Move shared files in net/quic/ into net/quic/core/

net/quic/congestion_control/rtt_stats.h

-// 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.
-//
-// A convenience class to store rtt samples and calculate smoothed rtt.
-
-#ifndef NET_QUIC_CONGESTION_CONTROL_RTT_STATS_H_
-#define NET_QUIC_CONGESTION_CONTROL_RTT_STATS_H_
-
-#include <stdint.h>
-
-#include <algorithm>
-
-#include "base/macros.h"
-#include "net/quic/congestion_control/windowed_filter.h"
-#include "net/quic/quic_bug_tracker.h"
-#include "net/quic/quic_protocol.h"
-#include "net/quic/quic_time.h"
-
-namespace net {
-
-namespace test {
-class RttStatsPeer;
-}  // namespace test
-
-class NET_EXPORT_PRIVATE RttStats {
- public:
-  RttStats();
-
-  // Updates the RTT from an incoming ack which is received |send_delta| after
-  // the packet is sent and the peer reports the ack being delayed |ack_delay|.
-  void UpdateRtt(QuicTime::Delta send_delta,
-                 QuicTime::Delta ack_delay,
-                 QuicTime now);
-
-  // Causes the smoothed_rtt to be increased to the latest_rtt if the latest_rtt
-  // is larger. The mean deviation is increased to the most recent deviation if
-  // it's larger.
-  void ExpireSmoothedMetrics();
-
-  // Forces RttStats to sample a new windowed min rtt within the next
-  // |num_samples| UpdateRtt calls.
-  void SampleNewWindowedMinRtt(uint32_t num_samples);
-
-  // Called when connection migrates and rtt measurement needs to be reset.
-  void OnConnectionMigration();
-
-  // Returns the EWMA smoothed RTT for the connection.
-  // May return Zero if no valid updates have occurred.
-  QuicTime::Delta smoothed_rtt() const { return smoothed_rtt_; }
-
-  // Returns the EWMA smoothed RTT prior to the most recent RTT sample.
-  QuicTime::Delta previous_srtt() const { return previous_srtt_; }
-
-  int64_t initial_rtt_us() const { return initial_rtt_us_; }
-
-  // Sets an initial RTT to be used for SmoothedRtt before any RTT updates.
-  void set_initial_rtt_us(int64_t initial_rtt_us) {
-    if (initial_rtt_us <= 0) {
-      QUIC_BUG << "Attempt to set initial rtt to <= 0.";
-      return;
-    }
-    initial_rtt_us_ = initial_rtt_us;
-  }
-
-  // The most recent rtt measurement.
-  // May return Zero if no valid updates have occurred.
-  QuicTime::Delta latest_rtt() const { return latest_rtt_; }
-
-  // Returns the min_rtt for the entire connection.
-  // May return Zero if no valid updates have occurred.
-  QuicTime::Delta min_rtt() const { return min_rtt_; }
-
-  QuicTime::Delta mean_deviation() const { return mean_deviation_; }
-
-  QuicTime::Delta WindowedMinRtt() { return windowed_min_rtt_.GetBest(); }
-
- private:
-  friend class test::RttStatsPeer;
-
-  // Updates the windowed min rtt. Also forces a new windowed_min_rtt sample,
-  // if set by a call to SampleNewWindowedMinRtt() above.
-  void UpdateWindowedMinRtt(QuicTime::Delta rtt_sample, QuicTime now);
-
-  QuicTime::Delta latest_rtt_;
-  QuicTime::Delta min_rtt_;
-  QuicTime::Delta smoothed_rtt_;
-  QuicTime::Delta previous_srtt_;
-  // Mean RTT deviation during this session.
-  // Approximation of standard deviation, the error is roughly 1.25 times
-  // larger than the standard deviation, for a normally distributed signal.
-  QuicTime::Delta mean_deviation_;
-  int64_t initial_rtt_us_;
-
-  // Variables used to force a new windowed_min_rtt measurement within
-  // num_samples_for_forced_min_.
-  QuicTime::Delta forced_windowed_min_rtt_;
-  QuicTime forced_windowed_min_rtt_time_;
-  uint32_t num_samples_for_forced_min_;
-
-  // Windowed min_rtt.
-  WindowedFilter<QuicTime::Delta,
-                 MinFilter<QuicTime::Delta>,
-                 QuicTime,
-                 QuicTime::Delta>
-      windowed_min_rtt_;
-
-  DISALLOW_COPY_AND_ASSIGN(RttStats);
-};
-
-}  // namespace net
-
-#endif  // NET_QUIC_CONGESTION_CONTROL_RTT_STATS_H_