base.h

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/* Copyright (c) 2019, 2024, Oracle and/or its affiliates.
 
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   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.
 
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
#ifndef CODECS_BASE_INCLUDED
#define CODECS_BASE_INCLUDED
 
#include <utility>
#include "libbinlogevents/include/binary_log.h"
 
namespace binary_log {
namespace codecs {
 
/**
  This is the abstract and base class for binary log codecs.
 
  It defines the codec API. Implementations of this class must
  be stateless.
 */
class Codec {
 public:
  /**
    Member function that shall decode the contents of the given buffer into a
    binary log event.
 
    @param from the buffer containing the encoded event.
    @param size the length of the data in the buffer.
    @param to the binary log event to populate.
 
    @return a pair containing the amount of bytes decoded from the buffer and a
            boolean stating whether there was an error or not. False if no
            error, true otherwise.
  */
  virtual std::pair<std::size_t, bool> decode(const unsigned char *from,
                                              std::size_t size,
                                              Binary_log_event &to) const = 0;
 
  /**
    Member function that shall encode the contents of the given binary log event
    into an in memory buffer.
 
    @param from the binary log event to encode.
    @param to the buffer where the encoded event should be saved into.
    @param size the size of the buffer.
 
    @return a pair containing the amount of bytes encoded and whether there was
            an error or not. False if no error, true otherwise.
  */
  virtual std::pair<std::size_t, bool> encode(const Binary_log_event &from,
                                              unsigned char *to,
                                              std::size_t size) const = 0;
  virtual ~Codec() = default;
};
 
}  // namespace codecs
}  // namespace binary_log
 
#endif