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, 5 insertions, 4 deletions

diff --git a/sql/opt_table_elimination.cc b/sql/opt_table_elimination.cc
index 1e4e87ebac7..be1471b7e2c 100644
--- a/sql/opt_table_elimination.cc
+++ b/sql/opt_table_elimination.cc
@@ -1783,7 +1783,7 @@ static void mark_as_eliminated(JOIN *join, TABLE_LIST *tbl)
     JOIN_TAB *tab= tbl->table->reginfo.join_tab;
     if (!(join->const_table_map & tab->table->map))
     {
-      DBUG_PRINT("info", ("Eliminated table %s", table->alias));
+      DBUG_PRINT("info", ("Eliminated table %s", table->alias.c_ptr()));
       tab->type= JT_CONST;
       join->eliminated_tables |= table->map;
       join->const_table_map|= table->map;
@@ -1818,7 +1818,7 @@ void Dep_analysis_context::dbug_print_deps()
       fprintf(DBUG_FILE, "  equality%ld: %s -> %s.%s\n", 
               (long)(eq_mod - equality_mods),
               str.c_ptr(),
-              eq_mod->field->table->table->alias,
+              eq_mod->field->table->table->alias.c_ptr(),
               eq_mod->field->field->field_name);
     }
     else
@@ -1836,12 +1836,13 @@ void Dep_analysis_context::dbug_print_deps()
     if ((table_dep= table_deps[i]))
     {
       /* Print table */
-      fprintf(DBUG_FILE, "  table %s\n", table_dep->table->alias);
+      fprintf(DBUG_FILE, "  table %s\n", table_dep->table->alias.c_ptr());
       /* Print fields */
       for (Dep_value_field *field_dep= table_dep->fields; field_dep; 
            field_dep= field_dep->next_table_field)
       {
-        fprintf(DBUG_FILE, "    field %s.%s ->", table_dep->table->alias,
+        fprintf(DBUG_FILE, "    field %s.%s ->",
+                table_dep->table->alias.c_ptr(),
                 field_dep->field->field_name);
         uint ofs= field_dep->bitmap_offset;
         for (uint bit= ofs; bit < ofs + n_equality_mods; bit++)