Index: net/quic/congestion_control/rtt_stats.cc |
diff --git a/net/quic/congestion_control/rtt_stats.cc b/net/quic/congestion_control/rtt_stats.cc |
deleted file mode 100644 |
index 6c2687df5646ff6c1e3eb5e27f4f4e74367befea..0000000000000000000000000000000000000000 |
--- a/net/quic/congestion_control/rtt_stats.cc |
+++ /dev/null |
@@ -1,130 +0,0 @@ |
-// Copyright 2014 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#include "net/quic/congestion_control/rtt_stats.h" |
- |
-#include <complex> // std::abs |
- |
-using std::max; |
- |
-namespace net { |
- |
-namespace { |
- |
-// Default initial rtt used before any samples are received. |
-const int kInitialRttMs = 100; |
-const float kAlpha = 0.125f; |
-const float kOneMinusAlpha = (1 - kAlpha); |
-const float kBeta = 0.25f; |
-const float kOneMinusBeta = (1 - kBeta); |
-const float kHalfWindow = 0.5f; |
-const float kQuarterWindow = 0.25f; |
- |
-} // namespace |
- |
-RttStats::RttStats() |
- : latest_rtt_(QuicTime::Delta::Zero()), |
- min_rtt_(QuicTime::Delta::Zero()), |
- smoothed_rtt_(QuicTime::Delta::Zero()), |
- mean_deviation_(QuicTime::Delta::Zero()), |
- initial_rtt_us_(kInitialRttMs * kNumMicrosPerMilli), |
- num_min_rtt_samples_remaining_(0), |
- recent_min_rtt_window_(QuicTime::Delta::Infinite()) {} |
- |
-void RttStats::SampleNewRecentMinRtt(uint32 num_samples) { |
- num_min_rtt_samples_remaining_ = num_samples; |
- new_min_rtt_ = RttSample(); |
-} |
- |
-void RttStats::ExpireSmoothedMetrics() { |
- mean_deviation_ = |
- max(mean_deviation_, |
- QuicTime::Delta::FromMicroseconds( |
- std::abs(smoothed_rtt_.Subtract(latest_rtt_).ToMicroseconds()))); |
- smoothed_rtt_ = max(smoothed_rtt_, latest_rtt_); |
-} |
- |
-// Updates the RTT based on a new sample. |
-void RttStats::UpdateRtt(QuicTime::Delta send_delta, |
- QuicTime::Delta ack_delay, |
- QuicTime now) { |
- if (send_delta.IsInfinite() || send_delta <= QuicTime::Delta::Zero()) { |
- LOG(WARNING) << "Ignoring measured send_delta, because it's is " |
- << "either infinite, zero, or negative. send_delta = " |
- << send_delta.ToMicroseconds(); |
- return; |
- } |
- |
- // Update min_rtt_ first. min_rtt_ does not use an rtt_sample corrected for |
- // ack_delay but the raw observed send_delta, since poor clock granularity at |
- // the client may cause a high ack_delay to result in underestimation of the |
- // min_rtt_. |
- if (min_rtt_.IsZero() || min_rtt_ > send_delta) { |
- min_rtt_ = send_delta; |
- } |
- UpdateRecentMinRtt(send_delta, now); |
- |
- // Correct for ack_delay if information received from the peer results in a |
- // positive RTT sample. Otherwise, we use the send_delta as a reasonable |
- // measure for smoothed_rtt. |
- QuicTime::Delta rtt_sample(send_delta); |
- if (rtt_sample > ack_delay) { |
- rtt_sample = rtt_sample.Subtract(ack_delay); |
- } |
- latest_rtt_ = rtt_sample; |
- // First time call. |
- if (smoothed_rtt_.IsZero()) { |
- smoothed_rtt_ = rtt_sample; |
- mean_deviation_ = QuicTime::Delta::FromMicroseconds( |
- rtt_sample.ToMicroseconds() / 2); |
- } else { |
- mean_deviation_ = QuicTime::Delta::FromMicroseconds(static_cast<int64>( |
- kOneMinusBeta * mean_deviation_.ToMicroseconds() + |
- kBeta * std::abs(smoothed_rtt_.Subtract(rtt_sample).ToMicroseconds()))); |
- smoothed_rtt_ = smoothed_rtt_.Multiply(kOneMinusAlpha).Add( |
- rtt_sample.Multiply(kAlpha)); |
- DVLOG(1) << " smoothed_rtt(us):" << smoothed_rtt_.ToMicroseconds() |
- << " mean_deviation(us):" << mean_deviation_.ToMicroseconds(); |
- } |
-} |
- |
-void RttStats::UpdateRecentMinRtt(QuicTime::Delta rtt_sample, QuicTime now) { |
- // Recent min_rtt update. |
- if (num_min_rtt_samples_remaining_ > 0) { |
- --num_min_rtt_samples_remaining_; |
- if (new_min_rtt_.rtt.IsZero() || rtt_sample <= new_min_rtt_.rtt) { |
- new_min_rtt_ = RttSample(rtt_sample, now); |
- } |
- if (num_min_rtt_samples_remaining_ == 0) { |
- quarter_window_rtt_ = half_window_rtt_ = recent_min_rtt_ = new_min_rtt_; |
- } |
- } |
- |
- // Update the three recent rtt samples. |
- if (recent_min_rtt_.rtt.IsZero() || rtt_sample <= recent_min_rtt_.rtt) { |
- recent_min_rtt_ = RttSample(rtt_sample, now); |
- quarter_window_rtt_ = half_window_rtt_ = recent_min_rtt_; |
- } else if (rtt_sample <= half_window_rtt_.rtt) { |
- half_window_rtt_ = RttSample(rtt_sample, now); |
- quarter_window_rtt_ = half_window_rtt_; |
- } else if (rtt_sample <= quarter_window_rtt_.rtt) { |
- quarter_window_rtt_ = RttSample(rtt_sample, now); |
- } |
- |
- // Expire old min rtt samples. |
- if (recent_min_rtt_.time < now.Subtract(recent_min_rtt_window_)) { |
- recent_min_rtt_ = half_window_rtt_; |
- half_window_rtt_ = quarter_window_rtt_; |
- quarter_window_rtt_ = RttSample(rtt_sample, now); |
- } else if (half_window_rtt_.time < |
- now.Subtract(recent_min_rtt_window_.Multiply(kHalfWindow))) { |
- half_window_rtt_ = quarter_window_rtt_; |
- quarter_window_rtt_ = RttSample(rtt_sample, now); |
- } else if (quarter_window_rtt_.time < |
- now.Subtract(recent_min_rtt_window_.Multiply(kQuarterWindow))) { |
- quarter_window_rtt_ = RttSample(rtt_sample, now); |
- } |
-} |
- |
-} // namespace net |