Refactoring: Create per-connection packet writers in QuicDispatcher.

net/tools/quic/quic_per_connection_packet_writer.h

+// Copyright (c) 2014 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.
+//
+#ifndef NET_TOOLS_QUIC_QUIC_PER_CONNECTION_PACKET_WRITER_H_
+#define NET_TOOLS_QUIC_QUIC_PER_CONNECTION_PACKET_WRITER_H_
+
+#include "net/quic/quic_connection.h"
+#include "net/quic/quic_packet_writer.h"
+
+namespace net {
+
+namespace tools {
+
+// A connection-specific packet writer that wraps a shared writer and keeps a
+// reference to the connection.
+class QuicPerConnectionPacketWriter : public QuicPacketWriter {
+ public:
+  // Does not take ownership of |shared_writer| or |connection|.
+  QuicPerConnectionPacketWriter(QuicPacketWriter* shared_writer,
+                                QuicConnection* connection);
+  virtual ~QuicPerConnectionPacketWriter();
+
+  QuicPacketWriter* shared_writer() { return shared_writer_; }
+  QuicConnection* connection() { return connection_; }
+
+  // Default implementation of the QuicPacketWriter interface: Passes everything
+  // to |shared_writer_|.
+  virtual WriteResult WritePacket(
+      const char* buffer,
+      size_t buf_len,
+      const IPAddressNumber& self_address,
+      const IPEndPoint& peer_address) override;
+  virtual bool IsWriteBlockedDataBuffered() const override;
+  virtual bool IsWriteBlocked() const override;
+  virtual void SetWritable() override;
+
+ private:
+  QuicPacketWriter* shared_writer_;  // Not owned.
+  QuicConnection* connection_;  // Not owned.
+
+  DISALLOW_COPY_AND_ASSIGN(QuicPerConnectionPacketWriter);
+};
+
+}  // namespace tools
+
+}  // namespace net
+
+#endif  // NET_TOOLS_QUIC_QUIC_PER_CONNECTION_PACKET_WRITER_H_