Store delay measurements as struct instead of std::pair
Bug: None
Change-Id: I60f375cda4f910550a86d2238acf39d429e2a17b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/160004
Commit-Queue: Björn Terelius <terelius@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29837}
diff --git a/modules/congestion_controller/goog_cc/trendline_estimator.cc b/modules/congestion_controller/goog_cc/trendline_estimator.cc
index d8d984e..8f4f133 100644
--- a/modules/congestion_controller/goog_cc/trendline_estimator.cc
+++ b/modules/congestion_controller/goog_cc/trendline_estimator.cc
@@ -52,23 +52,25 @@
}
absl::optional<double> LinearFitSlope(
- const std::deque<std::pair<double, double>>& points) {
- RTC_DCHECK(points.size() >= 2);
+ const std::deque<TrendlineEstimator::PacketTiming>& packets) {
+ RTC_DCHECK(packets.size() >= 2);
// Compute the "center of mass".
double sum_x = 0;
double sum_y = 0;
- for (const auto& point : points) {
- sum_x += point.first;
- sum_y += point.second;
+ for (const auto& packet : packets) {
+ sum_x += packet.arrival_time_ms;
+ sum_y += packet.smoothed_delay_ms;
}
- double x_avg = sum_x / points.size();
- double y_avg = sum_y / points.size();
+ double x_avg = sum_x / packets.size();
+ double y_avg = sum_y / packets.size();
// Compute the slope k = \sum (x_i-x_avg)(y_i-y_avg) / \sum (x_i-x_avg)^2
double numerator = 0;
double denominator = 0;
- for (const auto& point : points) {
- numerator += (point.first - x_avg) * (point.second - y_avg);
- denominator += (point.first - x_avg) * (point.first - x_avg);
+ for (const auto& packet : packets) {
+ double x = packet.arrival_time_ms;
+ double y = packet.smoothed_delay_ms;
+ numerator += (x - x_avg) * (y - y_avg);
+ denominator += (x - x_avg) * (x - x_avg);
}
if (denominator == 0)
return absl::nullopt;
@@ -138,9 +140,9 @@
smoothed_delay_);
// Simple linear regression.
- delay_hist_.push_back(std::make_pair(
+ delay_hist_.emplace_back(
static_cast<double>(arrival_time_ms - first_arrival_time_ms_),
- smoothed_delay_));
+ smoothed_delay_);
if (delay_hist_.size() > window_size_)
delay_hist_.pop_front();
double trend = prev_trend_;
diff --git a/modules/congestion_controller/goog_cc/trendline_estimator.h b/modules/congestion_controller/goog_cc/trendline_estimator.h
index 0f70943..5bec23b 100644
--- a/modules/congestion_controller/goog_cc/trendline_estimator.h
+++ b/modules/congestion_controller/goog_cc/trendline_estimator.h
@@ -49,9 +49,16 @@
BandwidthUsage State() const override;
+ struct PacketTiming {
+ PacketTiming(double arrival_time_ms, double smoothed_delay_ms)
+ : arrival_time_ms(arrival_time_ms),
+ smoothed_delay_ms(smoothed_delay_ms) {}
+ double arrival_time_ms;
+ double smoothed_delay_ms;
+ };
+
private:
friend class GoogCcStatePrinter;
-
void Detect(double trend, double ts_delta, int64_t now_ms);
void UpdateThreshold(double modified_offset, int64_t now_ms);
@@ -68,7 +75,7 @@
double accumulated_delay_;
double smoothed_delay_;
// Linear least squares regression.
- std::deque<std::pair<double, double>> delay_hist_;
+ std::deque<PacketTiming> delay_hist_;
const double k_up_;
const double k_down_;
