Make initialization of the QuicInMemoryCache explicit to avoid spooky action at a distance which co…

net/tools/quic/quic_server.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/tools/quic/quic_server.h"
 
 #include <errno.h>
 #ifndef __APPLE__
 // This is a GNU header that is not present in /usr/include on MacOS
 #include <features.h>
@@ skipping 22 matching lines @@
 // QuicServer.
 // TODO(rtenneti): Enable this flag after MMSG_MORE is set to 1.
 #define FLAGS_quic_use_optimized_packet_reader false
 
 #ifndef SO_RXQ_OVFL
 #define SO_RXQ_OVFL 40
 #endif
 
 namespace net {
 namespace tools {
+namespace {
 
-namespace {
+// Specifies the directory used during QuicInMemoryCache
+// construction to seed the cache. Cache directory can be
+// generated using `wget -p --save-headers <url>`
+std::string FLAGS_quic_in_memory_cache_dir = "";
 
 const PollBits kEpollFlags = PollBits(NET_POLLIN | NET_POLLOUT | NET_POLLET);
 const char kSourceAddressTokenSecret[] = "secret";
 
 }  // namespace
 
 QuicServer::QuicServer()
     : port_(0),
       fd_(-1),
       packets_dropped_(0),
@@ skipping 33 matching lines @@
     config_.SetInitialStreamFlowControlWindowToSend(
         kInitialStreamFlowControlWindow);
   }
   if (config_.GetInitialSessionFlowControlWindowToSend() ==
       kMinimumFlowControlSendWindow) {
     config_.SetInitialSessionFlowControlWindowToSend(
         kInitialSessionFlowControlWindow);
   }
 
   epoll_server_.set_timeout_in_us(50 * 1000);
-  // Initialize the in memory cache now.
-  QuicInMemoryCache::GetInstance();
+
+  if (!FLAGS_quic_in_memory_cache_dir.empty()) {
+    QuicInMemoryCache::GetInstance()->InitializeFromDirectory(
+        FLAGS_quic_in_memory_cache_dir);
+  }
 
   QuicEpollClock clock(&epoll_server_);
 
   scoped_ptr<CryptoHandshakeMessage> scfg(
       crypto_config_.AddDefaultConfig(
           QuicRandom::GetInstance(), &clock,
           QuicCryptoServerConfig::ConfigOptions()));
 }
 
 QuicServer::~QuicServer() {
@@ skipping 164 matching lines @@
   QuicEncryptedPacket packet(buf, bytes_read, false);
 
   IPEndPoint server_address(server_ip, port);
   processor->ProcessPacket(server_address, client_address, packet);
 
   return true;
 }
 
 }  // namespace tools
 }  // namespace net