commit 3eae7e4e3cdf1a7459905e734f2902876bdaa9cd
author Erik Språng <sprang@webrtc.org> Fri Oct 25 09:24:45 2019 +0200
committer Commit Bot <commit-bot@chromium.org> Mon Oct 28 10:06:23 2019 +0000
tree 64b0baad0931af80bc11dbf09a2bd57319777fbe
parent 632d57d3d0fd6926eb907cb9f8d818f9bfeac672

Add exponential backoff of retransmissions for a given packet

Bug: webrtc:8624
Change-Id: I8900c54935bf1da11ac74665426b0d198bd6d814
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/30900
Reviewed-by: Sergey Silkin <ssilkin@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29625}

modules/video_coding/nack_module.h

diff --git a/modules/video_coding/nack_module.h b/modules/video_coding/nack_module.h
index fba55b1..d4f705b 100644
--- a/modules/video_coding/nack_module.h
+++ b/modules/video_coding/nack_module.h
@@ -17,6 +17,7 @@
 #include <set>
 #include <vector>
 
+#include "api/units/time_delta.h"
 #include "modules/include/module.h"
 #include "modules/include/module_common_types.h"
 #include "modules/video_coding/histogram.h"
@@ -64,6 +65,19 @@
     int64_t sent_at_time;
     int retries;
   };
+
+  struct BackoffSettings {
+    BackoffSettings(TimeDelta min_retry, TimeDelta max_rtt, double base);
+    static absl::optional<BackoffSettings> ParseFromFieldTrials();
+
+    // Min time between nacks.
+    const TimeDelta min_retry_interval;
+    // Upper bound on link-delay considered for exponential backoff.
+    const TimeDelta max_rtt;
+    // Base for the exponential backoff.
+    const double base;
+  };
+
   void AddPacketsToNack(uint16_t seq_num_start, uint16_t seq_num_end)
       RTC_EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
@@ -106,6 +120,8 @@
 
   // Adds a delay before send nack on packet received.
   const int64_t send_nack_delay_ms_;
+
+  const absl::optional<BackoffSettings> backoff_settings_;
 };
 
 }  // namespace webrtc