Coalesce small buffers in net::BidirectionalStream

net/quic/bidirectional_stream_quic_impl.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/bidirectional_stream_quic_impl.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/timer/timer.h"
 #include "net/http/bidirectional_stream_request_info.h"
+#include "net/quic/quic_connection.h"
 #include "net/socket/next_proto.h"
 #include "net/spdy/spdy_header_block.h"
 #include "net/spdy/spdy_http_utils.h"
 
 namespace net {
 
 BidirectionalStreamQuicImpl::BidirectionalStreamQuicImpl(
     const base::WeakPtr<QuicChromiumClientSession>& session)
     : session_(session),
       was_handshake_confirmed_(session->IsCryptoHandshakeConfirmed()),
       stream_(nullptr),
       request_info_(nullptr),
       delegate_(nullptr),
       response_status_(OK),
       negotiated_protocol_(kProtoUnknown),
       read_buffer_len_(0),
       headers_bytes_received_(0),
       headers_bytes_sent_(0),
       closed_stream_received_bytes_(0),
       closed_stream_sent_bytes_(0),
       has_sent_headers_(false),
       has_received_headers_(false),
+      disable_auto_flush_(false),
       weak_factory_(this) {
   DCHECK(session_);
   session_->AddObserver(this);
 }
 
 BidirectionalStreamQuicImpl::~BidirectionalStreamQuicImpl() {
   Cancel();
   if (session_)
     session_->RemoveObserver(this);
 }
 
 void BidirectionalStreamQuicImpl::Start(
     const BidirectionalStreamRequestInfo* request_info,
     const BoundNetLog& net_log,
+    bool disable_auto_flush,
     BidirectionalStreamImpl::Delegate* delegate,
     scoped_ptr<base::Timer> /* timer */) {
   DCHECK(!stream_);
 
+  disable_auto_flush_ = disable_auto_flush;
   if (!session_) {
     NotifyError(was_handshake_confirmed_ ? ERR_QUIC_PROTOCOL_ERROR
                                          : ERR_QUIC_HANDSHAKE_FAILED);
     return;
   }
 
   delegate_ = delegate;
   request_info_ = request_info;
 
   int rv = stream_request_.StartRequest(
@@ skipping 43 matching lines @@
       base::Bind(&BidirectionalStreamQuicImpl::OnSendDataComplete,
                  weak_factory_.GetWeakPtr()));
   DCHECK(rv == OK || rv == ERR_IO_PENDING);
   if (rv == OK) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(&BidirectionalStreamQuicImpl::OnSendDataComplete,
                               weak_factory_.GetWeakPtr(), OK));
   }
 }
 
+void BidirectionalStreamQuicImpl::SendvData(
+    const std::vector<IOBuffer*>& buffers,
+    const std::vector<int>& lengths,
+    bool end_stream) {
+  DCHECK(stream_);
+  DCHECK_EQ(buffers.size(), lengths.size());
+
+  QuicConnection::ScopedPacketBundler bundler(
+      session_->connection(), QuicConnection::SEND_ACK_IF_PENDING);
+  if (!has_sent_headers_) {
+    SendRequestHeaders();
+  }
+
+  std::vector<base::StringPiece> input_buffers;
+  for (size_t i = 0; i < buffers.size(); ++i) {
+    base::StringPiece string_data(buffers[i]->data(), lengths[i]);
+    input_buffers.push_back(string_data);

[Ryan Hamilton, 2016/04/13 03:42:28]

Instead of allocating a new std::vector with StringPiece copies of the IOBuffers
and then passing them to a newly created Writev method, how about simply calling
WritevStreamData for each chunk of data to be written?

[xunjieli, 2016/04/13 14:53:15]

Done. I got rid of the newly allocated std::vector. But I am not sure if that is
what you meant. Calling WriteStreamData on each chunk is not feasible right?
Because WriteStreamData has a DCHECK to make sure that it is called only when
there is no buffered data. If we get rid of Writev and use WriteStreamData, then
won't we encounter the DCHECK(!HasBufferedData()) ?

+  }
+
+  int rv = stream_->WritevStreamData(
+      input_buffers, end_stream,
+      base::Bind(&BidirectionalStreamQuicImpl::OnSendDataComplete,
+                 weak_factory_.GetWeakPtr()));
+
+  DCHECK(rv == OK || rv == ERR_IO_PENDING);
+  if (rv == OK) {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(&BidirectionalStreamQuicImpl::OnSendDataComplete,
+                              weak_factory_.GetWeakPtr(), OK));
+  }
+}
+
 void BidirectionalStreamQuicImpl::Cancel() {
   if (stream_) {
     stream_->SetDelegate(nullptr);
     stream_->Reset(QUIC_STREAM_CANCELLED);
     ResetStream();
   }
 }
 
 NextProto BidirectionalStreamQuicImpl::GetProtocol() const {
   return negotiated_protocol_;
@@ skipping 76 matching lines @@
   DCHECK_NE(OK, error);
   session_.reset();
   NotifyError(error);
 }
 
 void BidirectionalStreamQuicImpl::OnStreamReady(int rv) {
   DCHECK_NE(ERR_IO_PENDING, rv);
   DCHECK(rv == OK || !stream_);
   if (rv == OK) {
     stream_->SetDelegate(this);
-    SendRequestHeaders();
+    if (!disable_auto_flush_) {
+      SendRequestHeaders();
+    }
+    delegate_->OnStreamReady();
   } else {
     NotifyError(rv);
   }
 }
 
 void BidirectionalStreamQuicImpl::OnSendDataComplete(int rv) {
   DCHECK(rv == OK || !stream_);
   if (rv == OK) {
     delegate_->OnDataSent();
   } else {
@@ skipping 11 matching lines @@
   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;
-  delegate_->OnHeadersSent();
 }
 
 void BidirectionalStreamQuicImpl::NotifyError(int error) {
   DCHECK_NE(OK, error);
   DCHECK_NE(ERR_IO_PENDING, error);
 
   response_status_ = error;
   ResetStream();
   delegate_->OnFailed(error);
 }
 
 void BidirectionalStreamQuicImpl::ResetStream() {
   if (!stream_)
     return;
   closed_stream_received_bytes_ = stream_->stream_bytes_read();
   closed_stream_sent_bytes_ = stream_->stream_bytes_written();
   stream_->SetDelegate(nullptr);
   stream_ = nullptr;
 }
 
 }  // namespace net