net/quic/quic_chromium_packet_writer.h

// Copyright 2013 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_QUIC_QUIC_CHROMIUM_PACKET_WRITER_H_
#define NET_QUIC_QUIC_CHROMIUM_PACKET_WRITER_H_

#include <stddef.h>

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "net/base/io_buffer.h"
#include "net/base/ip_endpoint.h"
#include "net/quic/quic_connection.h"
#include "net/quic/quic_packet_writer.h"
#include "net/quic/quic_protocol.h"
#include "net/quic/quic_types.h"
#include "net/udp/datagram_client_socket.h"

namespace net {

// Chrome specific packet writer which uses a datagram Socket for writing data.
class NET_EXPORT_PRIVATE QuicChromiumPacketWriter : public QuicPacketWriter {
 public:
  // Interface which receives notifications on socket write errors.
  class NET_EXPORT_PRIVATE WriteErrorObserver {
   public:
    // Called on socket write error, with the error code of the failure
    // and the packet that was not written as a result of the failure.
    // An implementation must return error code from the rewrite
    // attempt if there was one, else return |error_code|.
    virtual int OnWriteError(int error_code,
                             scoped_refptr<StringIOBuffer> last_packet) = 0;
  };

  QuicChromiumPacketWriter();
  explicit QuicChromiumPacketWriter(Socket* socket);
  ~QuicChromiumPacketWriter() override;

  void Initialize(WriteErrorObserver* observer, QuicConnection* connection);

  // Writes |packet| to the socket and returns the error code from the write.
  int WritePacketToSocket(StringIOBuffer* packet);

  // QuicPacketWriter
  WriteResult WritePacket(const char* buffer,
                          size_t buf_len,
                          const IPAddress& self_address,
                          const IPEndPoint& peer_address,
                          PerPacketOptions* options) override;
  bool IsWriteBlockedDataBuffered() const override;
  bool IsWriteBlocked() const override;
  void SetWritable() override;
  QuicByteCount GetMaxPacketSize(const IPEndPoint& peer_address) const override;

  void OnWriteComplete(int rv);

 protected:
  void set_write_blocked(bool is_blocked) { write_blocked_ = is_blocked; }

 private:
  Socket* socket_;
  QuicConnection* connection_;
  WriteErrorObserver* observer_;
  // When a write returns asynchronously, |packet_| stores the written
  // packet until OnWriteComplete is called.
  scoped_refptr<StringIOBuffer> packet_;

  // Whether a write is currently in flight.
  bool write_blocked_;

  base::WeakPtrFactory<QuicChromiumPacketWriter> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(QuicChromiumPacketWriter);
};

}  // namespace net

#endif  // NET_QUIC_QUIC_CHROMIUM_PACKET_WRITER_H_