transaction_with_guarantee_message.h

Go to the documentation of this file.

/* 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.
 
   This program is designed to work with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   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
   separately licensed software that they have either included with
   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
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
#ifndef TRANSACTION_WITH_GUARANTEE_MESSAGE_INCLUDED
#define TRANSACTION_WITH_GUARANTEE_MESSAGE_INCLUDED
 
#include <mysql/plugin_group_replication.h>
 
#include "plugin/group_replication/include/plugin_messages/transaction_message_interface.h"
 
/*
  @class Transaction_with_guarantee_message
  Class to convey the serialized contents of the TCLE, plus guarantees.
 */
class Transaction_with_guarantee_message
    : public Transaction_message_interface {
 public:
  enum enum_payload_item_type {
    // This type should not be used anywhere.
    PIT_UNKNOWN = 0,
 
    // Length of the payload item: variable
    PIT_TRANSACTION_DATA = 1,
 
    // Length of the payload item: 1 byte
    PIT_TRANSACTION_CONSISTENCY_LEVEL = 2,
 
    // Length of the payload item: 8 bytes
    PIT_SENT_TIMESTAMP = 3,
 
    // No valid type codes can appear after this one.
    PIT_MAX = 4
  };
 
  /**
   Constructor
 
   @param[in] payload_capacity  The transaction data size
   @param[in] consistency_level The transaction consistency level
   */
  Transaction_with_guarantee_message(
      uint64_t payload_capacity,
      enum_group_replication_consistency_level consistency_level);
  ~Transaction_with_guarantee_message() override;
 
  /**
     Overrides Basic_ostream::write().
     Transaction_with_guarantee_message is a Basic_ostream, which
     appends data into the a Gcs_message_data.
 
     @param[in] buffer  where the data will be read
     @param[in] length  the length of the data to write
 
     @return returns false if succeeds, otherwise true is returned.
  */
  bool write(const unsigned char *buffer, my_off_t length) override;
 
  /**
     Length of the message.
 
     @return message length
  */
  uint64_t length() override;
 
  /**
     Get the Gcs_message_data object, which contains the serialized
     transaction data.
     The internal Gcs_message_data is nullified, to avoid further usage
     of this Transaction object and the caller receives a pointer to the
     previously internal Gcs_message_data, which whom it is now responsible.
 
     @return the serialized transaction data in a Gcs_message_data object
  */
  Gcs_message_data *get_message_data_and_reset() override;
 
  /**
    Decode transaction consistency without unmarshal transaction data.
 
    @return the transaction consistency
  */
  static enum_group_replication_consistency_level
  decode_and_get_consistency_level(const unsigned char *buffer, size_t);
 
  /**
    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);
 
 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 *) override;
 
 private:
  Gcs_message_data *m_gcs_message_data{nullptr};
  static const uint64_t s_consistency_level_pit_size;
  enum_group_replication_consistency_level m_consistency_level;
  static const uint64_t s_sent_timestamp_pit_size;
};
 
#endif /* TRANSACTION_WITH_GUARANTEE_MESSAGE_INCLUDED */