Refactor QuicServerSessionBase::Visitor

net/quic/core/quic_session.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 QuicSession, which demuxes a single connection to individual streams.
 
 #ifndef NET_QUIC_QUIC_SESSION_H_
 #define NET_QUIC_QUIC_SESSION_H_
 
 #include <stddef.h>
@@ skipping 23 matching lines @@
 class QuicCryptoStream;
 class QuicFlowController;
 class ReliableQuicStream;
 
 namespace test {
 class QuicSessionPeer;
 }  // namespace test
 
 class NET_EXPORT_PRIVATE QuicSession : public QuicConnectionVisitorInterface {
  public:
+  // An interface from the session to the entity owning the session.
+  // This lets the session notify its owner (the Dispatcher) when the connection
+  // is closed, blocked, or added/removed from the time-wait std::list.
+  class Visitor {
+   public:
+    virtual ~Visitor() {}
+
+    // Called when the connection is closed after the streams have been closed.
+    virtual void OnConnectionClosed(QuicConnectionId connection_id,
+                                    QuicErrorCode error,
+                                    const std::string& error_details) = 0;
+
+    // Called when the session has become write blocked.
+    virtual void OnWriteBlocked(QuicBlockedWriterInterface* blocked_writer) = 0;
+  };
+
   // CryptoHandshakeEvent enumerates the events generated by a QuicCryptoStream.
   enum CryptoHandshakeEvent {
     // ENCRYPTION_FIRST_ESTABLISHED indicates that a full client hello has been
     // sent by a client and that subsequent packets will be encrypted. (Client
     // only.)
     ENCRYPTION_FIRST_ESTABLISHED,
     // ENCRYPTION_REESTABLISHED indicates that a client hello was rejected by
     // the server and thus the encryption key has been updated. Therefore the
     // connection should resend any packets that were sent under
     // ENCRYPTION_INITIAL. (Client only.)
     ENCRYPTION_REESTABLISHED,
     // HANDSHAKE_CONFIRMED, in a client, indicates the the server has accepted
     // our handshake. In a server it indicates that a full, valid client hello
     // has been received. (Client and server.)
     HANDSHAKE_CONFIRMED,
   };
 
-  // Does not take ownership of |connection|.
-  QuicSession(QuicConnection* connection, const QuicConfig& config);
+  // Does not take ownership of |connection| or |visitor|.
+  QuicSession(QuicConnection* connection,
+              Visitor* owner,
+              const QuicConfig& config);
 
   ~QuicSession() override;
 
   virtual void Initialize();
 
   // QuicConnectionVisitorInterface methods:
   void OnStreamFrame(const QuicStreamFrame& frame) override;
   void OnRstStream(const QuicRstStreamFrame& frame) override;
   void OnGoAway(const QuicGoAwayFrame& frame) override;
   void OnWindowUpdateFrame(const QuicWindowUpdateFrame& frame) override;
   void OnBlockedFrame(const QuicBlockedFrame& frame) override;
   void OnConnectionClosed(QuicErrorCode error,
                           const std::string& error_details,
                           ConnectionCloseSource source) override;
-  void OnWriteBlocked() override {}
+  void OnWriteBlocked() override;
   void OnSuccessfulVersionNegotiation(const QuicVersion& version) override;
   void OnCanWrite() override;
   void OnCongestionWindowChange(QuicTime /*now*/) override {}
   void OnConnectionMigration(PeerAddressChangeType type) override {}
   // Deletes streams that are safe to be deleted now that it's safe to do so (no
   // other operations are being done on the streams at this time).
   void PostProcessAfterData() override;
   bool WillingAndAbleToWrite() const override;
   bool HasPendingHandshake() const override;
   bool HasOpenDynamicStreams() const override;
@@ skipping 242 matching lines @@
   bool MaybeIncreaseLargestPeerStreamId(const QuicStreamId stream_id);
 
   void InsertLocallyClosedStreamsHighestOffset(const QuicStreamId id,
                                                QuicStreamOffset offset);
   // If stream is a locally closed stream, this RST will update FIN offset.
   // Otherwise stream is a preserved stream and the behavior of it depends on
   // derived class's own implementation.
   virtual void HandleRstOnValidNonexistentStream(
       const QuicRstStreamFrame& frame);
 
+  Visitor* visitor() { return visitor_; }
+
+  const Visitor* visitor() const { return visitor_; }
+
  private:
   friend class test::QuicSessionPeer;
 
   // Called in OnConfigNegotiated when we receive a new stream level flow
   // control window in a negotiated config. Closes the connection if invalid.
   void OnNewStreamFlowControlWindow(QuicStreamOffset new_window);
 
   // Called in OnConfigNegotiated when we receive a new connection level flow
   // control window in a negotiated config. Closes the connection if invalid.
   void OnNewSessionFlowControlWindow(QuicStreamOffset new_window);
 
   // Debug helper for |OnCanWrite()|, check that OnStreamWrite() makes
   // forward progress.  Returns false if busy loop detected.
   bool CheckStreamNotBusyLooping(ReliableQuicStream* stream,
                                  uint64_t previous_bytes_written,
                                  bool previous_fin_sent);
 
   // Keep track of highest received byte offset of locally closed streams, while
   // waiting for a definitive final highest offset from the peer.
   std::map<QuicStreamId, QuicStreamOffset>
       locally_closed_streams_highest_offset_;
 
   QuicConnection* connection_;
 
+  // May be null.
+  Visitor* visitor_;
+
   ClosedStreams closed_streams_;
 
   QuicConfig config_;
 
   // The maximum number of outgoing streams this connection can open.
   size_t max_open_outgoing_streams_;
 
   // The maximum number of incoming streams this connection will allow.
   size_t max_open_incoming_streams_;
 
@@ skipping 40 matching lines @@
   // The stream id which was last popped in OnCanWrite, or 0, if not under the
   // call stack of OnCanWrite.
   QuicStreamId currently_writing_stream_id_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicSession);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_SESSION_H_