Refactoring: Create per-connection packet writers in QuicDispatcher.

net/quic/quic_stream_factory.cc

 // Copyright (c) 2012 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/quic_stream_factory.h"
 
 #include <set>
 
 #include "base/cpu.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 82 matching lines @@
   config.EnablePacing(enable_pacing);
   if (enable_time_based_loss_detection)
     config.SetLossDetectionToSend(kTIME);
   config.set_idle_connection_state_lifetime(
       QuicTime::Delta::FromSeconds(kIdleConnectionTimeoutSeconds),
       QuicTime::Delta::FromSeconds(kIdleConnectionTimeoutSeconds));
   config.SetConnectionOptionsToSend(connection_options);
   return config;
 }
 
+class ClientPacketWriterFactory : public QuicConnection::PacketWriterFactory {

[wtc, 2014/08/13 21:01:34]

Note: I picked the "ClientPacketWriterFactory" name temporarily. Can you suggest
a better name? Perhaps "ChromiumPacketWriterFactory"? Or do you think
"ClientPacketWriterFactory" is a fine name?

[dmz, 2014/08/14 17:22:42]

I probably would have gone with DefaultPacketWriterFactory, but I think
ClientPacketWriterFactory is perfectly good. 

[wtc, 2014/08/14 20:05:00]

Ah, I now also prefer "Default" because this factory creates
QuicDefaultPacketWriter. Can you make this change?

[dmz, 2014/08/14 21:24:51]

Done.

+ public:
+  explicit ClientPacketWriterFactory(DatagramClientSocket* socket)
+      : socket_(socket) {}
+  virtual ~ClientPacketWriterFactory() {}
+
+  virtual QuicPacketWriter* Create(QuicConnection* connection) const OVERRIDE;
+
+ private:
+  DatagramClientSocket* socket_;
+};
+
+QuicPacketWriter* ClientPacketWriterFactory::Create(
+    QuicConnection* connection) const {
+  scoped_ptr<QuicDefaultPacketWriter> writer(
+      new QuicDefaultPacketWriter(socket_));
+  writer->SetConnection(connection);
+  return writer.release();
+}
+
 }  // namespace
 
 QuicStreamFactory::IpAliasKey::IpAliasKey() {}
 
 QuicStreamFactory::IpAliasKey::IpAliasKey(IPEndPoint ip_endpoint,
                                           bool is_https)
     : ip_endpoint(ip_endpoint),
       is_https(is_https) {}
 
 QuicStreamFactory::IpAliasKey::~IpAliasKey() {}
@@ skipping 702 matching lines @@
   }
   // Set a buffer large enough to contain the initial CWND's worth of packet
   // to work around the problem with CHLO packets being sent out with the
   // wrong encryption level, when the send buffer is full.
   rv = socket->SetSendBufferSize(kMaxPacketSize * 20);
   if (rv != OK) {
     HistogramCreateSessionFailure(CREATION_ERROR_SETTING_SEND_BUFFER);
     return rv;
   }
 
-  scoped_ptr<QuicDefaultPacketWriter> writer(
-      new QuicDefaultPacketWriter(socket.get()));
+  ClientPacketWriterFactory packet_writer_factory(socket.get());
 
   if (!helper_.get()) {
     helper_.reset(new QuicConnectionHelper(
         base::MessageLoop::current()->message_loop_proxy().get(),
         clock_.get(), random_generator_));
   }
 
   QuicConnection* connection = new QuicConnection(connection_id,
                                                   addr,
                                                   helper_.get(),
-                                                  writer.get(),
-                                                  false  /* owns_writer */,
+                                                  packet_writer_factory,
+                                                  true  /* owns_writer */,
                                                   false  /* is_server */,
                                                   supported_versions_);
-  writer->SetConnection(connection);
   connection->set_max_packet_length(max_packet_length_);
 
   InitializeCachedStateInCryptoConfig(server_id, server_info);
 
   QuicConfig config = config_;
   config.SetInitialCongestionWindowToSend(
       server_id.is_https() ? kServerSecureInitialCongestionWindow
                            : kServerInecureInitialCongestionWindow);
   config.SetInitialFlowControlWindowToSend(kInitialReceiveWindowSize);
   config.SetInitialStreamFlowControlWindowToSend(kInitialReceiveWindowSize);
   config.SetInitialSessionFlowControlWindowToSend(kInitialReceiveWindowSize);
   if (http_server_properties_) {
     const HttpServerProperties::NetworkStats* stats =
         http_server_properties_->GetServerNetworkStats(
             server_id.host_port_pair());
     if (stats != NULL) {
       config.SetInitialRoundTripTimeUsToSend(stats->srtt.InMicroseconds());
     }
   }
 
   *session = new QuicClientSession(
-      connection, socket.Pass(), writer.Pass(), this,
+      connection, socket.Pass(), this,
       quic_crypto_client_stream_factory_, server_info.Pass(), server_id,
       config, &crypto_config_,
       base::MessageLoop::current()->message_loop_proxy().get(),
       net_log.net_log());
   (*session)->InitializeSession();
   all_sessions_[*session] = server_id;  // owning pointer
   return OK;
 }
 
 bool QuicStreamFactory::HasActiveJob(const QuicServerId& key) const {
@@ skipping 86 matching lines @@
   http_server_properties_->ClearAlternateProtocol(server);
   http_server_properties_->SetAlternateProtocol(
       server, alternate.port, alternate.protocol, 1);
   DCHECK_EQ(QUIC,
             http_server_properties_->GetAlternateProtocol(server).protocol);
   DCHECK(http_server_properties_->WasAlternateProtocolRecentlyBroken(
       server));
 }
 
 }  // namespace net