mariadb/sql/ddl_log.h

/*
   Copyright (c) 2000, 2019, Oracle and/or its affiliates.
   Copyright (c) 2010, 2020, MariaDB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   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 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 02110-1335  USA
*/

/* External interfaces to ddl log functions */

#ifndef DDL_LOG_INCLUDED
#define DDL_LOG_INCLUDED

enum ddl_log_entry_code
{
  /*
    DDL_LOG_EXECUTE_CODE:
      This is a code that indicates that this is a log entry to
      be executed, from this entry a linked list of log entries
      can be found and executed.
    DDL_LOG_ENTRY_CODE:
      An entry to be executed in a linked list from an execute log
      entry.
    DDL_IGNORE_LOG_ENTRY_CODE:
      An entry that is to be ignored
  */
  DDL_LOG_EXECUTE_CODE = 'e',
  DDL_LOG_ENTRY_CODE = 'l',
  DDL_IGNORE_LOG_ENTRY_CODE = 'i'
};

enum ddl_log_action_code
{
  /*
    The type of action that a DDL_LOG_ENTRY_CODE entry is to
    perform.
    DDL_LOG_DELETE_ACTION:
      Delete an entity
    DDL_LOG_RENAME_ACTION:
      Rename an entity
    DDL_LOG_REPLACE_ACTION:
      Rename an entity after removing the previous entry with the
      new name, that is replace this entry.
    DDL_LOG_EXCHANGE_ACTION:
      Exchange two entities by renaming them a -> tmp, b -> a, tmp -> b.
  */
  DDL_LOG_DELETE_ACTION = 'd',
  DDL_LOG_RENAME_ACTION = 'r',
  DDL_LOG_REPLACE_ACTION = 's',
  DDL_LOG_EXCHANGE_ACTION = 'e'
};

enum enum_ddl_log_exchange_phase {
  EXCH_PHASE_NAME_TO_TEMP= 0,
  EXCH_PHASE_FROM_TO_NAME= 1,
  EXCH_PHASE_TEMP_TO_FROM= 2
};


typedef struct st_ddl_log_entry
{
  const char *name;
  const char *from_name;
  const char *handler_name;
  const char *tmp_name;
  uint next_entry;
  uint entry_pos;
  enum ddl_log_entry_code entry_type;
  enum ddl_log_action_code action_type;
  /*
    Most actions have only one phase. REPLACE does however have two
    phases. The first phase removes the file with the new name if
    there was one there before and the second phase renames the
    old name to the new name.
  */
  char phase;
} DDL_LOG_ENTRY;

typedef struct st_ddl_log_memory_entry
{
  uint entry_pos;
  struct st_ddl_log_memory_entry *next_log_entry;
  struct st_ddl_log_memory_entry *prev_log_entry;
  struct st_ddl_log_memory_entry *next_active_log_entry;
} DDL_LOG_MEMORY_ENTRY;


bool ddl_log_write_entry(DDL_LOG_ENTRY *ddl_log_entry,
                           DDL_LOG_MEMORY_ENTRY **active_entry);
bool ddl_log_write_execute_entry(uint first_entry,
                                   bool complete,
                                   DDL_LOG_MEMORY_ENTRY **active_entry);
bool ddl_log_increment_phase(uint entry_no);
void ddl_log_release_memory_entry(DDL_LOG_MEMORY_ENTRY *log_entry);
bool ddl_log_sync();
void ddl_log_release();
void ddl_log_execute_recovery();
bool ddl_log_execute_entry(THD *thd, uint first_entry);

extern mysql_mutex_t LOCK_gdl;
#endif /* DDL_LOG_INCLUDED */