WL#3337 (Event scheduler new architecture)

Third cut to simplify parsing phase. Now DROP EVENT works.

Overloaded few functions to be able to use either sp_name or pass two LEX_STRINGs
instead of a Event_timed pointer. This is transitional and eventually the old
functions will be removed. For now DROP EVENT also works, does not need anymore
a parsing object (Event_timed) and definer initialization because everyone who
has EVENT_ACL can drop events, and this is checked on execution time in sql_parse.cc
from the security context, as it should be.


sql/event_data_objects.cc:
  overload few functions
sql/event_scheduler.cc:
  Event_scheduler::drop_event() actually does not need Event_timed object
  but just an identifier, hence pass only sp_name.
  
  Overloaded Event_scheduler::find_event() to work with sp_name object. Eventually
  the old version will be removed. This is being done as transitional step to
  be able to test frequently code.
sql/event_scheduler.h:
  Event_scheduler::drop_event() actually does not need Event_timed object
  but just an identifier, hence pass only sp_name.
  
  Overloaded Event_scheduler::find_event() to work with sp_name object. Eventually
  the old version will be removed. This is being done as transitional step to
  be able to test frequently code.
sql/events.cc:
  Change db_drop_event() not to use Event_timed, either coming from parsing
  or from Event_timed::drop, but use LEX_STRINGs. sp_name is not convinient
  because in Event_timed::drop a temporary object has to be created. Hence, 
  dereference the sp_name in Events::drop_event() and pass the LEX_STRINGs.
sql/events.h:
  Change db_drop_event() not to use Event_timed, either coming from parsing
  or from Event_timed::drop, but use LEX_STRINGs. sp_name is not convinient
  because in Event_timed::drop a temporary object has to be created. Hence, 
  dereference the sp_name in Events::drop_event() and pass the LEX_STRINGs.
sql/events_priv.h:
  Change db_drop_event() not to use Event_timed, either coming from parsing
  or from Event_timed::drop, but use LEX_STRINGs. sp_name is not convinient
  because in Event_timed::drop a temporary object has to be created. Hence, 
  dereference the sp_name in Events::drop_event() and pass the LEX_STRINGs.
sql/sql_parse.cc:
  SQLCOM_DROP_EVENT does not need lex->event_parse_data object and 
  is more like SQLCOM_SHOW_CREATE_EVENT. Therefore, move it to the block that
  handles the latter.
sql/sql_yacc.yy:
  DROP EVENT does not need a parsing object, just a name.
  Store it as lex->spname. Pretty similar handling to the one of
  SHOW CREATE EVENT.

1 files changed, 46 insertions, 3 deletions

diff --git a/sql/event_scheduler.cc b/sql/event_scheduler.cc
index fc2ad75b272..f83bc5f25a3 100644
--- a/sql/event_scheduler.cc
+++ b/sql/event_scheduler.cc
@@ -833,12 +833,13 @@ end:
 */
 
 bool
-Event_scheduler::drop_event(THD *thd, Event_timed *et)
+Event_scheduler::drop_event(THD *thd, sp_name *name)
 {
   int res;
   Event_timed *et_old;
   DBUG_ENTER("Event_scheduler::drop_event");
-  DBUG_PRINT("enter", ("thd=%p et=%p lock=%p",thd,et,&LOCK_scheduler_data));
+  DBUG_PRINT("enter", ("thd=%p name=%p lock=%p", thd, name,
+             &LOCK_scheduler_data));
 
   LOCK_SCHEDULER_DATA();
   if (!is_running_or_suspended())
@@ -848,7 +849,7 @@ Event_scheduler::drop_event(THD *thd, Event_timed *et)
     DBUG_RETURN(OP_OK);
   }
 
-  if (!(et_old= find_event(et, TRUE)))
+  if (!(et_old= find_event(name, TRUE)))
     DBUG_PRINT("info", ("No such event found, probably DISABLED"));
 
   UNLOCK_SCHEDULER_DATA();
@@ -1050,6 +1051,48 @@ Event_scheduler::find_event(Event_timed *etn, bool remove_from_q)
 
 
 /*
+  Searches for an event in the scheduler queue
+
+  SYNOPSIS
+    Event_scheduler::find_event()
+      name           The event to find
+      comparator     The function to use for comparing
+      remove_from_q  If found whether to remove from the Q
+
+  RETURN VALUE
+    NULL       Not found
+    otherwise  Address
+
+  NOTE
+    The caller should do the locking also the caller is responsible for
+    actual signalling in case an event is removed from the queue 
+    (signalling COND_new_work for instance).
+*/
+
+Event_timed *
+Event_scheduler::find_event(sp_name *name, bool remove_from_q)
+{
+  uint i;
+  DBUG_ENTER("Event_scheduler::find_event");
+
+  for (i= 0; i < queue.elements; ++i)
+  {
+    Event_timed *et= (Event_timed *) queue_element(&queue, i);
+    DBUG_PRINT("info", ("[%s.%s]==[%s.%s]?", name->m_db.str, name->m_name.str,
+                        et->dbname.str, et->name.str));
+    if (event_timed_identifier_equal(name, et))
+    {
+      if (remove_from_q)
+        queue_remove(&queue, i);
+      DBUG_RETURN(et);
+    }
+  }
+
+  DBUG_RETURN(NULL);
+}
+
+
+/*
   Drops all events from the in-memory queue and disk that match
   certain pattern evaluated by a comparator function