transaction_prepared_message.h

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/* Copyright (c) 2018, 2024, Oracle and/or its affiliates.
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.
 
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   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
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   the program or referenced in the documentation.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.
 
   You should have received a copy of the GNU General Public License
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   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
#ifndef TRANSACTION_PREPARED_MESSAGE_INCLUDED
#define TRANSACTION_PREPARED_MESSAGE_INCLUDED
 
#include <mysql/group_replication_priv.h>
#include <vector>
 
#include "my_inttypes.h"
#include "plugin/group_replication/include/gcs_plugin_messages.h"
 
/*
  @class Transaction_prepared_message
 */
class Transaction_prepared_message : public Plugin_gcs_message {
 public:
  enum enum_payload_item_type {
    // This type should not be used anywhere.
    PIT_UNKNOWN = 0,
 
    // Length of the payload item: 8 bytes
    PIT_TRANSACTION_PREPARED_GNO = 1,
 
    // Length of the payload item: 16 bytes.
    // Optional item.
    PIT_TRANSACTION_PREPARED_SID = 2,
 
    // Length of the payload item: 8 bytes
    PIT_SENT_TIMESTAMP = 3,
 
    // Length of the payload item: 1-32
    // Optional item.
    PIT_TRANSACTION_PREPARED_TAG = 4,
 
    // No valid type codes can appear after this one.
    PIT_MAX = 5
  };
 
  /**
   Message constructor
 
   @param[in]  tsid             the prepared transaction tsid
   @param[in]  is_tsid_specified information on whether tsid is specified
   @param[in]  gno              the prepared transaction gno
  */
  Transaction_prepared_message(const gr::Gtid_tsid &tsid,
                               bool is_tsid_specified, rpl_gno gno);
 
  /**
   Message decode constructor
 
   @param[in]  buf              message buffer
   @param[in]  len              message buffer length
  */
  Transaction_prepared_message(const unsigned char *buf, size_t len);
  ~Transaction_prepared_message() override;
 
  rpl_gno get_gno();
 
  /**
    Return the time at which the message contained in the buffer was sent.
    @see Metrics_handler::get_current_time()
 
    @param[in] buffer            the buffer to decode from.
    @param[in] length            the buffer length
 
    @return the time on which the message was sent.
  */
  static uint64_t get_sent_timestamp(const unsigned char *buffer,
                                     size_t length);
 
  /// @brief returns information on whether TSID is specified for this trx
  /// @return information on whether TSID is specified for this trx
  bool is_tsid_specified() const { return m_tsid_specified; }
 
  /// @brief TSID accessor
  /// @return Const reference to transaction TSID
  const gr::Gtid_tsid &get_tsid();
 
  using Error_ptr = mysql::utils::Error_ptr;
 
  /// @brief Checks whether message encoding/decoding succeeded
  /// @return Message validity
  bool is_valid() const;
 
  /// @brief Gets information about decoding/encoding error
  /// @return Const reference to decoding/encoding error information
  const Error_ptr &get_error() const;
 
 protected:
  /*
   Implementation of the template methods
   */
  void encode_payload(std::vector<unsigned char> *buffer) const override;
  void decode_payload(const unsigned char *buffer,
                      const unsigned char *end) override;
 
 private:
  bool m_tsid_specified;
  rpl_gno m_gno;
  gr::Gtid_tsid m_tsid;
  /// Holds information about error that might occur during encoding/decoding
  Error_ptr m_error;
};
 
#endif /* TRANSACTION_PREPARED_MESSAGE_INCLUDED */