single_primary_message.h

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/* Copyright (c) 2016, 2024, Oracle and/or its affiliates.
 
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   it under the terms of the GNU General Public License, version 2.0,
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   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 SINGLE_PRIMARY_MESSAGE_INCLUDED
#define SINGLE_PRIMARY_MESSAGE_INCLUDED
 
#include <set>
#include <string>
#include <vector>
 
#include "my_inttypes.h"
#include "plugin/group_replication/include/gcs_plugin_messages.h"
#include "plugin/group_replication/include/plugin_handlers/primary_election_include.h"
 
class Single_primary_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: 2 bytes
    PIT_SINGLE_PRIMARY_MESSAGE_TYPE = 1,
 
    // Uuid to elect: variable
    PIT_SINGLE_PRIMARY_SERVER_UUID = 2,
 
    // The election mode: 2 bytes
    PIT_SINGLE_PRIMARY_ELECTION_MODE = 3,
 
    // Length of the payload item: 8 bytes
    PIT_SENT_TIMESTAMP = 4,
 
    // No valid type codes can appear after this one.
    PIT_MAX = 5
  };
 
  /**
   The several single primary type messages.
  */
  typedef enum {
    /**This type should not be used anywhere.*/
    SINGLE_PRIMARY_UNKNOWN = 0,
    /**A new primary was elected.*/
    SINGLE_PRIMARY_NEW_PRIMARY_MESSAGE = 1,
    /**Primary did apply queue after election.*/
    SINGLE_PRIMARY_QUEUE_APPLIED_MESSAGE = 2,
    /**No more forbidden transactions on multi master remain*/
    SINGLE_PRIMARY_NO_RESTRICTED_TRANSACTIONS = 3,
    /**Invoke a new election*/
    SINGLE_PRIMARY_PRIMARY_ELECTION = 4,
    /**The primary is now ready, processed all the backlog*/
    SINGLE_PRIMARY_PRIMARY_READY = 5,
    /**The member as set the read on the election context*/
    SINGLE_PRIMARY_READ_MODE_SET = 6,
    /**The end of the enum.*/
    SINGLE_PRIMARY_MESSAGE_TYPE_END = 7
  } Single_primary_message_type;
 
  /**
    Message constructor
 
    @param[in] type         the single primary message type
  */
  Single_primary_message(Single_primary_message_type type);
 
  /**
    Message constructor for primary election invocations
 
    @note this message will use type SINGLE_PRIMARY_PRIMARY_ELECTION
 
    @param primary_uuid  The primary uuid to elect
    @param election_mode The election mode to perform
  */
  Single_primary_message(std::string &primary_uuid,
                         enum_primary_election_mode election_mode);
 
  /**
    Message destructor
   */
  ~Single_primary_message() override;
 
  /**
    Message constructor for raw data
 
    @param[in] buf raw data
    @param[in] len raw length
  */
  Single_primary_message(const uchar *buf, size_t len);
 
  /** Returns this single primary message type */
  Single_primary_message_type get_single_primary_message_type() const {
    return single_primary_message_type;
  }
 
  /**
    @note This method should only be used with type
    SINGLE_PRIMARY_PRIMARY_ELECTION
    @return the primary uuid associated to this message
  */
  std::string &get_primary_uuid();
 
  /**
    @note This method should only be used with type
    SINGLE_PRIMARY_PRIMARY_ELECTION
    @return the election mode associated to this message
  */
  enum_primary_election_mode get_election_mode();
 
  /**
    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:
  /**
    Encodes the message contents for transmission.
 
    @param[out] buffer   the message buffer to be written
  */
  void encode_payload(std::vector<unsigned char> *buffer) const override;
 
  /**
    Message decoding method
 
    @param[in] buffer the received data
    @param[in] end    the end of the buffer.
  */
  void decode_payload(const unsigned char *buffer,
                      const unsigned char *end) override;
 
 private:
  /**The message type*/
  Single_primary_message_type single_primary_message_type;
 
  /** The uuid for the primary member */
  std::string primary_uuid;
  /** The mode for election requests */
  enum_primary_election_mode election_mode;
};
 
#endif /* SINGLE_PRIMARY_MESSAGE_INCLUDED */