From 7baa63ff9c35f2f0d9845316031bb33b859cd216 Mon Sep 17 00:00:00 2001
From: Philipp Hancke <phancke@microsoft.com>
Date: Thu, 1 Sep 2022 15:39:50 +0200
Subject: [PATCH] peerconnection: invalidate stats cache during SLD/SRD
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which may allow caching some relatively persistent statistics
such as codec statistics that only change during renegotiation.

BUG=webrtc:8693

Change-Id: Ifd68c9d666d9f328d0efecb64e4201d003788ca8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/273324
Commit-Queue: Philipp Hancke <phancke@microsoft.com>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37981}
---
 api/peer_connection_interface.h |  2 --
 pc/peer_connection.cc           |  3 +++
 pc/peer_connection_internal.h   |  2 ++
 pc/sdp_offer_answer.cc          | 16 ++++++++--------
 4 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/api/peer_connection_interface.h b/api/peer_connection_interface.h
index 373b7586de..66a12f4fac 100644
--- a/api/peer_connection_interface.h
+++ b/api/peer_connection_interface.h
@@ -950,8 +950,6 @@ class RTC_EXPORT PeerConnectionInterface : public rtc::RefCountInterface {
       rtc::scoped_refptr<RtpReceiverInterface> selector,
       rtc::scoped_refptr<RTCStatsCollectorCallback> callback) = 0;
   // Clear cached stats in the RTCStatsCollector.
-  // Exposed for testing while waiting for automatic cache clear to work.
-  // https://bugs.webrtc.org/8693
   virtual void ClearStatsCache() {}
 
   // Create a data channel with the provided config, or default config if none
diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index 367341bbb3..1c0e695158 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -2985,6 +2985,9 @@ CryptoOptions PeerConnection::GetCryptoOptions() {
 
 void PeerConnection::ClearStatsCache() {
   RTC_DCHECK_RUN_ON(signaling_thread());
+  if (legacy_stats_) {
+    legacy_stats_->InvalidateCache();
+  }
   if (stats_collector_) {
     stats_collector_->ClearCachedStatsReport();
   }
diff --git a/pc/peer_connection_internal.h b/pc/peer_connection_internal.h
index bc1ce183e7..1bca156316 100644
--- a/pc/peer_connection_internal.h
+++ b/pc/peer_connection_internal.h
@@ -125,6 +125,8 @@ class PeerConnectionSdpMethods {
   virtual void ResetSctpDataMid() = 0;
 
   virtual const FieldTrialsView& trials() const = 0;
+
+  virtual void ClearStatsCache() = 0;
 };
 
 // Functions defined in this class are called by other objects,
diff --git a/pc/sdp_offer_answer.cc b/pc/sdp_offer_answer.cc
index 6936029b50..9a5023cd0b 100644
--- a/pc/sdp_offer_answer.cc
+++ b/pc/sdp_offer_answer.cc
@@ -1488,10 +1488,10 @@ RTCError SdpOfferAnswerHandler::ApplyLocalDescription(
   RTC_DCHECK_RUN_ON(signaling_thread());
   RTC_DCHECK(desc);
 
-  // Invalidate the legacy stats cache to make sure that it gets updated next
-  // time getStats() gets called, as updating the session description affects
-  // the stats.
-  pc_->legacy_stats()->InvalidateCache();
+  // Invalidate the stats caches to make sure that they get
+  // updated the next time getStats() gets called, as updating the session
+  // description affects the stats.
+  pc_->ClearStatsCache();
 
   // Take a reference to the old local description since it's used below to
   // compare against the new local description. When setting the new local
@@ -1823,10 +1823,10 @@ void SdpOfferAnswerHandler::ApplyRemoteDescription(
   RTC_DCHECK_RUN_ON(signaling_thread());
   RTC_DCHECK(operation->description());
 
-  // Invalidate the [legacy] stats cache to make sure that it gets updated next
-  // time getStats() gets called, as updating the session description affects
-  // the stats.
-  pc_->legacy_stats()->InvalidateCache();
+  // Invalidate the stats caches to make sure that they get
+  // updated next time getStats() gets called, as updating the session
+  // description affects the stats.
+  pc_->ClearStatsCache();
 
   if (!operation->ReplaceRemoteDescriptionAndCheckEror())
     return;