From 3821ff8df57e8d9622b13ea0636bf833ab4733a4 Mon Sep 17 00:00:00 2001
From: stefan <stefan@webrtc.org>
Date: Sun, 4 Sep 2016 05:07:26 -0700
Subject: [PATCH] Only log BWE updates if the actual estimate changed or if we
 have non-zero loss reports.

BUG=webrtc:6295

Review-Url: https://codereview.webrtc.org/2306963002
Cr-Commit-Position: refs/heads/master@{#14061}
---
 .../send_side_bandwidth_estimation.cc         | 24 ++++++++++++-------
 .../send_side_bandwidth_estimation.h          |  2 ++
 ...send_side_bandwidth_estimation_unittest.cc |  2 +-
 3 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc b/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc
index e47d4917e9..7d9d5c3be6 100644
--- a/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc
+++ b/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc
@@ -29,6 +29,7 @@ const int kLimitNumPackets = 20;
 const int kDefaultMinBitrateBps = 10000;
 const int kDefaultMaxBitrateBps = 1000000000;
 const int64_t kLowBitrateLogPeriodMs = 10000;
+const int64_t kRtcEventLogPeriodMs = 5000;
 
 struct UmaRampUpMetric {
   const char* metric_name;
@@ -54,6 +55,7 @@ SendSideBandwidthEstimation::SendSideBandwidthEstimation(RtcEventLog* event_log)
       has_decreased_since_last_fraction_loss_(false),
       time_last_receiver_block_ms_(-1),
       last_fraction_loss_(0),
+      last_logged_fraction_loss_(0),
       last_round_trip_time_ms_(0),
       bwe_incoming_(0),
       delay_based_bitrate_bps_(0),
@@ -63,7 +65,8 @@ SendSideBandwidthEstimation::SendSideBandwidthEstimation(RtcEventLog* event_log)
       bitrate_at_2_seconds_kbps_(0),
       uma_update_state_(kNoUpdate),
       rampup_uma_stats_updated_(kNumUmaRampupMetrics, false),
-      event_log_(event_log) {
+      event_log_(event_log),
+      last_rtc_event_log_ms_(-1) {
   RTC_DCHECK(event_log);
 }
 
@@ -228,10 +231,6 @@ void SendSideBandwidthEstimation::UpdateEstimate(int64_t now_ms) {
       // (gives a little extra increase at low rates, negligible at higher
       // rates).
       bitrate_ += 1000;
-
-      event_log_->LogBwePacketLossEvent(
-          bitrate_, last_fraction_loss_,
-          expected_packets_since_last_loss_update_);
     } else if (last_fraction_loss_ <= 26) {
       // Loss between 2% - 10%: Do nothing.
     } else {
@@ -250,12 +249,19 @@ void SendSideBandwidthEstimation::UpdateEstimate(int64_t now_ms) {
             512.0);
         has_decreased_since_last_fraction_loss_ = true;
       }
-      event_log_->LogBwePacketLossEvent(
-          bitrate_, last_fraction_loss_,
-          expected_packets_since_last_loss_update_);
     }
   }
-  bitrate_ = CapBitrateToThresholds(now_ms, bitrate_);
+  uint32_t capped_bitrate = CapBitrateToThresholds(now_ms, bitrate_);
+  if (capped_bitrate != bitrate_ ||
+      last_fraction_loss_ != last_logged_fraction_loss_ ||
+      last_rtc_event_log_ms_ == -1 ||
+      now_ms - last_rtc_event_log_ms_ > kRtcEventLogPeriodMs) {
+    event_log_->LogBwePacketLossEvent(capped_bitrate, last_fraction_loss_,
+                                      expected_packets_since_last_loss_update_);
+    last_logged_fraction_loss_ = last_fraction_loss_;
+    last_rtc_event_log_ms_ = now_ms;
+  }
+  bitrate_ = capped_bitrate;
 }
 
 bool SendSideBandwidthEstimation::IsInStartPhase(int64_t now_ms) const {
diff --git a/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.h b/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.h
index c97714f7e8..dc9de10f7f 100644
--- a/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.h
+++ b/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.h
@@ -84,6 +84,7 @@ class SendSideBandwidthEstimation {
   bool has_decreased_since_last_fraction_loss_;
   int64_t time_last_receiver_block_ms_;
   uint8_t last_fraction_loss_;
+  uint8_t last_logged_fraction_loss_;
   int64_t last_round_trip_time_ms_;
 
   uint32_t bwe_incoming_;
@@ -95,6 +96,7 @@ class SendSideBandwidthEstimation {
   UmaState uma_update_state_;
   std::vector<bool> rampup_uma_stats_updated_;
   RtcEventLog* event_log_;
+  int64_t last_rtc_event_log_ms_;
 };
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_BITRATE_CONTROLLER_SEND_SIDE_BANDWIDTH_ESTIMATION_H_
diff --git a/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation_unittest.cc b/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation_unittest.cc
index 64cb2fee51..12f8603068 100644
--- a/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation_unittest.cc
+++ b/webrtc/modules/bitrate_controller/send_side_bandwidth_estimation_unittest.cc
@@ -67,7 +67,7 @@ TEST(SendSideBweTest, DoesntReapplyBitrateDecreaseWithoutFollowingRemb) {
   MockRtcEventLog event_log;
   EXPECT_CALL(event_log,
               LogBwePacketLossEvent(testing::Gt(0), testing::Gt(0), 0))
-      .Times(3);
+      .Times(1);
   SendSideBandwidthEstimation bwe(&event_log);
   static const int kMinBitrateBps = 100000;
   static const int kInitialBitrateBps = 1000000;