Code cleanup to get fewer reallocs() during execution.

- Changed TABLE->alias to String to get fewer reallocs when alias are used.
- Preallocate some buffers

Changed some String->c_ptr() -> String->ptr() when \0 is not needed.
Fixed wrong usage of String->ptr() when we need a \0 terminated string.
Use my_strtod() instead of my_atof() to avoid having to add \0 to string.
c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
zr 

sql/event_db_repository.cc:
  Update usage of TABLE->alias
sql/event_scheduler.cc:
  c_ptr() -> c_ptr_safe()
sql/events.cc:
  c_ptr() -> ptr() as \0 was not needed
sql/field.cc:
  Update usage of TABLE->alias
sql/field.h:
  Update usage of TABLE->alias
sql/ha_partition.cc:
  Update usage of TABLE->alias
sql/handler.cc:
  Update usage of TABLE->alias
  Fixed wrong usage of str.ptr()
sql/item.cc:
  Fixed error where code wrongly assumed string was \0 terminated.
sql/item_func.cc:
  c_ptr() -> c_ptr_safe()
  Update usage of TABLE->alias
sql/item_sum.h:
  Use my_strtod() instead of my_atof() to avoid having to add \0 to string
sql/lock.cc:
  Update usage of TABLE->alias
sql/log.cc:
  c_ptr() -> ptr() as \0 was not needed
sql/log_event.cc:
  c_ptr_quick() -> ptr() as \0 was not needed
sql/opt_range.cc:
  ptr() -> c_ptr() as \0 is needed
sql/opt_subselect.cc:
  Update usage of TABLE->alias
sql/opt_table_elimination.cc:
  Update usage of TABLE->alias
sql/set_var.cc:
  ptr() -> c_ptr() as \0 is needed
  c_ptr() -> c_ptr_safe()
sql/sp.cc:
  c_ptr() -> ptr() as \0 was not needed
sql/sp_rcontext.cc:
  
  Update usage of TABLE->alias
sql/sql_base.cc:
  Preallocate buffers
  Update usage of TABLE->alias
sql/sql_class.cc:
  Fix arguments to sprintf() to work even if string is not \0 terminated
sql/sql_insert.cc:
  Update usage of TABLE->alias
  c_ptr() -> ptr() as \0 was not needed
sql/sql_load.cc:
  Preallocate buffers
  Trivial optimizations
sql/sql_parse.cc:
  Trivial optimization
sql/sql_plugin.cc:
  c_ptr() -> ptr() as \0 was not needed
sql/sql_select.cc:
  Update usage of TABLE->alias
sql/sql_show.cc:
  Update usage of TABLE->alias
sql/sql_string.h:
  Added move() function to move allocated memory from one object to another.
sql/sql_table.cc:
  Update usage of TABLE->alias
  c_ptr() -> c_ptr_safe()
sql/sql_test.cc:
  ptr() -> c_ptr_safe()
sql/sql_trigger.cc:
  Update usage of TABLE->alias
  c_ptr() -> c_ptr_safe()
sql/sql_update.cc:
  Update usage of TABLE->alias
sql/sql_view.cc:
  ptr() -> c_ptr_safe()
sql/sql_yacc.yy:
  ptr() -> c_ptr()
sql/table.cc:
  
  Update usage of TABLE->alias
sql/table.h:
  Changed TABLE->alias to String to get fewer reallocs when alias are used.
storage/federatedx/ha_federatedx.cc:
  Use c_ptr_safe() to ensure strings are \0 terminated.
storage/maria/ha_maria.cc:
  Update usage of TABLE->alias
storage/myisam/ha_myisam.cc:
  Update usage of TABLE->alias
storage/xtradb/row/row0sel.c:
  Ensure that null bits in record are properly reset.
  (Old code didn't work as row_search_for_mysql() can be called twice while reading fields from one row.

1 files changed, 12 insertions, 8 deletions

diff --git a/sql/set_var.cc b/sql/set_var.cc
index 7e00ae5aa19..193b47704c6 100644
--- a/sql/set_var.cc
+++ b/sql/set_var.cc
@@ -990,7 +990,7 @@ bool sys_var_str::check(THD *thd, set_var *var)
 
   if ((res=(*check_func)(thd, var)) < 0)
     my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0),
-             name, var->value->str_value.ptr());
+             name, var->value->str_value.c_ptr());
   return res;
 }
 
@@ -2281,11 +2281,15 @@ bool sys_var_character_set::check(THD *thd, set_var *var)
       }
       tmp= NULL;
     }
-    else if (!(tmp=get_charset_by_csname(res->c_ptr(),MY_CS_PRIMARY,MYF(0))) &&
-             !(tmp=get_old_charset_by_name(res->c_ptr())))
+    else
     {
-      my_error(ER_UNKNOWN_CHARACTER_SET, MYF(0), res->c_ptr());
-      return 1;
+      const char *name= res->c_ptr_safe();
+      if (!(tmp=get_charset_by_csname(name,MY_CS_PRIMARY,MYF(0))) &&
+             !(tmp=get_old_charset_by_name(name)))
+      {
+        my_error(ER_UNKNOWN_CHARACTER_SET, MYF(0), res->c_ptr());
+        return 1;
+      }
     }
   }
   else // INT_RESULT
@@ -2622,7 +2626,7 @@ static int  sys_check_log_path(THD *thd,  set_var *var)
   if (!(res= var->value->val_str(&str)))
     goto err;
 
-  log_file_str= res->c_ptr();
+  log_file_str= res->c_ptr_safe();
   bzero(&f_stat, sizeof(MY_STAT));
 
   path_length= unpack_filename(path, log_file_str);
@@ -3085,7 +3089,7 @@ bool sys_var_thd_lc_time_names::check(THD *thd, set_var *var)
       my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), name, "NULL");
       return 1;
     }
-    const char *locale_str= res->c_ptr();
+    const char *locale_str= res->c_ptr_safe();
     if (!(locale_match= my_locale_by_name(locale_str)))
     {
       my_printf_error(ER_UNKNOWN_ERROR,
@@ -4117,7 +4121,7 @@ bool sys_var_thd_optimizer_switch::check(THD *thd, set_var *var)
                                optimizer_switch_typelib.count, 
                                thd->variables.optimizer_switch,
                                global_system_variables.optimizer_switch,
-                               res->c_ptr_safe(), res->length(), NULL,
+                               res->ptr(), res->length(), NULL,
                                &error, &error_len, &not_used);
   if (error_len)
   {