WL#1218 "Triggers". Some very preliminary version of patch.

Mostly needed for Monty for him getting notion what needed for triggers 
from new .FRM format. 

Things to be done:
- Right placement of trigger's invocations
- Right handling of errors in triggers (including transaction rollback)
- Support for priviliges
- Right handling of DROP/RENAME table (hope that it will be handled automatically
  with merging of .TRG into .FRM file)
- Saving/restoring some information critical for trigger creation and replication
  with their definitions (e.g. sql_mode, creator, ...)
- Replication

Already has some known bugs so probably not for general review.


include/mysqld_error.h:
  Added trigger related error codes.
sql/Makefile.am:
  Added sql_trigger.* files to list of sources from which mysqld is built.
sql/item.cc:
  Added Item_trigger_field class representing field of new/old version of row which is 
  inserted/updated/deleted and for which trigger is invoked.
sql/item.h:
  Added enums for describing trigger properties. (Here because of dependencies).
  Added Item_trigger_field class representing field of new/old version of row which is 
  inserted/updated/deleted and for which trigger is invoked.
sql/item_func.cc:
  Added Item_func_set_user_var::print_as_stmt() for printing of assignment to ser variable
  from stored procedures.
  Added comment clarifying why we don't need set no_send_ok when calling stored functions.
sql/item_func.h:
  Added Item_func_set_user_var::print_as_stmt() for printing of assignment to ser variable
  from stored procedures.
sql/lex.h:
  Symbols used in statements defining triggers were added.
sql/mysql_priv.h:
  Exported some functions needed for triggers implementation.
sql/parse_file.cc:
  Cleaned up FILE_OPTIONS_STRLIST handling (needed for triggers).
sql/parse_file.h:
  Cleaned up FILE_OPTIONS_STRLIST handling (needed for triggers).
sql/share/czech/errmsg.txt:
  Added trigger related error messages.
sql/share/danish/errmsg.txt:
  Added trigger related error messages.
sql/share/dutch/errmsg.txt:
  Added trigger related error messages.
sql/share/english/errmsg.txt:
  Added trigger related error messages.
sql/share/estonian/errmsg.txt:
  Added trigger related error messages.
sql/share/french/errmsg.txt:
  Added trigger related error messages.
sql/share/german/errmsg.txt:
  Added trigger related error messages.
sql/share/greek/errmsg.txt:
  Added trigger related error messages.
sql/share/hungarian/errmsg.txt:
  Added trigger related error messages.
sql/share/italian/errmsg.txt:
  Added trigger related error messages.
sql/share/japanese/errmsg.txt:
  Added trigger related error messages.
sql/share/korean/errmsg.txt:
  Added trigger related error messages.
sql/share/norwegian-ny/errmsg.txt:
  Added trigger related error messages.
sql/share/norwegian/errmsg.txt:
  Added trigger related error messages.
sql/share/polish/errmsg.txt:
  Added trigger related error messages.
sql/share/portuguese/errmsg.txt:
  Added trigger related error messages.
sql/share/romanian/errmsg.txt:
  Added trigger related error messages.
sql/share/russian/errmsg.txt:
  Added trigger related error messages.
sql/share/serbian/errmsg.txt:
  Added trigger related error messages.
sql/share/slovak/errmsg.txt:
  Added trigger related error messages.
sql/share/spanish/errmsg.txt:
  Added trigger related error messages.
sql/share/swedish/errmsg.txt:
  Added trigger related error messages.
sql/share/ukrainian/errmsg.txt:
  Added trigger related error messages.
sql/sp_head.cc:
  sp_head::init_strings(): added support for triggers 
    (we don't have most of strings for them)
  sp_head::execute_function(): triggers don't require RETURN
  sp_head::reset_lex(): added propagation of trigger properties to LEX used for 
   parsing of statements composing trigger body.
  Added two more SP instructions:
  - sp_instr_set_user_var for setting user variables in stored functions and triggers
    (we can't use sp_instr_stmt and "SET @a:=..." statement since it will close open 
    tables and thus break execution of calling statement.
  - sp_instr_set_trigger_field for assignment to fields of row being updated/inserted in
    triggers
sql/sp_head.h:
  Added new type of sp_head object - TYPE_ENUM_TRIGGER
  Added two more SP instructions:
  - sp_instr_set_user_var for setting user variables in stored functions and triggers
    (we can't use sp_instr_stmt and "SET @a:=..." statement since it will close open 
    tables and thus break execution of calling statement.
  - sp_instr_set_trigger_field for assignment to fields of row being updated/inserted in
    triggers
sql/sql_base.cc:
  Now freeing memory occupied by trigger related structures when closing tables.
  open_unireg_entry(): added loading of triggers for table.
  find_field_in_real_table() is now public since it required by Item_trigger_field in item.cc
sql/sql_delete.cc:
  Added triggers invocation for DELETE (should be fixed for sure :))
sql/sql_insert.cc:
  Added triggers invocation for INSERT (should be fixed for sure :))
sql/sql_lex.cc:
  Added trg_new_row_fake_var variable pointer to which is used for distinguishing between
  assignment to NEW row field (when parsing trigger definition) and structured variable.
  Added initialization of LEX->trg_table to lex_start(). (When triggers are parsed during
  opening of table it points to table object.)
sql/sql_lex.h:
  Added trigger related commands.
  Added st_trg_chistics structure describing properties of trigger being created
  (as struct and as LEX member).
  Added trg_new_row_fake_var variable pointer to which is used for
  distinguishing between assignment to NEW row field (when parsing trigger definition)
  and structured variable.
  Added LEX::trg_table which points to table being opened when we are parsing trigger
  definition while opening table.
sql/sql_parse.cc:
  Added support for CREATE/DROP TRIGGER commands.
sql/sql_table.cc:
  Cleanup. close_cached_table() always returns 0 and its result is not analyzed in most
  places so chenged its return type to void.
sql/sql_update.cc:
  Added triggers invocation for UPDATE (should be fixed for sure :))
sql/sql_yacc.yy:
  Added support for CREATE/DROP TRIGGER statements.
  Added support for OLD/NEW row identifiers in trigger.
  Made assignment to user variables not to break execution of stored function or trigger.
sql/table.h:
  Added TABLE::triggers member representing triggers for this table.

1 files changed, 14 insertions, 8 deletions

diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 781e7273e7a..1060c9cd25d 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -20,6 +20,8 @@
 #include "mysql_priv.h"
 #include "sql_acl.h"
 #include "sql_select.h"
+#include "sp_head.h"
+#include "sql_trigger.h"
 #include <m_ctype.h>
 #include <my_dir.h>
 #include <hash.h>
@@ -41,10 +43,6 @@ static my_bool open_new_frm(const char *path, const char *alias,
 			    uint db_stat, uint prgflag,
 			    uint ha_open_flags, TABLE *outparam,
 			    TABLE_LIST *table_desc, MEM_ROOT *mem_root);
-static Field *find_field_in_real_table(THD *thd, TABLE *table,
-				       const char *name, uint length,
-				       bool check_grants, bool allow_rowid, 
-				       uint *cached_field_index_ptr);
 
 extern "C" byte *table_cache_key(const byte *record,uint *length,
 				 my_bool not_used __attribute__((unused)))
@@ -209,6 +207,7 @@ OPEN_TABLE_LIST *list_open_tables(THD *thd, const char *wild)
 void intern_close_table(TABLE *table)
 {						// Free all structures
   free_io_cache(table);
+  delete table->triggers;
   if (table->file)
     VOID(closefrm(table));			// close file
 }
@@ -790,6 +789,7 @@ TABLE *reopen_name_locked_table(THD* thd, TABLE_LIST* table_list)
       !(table->table_cache_key =memdup_root(&table->mem_root,(char*) key,
 					    key_length)))
   {
+    delete table->triggers;
     closefrm(table);
     pthread_mutex_unlock(&LOCK_open);
     DBUG_RETURN(0);
@@ -1053,6 +1053,7 @@ bool reopen_table(TABLE *table,bool locked)
   if (!(tmp.table_cache_key= memdup_root(&tmp.mem_root,db,
 					 table->key_length)))
   {
+    delete tmp.triggers;
     closefrm(&tmp);				// End of memory
     goto end;
   }
@@ -1081,6 +1082,7 @@ bool reopen_table(TABLE *table,bool locked)
   tmp.next=		table->next;
   tmp.prev=		table->prev;
 
+  delete table->triggers;
   if (table->file)
     VOID(closefrm(table));		// close file, free everything
 
@@ -1469,6 +1471,9 @@ static int open_unireg_entry(THD *thd, TABLE *entry, const char *db,
   if (error == 5)
     DBUG_RETURN(0);	// we have just opened VIEW
 
+  if (Table_triggers_list::check_n_load(thd, db, name, entry))
+    goto err;
+
   /*
     If we are here, there was no fatal error (but error may be still
     unitialized).
@@ -1497,6 +1502,7 @@ static int open_unireg_entry(THD *thd, TABLE *entry, const char *db,
         */
         sql_print_error("Error: when opening HEAP table, could not allocate \
 memory to write 'DELETE FROM `%s`.`%s`' to the binary log",db,name);
+        delete entry->triggers;
         if (entry->file)
           closefrm(entry);
         goto err;
@@ -1998,10 +2004,10 @@ Field *find_field_in_table(THD *thd, TABLE_LIST *table_list,
     #			pointer to field
 */
 
-static Field *find_field_in_real_table(THD *thd, TABLE *table,
-				       const char *name, uint length,
-				       bool check_grants, bool allow_rowid, 
-				       uint *cached_field_index_ptr)
+Field *find_field_in_real_table(THD *thd, TABLE *table,
+                                const char *name, uint length,
+                                bool check_grants, bool allow_rowid,
+                                uint *cached_field_index_ptr)
 {
   Field **field_ptr, *field;
   uint cached_field_index= *cached_field_index_ptr;