// 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/net_export.h"
#include "net/quic/core/quic_connection.h"
#include "net/quic/core/quic_packet_writer.h"
#include "net/quic/core/quic_packets.h"
#include "net/quic/core/quic_types.h"
#include "net/socket/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:
  // Delegate interface which receives notifications on socket write events.
  class NET_EXPORT_PRIVATE Delegate {
   public:
    // Called when a socket write attempt results in a failure, so
    // that the delegate may recover from it by perhaps rewriting the
    // packet to a different socket. An implementation must return the
    // return value from the rewrite attempt if there is one, and
    // |error_code| otherwise.
    virtual int HandleWriteError(int error_code,
                                 scoped_refptr<StringIOBuffer> last_packet) = 0;

    // Called to propagate the final write error to the delegate.
    virtual void OnWriteError(int error_code) = 0;

    // Called when the writer is unblocked due to a write completion.
    virtual void OnWriteUnblocked() = 0;
  };

  QuicChromiumPacketWriter();
  // |socket| must outlive writer.
  explicit QuicChromiumPacketWriter(Socket* socket);
  ~QuicChromiumPacketWriter() override;

  // |delegate| must outlive writer.
  void set_delegate(Delegate* delegate) { delegate_ = delegate; }

  void set_write_blocked(bool write_blocked) { write_blocked_ = write_blocked; }

  // Writes |packet| to the socket and returns the error code from the write.
  WriteResult WritePacketToSocket(scoped_refptr<StringIOBuffer> packet);

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

  void OnWriteComplete(int rv);

 private:
  Socket* socket_;      // Unowned.
  Delegate* delegate_;  // Unowned.
  // 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_