[Cronet] Make delaying sending request headers explicit in bidirectional stream

net/quic/bidirectional_stream_quic_impl.cc

Index: net/quic/bidirectional_stream_quic_impl.cc
diff --git a/net/quic/bidirectional_stream_quic_impl.cc b/net/quic/bidirectional_stream_quic_impl.cc
index b85997b67f2cd479e66dcf7191657bfd439fea2c..3d1ae3cd4b31020e8638845d9e2ab2494acc7b27 100644
--- a/net/quic/bidirectional_stream_quic_impl.cc
+++ b/net/quic/bidirectional_stream_quic_impl.cc
@@ -32,7 +32,7 @@ BidirectionalStreamQuicImpl::BidirectionalStreamQuicImpl(
       closed_stream_sent_bytes_(0),
       has_sent_headers_(false),
       has_received_headers_(false),
-      disable_auto_flush_(false),
+      send_request_headers_automatically_(true),
       weak_factory_(this) {
   DCHECK(session_);
   session_->AddObserver(this);
@@ -47,12 +47,12 @@ BidirectionalStreamQuicImpl::~BidirectionalStreamQuicImpl() {
 void BidirectionalStreamQuicImpl::Start(
     const BidirectionalStreamRequestInfo* request_info,
     const BoundNetLog& net_log,
-    bool disable_auto_flush,
+    bool send_request_headers_automatically,
     BidirectionalStreamImpl::Delegate* delegate,
     std::unique_ptr<base::Timer> /* timer */) {
   DCHECK(!stream_);
 
-  disable_auto_flush_ = disable_auto_flush;
+  send_request_headers_automatically_ = send_request_headers_automatically;
   if (!session_) {
     NotifyError(was_handshake_confirmed_ ? ERR_QUIC_PROTOCOL_ERROR
                                          : ERR_QUIC_HANDSHAKE_FAILED);
@@ -73,6 +73,25 @@ void BidirectionalStreamQuicImpl::Start(
   }
 }
 
+void BidirectionalStreamQuicImpl::SendRequestHeaders() {
+  DCHECK(!has_sent_headers_);
+  DCHECK(stream_);
+
+  SpdyHeaderBlock headers;
+  HttpRequestInfo http_request_info;
+  http_request_info.url = request_info_->url;
+  http_request_info.method = request_info_->method;

[mef, 2016/06/01 21:33:21]

Not for this CL, but we may consider making BidirectionalStreamRequestInfo based
on HttpRequestInfo to avoid needless copy here.

Not sure how expensive is copying the content of HttpRequestHeaders.

[xunjieli, 2016/06/01 22:27:17]

Acknowledged.

+  http_request_info.extra_headers = request_info_->extra_headers;
+
+  CreateSpdyHeadersFromHttpRequest(http_request_info,
+                                   http_request_info.extra_headers, HTTP2, true,
+                                   &headers);
+  size_t frame_len = stream_->WriteHeaders(

[mef, 2016/06/01 21:33:21]

nit: size_t frame_len => headers_bytes_sent_

[xunjieli, 2016/06/01 22:27:17]

Done.

+      headers, request_info_->end_stream_on_headers, nullptr);
+  headers_bytes_sent_ += frame_len;
+  has_sent_headers_ = true;
+}
+
 int BidirectionalStreamQuicImpl::ReadData(IOBuffer* buffer, int buffer_len) {
   DCHECK(buffer);
   DCHECK(buffer_len);
@@ -103,6 +122,16 @@ void BidirectionalStreamQuicImpl::SendData(const scoped_refptr<IOBuffer>& data,
   DCHECK(stream_);
   DCHECK(length > 0 || (length == 0 && end_stream));
 
+  std::unique_ptr<QuicConnection::ScopedPacketBundler> bundler;
+  if (!has_sent_headers_) {
+    DCHECK(!send_request_headers_automatically_);
+    // Creates a bundler only if there are headers to be sent along with the
+    // single data buffer.
+    bundler.reset(new QuicConnection::ScopedPacketBundler(
+        session_->connection(), QuicConnection::SEND_ACK_IF_PENDING));
+    SendRequestHeaders();
+  }
+
   base::StringPiece string_data(data->data(), length);
   int rv = stream_->WriteStreamData(
       string_data, end_stream,
@@ -126,6 +155,7 @@ void BidirectionalStreamQuicImpl::SendvData(
   QuicConnection::ScopedPacketBundler bundler(
       session_->connection(), QuicConnection::SEND_ACK_IF_PENDING);
   if (!has_sent_headers_) {
+    DCHECK(!send_request_headers_automatically_);
     SendRequestHeaders();
   }
 
@@ -238,10 +268,10 @@ void BidirectionalStreamQuicImpl::OnStreamReady(int rv) {
   DCHECK(rv == OK || !stream_);
   if (rv == OK) {
     stream_->SetDelegate(this);
-    if (!disable_auto_flush_) {
+    if (send_request_headers_automatically_) {
       SendRequestHeaders();
     }
-    delegate_->OnStreamReady();
+    delegate_->OnStreamReady(send_request_headers_automatically_);

[mef, 2016/06/01 21:33:21]

send_request_headers_automatically_ => has_sent_headers_

[xunjieli, 2016/06/01 22:27:16]

Done.

   } else {
     NotifyError(rv);
   }
@@ -256,25 +286,6 @@ void BidirectionalStreamQuicImpl::OnSendDataComplete(int rv) {
   }
 }
 
-void BidirectionalStreamQuicImpl::SendRequestHeaders() {
-  DCHECK(!has_sent_headers_);
-  DCHECK(stream_);
-
-  SpdyHeaderBlock headers;
-  HttpRequestInfo http_request_info;
-  http_request_info.url = request_info_->url;
-  http_request_info.method = request_info_->method;
-  http_request_info.extra_headers = request_info_->extra_headers;
-
-  CreateSpdyHeadersFromHttpRequest(http_request_info,
-                                   http_request_info.extra_headers, HTTP2, true,
-                                   &headers);
-  size_t frame_len = stream_->WriteHeaders(
-      headers, request_info_->end_stream_on_headers, nullptr);
-  headers_bytes_sent_ += frame_len;
-  has_sent_headers_ = true;
-}
-
 void BidirectionalStreamQuicImpl::NotifyError(int error) {
   DCHECK_NE(OK, error);
   DCHECK_NE(ERR_IO_PENDING, error);