Removed Item::common_flags and replaced it with bit fields

This is to make the Item instances smaller

Author: montywi

sql/item.cc

@@ -413,11 +413,12 @@ Item::Item(THD *thd):
  name(null_clex_str), orig_name(0), is_expensive_cache(-1)
 {
  DBUG_ASSERT(thd);
- common_flags= IS_AUTO_GENERATED_NAME;
- marker= 0;
  maybe_null= with_window_func= with_field= in_rollup= with_param= 0;
+ is_in_with_cycle= 0;
  fixed= 1; // Simple Item's doesn't have to be fixed
+ is_autogenerated_name= 1;
  null_value= 0;
+ marker= 0;
 
  /* Initially this item is not attached to any JOIN_TAB. */
  join_tab_idx= MAX_TABLES;
@@ -447,10 +448,12 @@ Item::Item():
  name(null_clex_str), orig_name(0), is_expensive_cache(-1)
 {
  DBUG_ASSERT(my_progname == NULL); // before main()
- common_flags= IS_AUTO_GENERATED_NAME;
- marker= 0;
  maybe_null= with_window_func= with_field= in_rollup= with_param= 0;
- fixed= 1;
+ is_in_with_cycle= 0;
+ fixed= 1; // Simple Item's doesn't have to be fixed
+ is_autogenerated_name= 1;
+ null_value= 0;
+ marker= 0;
  join_tab_idx= MAX_TABLES;
 }
 
@@ -481,10 +484,11 @@ Item::Item(THD *thd, Item *item):
  with_param(item->with_param),
  with_window_func(item->with_window_func),
  with_field(item->with_field),
+ is_autogenerated_name(item->is_autogenerated_name),
+ is_in_with_cycle(item->is_in_with_cycle),
  marker(item->marker),
  null_value(item->null_value),
  is_expensive_cache(-1),
- common_flags(item->common_flags),
  join_tab_idx(item->join_tab_idx)
 {
  next= thd->free_list;// Put in free list
@@ -1164,7 +1168,7 @@ void Item::set_name(THD *thd, const char *str, size_t length, CHARSET_INFO *cs)
  str++;
  }
  }
- if (str != str_start && !is_autogenerated_name())
+ if (str != str_start && !is_autogenerated_name)
  {
  char buff[SAFE_NAME_LEN];
 
@@ -5227,7 +5231,7 @@ static Item** find_field_in_group_list(Item *find_item, ORDER *group_list)
 
  /* SELECT list element with explicit alias */
  if ((*(cur_group->item))->name.str && !table_name.str &&
- !(*(cur_group->item))->is_autogenerated_name() &&
+ !(*(cur_group->item))->is_autogenerated_name &&
  !lex_string_cmp(system_charset_info,
  &(*(cur_group->item))->name, &field_name))
  {

sql/item.h

@@ -633,13 +633,6 @@ class st_select_lex_unit;
 class Item_func_not;
 class Item_splocal;
 
-/* Item::common_flags */
-/* Indicates that name of this Item autogenerated or set by user */
-#define IS_AUTO_GENERATED_NAME 1
-/* Indicates that this item is in CYCLE clause of WITH */
-#define IS_IN_WITH_CYCLE 2
-
-
 /**
  String_copier that sends Item specific warnings.
 */
@@ -931,7 +924,11 @@ class Item :public Value_source,
  with_window_func:1, /* True if item contains a window func */
  with_field:1, /* True if any item except Item_sum contains a field.
  Set during parsing. */
- fixed:1; /* If item was fixed with fix_fields */
+ fixed:1, /* If item was fixed with fix_fields */
+ /* Indicates that name of this Item autogenerated or set by user */
+ is_autogenerated_name:1,
+ /* Indicates that this item is in CYCLE clause of WITH */
+ is_in_with_cycle:1;
 
  int16 marker;
 
@@ -943,7 +940,6 @@ class Item :public Value_source,
  bool null_value;
  /* Cache of the result of is_expensive(). */
  int8 is_expensive_cache;
- uint8 common_flags; /* To be integrated into above flags soon... */
  /**
  The index in the JOIN::join_tab array of the JOIN_TAB this Item is attached
  to. Items are attached (or 'pushed') to JOIN_TABs during optimization by the
@@ -955,8 +951,6 @@ class Item :public Value_source,
  */
  uint8 join_tab_idx;
 
- bool is_autogenerated_name()
- { return (common_flags & IS_AUTO_GENERATED_NAME); }
  // alloc & destruct is done as start of select on THD::mem_root
  Item(THD *thd);
  /*
@@ -992,9 +986,7 @@ class Item :public Value_source,
  void share_name_with(const Item *item)
  {
  name= item->name;
- common_flags= static_cast<uint8>
- ((common_flags & ~IS_AUTO_GENERATED_NAME) |
- (item->common_flags & IS_AUTO_GENERATED_NAME));
+ is_autogenerated_name= item->is_autogenerated_name;
  }
  virtual void cleanup();
  virtual void make_send_field(THD *thd, Send_field *field);
@@ -7432,7 +7424,8 @@ class Item_type_holder: public Item,
  name= item->name;
  Type_std_attributes::set(*attr);
  maybe_null= maybe_null_arg;
- common_flags= item->common_flags;
+ is_autogenerated_name= item->is_autogenerated_name;
+ is_in_with_cycle= item->is_in_with_cycle;
  }
 
  const Type_handler *type_handler() const override

sql/item_create.cc

@@ -2387,7 +2387,7 @@ static bool has_named_parameters(List<Item> *params)
  List_iterator<Item> it(*params);
  while ((param= it++))
  {
- if (! param->is_autogenerated_name())
+ if (! param->is_autogenerated_name)
  return true;
  }
  }
@@ -2633,7 +2633,7 @@ Create_func_arg1::create_func(THD *thd, LEX_CSTRING *name, List<Item> *item_list
 
  Item *param_1= item_list->pop();
 
- if (unlikely(! param_1->is_autogenerated_name()))
+ if (unlikely(! param_1->is_autogenerated_name))
  {
  my_error(ER_WRONG_PARAMETERS_TO_NATIVE_FCT, MYF(0), name->str);
  return NULL;
@@ -2660,8 +2660,8 @@ Create_func_arg2::create_func(THD *thd, LEX_CSTRING *name, List<Item> *item_list
  Item *param_1= item_list->pop();
  Item *param_2= item_list->pop();
 
- if (unlikely(!param_1->is_autogenerated_name() ||
- !param_2->is_autogenerated_name()))
+ if (unlikely(!param_1->is_autogenerated_name ||
+ !param_2->is_autogenerated_name))
  {
  my_error(ER_WRONG_PARAMETERS_TO_NATIVE_FCT, MYF(0), name->str);
  return NULL;
@@ -2689,9 +2689,9 @@ Create_func_arg3::create_func(THD *thd, LEX_CSTRING *name, List<Item> *item_list
  Item *param_2= item_list->pop();
  Item *param_3= item_list->pop();
 
- if (unlikely(!param_1->is_autogenerated_name() ||
- !param_2->is_autogenerated_name() ||
- !param_3->is_autogenerated_name()))
+ if (unlikely(!param_1->is_autogenerated_name ||
+ !param_2->is_autogenerated_name ||
+ !param_3->is_autogenerated_name))
  {
  my_error(ER_WRONG_PARAMETERS_TO_NATIVE_FCT, MYF(0), name->str);
  return NULL;

sql/sql_base.cc

@@ -5849,7 +5849,7 @@ find_field_in_view(THD *thd, TABLE_LIST *table_list,
  replace. If the item was aliased by the user, set the alias to
  the replacing item.
  */
- if (*ref && !(*ref)->is_autogenerated_name())
+ if (*ref && !(*ref)->is_autogenerated_name)
  item->set_name(thd, (*ref)->name);
  if (register_tree_change)
  thd->change_item_tree(ref, item);
@@ -5940,7 +5940,7 @@ find_field_in_natural_join(THD *thd, TABLE_LIST *table_ref, const char *name, si
  replace. If the item was aliased by the user, set the alias to
  the replacing item.
  */
- if (*ref && !(*ref)->is_autogenerated_name())
+ if (*ref && !(*ref)->is_autogenerated_name)
  item->set_name(thd, (*ref)->name);
  if (register_tree_change && arena)
  thd->restore_active_arena(arena, &backup);

sql/sql_cte.cc

@@ -993,7 +993,7 @@ With_element::process_columns_of_derived_unit(THD *thd,
  while ((item= it++, name= nm++))
  {
  item->set_name(thd, *name);
- item->common_flags&= ~IS_AUTO_GENERATED_NAME;
+ item->is_autogenerated_name= 0;
  }
 
  if (arena)
@@ -1036,7 +1036,7 @@ With_element::process_columns_of_derived_unit(THD *thd,
  my_error(ER_BAD_FIELD_ERROR, MYF(0), name->str, "CYCLE clause");
  return true;
  }
- item->common_flags|= IS_IN_WITH_CYCLE;
+ item->is_in_with_cycle= 1;
  }
  }
  unit->columns_are_renamed= true;

sql/sql_select.cc

@@ -18644,7 +18644,7 @@ bool Create_tmp_table::add_fields(THD *thd,
  Item *item;
  Field **tmp_from_field= m_from_field;
  while (!m_with_cycle && (item= li++))
- if (item->common_flags & IS_IN_WITH_CYCLE)
+ if (item->is_in_with_cycle)
  {
  m_with_cycle= true;
  /*
@@ -18662,8 +18662,7 @@ bool Create_tmp_table::add_fields(THD *thd,
  uint uneven_delta;
  current_counter= (((param->hidden_field_count < (fieldnr + 1)) &&
  distinct_record_structure &&
- (!m_with_cycle ||
- (item->common_flags & IS_IN_WITH_CYCLE)))?
+ (!m_with_cycle || item->is_in_with_cycle)) ?
  distinct :
  other);
  Item::Type type= item->type();
@@ -27993,7 +27992,7 @@ void st_select_lex::print(THD *thd, String *str, enum_query_type query_type)
  else
  str->append(',');
 
- if (is_subquery_function() && item->is_autogenerated_name())
+ if (is_subquery_function() && item->is_autogenerated_name)
  {
  /*
  Do not print auto-generated aliases in subqueries. It has no purpose

sql/sql_view.cc

@@ -137,17 +137,17 @@ bool check_duplicate_names(THD *thd, List<Item> &item_list, bool gen_unique_view
  Item *check;
  /* treat underlying fields like set by user names */
  if (item->real_item()->type() == Item::FIELD_ITEM)
- item->common_flags&= ~IS_AUTO_GENERATED_NAME;
+ item->is_autogenerated_name= 0;
  itc.rewind();
  while ((check= itc++) && check != item)
  {
  if (lex_string_cmp(system_charset_info, &item->name, &check->name) == 0)
  {
  if (!gen_unique_view_name)
  goto err;
- if (item->is_autogenerated_name())
+ if (item->is_autogenerated_name)
  make_unique_view_field_name(thd, item, item_list, item);
- else if (check->is_autogenerated_name())
+ else if (check->is_autogenerated_name)
  make_unique_view_field_name(thd, check, item_list, item);
  else
  goto err;
@@ -179,7 +179,7 @@ void make_valid_column_names(THD *thd, List<Item> &item_list)
 
  for (uint column_no= 1; (item= it++); column_no++)
  {
- if (!item->is_autogenerated_name() || !check_column_name(item->name.str))
+ if (!item->is_autogenerated_name || !check_column_name(item->name.str))
  continue;
  name_len= my_snprintf(buff, NAME_LEN, "Name_exp_%u", column_no);
  item->orig_name= item->name.str;
@@ -566,7 +566,7 @@ bool mysql_create_view(THD *thd, TABLE_LIST *views,
  while ((item= it++, name= nm++))
  {
  item->set_name(thd, *name);
- item->common_flags&= ~IS_AUTO_GENERATED_NAME;
+ item->is_autogenerated_name= 0;
  }
  }
 

sql/sql_yacc.yy

@@ -9223,7 +9223,7 @@ select_item:
  if (unlikely(Lex->sql_command == SQLCOM_CREATE_VIEW &&
  check_column_name($4.str)))
  my_yyabort_error((ER_WRONG_COLUMN_NAME, MYF(0), $4.str));
- $2->common_flags&= ~IS_AUTO_GENERATED_NAME;
+ $2->is_autogenerated_name= 0;
  $2->set_name(thd, $4);
  }
  else if (!$2->name.str || $2->name.str == item_empty_name)
@@ -10801,7 +10801,7 @@ udf_expr:
  */
  if ($4.str)
  {
- $2->common_flags&= ~IS_AUTO_GENERATED_NAME;
+ $2->is_autogenerated_name= 0;
  $2->set_name(thd, $4);
  }
  /*