Land Recent QUIC Changes.

net/tools/quic/quic_dispatcher.h

 // 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.
 //
 // A server side dispatcher which dispatches a given client's data to their
 // stream.
 
 #ifndef NET_TOOLS_QUIC_QUIC_DISPATCHER_H_
 #define NET_TOOLS_QUIC_QUIC_DISPATCHER_H_
 
 #include <list>
 
+#include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "net/base/ip_endpoint.h"
 #include "net/base/linked_hash_map.h"
 #include "net/quic/quic_blocked_writer_interface.h"
 #include "net/quic/quic_packet_writer.h"
 #include "net/quic/quic_protocol.h"
 #include "net/tools/epoll_server/epoll_server.h"
 #include "net/tools/quic/quic_server_session.h"
 #include "net/tools/quic/quic_time_wait_list_manager.h"
 
 #if defined(COMPILER_GCC)
 namespace BASE_HASH_NAMESPACE {
 template<>
 struct hash<net::QuicBlockedWriterInterface*> {
   std::size_t operator()(
       const net::QuicBlockedWriterInterface* ptr) const {
     return hash<size_t>()(reinterpret_cast<size_t>(ptr));
   }
 };
 }
 #endif
 
 namespace net {
 
 class EpollServer;
 class QuicConfig;
+class QuicConnectionHelper;
 class QuicCryptoServerConfig;
 class QuicSession;
 
 namespace tools {
 
+class QuicPacketWriterWrapper;
+
 namespace test {
 class QuicDispatcherPeer;
 }  // namespace test
 
 class DeleteSessionsAlarm;
 class QuicEpollConnectionHelper;
 
-class QuicDispatcher : public QuicPacketWriter, public QuicSessionOwner {
+class QuicDispatcher : public QuicPacketWriter,
+                       public QuicServerSessionVisitor {
  public:
   // Ideally we'd have a linked_hash_set: the  boolean is unused.
   typedef linked_hash_map<QuicBlockedWriterInterface*, bool> WriteBlockedList;
 
   // Due to the way delete_sessions_closure_ is registered, the Dispatcher
   // must live until epoll_server Shutdown. |supported_versions| specifies the
   // list of supported QUIC versions.
   QuicDispatcher(const QuicConfig& config,
                  const QuicCryptoServerConfig& crypto_config,
                  const QuicVersionVector& supported_versions,
-                 int fd,
                  EpollServer* epoll_server);
+
   virtual ~QuicDispatcher();
 
+  void Initialize(int fd);
+
   // QuicPacketWriter
   virtual WriteResult WritePacket(
       const char* buffer, size_t buf_len,
       const IPAddressNumber& self_address,
       const IPEndPoint& peer_address,
       QuicBlockedWriterInterface* writer) OVERRIDE;
   virtual bool IsWriteBlockedDataBuffered() const OVERRIDE;
   virtual bool IsWriteBlocked() const OVERRIDE;
   virtual void SetWritable() OVERRIDE;
 
   // Process the incoming packet by creating a new session, passing it to
   // an existing session, or passing it to the TimeWaitListManager.
   virtual void ProcessPacket(const IPEndPoint& server_address,
                              const IPEndPoint& client_address,
                              const QuicEncryptedPacket& packet);
 
   // Called when the underyling connection becomes writable to allow
   // queued writes to happen.
   //
   // Returns true if more writes are possible, false otherwise.
   virtual bool OnCanWrite();
 
   // Sends ConnectionClose frames to all connected clients.
   void Shutdown();
 
+  // QuicServerSessionVisitor interface implementation:
   // Ensure that the closed connection is cleaned up asynchronously.
   virtual void OnConnectionClosed(QuicGuid guid, QuicErrorCode error) OVERRIDE;
 
-  // Sets the fd and creates a default packet writer with that fd.
-  void set_fd(int fd);
+  // Queues the blocked writer for later resumption.
+  virtual void OnWriteBlocked(QuicBlockedWriterInterface* writer) OVERRIDE;
 
   typedef base::hash_map<QuicGuid, QuicSession*> SessionMap;
 
   virtual QuicSession* CreateQuicSession(
       QuicGuid guid,
       const IPEndPoint& server_address,
       const IPEndPoint& client_address);
 
   // Deletes all sessions on the closed session list and clears the list.
   void DeleteSessions();
 
   const SessionMap& session_map() const { return session_map_; }
 
   WriteBlockedList* write_blocked_list() { return &write_blocked_list_; }
 
  protected:
-  const QuicConfig& config_;
-  const QuicCryptoServerConfig& crypto_config_;
+  // Instantiates a new low-level packet writer. Caller takes ownership of the
+  // returned object.
+  QuicPacketWriter* CreateWriter(int fd);
+
+  // Instantiates a new top-level writer wrapper. Takes ownership of |writer|.
+  // Caller takes ownership of the returned object.
+  virtual QuicPacketWriterWrapper* CreateWriterWrapper(
+      QuicPacketWriter* writer);
+
+  // Replaces the packet writer with |writer|. Takes ownership of |writer|.
+  void set_writer(QuicPacketWriter* writer);
 
   QuicTimeWaitListManager* time_wait_list_manager() {
     return time_wait_list_manager_.get();
   }
 
   QuicEpollConnectionHelper* helper() { return helper_.get(); }
   EpollServer* epoll_server() { return epoll_server_; }
 
   const QuicVersionVector& supported_versions() const {
     return supported_versions_;
   }
 
- protected:
   // Called by |framer_visitor_| when the public header has been parsed.
   virtual bool OnUnauthenticatedPublicHeader(
       const QuicPacketPublicHeader& header);
 
   // Information about the packet currently being dispatched.
   const IPEndPoint& current_client_address() {
     return current_client_address_;
   }
   const IPEndPoint& current_server_address() {
     return current_server_address_;
   }
   const QuicEncryptedPacket& current_packet() {
     return *current_packet_;
   }
 
+  const QuicConfig& config() const { return config_; }
+
+  const QuicCryptoServerConfig& crypto_config() const { return crypto_config_; }
+
  private:
   class QuicFramerVisitor;
   friend class net::tools::test::QuicDispatcherPeer;
 
   // Called by |framer_visitor_| when the private header has been parsed
   // of a data packet that is destined for the time wait manager.
   void OnUnauthenticatedHeader(const QuicPacketHeader& header);
 
   // Removes the session from the session map and write blocked list, and
   // adds the GUID to the time-wait list.
   void CleanUpSession(SessionMap::iterator it);
 
   bool HandlePacketForTimeWait(const QuicPacketPublicHeader& header);
 
+  const QuicConfig& config_;
+
+  const QuicCryptoServerConfig& crypto_config_;
+
   // The list of connections waiting to write.
   WriteBlockedList write_blocked_list_;
 
   SessionMap session_map_;
 
   // Entity that manages guids in time wait state.
   scoped_ptr<QuicTimeWaitListManager> time_wait_list_manager_;
 
   // An alarm which deletes closed sessions.
   scoped_ptr<DeleteSessionsAlarm> delete_sessions_alarm_;
 
   // The list of closed but not-yet-deleted sessions.
   std::list<QuicSession*> closed_session_list_;
 
   EpollServer* epoll_server_;  // Owned by the server.
 
-  // The connection for client-server communication
-  int fd_;
-
   // The helper used for all connections.
   scoped_ptr<QuicEpollConnectionHelper> helper_;
 
-  // The writer to write to the socket with.
-  scoped_ptr<QuicPacketWriter> writer_;
+  // The writer to write to the socket with. We require a writer wrapper to
+  // allow replacing writer implementation without disturbing running
+  // connections.
+  scoped_ptr<QuicPacketWriterWrapper> writer_;
 
   // This vector contains QUIC versions which we currently support.
   // This should be ordered such that the highest supported version is the first
   // element, with subsequent elements in descending order (versions can be
   // skipped as necessary).
   const QuicVersionVector supported_versions_;
 
   // Information about the packet currently being handled.
   IPEndPoint current_client_address_;
   IPEndPoint current_server_address_;
   const QuicEncryptedPacket* current_packet_;
 
   QuicFramer framer_;
   scoped_ptr<QuicFramerVisitor> framer_visitor_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicDispatcher);
 };
 
 }  // namespace tools
 }  // namespace net
 
 #endif  // NET_TOOLS_QUIC_QUIC_DISPATCHER_H_