polardbxengine/storage/ndb/plugin/ndb_binlog_thread.h

/*
   Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.

   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 also distributed 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 included with MySQL.

   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 NDB_BINLOG_THREAD_H
#define NDB_BINLOG_THREAD_H

#include <mutex>
#include <string>
#include <vector>

#include "storage/ndb/plugin/ndb_binlog_hooks.h"
#include "storage/ndb/plugin/ndb_component.h"
#include "storage/ndb/plugin/ndb_metadata_sync.h"

class Ndb;

class Ndb_binlog_thread : public Ndb_component {
  Ndb_binlog_hooks binlog_hooks;
  static int do_after_reset_master(void *);
  Ndb_metadata_sync metadata_sync;

 public:
  Ndb_binlog_thread();
  virtual ~Ndb_binlog_thread();

  /*
    @brief Check if purge of the specified binlog file can be handled
    by the binlog thread.

    @param filename Name of the binlog file which has been purged

    @return true the binlog thread will handle the purge
    @return false the binlog thread will not handle the purge
  */
  bool handle_purge(const char *filename);

  /*
    @brief Iterate through the blacklist of objects and check if the mismatches
           are still present or if the user has manually synchronized the
           objects

    @param thd  Thread handle

    @return void
  */
  void validate_sync_blacklist(THD *thd);

  /*
    @brief Pass the logfile group object detected to the internal implementation
           that shall eventually synchronize the object

    @param logfile_group_name  Name of the logfile group

    @return true on success, false on failure
  */
  bool add_logfile_group_to_check(const std::string &logfile_group_name);

  /*
    @brief Pass the tablespace object detected to the internal implementation
           that shall eventually synchronize the object

    @param tablespace_name  Name of the tablespace

    @return true on success, false on failure
  */
  bool add_tablespace_to_check(const std::string &tablespace_name);

  /*
    @brief Pass the table object detected to the internal implementation that
           shall eventually synchronize the object

    @param db_name     Name of the database that the table belongs to
    @param table_name  Name of the table

    @return true on success, false on failure
  */
  bool add_table_to_check(const std::string &db_name,
                          const std::string &table_name);

 private:
  virtual int do_init();
  virtual void do_run();
  virtual int do_deinit();
  // Wake up for stop
  virtual void do_wakeup();

  /*
     The Ndb_binlog_thread is supposed to make a continuous recording
     of the activity in the cluster to the mysqlds binlog. When this
     recording is interrupted an incident event(aka. GAP event) is
     written to the binlog thus allowing consumers of the binlog to
     notice that the recording is most likely not continuous.
  */
  enum Reconnect_type {
    // Incident occurred because the mysqld was stopped and
    // is now starting up again
    MYSQLD_STARTUP,
    // Incident occurred because the mysqld was disconnected
    // from the cluster
    CLUSTER_DISCONNECT
  };
  bool check_reconnect_incident(THD *thd, class injector *inj,
                                Reconnect_type incident_id) const;

  /**
    @brief Perform any purge requests which has been queued up earlier.

    @param thd Thread handle
  */
  void recall_pending_purges(THD *thd);
  std::mutex m_purge_mutex;                   // Protects m_pending_purges
  std::vector<std::string> m_pending_purges;  // List of pending purges

  /**
     @brief Remove event operations belonging to one Ndb object

     @param ndb The Ndb object to remove event operations from
  */
  void remove_event_operations(Ndb *ndb) const;

  /**
     @brief Remove event operations belonging to the two different Ndb objects
     owned by the binlog thread

     @note The function also release references to NDB_SHARE's owned by the
     binlog thread

     @param s_ndb The schema Ndb object to remove event operations from
     @param i_ndb The injector Ndb object to remove event operations from
  */
  void remove_all_event_operations(Ndb *s_ndb, Ndb *i_ndb) const;

  /**
     @brief Synchronize the object that is currently at the front of the queue
     of objects detected for automatic synchronization

     @param thd Thread handle

     @return void
  */
  void synchronize_detected_object(THD *thd);
};

#endif