commit 95cf38306a61024b090910e8bec4b756832dbde1
author ianswett <ianswett@google.com> Tue Jan 21 07:58:25 2020 -0800
committer Copybara-Service <copybara-worker@google.com> Tue Jan 21 07:59:10 2020 -0800
tree 20230ec61305016838a579b275f04b197d0aed9c
parent dfabdfb6884bf8ccd92c6f818aa8764a84f5a984

gfe-relnote: Add a connection option(1ACK) to send only one immediate ACK in QUIC after reordering, instead of 4.  Protected by gfe2_reloadable_flag_quic_one_immediate_ack

PiperOrigin-RevId: 290743392
Change-Id: I0c1a557d48f3b0b0c3e58c235d6c97dd79973c68

quic/core/quic_received_packet_manager.cc

diff --git a/quic/core/quic_received_packet_manager.cc b/quic/core/quic_received_packet_manager.cc
index 9e33ea4..4333323 100644
--- a/quic/core/quic_received_packet_manager.cc
+++ b/quic/core/quic_received_packet_manager.cc
@@ -12,6 +12,7 @@
 #include "net/third_party/quiche/src/quic/core/crypto/crypto_protocol.h"
 #include "net/third_party/quiche/src/quic/core/quic_connection_stats.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_bug_tracker.h"
+#include "net/third_party/quiche/src/quic/platform/api/quic_flags.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_logging.h"
 
 namespace quic {
@@ -50,6 +51,7 @@
       ack_decimation_delay_(kAckDecimationDelay),
       unlimited_ack_decimation_(false),
       fast_ack_after_quiescence_(false),
+      one_immediate_ack_(false),
       local_max_ack_delay_(
           QuicTime::Delta::FromMilliseconds(kDefaultDelayedAckTimeMs)),
       ack_timeout_(QuicTime::Zero()),
@@ -88,6 +90,11 @@
   if (config.HasClientSentConnectionOption(kACKQ, perspective)) {
     fast_ack_after_quiescence_ = true;
   }
+  if (GetQuicReloadableFlag(quic_one_immediate_ack) &&
+      config.HasClientSentConnectionOption(k1ACK, perspective)) {
+    QUIC_RELOADABLE_FLAG_COUNT(quic_one_immediate_ack);
+    one_immediate_ack_ = true;
+  }
 }
 
 void QuicReceivedPacketManager::RecordPacketReceived(
@@ -315,6 +322,9 @@
 }
 
 bool QuicReceivedPacketManager::HasNewMissingPackets() const {
+  if (one_immediate_ack_) {
+    return HasMissingPackets() && ack_frame_.packets.LastIntervalLength() == 1;
+  }
   return HasMissingPackets() &&
          ack_frame_.packets.LastIntervalLength() <= kMaxPacketsAfterNewMissing;
 }