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.

sql/event_data_objects.cc

@@ -1299,7 +1299,7 @@ Event_timed::drop(THD *thd)
   uint tmp= 0;
   DBUG_ENTER("Event_timed::drop");
 
-  DBUG_RETURN(db_drop_event(thd, this, false, &tmp));
+  DBUG_RETURN(db_drop_event(thd, dbname, name, false, &tmp));
 }
 
 
@@ -1903,8 +1903,62 @@ bool
 event_timed_identifier_equal(Event_timed *a, Event_timed *b)
 {
   return event_timed_name_equal(a, &b->name) &&
-         event_timed_db_equal(a, &b->dbname) &&
-         event_timed_definer_equal(a, &b->definer);
+         event_timed_db_equal(a, &b->dbname);
+}
+
+
+/*
+  Checks whether two events have the same name
+
+  SYNOPSIS
+    event_timed_name_equal()
+
+  RETURN VALUE
+    TRUE  names are equal
+    FALSE names are not equal
+*/
+
+bool
+event_timed_name_equal(sp_name *name, LEX_STRING *event_name)
+{
+  return !sortcmp_lex_string(name->m_name, *event_name, system_charset_info);
+}
+
+
+/*
+  Checks whether two events are in the same schema
+
+  SYNOPSIS
+    event_timed_db_equal()
+
+  RETURN VALUE
+    TRUE  schemas are equal
+    FALSE schemas are not equal
+*/
+
+bool
+event_timed_db_equal(sp_name *name, LEX_STRING *db)
+{
+  return !sortcmp_lex_string(name->m_db, *db, system_charset_info);
+}
+
+
+/*
+  Checks whether two events are equal by identifiers
+
+  SYNOPSIS
+    event_timed_identifier_equal()
+
+  RETURN VALUE
+    TRUE   equal
+    FALSE  not equal
+*/
+
+bool
+event_timed_identifier_equal(sp_name *a, Event_timed *b)
+{
+  return event_timed_name_equal(a, &b->name) &&
+         event_timed_db_equal(a, &b->dbname);
 }
 
 

sql/event_scheduler.cc

@@ -833,12 +833,13 @@ Event_scheduler::create_event(THD *thd, Event_timed *et, bool check_existence)
 */
 
 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();
@@ -1049,6 +1050,48 @@ 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

sql/event_scheduler.h

@@ -16,6 +16,7 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
+class sp_name;
 class Event_timed;
 
 class THD;
@@ -73,7 +74,7 @@ class Event_scheduler
                 LEX_STRING *new_name);
 
   bool
-  drop_event(THD *thd, Event_timed *et);
+  drop_event(THD *thd, sp_name *name);
 
 
   int
@@ -136,6 +137,9 @@ class Event_scheduler
   Event_timed *
   find_event(Event_timed *etn, bool remove_from_q);
 
+  Event_timed *
+  find_event(sp_name *name, bool remove_from_q);
+
   uint
   workers_count();
 

sql/events.cc

@@ -988,14 +988,15 @@ Events::update_event(THD *thd, Event_timed *et, Event_parse_data *parse_data,
     !0  Error (my_error() called)
 */
 
-int db_drop_event(THD *thd, Event_timed *et, bool drop_if_exists,
-                  uint *rows_affected)
+int db_drop_event(THD *thd, LEX_STRING db, LEX_STRING name,
+                  bool drop_if_exists, uint *rows_affected)
 {
   TABLE *table;
   Open_tables_state backup;
   int ret;
 
   DBUG_ENTER("db_drop_event");
+  DBUG_PRINT("enter", ("db=%s name=%s", db.str, name.str));
   ret= EVEX_OPEN_TABLE_FAILED;
 
   thd->reset_n_backup_open_tables_state(&backup);
@@ -1005,13 +1006,10 @@ int db_drop_event(THD *thd, Event_timed *et, bool drop_if_exists,
     goto done;
   }
 
-  if (!(ret= evex_db_find_event_aux(thd, et, table)))
+  if (!(ret= evex_db_find_event_by_name(thd, db, name, table)))
   {
     if ((ret= table->file->ha_delete_row(table->record[0])))
-    { 	
       my_error(ER_EVENT_CANNOT_DELETE, MYF(0));
-      goto done;
-    }
   }
   else if (ret == EVEX_KEY_NOT_FOUND)
   { 
@@ -1019,14 +1017,12 @@ int db_drop_event(THD *thd, Event_timed *et, bool drop_if_exists,
     {
       push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
                           ER_SP_DOES_NOT_EXIST, ER(ER_SP_DOES_NOT_EXIST),
-                          "Event", et->name.str);
+                          "Event", name.str);
       ret= 0;
     } else
-      my_error(ER_EVENT_DOES_NOT_EXIST, MYF(0), et->name.str);
-    goto done;
+      my_error(ER_EVENT_DOES_NOT_EXIST, MYF(0), name.str);
   }
 
-
 done:
   /*
     evex_drop_event() is used by Event_timed::drop therefore
@@ -1044,7 +1040,7 @@ int db_drop_event(THD *thd, Event_timed *et, bool drop_if_exists,
   SYNOPSIS
     Events::drop_event()
       thd             THD
-      et              event's name
+      name            event's name
       drop_if_exists  if set and the event not existing => warning onto the stack
       rows_affected   affected number of rows is returned heres
 
@@ -1054,16 +1050,17 @@ int db_drop_event(THD *thd, Event_timed *et, bool drop_if_exists,
 */
 
 int
-Events::drop_event(THD *thd, Event_timed *et, Event_parse_data *parse_data,
-                   bool drop_if_exists, uint *rows_affected)
+Events::drop_event(THD *thd, sp_name *name, bool drop_if_exists,
+                   uint *rows_affected)
 {
   int ret;
 
   DBUG_ENTER("Events::drop_event");
-  if (!(ret= db_drop_event(thd, et, drop_if_exists, rows_affected)))
+  if (!(ret= db_drop_event(thd, name->m_db, name->m_name, drop_if_exists,
+                           rows_affected)))
   {
     Event_scheduler *scheduler= Event_scheduler::get_instance();
-    if (scheduler->initialized() && (ret= scheduler->drop_event(thd, et)))
+    if (scheduler->initialized() && (ret= scheduler->drop_event(thd, name)))
       my_error(ER_EVENT_MODIFY_QUEUE_ERROR, MYF(0), ret);
   }
 

sql/events.h

@@ -16,7 +16,7 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
-
+class sp_name;
 class Event_timed;
 class Event_parse_data;
 
@@ -56,8 +56,7 @@ class Events
                sp_name *new_name, uint *rows_affected);
 
   static int
-  drop_event(THD *thd, Event_timed *et, Event_parse_data *parse_data,
-             bool drop_if_exists, uint *rows_affected);
+  drop_event(THD *thd, sp_name *name, bool drop_if_exists, uint *rows_affected);
 
   static int
   open_event_table(THD *thd, enum thr_lock_type lock_type, TABLE **table);

sql/events_priv.h

@@ -25,6 +25,7 @@
 #define EVEX_MAX_INTERVAL_VALUE 2147483647L
 
 class Event_timed;
+class sp_name;
 
 int
 evex_db_find_event_by_name(THD *thd, const LEX_STRING dbname,
@@ -32,7 +33,7 @@ evex_db_find_event_by_name(THD *thd, const LEX_STRING dbname,
                           TABLE *table);
 
 int
-db_drop_event(THD *thd, Event_timed *et, bool drop_if_exists,
+db_drop_event(THD *thd, LEX_STRING db, LEX_STRING name, bool drop_if_exists,
               uint *rows_affected);
 int
 db_find_event(THD *thd, sp_name *name, Event_timed **ett, TABLE *tbl,
@@ -68,6 +69,20 @@ bool
 event_timed_identifier_equal(Event_timed *a, Event_timed *b);
 
 
+
+/* Compares only the name part of the identifier */
+bool
+event_timed_name_equal(sp_name *name, LEX_STRING *event_name);
+
+/* Compares only the schema part of the identifier */
+bool
+event_timed_db_equal(sp_name *name, LEX_STRING *db);
+
+/* Compares the whole identifier*/
+bool
+event_timed_identifier_equal(sp_name *a, Event_timed *b);
+
+
 bool
 change_security_context(THD *thd, LEX_STRING user, LEX_STRING host,
                         LEX_STRING db, Security_context *s_ctx,

sql/sql_parse.cc

@@ -3819,7 +3819,6 @@ mysql_execute_command(THD *thd)
   }
   case SQLCOM_CREATE_EVENT:
   case SQLCOM_ALTER_EVENT:
-  case SQLCOM_DROP_EVENT:
   {
     uint rows_affected= 1;
     DBUG_ASSERT(lex->et);
@@ -3856,9 +3855,6 @@ mysql_execute_command(THD *thd)
         res= Events::update_event(thd, lex->et, lex->event_parse_data,
                                   lex->spname, &rows_affected);
         break;
-      case SQLCOM_DROP_EVENT:
-        res= Events::drop_event(thd, lex->et, lex->event_parse_data,
-                                lex->drop_if_exists, &rows_affected);
       default:;
       }
       DBUG_PRINT("info", ("CREATE/ALTER/DROP returned error code=%d af_rows=%d",
@@ -3877,6 +3873,7 @@ mysql_execute_command(THD *thd)
     
     break;
   }
+  case SQLCOM_DROP_EVENT:
   case SQLCOM_SHOW_CREATE_EVENT:
   {
     DBUG_ASSERT(lex->spname);
@@ -3893,9 +3890,24 @@ mysql_execute_command(THD *thd)
     if (lex->spname->m_name.length > NAME_LEN)
     {
       my_error(ER_TOO_LONG_IDENT, MYF(0), lex->spname->m_name.str);
+      /* this jumps to the end of the function and skips own messaging */
       goto error;
     }
-    res= Events::show_create_event(thd, lex->spname);
+
+    if (lex->sql_command == SQLCOM_SHOW_CREATE_EVENT)
+      res= Events::show_create_event(thd, lex->spname);
+    else
+    {
+      uint rows_affected= 1;
+      if (end_active_trans(thd))
+      {
+        res= -1;
+        break;
+      }
+      if (!(res= Events::drop_event(thd, lex->spname, lex->drop_if_exists,
+                                    &rows_affected)))
+        send_ok(thd, rows_affected);     
+    }
     break;
   }
 #ifndef DBUG_OFF

sql/sql_yacc.yy

@@ -7686,33 +7686,9 @@ drop:
 	  }
         | DROP EVENT_SYM if_exists sp_name
           {
-            if (!(Lex->event_parse_data= Event_parse_data::new_instance(YYTHD)))
-              YYABORT;
-            Lex->event_parse_data->identifier= $4;
-
-            LEX *lex=Lex;
-
-            if (lex->et)
-            {
-              /*
-                Recursive events are not possible because recursive SPs
-                are not also possible. lex->sp_head is not stacked.
-              */
-              my_error(ER_SP_NO_RECURSIVE_CREATE, MYF(0), "EVENT");
-              YYABORT;
-            }
-
-            if (!(lex->et= new (YYTHD->mem_root) Event_timed()))
-              YYABORT;
-	  
-            if (!lex->et_compile_phase)
-            {
-              lex->et->init_name(YYTHD, $4);
-              lex->et->init_definer(YYTHD);
-            }
-
-            lex->sql_command = SQLCOM_DROP_EVENT;
-            lex->drop_if_exists= $3;
+            Lex->drop_if_exists= $3;
+            Lex->spname= $4;
+            Lex->sql_command = SQLCOM_DROP_EVENT;
           }
         | DROP TRIGGER_SYM sp_name
           {