mariadb/sql/event_data_objects.h
unknown 3c39b0d831 Fix for bug#22740 Events: Decouple Event_queue from Event_db_repository
This patch implements the idea of the bug report by making Event_queue
unaware of Event_db_repository by making a higher level class - Events,
which is aware of most of all classes, responsible for passing all data
needed for adding/updating/deleting an event to/from the queue.

Introduces few new classes :
 - Event_worker_thread
 - Event_queue_element_for_exec


sql/event_data_objects.cc:
  Introduced a new class Event_queue_element_for_exec
  According to Konstantin it should be named Event_name and hold
  only two LEX_STRINGs but `dropped` is not saved on disk and will
  require additional logic in Event_worker_thread class, after loading
  to compute whether the event should be dropped or not. It's easier
  just to pass this flag around.
  
  Removed Event_queue_element::drop(). This method was a source of a
  race condition. At the place where the event should be dropped we
  call Events::drop_event() which is the only code-flow for dropping.
  In addition, because ::drop_event() holds Events::LOCK_metadata there is
  no source of race conditions. Before this patch dropping from ::drop()
  wasn't under LOCK_metadata and races were possible.
  
  Because Events::open_event_table was removed as a method, provisionally
  events_event_db_repository was exported from events.cc till a solution is
  build where Event_queue_element does not access directly mysql.event.
sql/event_data_objects.h:
  New class Event_queue_element_for_exec added which is returned
  from Event_queue::get_top_if_time() and passed through Event_scheduler
  to Event_worker_thread. There by using the (db)name Event_job_data is
  instanciated and executed.
  
  Dropped Event_queue_element::drop()
  
  thd was moved out of Event_job_data as it is now part of
  Event_queue_element_for_exec
sql/event_queue.cc:
  Removed dependency of Event_queue on Event_db_repository.
  The instantiation of Event_job_data was moved to class Event_worker_thread
  In place is a return of an object of Event_queue_element_for_exec is used
  later for instantiating Event_job_data.
  
  The `dropped` flag of Event_queue_element is passed over
  Event_queue_element_for_exec to the code in Event_worker_thread.
sql/event_queue.h:
  Removed dependency of Event_queue on Event_db_repository
  Removed dependency on Event_scheduler
sql/event_scheduler.cc:
  Added class Event_worker_thread, which is used during
  the execution of an event. It has a static init() method
  to get a pointer to Event_db_repository to be used for
  instantiation of Event_job_data object. This object it then
  executed.
sql/event_scheduler.h:
  Added class Event_worker_thread, which is used during
  the execution of an event.
sql/events.cc:
  Removed Events::open_event_table() because it was a product of
  a bad architecture.
sql/events.h:
  Removed friend definition, unneeded.
  
  Fixed Events::drop_event() to have the previous signature without
  bool only_from_disk
sql/sql_parse.cc:
  Fix call
2007-01-29 20:46:29 +03:00

301 lines
5.4 KiB
C++

#ifndef _EVENT_DATA_OBJECTS_H_
#define _EVENT_DATA_OBJECTS_H_
/* Copyright (C) 2004-2006 MySQL AB
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#define EVEX_GET_FIELD_FAILED -2
#define EVEX_COMPILE_ERROR -3
#define EVEX_GENERAL_ERROR -4
#define EVEX_BAD_PARAMS -5
#define EVEX_MICROSECOND_UNSUP -6
class sp_head;
class Sql_alloc;
class Event_queue_element_for_exec
{
public:
Event_queue_element_for_exec(){};
~Event_queue_element_for_exec();
bool
init(LEX_STRING dbname, LEX_STRING name);
LEX_STRING dbname;
LEX_STRING name;
bool dropped;
THD *thd;
private:
/* Prevent use of these */
Event_queue_element_for_exec(const Event_queue_element_for_exec &);
void operator=(Event_queue_element_for_exec &);
};
class Event_basic
{
protected:
MEM_ROOT mem_root;
public:
LEX_STRING dbname;
LEX_STRING name;
LEX_STRING definer;// combination of user and host
Event_basic();
virtual ~Event_basic();
virtual int
load_from_row(TABLE *table) = 0;
protected:
bool
load_string_fields(Field **fields, ...);
};
class Event_queue_element : public Event_basic
{
protected:
bool status_changed;
bool last_executed_changed;
public:
enum enum_status
{
ENABLED = 1,
DISABLED
};
enum enum_on_completion
{
ON_COMPLETION_DROP = 1,
ON_COMPLETION_PRESERVE
};
enum enum_on_completion on_completion;
enum enum_status status;
TIME last_executed;
TIME execute_at;
TIME starts;
TIME ends;
my_bool starts_null;
my_bool ends_null;
my_bool execute_at_null;
longlong expression;
interval_type interval;
bool dropped;
uint execution_count;
Event_queue_element();
virtual ~Event_queue_element();
virtual int
load_from_row(TABLE *table);
bool
compute_next_execution_time();
void
mark_last_executed(THD *thd);
bool
update_timing_fields(THD *thd);
static void *operator new(size_t size)
{
void *p;
DBUG_ENTER("Event_queue_element::new(size)");
p= my_malloc(size, MYF(0));
DBUG_PRINT("info", ("alloc_ptr: 0x%lx", (long) p));
DBUG_RETURN(p);
}
static void operator delete(void *ptr, size_t size)
{
DBUG_ENTER("Event_queue_element::delete(ptr,size)");
DBUG_PRINT("enter", ("free_ptr: 0x%lx", (long) ptr));
TRASH(ptr, size);
my_free((gptr) ptr, MYF(0));
DBUG_VOID_RETURN;
}
};
class Event_timed : public Event_queue_element
{
Event_timed(const Event_timed &); /* Prevent use of these */
void operator=(Event_timed &);
public:
LEX_STRING body;
LEX_STRING definer_user;
LEX_STRING definer_host;
LEX_STRING comment;
ulonglong created;
ulonglong modified;
ulong sql_mode;
Event_timed();
virtual ~Event_timed();
void
init();
virtual int
load_from_row(TABLE *table);
int
get_create_event(THD *thd, String *buf);
};
class Event_job_data : public Event_basic
{
public:
sp_head *sphead;
LEX_STRING body;
LEX_STRING definer_user;
LEX_STRING definer_host;
ulong sql_mode;
uint execution_count;
Event_job_data();
virtual ~Event_job_data();
virtual int
load_from_row(TABLE *table);
int
execute(THD *thd);
int
compile(THD *thd, MEM_ROOT *mem_root);
private:
int
get_fake_create_event(THD *thd, String *buf);
Event_job_data(const Event_job_data &); /* Prevent use of these */
void operator=(Event_job_data &);
};
class Event_parse_data : public Sql_alloc
{
public:
enum enum_status
{
ENABLED = 1,
DISABLED
};
enum enum_on_completion
{
ON_COMPLETION_DROP = 1,
ON_COMPLETION_PRESERVE
};
enum enum_on_completion on_completion;
enum enum_status status;
const uchar *body_begin;
LEX_STRING dbname;
LEX_STRING name;
LEX_STRING definer;// combination of user and host
LEX_STRING body;
LEX_STRING comment;
Item* item_starts;
Item* item_ends;
Item* item_execute_at;
TIME starts;
TIME ends;
TIME execute_at;
my_bool starts_null;
my_bool ends_null;
my_bool execute_at_null;
sp_name *identifier;
Item* item_expression;
longlong expression;
interval_type interval;
static Event_parse_data *
new_instance(THD *thd);
bool
check_parse_data(THD *thd);
void
init_body(THD *thd);
private:
void
init_definer(THD *thd);
void
init_name(THD *thd, sp_name *spn);
int
init_execute_at(THD *thd);
int
init_interval(THD *thd);
int
init_starts(THD *thd);
int
init_ends(THD *thd);
Event_parse_data();
~Event_parse_data();
void
report_bad_value(const char *item_name, Item *bad_item);
Event_parse_data(const Event_parse_data &); /* Prevent use of these */
void operator=(Event_parse_data &);
};
/* Compares only the schema part of the identifier */
bool
event_basic_db_equal(LEX_STRING db, Event_basic *et);
/* Compares the whole identifier*/
bool
event_basic_identifier_equal(LEX_STRING db, LEX_STRING name, Event_basic *b);
#endif /* _EVENT_DATA_OBJECTS_H_ */