commit 7498c8c59b8a8ea83db9368a889323bd0b146544
author renjietang <renjietang@google.com> Tue Jul 02 19:28:42 2019 -0700
committer Copybara-Service <copybara-worker@google.com> Tue Jul 02 19:34:41 2019 -0700
tree f22596a52c5dc0412656e5a757690b234739b329
parent 014740d305715301a61e322f254aa2819c323349

In HTTP/3, write Priority on control stream before writing headers.

Currently the priority is in gQUIC fashion, where we only use the weight to build priority queue.

Priority might be sent on the control stream before handshake is confirmed. So this CL modifies QuicSendControlStream to send stream type and settings before any other data is sent.

gfe-relnote: v99 only, not in prod.
PiperOrigin-RevId: 256285943
Change-Id: Iaf72f9d6256a2692b284e3f6142755ff0d04d710

quic/core/http/quic_spdy_stream.cc

diff --git a/quic/core/http/quic_spdy_stream.cc b/quic/core/http/quic_spdy_stream.cc
index 9966f81..c625410 100644
--- a/quic/core/http/quic_spdy_stream.cc
+++ b/quic/core/http/quic_spdy_stream.cc
@@ -168,6 +168,7 @@
       trailers_length_(0, 0),
       trailers_decompressed_(false),
       trailers_consumed_(false),
+      priority_sent_(false),
       headers_bytes_to_be_marked_consumed_(0),
       pretend_blocked_decoding_for_tests_(false),
       http_decoder_visitor_(new HttpDecoderVisitor(this)),
@@ -204,6 +205,7 @@
       trailers_length_(0, 0),
       trailers_decompressed_(false),
       trailers_consumed_(false),
+      priority_sent_(false),
       headers_bytes_to_be_marked_consumed_(0),
       pretend_blocked_decoding_for_tests_(false),
       http_decoder_visitor_(new HttpDecoderVisitor(this)),
@@ -920,6 +922,13 @@
         std::move(ack_listener));
   }
 
+  if (session()->perspective() == Perspective::IS_CLIENT && !priority_sent_) {
+    PriorityFrame frame;
+    PopulatePriorityFrame(&frame);
+    spdy_session_->WriteH3Priority(frame);
+    priority_sent_ = true;
+  }
+
   // Encode header list.
   std::string encoded_headers =
       spdy_session_->qpack_encoder()->EncodeHeaderList(id(), &header_block);
@@ -948,5 +957,12 @@
   return encoded_headers.size();
 }
 
+void QuicSpdyStream::PopulatePriorityFrame(PriorityFrame* frame) {
+  frame->weight = priority();
+  frame->dependency_type = ROOT_OF_TREE;
+  frame->prioritized_type = REQUEST_STREAM;
+  frame->prioritized_element_id = id();
+}
+
 #undef ENDPOINT  // undef for jumbo builds
 }  // namespace quic