release/src/router/mysql/sql/events.h

   1 #ifndef _EVENT_H_
   2 #define _EVENT_H_
   3 /* Copyright (c) 2004-2007 MySQL AB
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; version 2 of the License.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA */
  17
  18 /**
  19   @defgroup Event_Scheduler Event Scheduler
  20   @ingroup Runtime_Environment
  21   @{
  22
  23   @file events.h
  24
  25   A public interface of Events_Scheduler module.
  26 */
  27
  28 class Event_parse_data;
  29 class Event_db_repository;
  30 class Event_queue;
  31 class Event_scheduler;
  32
  33 /* Return codes */
  34 enum enum_events_error_code
  35 {
  36   OP_OK= 0,
  37   OP_NOT_RUNNING,
  38   OP_CANT_KILL,
  39   OP_CANT_INIT,
  40   OP_DISABLED_EVENT,
  41   OP_LOAD_ERROR,
  42   OP_ALREADY_EXISTS
  43 };
  44
  45
  46 int
  47 sortcmp_lex_string(LEX_STRING s, LEX_STRING t, CHARSET_INFO *cs);
  48
  49 /**
  50   @brief A facade to the functionality of the Event Scheduler.
  51
  52   Every public operation against the scheduler has to be executed via the
  53   interface provided by a static method of this class. No instance of this
  54   class is ever created and it has no non-static data members.
  55
  56   The life cycle of the Events module is the following:
  57
  58   At server start up:
  59      set_opt_event_scheduler() -> init_mutexes() -> init()
  60   When the server is running:
  61      create_event(), drop_event(), start_or_stop_event_scheduler(), etc
  62   At shutdown:
  63      deinit(), destroy_mutexes().
  64
  65   The peculiar initialization and shutdown cycle is an adaptation to the
  66   outside server startup/shutdown framework and mimics the rest of MySQL
  67   subsystems (ACL, time zone tables, etc).
  68 */
  69
  70 class Events
  71 {
  72 public:
  73   /* The order should match the order in opt_typelib */
  74   enum enum_opt_event_scheduler
  75   {
  76     EVENTS_OFF= 0,
  77     EVENTS_ON= 1,
  78     EVENTS_DISABLED= 4
  79   };
  80
  81   /* Possible values of @@event_scheduler variable */
  82   static const TYPELIB var_typelib;
  83
  84   static bool
  85   set_opt_event_scheduler(char *argument);
  86
  87   static const char *
  88   get_opt_event_scheduler_str();
  89
  90   /* A hack needed for Event_queue_element */
  91   static Event_db_repository *
  92   get_db_repository() { return db_repository; }
  93
  94   static bool
  95   init(my_bool opt_noacl);
  96
  97   static void
  98   deinit();
  99
 100   static void
 101   init_mutexes();
 102
 103   static void
 104   destroy_mutexes();
 105
 106   static bool
 107   switch_event_scheduler_state(enum enum_opt_event_scheduler new_state);
 108
 109   static bool
 110   create_event(THD *thd, Event_parse_data *parse_data, bool if_exists);
 111
 112   static bool
 113   update_event(THD *thd, Event_parse_data *parse_data,
 114                LEX_STRING *new_dbname, LEX_STRING *new_name);
 115
 116   static bool
 117   drop_event(THD *thd, LEX_STRING dbname, LEX_STRING name, bool if_exists);
 118
 119   static void
 120   drop_schema_events(THD *thd, char *db);
 121
 122   static bool
 123   show_create_event(THD *thd, LEX_STRING dbname, LEX_STRING name);
 124
 125   /* Needed for both SHOW CREATE EVENT and INFORMATION_SCHEMA */
 126   static int
 127   reconstruct_interval_expression(String *buf, interval_type interval,
 128                                   longlong expression);
 129
 130   static int
 131   fill_schema_events(THD *thd, TABLE_LIST *tables, COND * /* cond */);
 132
 133   static void
 134   dump_internal_status();
 135
 136 private:
 137   static bool check_if_system_tables_error();
 138
 139   static bool
 140   load_events_from_db(THD *thd);
 141
 142 private:
 143   /* Command line option names */
 144   static const TYPELIB opt_typelib;
 145   static pthread_mutex_t LOCK_event_metadata;
 146   static Event_queue         *event_queue;
 147   static Event_scheduler     *scheduler;
 148   static Event_db_repository *db_repository;
 149   /* Current state of Event Scheduler */
 150   static enum enum_opt_event_scheduler opt_event_scheduler;
 151   /* Set to TRUE if an error at start up */
 152   static bool check_system_tables_error;
 153
 154 private:
 155   /* Prevent use of these */
 156   Events(const Events &);
 157   void operator=(Events &);
 158 };
 159
 160 /**
 161   @} (end of group Event Scheduler)
 162 */
 163
 164 #endif /* _EVENT_H_ */