30bd4038cf
This CL moves the network units files into a separate folder with a separate BUILD file. It also splits the units into separate files. This prepares for moving all or some of the units to somewhere that can be accessed by more components. Bug: None Change-Id: I4ebbc19088b024ba920b0b3c64e5f57431f4f955 Reviewed-on: https://webrtc-review.googlesource.com/68660 Commit-Queue: Sebastian Jansson <srte@webrtc.org> Reviewed-by: Björn Terelius <terelius@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22861}
97 lines
3.3 KiB
C++
97 lines
3.3 KiB
C++
/*
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* Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "modules/congestion_controller/bbr/rtt_stats.h"
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#include <cstdlib>
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#include "modules/congestion_controller/network_control/units/network_units.h"
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#include "rtc_base/logging.h"
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namespace webrtc {
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namespace bbr {
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namespace {
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// Default initial rtt used before any samples are received.
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const int kInitialRttMs = 100;
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const double kAlpha = 0.125;
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const double kOneMinusAlpha = (1 - kAlpha);
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const double kBeta = 0.25;
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const double kOneMinusBeta = (1 - kBeta);
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const int64_t kNumMicrosPerMilli = 1000;
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} // namespace
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RttStats::RttStats()
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: latest_rtt_(TimeDelta::Zero()),
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min_rtt_(TimeDelta::Zero()),
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smoothed_rtt_(TimeDelta::Zero()),
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previous_srtt_(TimeDelta::Zero()),
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mean_deviation_(TimeDelta::Zero()),
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initial_rtt_us_(kInitialRttMs * kNumMicrosPerMilli) {}
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void RttStats::ExpireSmoothedMetrics() {
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mean_deviation_ =
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std::max(mean_deviation_, (smoothed_rtt_ - latest_rtt_).Abs());
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smoothed_rtt_ = std::max(smoothed_rtt_, latest_rtt_);
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}
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// Updates the RTT based on a new sample.
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void RttStats::UpdateRtt(TimeDelta send_delta,
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TimeDelta ack_delay,
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Timestamp now) {
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if (send_delta.IsInfinite() || send_delta <= TimeDelta::Zero()) {
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RTC_LOG(LS_WARNING) << "Ignoring measured send_delta, because it's is "
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<< "either infinite, zero, or negative. send_delta = "
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<< ToString(send_delta);
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return;
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}
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// Update min_rtt_ first. min_rtt_ does not use an rtt_sample corrected for
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// ack_delay but the raw observed send_delta, since poor clock granularity at
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// the client may cause a high ack_delay to result in underestimation of the
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// min_rtt_.
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if (min_rtt_.IsZero() || min_rtt_ > send_delta) {
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min_rtt_ = send_delta;
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}
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// Correct for ack_delay if information received from the peer results in a
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// positive RTT sample. Otherwise, we use the send_delta as a reasonable
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// measure for smoothed_rtt.
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TimeDelta rtt_sample = send_delta;
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previous_srtt_ = smoothed_rtt_;
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if (rtt_sample > ack_delay) {
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rtt_sample = rtt_sample - ack_delay;
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}
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latest_rtt_ = rtt_sample;
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// First time call.
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if (smoothed_rtt_.IsZero()) {
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smoothed_rtt_ = rtt_sample;
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mean_deviation_ = rtt_sample / 2;
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} else {
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mean_deviation_ = kOneMinusBeta * mean_deviation_ +
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kBeta * (smoothed_rtt_ - rtt_sample).Abs();
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smoothed_rtt_ = kOneMinusAlpha * smoothed_rtt_ + kAlpha * rtt_sample;
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RTC_LOG(LS_VERBOSE) << " smoothed_rtt(us):" << smoothed_rtt_.us()
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<< " mean_deviation(us):" << mean_deviation_.us();
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}
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}
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void RttStats::OnConnectionMigration() {
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latest_rtt_ = TimeDelta::Zero();
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min_rtt_ = TimeDelta::Zero();
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smoothed_rtt_ = TimeDelta::Zero();
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mean_deviation_ = TimeDelta::Zero();
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initial_rtt_us_ = kInitialRttMs * kNumMicrosPerMilli;
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}
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} // namespace bbr
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} // namespace webrtc
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