commit be634b753728c7d6f0a041a2da9f5c99b398814f
author wub <wub@google.com> Tue Jun 16 08:41:26 2020 -0700
committer Copybara-Service <copybara-worker@google.com> Tue Jun 16 08:42:15 2020 -0700
tree 21ef86222d221d1cf5c1e6781f3caabbfb6797c7
parent 5c3628823dc76b22f5b020177514b1db36f505e4

For loss detection tuning, if user agent is available, save it into quicsession. protected by --gfe2_reloadable_flag_quic_save_user_agent_in_quic_session.

PiperOrigin-RevId: 316688269
Change-Id: I2a25beeb081b38ae204a62c14459427341efa5e0

quic/core/quic_crypto_server_stream.cc

diff --git a/quic/core/quic_crypto_server_stream.cc b/quic/core/quic_crypto_server_stream.cc
index b21745c..6c84067 100644
--- a/quic/core/quic_crypto_server_stream.cc
+++ b/quic/core/quic_crypto_server_stream.cc
@@ -8,6 +8,7 @@
 #include <string>
 
 #include "third_party/boringssl/src/include/openssl/sha.h"
+#include "net/third_party/quiche/src/quic/platform/api/quic_flag_utils.h"
 #include "net/third_party/quiche/src/common/platform/api/quiche_arraysize.h"
 #include "net/third_party/quiche/src/common/platform/api/quiche_string_piece.h"
 #include "net/third_party/quiche/src/common/platform/api/quiche_text_utils.h"
@@ -400,6 +401,17 @@
                  nullptr);
     return;
   }
+
+  if (GetQuicReloadableFlag(quic_save_user_agent_in_quic_session)) {
+    QUIC_RELOADABLE_FLAG_COUNT_N(quic_save_user_agent_in_quic_session, 1, 3);
+    quiche::QuicheStringPiece user_agent_id;
+    message.GetStringPiece(quic::kUAID, &user_agent_id);
+    if (!session()->user_agent_id().has_value()) {
+      std::string uaid = user_agent_id.empty() ? "" : user_agent_id.data();
+      session()->SetUserAgentId(std::move(uaid));
+    }
+  }
+
   if (!result->info.server_nonce.empty()) {
     ++num_handshake_messages_with_server_nonces_;
   }