Add interval estimator to remote bitrate estimator

webrtc/modules/remote_bitrate_estimator/aimd_rate_control_unittest.cc

Index: webrtc/modules/remote_bitrate_estimator/aimd_rate_control_unittest.cc
diff --git a/webrtc/modules/remote_bitrate_estimator/aimd_rate_control_unittest.cc b/webrtc/modules/remote_bitrate_estimator/aimd_rate_control_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6cf693c8008d97ef9936baf4367b4ac0eab80fb5
--- /dev/null
+++ b/webrtc/modules/remote_bitrate_estimator/aimd_rate_control_unittest.cc
@@ -0,0 +1,110 @@
+/*
+ *  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 <memory>
+
+#include "webrtc/modules/audio_coding/audio_network_adaptor/smoothing_filter.h"
+#include "webrtc/modules/remote_bitrate_estimator/aimd_rate_control.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+// constexpr int kTimeConstantMs = 1000;
+// constexpr float kMaxAbsError = 0.0001f;
+constexpr int64_t kClockInitialTime = 123456;
+
+struct AimdRateControlStates {
+  std::unique_ptr<AimdRateControl> aimd_rate_control;
+  std::unique_ptr<SimulatedClock> simulated_clock;
+};
+
+AimdRateControlStates CreateAimdRateControlStates() {
+  AimdRateControlStates states;
+  states.aimd_rate_control.reset(new AimdRateControl());
+  states.simulated_clock.reset(new SimulatedClock(kClockInitialTime));
+  return states;
+}
+
+void InitToBitrate(const AimdRateControlStates& states,
+                   int bitrate,
+                   int64_t now_ms) {
+  states.aimd_rate_control->SetEstimate(bitrate, now_ms);
+}
+
+void UpdateRateControl(const AimdRateControlStates& states,
+                       const BandwidthUsage& bandwidth_usage,
+                       int bitrate,
+                       int64_t now_ms) {
+  RateControlInput input(bandwidth_usage, rtc::Optional<uint32_t>(bitrate),
+                         now_ms);
+  states.aimd_rate_control->Update(&input, now_ms);
+  states.aimd_rate_control->UpdateBandwidthEstimate(now_ms);
+}
+
+}  // namespace
+
+TEST(AimdRateControlTest, UnknownNearMaxIncreaseRateBeforeFirstOveruse) {
+  auto aimd_rate_control_states = CreateAimdRateControlStates();
+  EXPECT_EQ(
+      rtc::Optional<int>(),
+      aimd_rate_control_states.aimd_rate_control->GetNearMaxIncreaseRate());
+}
+
+TEST(AimdRateControlTest, NearMaxIncreaseRateOnIntervalOf200ms) {
+  auto states = CreateAimdRateControlStates();
+  constexpr int kBitrate = 300000;
+  InitToBitrate(states, kBitrate, states.simulated_clock->TimeInMilliseconds());
+  UpdateRateControl(states, kBwOverusing, kBitrate,
+                    states.simulated_clock->TimeInMilliseconds());
+  UpdateRateControl(states, kBwNormal, kBitrate,
+                    states.simulated_clock->TimeInMilliseconds());
+  states.simulated_clock->AdvanceTimeMilliseconds(200);
+  UpdateRateControl(states, kBwNormal, kBitrate,
+                    states.simulated_clock->TimeInMilliseconds());
+  EXPECT_EQ(rtc::Optional<int>(14220),
+            states.aimd_rate_control->GetNearMaxIncreaseRate());
+}
+
+TEST(AimdRateControlTest,
+     DontUpdateNearMaxIncreaseRateWhenLastStateWasNotNearMax) {
+  auto states = CreateAimdRateControlStates();
+  constexpr int kBitrate = 300000;
+  InitToBitrate(states, kBitrate, states.simulated_clock->TimeInMilliseconds());
+  UpdateRateControl(states, kBwOverusing, kBitrate,
+                    states.simulated_clock->TimeInMilliseconds());
+  UpdateRateControl(states, kBwNormal, kBitrate,
+                    states.simulated_clock->TimeInMilliseconds());
+  states.simulated_clock->AdvanceTimeMilliseconds(200);
+  UpdateRateControl(states, kBwNormal, kBitrate,
+                    states.simulated_clock->TimeInMilliseconds());
+  UpdateRateControl(states, kBwOverusing, kBitrate,
+                    states.simulated_clock->TimeInMilliseconds());
+  UpdateRateControl(states, kBwNormal, kBitrate - 200000,
+                    states.simulated_clock->TimeInMilliseconds());
+  EXPECT_EQ(rtc::Optional<int>(14220),
+            states.aimd_rate_control->GetNearMaxIncreaseRate());
+}
+
+TEST(AimdRateControlTest, UnknownDropHightBeforeFirstOveruse) {
+  auto states = CreateAimdRateControlStates();
+  EXPECT_EQ(rtc::Optional<int>(), states.aimd_rate_control->GetLastDecrease());
+}
+
+TEST(AimdRateControlTest, GetLastBitrateDrop) {
+  auto states = CreateAimdRateControlStates();
+  constexpr int kBitrate = 300000;
+  InitToBitrate(states, kBitrate, states.simulated_clock->TimeInMilliseconds());
+  UpdateRateControl(states, kBwOverusing, kBitrate,
+                    states.simulated_clock->TimeInMilliseconds());
+  EXPECT_EQ(rtc::Optional<int>(46000),
+            states.aimd_rate_control->GetLastDecrease());
+}
+
+}  // namespace webrtc