1 files changed, 245 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/congestion_controller/goog_cc/send_side_bandwidth_estimation_unittest.cc b/third_party/libwebrtc/modules/congestion_controller/goog_cc/send_side_bandwidth_estimation_unittest.cc
new file mode 100644
index 0000000000..866700b09a
--- /dev/null
+++ b/third_party/libwebrtc/modules/congestion_controller/goog_cc/send_side_bandwidth_estimation_unittest.cc
@@ -0,0 +1,245 @@
+/*
+ *  Copyright (c) 2014 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/congestion_controller/goog_cc/send_side_bandwidth_estimation.h"
+
+#include <cstdint>
+
+#include "api/rtc_event_log/rtc_event.h"
+#include "api/units/data_rate.h"
+#include "api/units/time_delta.h"
+#include "api/units/timestamp.h"
+#include "logging/rtc_event_log/events/rtc_event_bwe_update_loss_based.h"
+#include "logging/rtc_event_log/mock/mock_rtc_event_log.h"
+#include "test/explicit_key_value_config.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+
+MATCHER(LossBasedBweUpdateWithBitrateOnly, "") {
+  if (arg->GetType() != RtcEvent::Type::BweUpdateLossBased) {
+    return false;
+  }
+  auto bwe_event = static_cast<RtcEventBweUpdateLossBased*>(arg);
+  return bwe_event->bitrate_bps() > 0 && bwe_event->fraction_loss() == 0;
+}
+
+MATCHER(LossBasedBweUpdateWithBitrateAndLossFraction, "") {
+  if (arg->GetType() != RtcEvent::Type::BweUpdateLossBased) {
+    return false;
+  }
+  auto bwe_event = static_cast<RtcEventBweUpdateLossBased*>(arg);
+  return bwe_event->bitrate_bps() > 0 && bwe_event->fraction_loss() > 0;
+}
+
+void TestProbing(bool use_delay_based) {
+  ::testing::NiceMock<MockRtcEventLog> event_log;
+  test::ExplicitKeyValueConfig key_value_config("");
+  SendSideBandwidthEstimation bwe(&key_value_config, &event_log);
+  int64_t now_ms = 0;
+  bwe.SetMinMaxBitrate(DataRate::BitsPerSec(100000),
+                       DataRate::BitsPerSec(1500000));
+  bwe.SetSendBitrate(DataRate::BitsPerSec(200000), Timestamp::Millis(now_ms));
+
+  const int kRembBps = 1000000;
+  const int kSecondRembBps = kRembBps + 500000;
+
+  bwe.UpdatePacketsLost(/*packets_lost=*/0, /*number_of_packets=*/1,
+                        Timestamp::Millis(now_ms));
+  bwe.UpdateRtt(TimeDelta::Millis(50), Timestamp::Millis(now_ms));
+
+  // Initial REMB applies immediately.
+  if (use_delay_based) {
+    bwe.UpdateDelayBasedEstimate(Timestamp::Millis(now_ms),
+                                 DataRate::BitsPerSec(kRembBps));
+  } else {
+    bwe.UpdateReceiverEstimate(Timestamp::Millis(now_ms),
+                               DataRate::BitsPerSec(kRembBps));
+  }
+  bwe.UpdateEstimate(Timestamp::Millis(now_ms));
+  EXPECT_EQ(kRembBps, bwe.target_rate().bps());
+
+  // Second REMB doesn't apply immediately.
+  now_ms += 2001;
+  if (use_delay_based) {
+    bwe.UpdateDelayBasedEstimate(Timestamp::Millis(now_ms),
+                                 DataRate::BitsPerSec(kSecondRembBps));
+  } else {
+    bwe.UpdateReceiverEstimate(Timestamp::Millis(now_ms),
+                               DataRate::BitsPerSec(kSecondRembBps));
+  }
+  bwe.UpdateEstimate(Timestamp::Millis(now_ms));
+  EXPECT_EQ(kRembBps, bwe.target_rate().bps());
+}
+
+TEST(SendSideBweTest, InitialRembWithProbing) {
+  TestProbing(false);
+}
+
+TEST(SendSideBweTest, InitialDelayBasedBweWithProbing) {
+  TestProbing(true);
+}
+
+TEST(SendSideBweTest, DoesntReapplyBitrateDecreaseWithoutFollowingRemb) {
+  MockRtcEventLog event_log;
+  EXPECT_CALL(event_log, LogProxy(LossBasedBweUpdateWithBitrateOnly()))
+      .Times(1);
+  EXPECT_CALL(event_log,
+              LogProxy(LossBasedBweUpdateWithBitrateAndLossFraction()))
+      .Times(1);
+  test::ExplicitKeyValueConfig key_value_config("");
+  SendSideBandwidthEstimation bwe(&key_value_config, &event_log);
+  static const int kMinBitrateBps = 100000;
+  static const int kInitialBitrateBps = 1000000;
+  int64_t now_ms = 1000;
+  bwe.SetMinMaxBitrate(DataRate::BitsPerSec(kMinBitrateBps),
+                       DataRate::BitsPerSec(1500000));
+  bwe.SetSendBitrate(DataRate::BitsPerSec(kInitialBitrateBps),
+                     Timestamp::Millis(now_ms));
+
+  static const uint8_t kFractionLoss = 128;
+  static const int64_t kRttMs = 50;
+  now_ms += 10000;
+
+  EXPECT_EQ(kInitialBitrateBps, bwe.target_rate().bps());
+  EXPECT_EQ(0, bwe.fraction_loss());
+  EXPECT_EQ(0, bwe.round_trip_time().ms());
+
+  // Signal heavy loss to go down in bitrate.
+  bwe.UpdatePacketsLost(/*packets_lost=*/50, /*number_of_packets=*/100,
+                        Timestamp::Millis(now_ms));
+  bwe.UpdateRtt(TimeDelta::Millis(kRttMs), Timestamp::Millis(now_ms));
+
+  // Trigger an update 2 seconds later to not be rate limited.
+  now_ms += 1000;
+  bwe.UpdateEstimate(Timestamp::Millis(now_ms));
+  EXPECT_LT(bwe.target_rate().bps(), kInitialBitrateBps);
+  // Verify that the obtained bitrate isn't hitting the min bitrate, or this
+  // test doesn't make sense. If this ever happens, update the thresholds or
+  // loss rates so that it doesn't hit min bitrate after one bitrate update.
+  EXPECT_GT(bwe.target_rate().bps(), kMinBitrateBps);
+  EXPECT_EQ(kFractionLoss, bwe.fraction_loss());
+  EXPECT_EQ(kRttMs, bwe.round_trip_time().ms());
+
+  // Triggering an update shouldn't apply further downgrade nor upgrade since
+  // there's no intermediate receiver block received indicating whether this is
+  // currently good or not.
+  int last_bitrate_bps = bwe.target_rate().bps();
+  // Trigger an update 2 seconds later to not be rate limited (but it still
+  // shouldn't update).
+  now_ms += 1000;
+  bwe.UpdateEstimate(Timestamp::Millis(now_ms));
+
+  EXPECT_EQ(last_bitrate_bps, bwe.target_rate().bps());
+  // The old loss rate should still be applied though.
+  EXPECT_EQ(kFractionLoss, bwe.fraction_loss());
+  EXPECT_EQ(kRttMs, bwe.round_trip_time().ms());
+}
+
+TEST(SendSideBweTest, SettingSendBitrateOverridesDelayBasedEstimate) {
+  ::testing::NiceMock<MockRtcEventLog> event_log;
+  test::ExplicitKeyValueConfig key_value_config("");
+  SendSideBandwidthEstimation bwe(&key_value_config, &event_log);
+  static const int kMinBitrateBps = 10000;
+  static const int kMaxBitrateBps = 10000000;
+  static const int kInitialBitrateBps = 300000;
+  static const int kDelayBasedBitrateBps = 350000;
+  static const int kForcedHighBitrate = 2500000;
+
+  int64_t now_ms = 0;
+
+  bwe.SetMinMaxBitrate(DataRate::BitsPerSec(kMinBitrateBps),
+                       DataRate::BitsPerSec(kMaxBitrateBps));
+  bwe.SetSendBitrate(DataRate::BitsPerSec(kInitialBitrateBps),
+                     Timestamp::Millis(now_ms));
+
+  bwe.UpdateDelayBasedEstimate(Timestamp::Millis(now_ms),
+                               DataRate::BitsPerSec(kDelayBasedBitrateBps));
+  bwe.UpdateEstimate(Timestamp::Millis(now_ms));
+  EXPECT_GE(bwe.target_rate().bps(), kInitialBitrateBps);
+  EXPECT_LE(bwe.target_rate().bps(), kDelayBasedBitrateBps);
+
+  bwe.SetSendBitrate(DataRate::BitsPerSec(kForcedHighBitrate),
+                     Timestamp::Millis(now_ms));
+  EXPECT_EQ(bwe.target_rate().bps(), kForcedHighBitrate);
+}
+
+TEST(RttBasedBackoff, DefaultEnabled) {
+  test::ExplicitKeyValueConfig key_value_config("");
+  RttBasedBackoff rtt_backoff(&key_value_config);
+  EXPECT_TRUE(rtt_backoff.rtt_limit_.IsFinite());
+}
+
+TEST(RttBasedBackoff, CanBeDisabled) {
+  test::ExplicitKeyValueConfig key_value_config(
+      "WebRTC-Bwe-MaxRttLimit/Disabled/");
+  RttBasedBackoff rtt_backoff(&key_value_config);
+  EXPECT_TRUE(rtt_backoff.rtt_limit_.IsPlusInfinity());
+}
+
+TEST(SendSideBweTest, FractionLossIsNotOverflowed) {
+  MockRtcEventLog event_log;
+  test::ExplicitKeyValueConfig key_value_config("");
+  SendSideBandwidthEstimation bwe(&key_value_config, &event_log);
+  static const int kMinBitrateBps = 100000;
+  static const int kInitialBitrateBps = 1000000;
+  int64_t now_ms = 1000;
+  bwe.SetMinMaxBitrate(DataRate::BitsPerSec(kMinBitrateBps),
+                       DataRate::BitsPerSec(1500000));
+  bwe.SetSendBitrate(DataRate::BitsPerSec(kInitialBitrateBps),
+                     Timestamp::Millis(now_ms));
+
+  now_ms += 10000;
+
+  EXPECT_EQ(kInitialBitrateBps, bwe.target_rate().bps());
+  EXPECT_EQ(0, bwe.fraction_loss());
+
+  // Signal negative loss.
+  bwe.UpdatePacketsLost(/*packets_lost=*/-1, /*number_of_packets=*/100,
+                        Timestamp::Millis(now_ms));
+  EXPECT_EQ(0, bwe.fraction_loss());
+}
+
+TEST(SendSideBweTest, RttIsAboveLimitIfRttGreaterThanLimit) {
+  ::testing::NiceMock<MockRtcEventLog> event_log;
+  test::ExplicitKeyValueConfig key_value_config("");
+  SendSideBandwidthEstimation bwe(&key_value_config, &event_log);
+  static const int kMinBitrateBps = 10000;
+  static const int kMaxBitrateBps = 10000000;
+  static const int kInitialBitrateBps = 300000;
+  int64_t now_ms = 0;
+  bwe.SetMinMaxBitrate(DataRate::BitsPerSec(kMinBitrateBps),
+                       DataRate::BitsPerSec(kMaxBitrateBps));
+  bwe.SetSendBitrate(DataRate::BitsPerSec(kInitialBitrateBps),
+                     Timestamp::Millis(now_ms));
+  bwe.UpdatePropagationRtt(/*at_time=*/Timestamp::Millis(now_ms),
+                           /*propagation_rtt=*/TimeDelta::Millis(5000));
+  EXPECT_TRUE(bwe.IsRttAboveLimit());
+}
+
+TEST(SendSideBweTest, RttIsBelowLimitIfRttLessThanLimit) {
+  ::testing::NiceMock<MockRtcEventLog> event_log;
+  test::ExplicitKeyValueConfig key_value_config("");
+  SendSideBandwidthEstimation bwe(&key_value_config, &event_log);
+  static const int kMinBitrateBps = 10000;
+  static const int kMaxBitrateBps = 10000000;
+  static const int kInitialBitrateBps = 300000;
+  int64_t now_ms = 0;
+  bwe.SetMinMaxBitrate(DataRate::BitsPerSec(kMinBitrateBps),
+                       DataRate::BitsPerSec(kMaxBitrateBps));
+  bwe.SetSendBitrate(DataRate::BitsPerSec(kInitialBitrateBps),
+                     Timestamp::Millis(now_ms));
+  bwe.UpdatePropagationRtt(/*at_time=*/Timestamp::Millis(now_ms),
+                           /*propagation_rtt=*/TimeDelta::Millis(1000));
+  EXPECT_FALSE(bwe.IsRttAboveLimit());
+}
+
+}  // namespace webrtc