nack_module_.OnReceivedPacket(0, false, false));
+  EXPECT_EQ(0, nack_module_.OnReceivedPacket(2, false, false));
+  EXPECT_EQ(1, nack_module_.OnReceivedPacket(1, false, false));
+
+  sent_nacks_.clear();
+  nack_module_.UpdateRtt(100);
+  EXPECT_EQ(0, nack_module_.OnReceivedPacket(5, false, false));
+  clock_->AdvanceTimeMilliseconds(100);
+  nack_module_.Process();
+  clock_->AdvanceTimeMilliseconds(125);
+  nack_module_.Process();
+  EXPECT_EQ(3, nack_module_.OnReceivedPacket(3, false, false));
+  EXPECT_EQ(3, nack_module_.OnReceivedPacket(4, false, false));
+  EXPECT_EQ(0, nack_module_.OnReceivedPacket(4, false, false));
+}
+
+TEST_P(TestNackModule2, NackListFullAndNoOverlapWithKeyframes) {
+  const int kMaxNackPackets = 1000;
+  const unsigned int kFirstGap = kMaxNackPackets - 20;
+  const unsigned int kSecondGap = 200;
+  uint16_t seq_num = 0;
+  nack_module_.OnReceivedPacket(seq_num++, true, false);
+  seq_num += kFirstGap;
+  nack_module_.OnReceivedPacket(seq_num++, true, false);
+  EXPECT_EQ(kFirstGap, sent_nacks_.size());
+  sent_nacks_.clear();
+  seq_num += kSecondGap;
+  nack_module_.OnReceivedPacket(seq_num, true, false);
+  EXPECT_EQ(kSecondGap, sent_nacks_.size());
+}
+
+TEST_P(TestNackModule2, HandleFecRecoveredPacket) {
+  nack_module_.OnReceivedPacket(1, false, false);
+  nack_module_.OnReceivedPacket(4, false, true);
+  EXPECT_EQ(0u, sent_nacks_.size());
+  nack_module_.OnReceivedPacket(5, false, false);
+  EXPECT_EQ(2u, sent_nacks_.size());
+}
+
+TEST_P(TestNackModule2, SendNackWithoutDelay) {
+  nack_module_.OnReceivedPacket(0, false, false);
+  nack_module_.OnReceivedPacket(100, false, false);
+  EXPECT_EQ(99u, sent_nacks_.size());
+}
+
+INSTANTIATE_TEST_SUITE_P(WithAndWithoutBackoff,
+                         TestNackModule2,
+                         ::testing::Values(true, false));
+
+class TestNackModule2WithFieldTrial : public ::testing::Test,
+                                      public NackSender,
+                                      public KeyFrameRequestSender {
+ protected:
+  TestNackModule2WithFieldTrial()
+      : nack_delay_field_trial_("WebRTC-SendNackDelayMs/10/"),
+        clock_(new SimulatedClock(0)),
+        nack_module_(clock_.get(), this, this),
+        keyframes_requested_(0) {}
+
+  void SendNack(const std::vector<uint16_t>& sequence_numbers,
+                bool buffering_allowed) override {
+    sent_nacks_.insert(sent_nacks_.end(), sequence_numbers.begin(),
+                       sequence_numbers.end());
+  }
+
+  void RequestKeyFrame() override { ++keyframes_requested_; }
+
+  test::ScopedFieldTrials nack_delay_field_trial_;
+  std::unique_ptr<SimulatedClock> clock_;
+  NackModule2 nack_module_;
+  std::vector<uint16_t> sent_nacks_;
+  int keyframes_requested_;
+};
+
+TEST_F(TestNackModule2WithFieldTrial, SendNackWithDelay) {
+  nack_module_.OnReceivedPacket(0, false, false);
+  nack_module_.OnReceivedPacket(100, false, false);
+  EXPECT_EQ(0u, sent_nacks_.size());
+  clock_->AdvanceTimeMilliseconds(10);
+  nack_module_.OnReceivedPacket(106, false, false);
+  EXPECT_EQ(99u, sent_nacks_.size());
+  clock_->AdvanceTimeMilliseconds(10);
+  nack_module_.OnReceivedPacket(109, false, false);
+  EXPECT_EQ(104u, sent_nacks_.size());
+}
+}  // namespace webrtc