From 1fe14f2752a35932bea6d6ccff7433a6716c6391 Mon Sep 17 00:00:00 2001
From: Philipp Hancke <philipp.hancke@googlemail.com>
Date: Fri, 17 Jun 2022 11:34:31 +0200
Subject: [PATCH] pc: invalidate stats cache when firing onicecandidate
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

https://w3c.github.io/webrtc-stats/#guidelines-for-getstats-results-caching-throttling
"When the state of the RTCPeerConnection visibly changes as a result of an API call, a promise resolving or an event firing, subsequent new getStats() calls must return up-to-date dictionaries for the affected objects."

BUG=webrtc:14190

Change-Id: I4560be22795f30e0369d573bda0100e490efb57b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/265870
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Commit-Queue: Philipp Hancke <philipp.hancke@googlemail.com>
Cr-Commit-Position: refs/heads/main@{#37255}
---
 pc/peer_connection.cc                 |  1 +
 pc/peer_connection_integrationtest.cc | 32 +++++++++++++++++++++++++++
 pc/test/integration_test_helpers.h    |  5 +++++
 3 files changed, 38 insertions(+)

diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index 557f2e6899..11004ba743 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -2000,6 +2000,7 @@ void PeerConnection::OnIceCandidate(
     return;
   }
   ReportIceCandidateCollected(candidate->candidate());
+  ClearStatsCache();
   Observer()->OnIceCandidate(candidate.get());
 }
 
diff --git a/pc/peer_connection_integrationtest.cc b/pc/peer_connection_integrationtest.cc
index 9811392bbd..d6ac0c82c9 100644
--- a/pc/peer_connection_integrationtest.cc
+++ b/pc/peer_connection_integrationtest.cc
@@ -2418,6 +2418,38 @@ TEST_P(PeerConnectionIntegrationTestWithFakeClock,
   ClosePeerConnections();
 }
 
+TEST_P(PeerConnectionIntegrationTestWithFakeClock,
+       OnIceCandidateFlushesGetStatsCache) {
+  ASSERT_TRUE(CreatePeerConnectionWrappers());
+  ConnectFakeSignaling();
+  caller()->AddAudioTrack();
+
+  // Call getStats, assert there are no candidates.
+  rtc::scoped_refptr<const webrtc::RTCStatsReport> first_report =
+      caller()->NewGetStats();
+  ASSERT_TRUE(first_report);
+  auto first_candidate_stats =
+      first_report->GetStatsOfType<webrtc::RTCLocalIceCandidateStats>();
+  ASSERT_EQ(first_candidate_stats.size(), 0u);
+
+  // Start candidate gathering and wait for it to complete.
+  caller()->CreateAndSetAndSignalOffer();
+  ASSERT_TRUE_SIMULATED_WAIT(caller()->IceGatheringStateComplete(),
+                             kDefaultTimeout, FakeClock());
+
+  // Call getStats again, assert there are candidates now.
+  rtc::scoped_refptr<const webrtc::RTCStatsReport> second_report =
+      caller()->NewGetStats();
+  ASSERT_TRUE(second_report);
+  auto second_candidate_stats =
+      second_report->GetStatsOfType<webrtc::RTCLocalIceCandidateStats>();
+  ASSERT_NE(second_candidate_stats.size(), 0u);
+
+  // The fake clock ensures that no time has passed so the cache must have been
+  // explicitly invalidated.
+  EXPECT_EQ(first_report->timestamp_us(), second_report->timestamp_us());
+}
+
 #endif  // !defined(THREAD_SANITIZER)
 
 // Verify that a TurnCustomizer passed in through RTCConfiguration
diff --git a/pc/test/integration_test_helpers.h b/pc/test/integration_test_helpers.h
index 53df9fc478..460148c559 100644
--- a/pc/test/integration_test_helpers.h
+++ b/pc/test/integration_test_helpers.h
@@ -410,6 +410,11 @@ class PeerConnectionIntegrationWrapper : public webrtc::PeerConnectionObserver,
     return pc()->signaling_state() == webrtc::PeerConnectionInterface::kStable;
   }
 
+  bool IceGatheringStateComplete() {
+    return pc()->ice_gathering_state() ==
+           webrtc::PeerConnectionInterface::kIceGatheringComplete;
+  }
+
   void CreateDataChannel() { CreateDataChannel(nullptr); }
 
   void CreateDataChannel(const webrtc::DataChannelInit* init) {