Move the logic from SendAlgorithmInterface::RetransmissionDelay() into QuicSentPacketManager, becau…

net/quic/core/quic_sent_packet_manager.cc

 // Copyright 2013 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/core/quic_sent_packet_manager.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 841 matching lines @@
   if (!unacked_packets_.HasMultipleInFlightPackets()) {
     return std::max(2 * srtt, 1.5 * srtt + QuicTime::Delta::FromMilliseconds(
                                                kMinRetransmissionTimeMs / 2));
   }
   return QuicTime::Delta::FromMilliseconds(
       max(kMinTailLossProbeTimeoutMs,
           static_cast<int64_t>(2 * srtt.ToMilliseconds())));
 }
 
 const QuicTime::Delta QuicSentPacketManager::GetRetransmissionDelay() const {
-  QuicTime::Delta retransmission_delay = send_algorithm_->RetransmissionDelay();
-  if (retransmission_delay.IsZero()) {
+  QuicTime::Delta retransmission_delay = QuicTime::Delta::Zero();
+  if (rtt_stats_.smoothed_rtt().IsZero()) {
     // We are in the initial state, use default timeout values.
     retransmission_delay =
         QuicTime::Delta::FromMilliseconds(kDefaultRetransmissionTimeMs);
-  } else if (retransmission_delay.ToMilliseconds() < kMinRetransmissionTimeMs) {
+  } else {
     retransmission_delay =
-        QuicTime::Delta::FromMilliseconds(kMinRetransmissionTimeMs);
+        rtt_stats_.smoothed_rtt() + 4 * rtt_stats_.mean_deviation();
+    if (retransmission_delay.ToMilliseconds() < kMinRetransmissionTimeMs) {
+      retransmission_delay =
+          QuicTime::Delta::FromMilliseconds(kMinRetransmissionTimeMs);
+    }
   }
 
   // Calculate exponential back off.
   retransmission_delay =
       retransmission_delay *
       (1 << min<size_t>(consecutive_rto_count_, kMaxRetransmissions));
 
   if (retransmission_delay.ToMilliseconds() > kMaxRetransmissionTimeMs) {
     return QuicTime::Delta::FromMilliseconds(kMaxRetransmissionTimeMs);
   }
@@ skipping 71 matching lines @@
     // Rtt and cwnd do not need to be reset when the peer address change is
     // considered to be caused by NATs.
     return;
   }
   consecutive_rto_count_ = 0;
   consecutive_tlp_count_ = 0;
   rtt_stats_.OnConnectionMigration();
   send_algorithm_->OnConnectionMigration();
 }
 
-
 void QuicSentPacketManager::SetDebugDelegate(DebugDelegate* debug_delegate) {
   debug_delegate_ = debug_delegate;
 }
 
 QuicPacketNumber QuicSentPacketManager::GetLargestObserved(QuicPathId) const {
   return unacked_packets_.largest_observed();
 }
 
 QuicPacketNumber QuicSentPacketManager::GetLargestSentPacket(QuicPathId) const {
   return unacked_packets_.largest_sent_packet();
@@ skipping 31 matching lines @@
 
 void QuicSentPacketManager::RemoveObsoletePackets() {
   unacked_packets_.RemoveObsoletePackets();
 }
 
 void QuicSentPacketManager::OnApplicationLimited() {
   send_algorithm_->OnApplicationLimited(unacked_packets_.bytes_in_flight());
 }
 
 }  // namespace net