Deployment of centralized Item change registry, step 2: Item_ref

doesn't need to have it's own recovery mechanism.

sql/item.cc

@@ -1334,7 +1334,6 @@ bool Item_field::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
 
 	Item_ref *rf;
 	*ref= rf= new Item_ref(last->ref_pointer_array + counter,
-			       0,
 			       (char *)table_name,
 			       (char *)field_name);
         thd->register_item_tree_change(ref, this, &thd->mem_root);
@@ -1357,10 +1356,8 @@ bool Item_field::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
 	{
 	  Item_ref *rf;
           thd->register_item_tree_change(ref, *ref, &thd->mem_root);
-	  *ref= rf= new Item_ref(ref, 0,
-				 (where->db[0]?where->db:0), 
-				 (char *)where->alias,
-				 (char *)field_name);
+          *ref= rf= new Item_ref((where->db[0] ? where->db : 0),
+                                 (char*) where->alias, (char*) field_name);
 	  if (!rf)
 	    return 1;
 	  /*
@@ -2061,16 +2058,6 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference)
 }
 
 
-void Item_ref::cleanup()
-{
-  DBUG_ENTER("Item_ref::cleanup");
-  Item_ident::cleanup();
-  if (hook_ptr)
-    *hook_ptr= orig_item;
-  DBUG_VOID_RETURN;
-}
-
-
 void Item_ref::print(String *str)
 {
   if (ref && *ref)

sql/item.h

@@ -237,7 +237,8 @@ public:
   virtual void print(String *str_arg) { str_arg->append(full_name()); }
   void print_item_w_name(String *);
   virtual void update_used_tables() {}
-  virtual void split_sum_func(Item **ref_pointer_array, List<Item> &fields) {}
+  virtual void split_sum_func(THD *thd, Item **ref_pointer_array,
+                              List<Item> &fields) {}
   virtual bool get_date(TIME *ltime,uint fuzzydate);
   virtual bool get_time(TIME *ltime);
   virtual bool get_date_result(TIME *ltime,uint fuzzydate)
@@ -781,20 +782,13 @@ class Item_ref :public Item_ident
 public:
   Field *result_field;			 /* Save result here */
   Item **ref;
-  Item **hook_ptr;                       /* These two to restore  */
-  Item *orig_item;                       /* things in 'cleanup()' */
-  Item_ref(Item **hook, Item *original,const char *db_par,
-	   const char *table_name_par, const char *field_name_par)
-    :Item_ident(db_par,table_name_par,field_name_par),ref(0), hook_ptr(hook),
-    orig_item(original) {}
-  Item_ref(Item **item, Item **hook, 
-	   const char *table_name_par, const char *field_name_par)
-    :Item_ident(NullS,table_name_par,field_name_par),
-    ref(item), hook_ptr(hook), orig_item(hook ? *hook:0) {}
-  // Constructor need to process subselect with temporary tables (see Item)
-  Item_ref(THD *thd, Item_ref *item, Item **hook)
-    :Item_ident(thd, item), ref(item->ref), 
-    hook_ptr(hook), orig_item(hook ? *hook : 0) {}
+  Item_ref(const char *db_par, const char *table_name_par,
+           const char *field_name_par)
+    :Item_ident(db_par, table_name_par, field_name_par), ref(0) {}
+  Item_ref(Item **item, const char *table_name_par, const char *field_name_par)
+    :Item_ident(NullS, table_name_par, field_name_par), ref(item) {}
+  /* Constructor need to process subselect with temporary tables (see Item) */
+  Item_ref(THD *thd, Item_ref *item) :Item_ident(thd, item), ref(item->ref) {}
   enum Type type() const		{ return REF_ITEM; }
   bool eq(const Item *item, bool binary_cmp) const
   { return ref && (*ref)->eq(item, binary_cmp); }
@@ -845,7 +839,6 @@ public:
   }
   Item *real_item() { return *ref; }
   void print(String *str);
-  void cleanup();
 };
 
 class Item_in_subselect;
@@ -856,7 +849,7 @@ protected:
 public:
   Item_ref_null_helper(Item_in_subselect* master, Item **item,
 		       const char *table_name_par, const char *field_name_par):
-    Item_ref(item, NULL, table_name_par, field_name_par), owner(master) {}
+    Item_ref(item, table_name_par, field_name_par), owner(master) {}
   double val();
   longlong val_int();
   String* val_str(String* s);

sql/item_cmpfunc.cc

@@ -2018,7 +2018,8 @@ bool Item_cond::walk(Item_processor processor, byte *arg)
   return Item_func::walk(processor, arg);
 }
 
-void Item_cond::split_sum_func(Item **ref_pointer_array, List<Item> &fields)
+void Item_cond::split_sum_func(THD *thd, Item **ref_pointer_array,
+                               List<Item> &fields)
 {
   List_iterator<Item> li(list);
   Item *item;
@@ -2027,13 +2028,15 @@ void Item_cond::split_sum_func(Item **ref_pointer_array, List<Item> &fields)
   while ((item=li++))
   {
     if (item->with_sum_func && item->type() != SUM_FUNC_ITEM)
-      item->split_sum_func(ref_pointer_array, fields);
+      item->split_sum_func(thd, ref_pointer_array, fields);
     else if (item->used_tables() || item->type() == SUM_FUNC_ITEM)
     {
+      Item **ref= li.ref();
       uint el= fields.elements;
       fields.push_front(item);
       ref_pointer_array[el]= item;
-      li.replace(new Item_ref(ref_pointer_array + el, li.ref(), 0, item->name));
+      thd->register_item_tree_change(ref, *ref, &thd->mem_root);
+      li.replace(new Item_ref(ref_pointer_array + el, 0, item->name));
     }
     item->update_used_tables();
     used_tables_cache|=item->used_tables();

sql/item_cmpfunc.h

@@ -931,7 +931,7 @@ public:
   table_map used_tables() const;
   void update_used_tables();
   void print(String *str);
-  void split_sum_func(Item **ref_pointer_array, List<Item> &fields);
+  void split_sum_func(THD *thd, Item **ref_pointer_array, List<Item> &fields);
   friend int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds);
   void top_level_item() { abort_on_null=1; }
   void copy_andor_arguments(THD *thd, Item_cond *item);

sql/item_func.cc

@@ -257,20 +257,22 @@ bool Item_func::walk (Item_processor processor, byte *argument)
   return (this->*processor)(argument);
 }
 
-void Item_func::split_sum_func(Item **ref_pointer_array, List<Item> &fields)
+void Item_func::split_sum_func(THD *thd, Item **ref_pointer_array,
+                               List<Item> &fields)
 {
   Item **arg, **arg_end;
   for (arg= args, arg_end= args+arg_count; arg != arg_end ; arg++)
   {
     Item *item=* arg;
     if (item->with_sum_func && item->type() != SUM_FUNC_ITEM)
-      item->split_sum_func(ref_pointer_array, fields);
+      item->split_sum_func(thd, ref_pointer_array, fields);
     else if (item->used_tables() || item->type() == SUM_FUNC_ITEM)
     {
       uint el= fields.elements;
       fields.push_front(item);
       ref_pointer_array[el]= item;
-      *arg= new Item_ref(ref_pointer_array + el, arg, 0, item->name);
+      thd->register_item_tree_change(arg, *arg, &thd->mem_root);
+      *arg= new Item_ref(ref_pointer_array + el, 0, item->name);
     }
   }
 }

sql/item_func.h

@@ -121,7 +121,7 @@ public:
   void set_arguments(List<Item> &list);
   inline uint argument_count() const { return arg_count; }
   inline void remove_arguments() { arg_count=0; }
-  virtual void split_sum_func(Item **ref_pointer_array, List<Item> &fields);
+  void split_sum_func(THD *thd, Item **ref_pointer_array, List<Item> &fields);
   void print(String *str);
   void print_op(String *str);
   void print_args(String *str, uint from);

sql/item_row.cc

@@ -84,19 +84,21 @@ bool Item_row::fix_fields(THD *thd, TABLE_LIST *tabl, Item **ref)
   return 0;
 }
 
-void Item_row::split_sum_func(Item **ref_pointer_array, List<Item> &fields)
+void Item_row::split_sum_func(THD *thd, Item **ref_pointer_array,
+                              List<Item> &fields)
 {
   Item **arg, **arg_end;
   for (arg= items, arg_end= items+arg_count; arg != arg_end ; arg++)
   {
     if ((*arg)->with_sum_func && (*arg)->type() != SUM_FUNC_ITEM)
-      (*arg)->split_sum_func(ref_pointer_array, fields);
+      (*arg)->split_sum_func(thd, ref_pointer_array, fields);
     else if ((*arg)->used_tables() || (*arg)->type() == SUM_FUNC_ITEM)
     {
       uint el= fields.elements;
       fields.push_front(*arg);
       ref_pointer_array[el]= *arg;
-      *arg= new Item_ref(ref_pointer_array + el, arg, 0, (*arg)->name);
+      thd->register_item_tree_change(arg, *arg, &thd->mem_root);
+      *arg= new Item_ref(ref_pointer_array + el, 0, (*arg)->name);
     }
   }
 }

sql/item_row.h

@@ -57,7 +57,7 @@ public:
     return 0;
   };
   bool fix_fields(THD *thd, TABLE_LIST *tables, Item **ref);
-  void split_sum_func(Item **ref_pointer_array, List<Item> &fields);
+  void split_sum_func(THD *thd, Item **ref_pointer_array, List<Item> &fields);
   table_map used_tables() const { return used_tables_cache; };
   bool const_item() const { return const_item_cache; };
   enum Item_result result_type() const { return ROW_RESULT; }

sql/item_strfunc.cc

@@ -635,20 +635,20 @@ null:
   return 0;
 }
 
-void Item_func_concat_ws::split_sum_func(Item **ref_pointer_array,
+void Item_func_concat_ws::split_sum_func(THD *thd, Item **ref_pointer_array,
 					 List<Item> &fields)
 {
   if (separator->with_sum_func && separator->type() != SUM_FUNC_ITEM)
-    separator->split_sum_func(ref_pointer_array, fields);
+    separator->split_sum_func(thd, ref_pointer_array, fields);
   else if (separator->used_tables() || separator->type() == SUM_FUNC_ITEM)
   {
     uint el= fields.elements;
     fields.push_front(separator);
     ref_pointer_array[el]= separator;
-    separator= new Item_ref(ref_pointer_array + el,
-			    &separator, 0, separator->name);
+    thd->register_item_tree_change(&separator, separator, &thd->mem_root);
+    separator= new Item_ref(ref_pointer_array + el, 0, separator->name);
   }
-  Item_str_func::split_sum_func(ref_pointer_array, fields);
+  Item_str_func::split_sum_func(thd, ref_pointer_array, fields);
 }
 
 void Item_func_concat_ws::fix_length_and_dec()
@@ -1771,19 +1771,20 @@ String *Item_func_elt::val_str(String *str)
 }
 
 
-void Item_func_make_set::split_sum_func(Item **ref_pointer_array,
+void Item_func_make_set::split_sum_func(THD *thd, Item **ref_pointer_array,
 					List<Item> &fields)
 {
   if (item->with_sum_func && item->type() != SUM_FUNC_ITEM)
-    item->split_sum_func(ref_pointer_array, fields);
+    item->split_sum_func(thd, ref_pointer_array, fields);
   else if (item->used_tables() || item->type() == SUM_FUNC_ITEM)
   {
     uint el= fields.elements;
     fields.push_front(item);
     ref_pointer_array[el]= item;
-    item= new Item_ref(ref_pointer_array + el, &item, 0, item->name);
+    thd->register_item_tree_change(&item, item, &thd->mem_root);
+    item= new Item_ref(ref_pointer_array + el, 0, item->name);
   }
-  Item_str_func::split_sum_func(ref_pointer_array, fields);
+  Item_str_func::split_sum_func(thd, ref_pointer_array, fields);
 }
 
 

sql/item_strfunc.h

@@ -105,7 +105,7 @@ public:
 	    separator->check_cols(1) ||
 	    Item_func::fix_fields(thd, tlist, ref));
   }
-  void split_sum_func(Item **ref_pointer_array, List<Item> &fields);
+  void split_sum_func(THD *thd, Item **ref_pointer_array, List<Item> &fields);
   const char *func_name() const { return "concat_ws"; }
   bool walk(Item_processor processor, byte *arg)
   {
@@ -418,7 +418,7 @@ public:
 	    item->check_cols(1) ||
 	    Item_func::fix_fields(thd, tlist, ref));
   }
-  void split_sum_func(Item **ref_pointer_array, List<Item> &fields);
+  void split_sum_func(THD *thd, Item **ref_pointer_array, List<Item> &fields);
   void fix_length_and_dec();
   void update_used_tables();
   const char *func_name() const { return "make_set"; }

sql/item_subselect.cc

@@ -770,7 +770,6 @@ Item_in_subselect::single_value_transformer(JOIN *join,
       we can use same item for all selects.
     */
     expr= new Item_ref((Item**)optimizer->get_cache(),
-		       NULL,
 		       (char *)"<no matter>",
 		       (char *)in_left_expr_name);
 
@@ -966,9 +965,7 @@ Item_in_subselect::row_value_transformer(JOIN *join)
 					   (char *) "<no matter>",
 					   (char *) "<list ref>");
       func=
-	eq_creator.create(new Item_ref((*optimizer->get_cache())->
-				       addr(i),
-				       NULL,
+	eq_creator.create(new Item_ref((*optimizer->get_cache())->addr(i),
 				       (char *)"<no matter>",
 				     (char *)in_left_expr_name),
 			  func);

sql/sql_base.cc

@@ -2384,7 +2384,7 @@ int setup_fields(THD *thd, Item **ref_pointer_array, TABLE_LIST *tables,
       *(ref++)= item;
     if (item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM &&
 	sum_func_list)
-      item->split_sum_func(ref_pointer_array, *sum_func_list);
+      item->split_sum_func(thd, ref_pointer_array, *sum_func_list);
     thd->used_tables|=item->used_tables();
   }
   DBUG_RETURN(test(thd->net.report_error));

sql/sql_select.cc

@@ -292,7 +292,7 @@ JOIN::prepare(Item ***rref_pointer_array,
     if (having_fix_rc || thd->net.report_error)
       DBUG_RETURN(-1);				/* purecov: inspected */
     if (having->with_sum_func)
-      having->split_sum_func(ref_pointer_array, all_fields);
+      having->split_sum_func(thd, ref_pointer_array, all_fields);
   }
 
   // Is it subselect

sql/sql_yacc.yy

@@ -4879,7 +4879,7 @@ simple_ident:
 	  $$= (sel->parsing_place != IN_HAVING ||
 	       sel->get_in_sum_expr() > 0) ?
               (Item*) new Item_field(NullS,NullS,$1.str) :
-	      (Item*) new Item_ref(0,0, NullS,NullS,$1.str);
+	      (Item*) new Item_ref(NullS, NullS, $1.str);
 	}
 	| ident '.' ident
 	{
@@ -4895,7 +4895,7 @@ simple_ident:
 	  $$= (sel->parsing_place != IN_HAVING ||
 	       sel->get_in_sum_expr() > 0) ?
 	      (Item*) new Item_field(NullS,$1.str,$3.str) :
-	      (Item*) new Item_ref(0,0,NullS,$1.str,$3.str);
+	      (Item*) new Item_ref(NullS, $1.str, $3.str);
 	}
 	| '.' ident '.' ident
 	{
@@ -4911,7 +4911,7 @@ simple_ident:
 	  $$= (sel->parsing_place != IN_HAVING ||
 	       sel->get_in_sum_expr() > 0) ?
 	      (Item*) new Item_field(NullS,$2.str,$4.str) :
-              (Item*) new Item_ref(0,0,NullS,$2.str,$4.str);
+              (Item*) new Item_ref(NullS, $2.str, $4.str);
 	}
 	| ident '.' ident '.' ident
 	{
@@ -4929,7 +4929,7 @@ simple_ident:
 	      (Item*) new Item_field((YYTHD->client_capabilities &
 				      CLIENT_NO_SCHEMA ? NullS : $1.str),
 				     $3.str, $5.str) :
-	      (Item*) new Item_ref(0,0,(YYTHD->client_capabilities &
+	      (Item*) new Item_ref((YYTHD->client_capabilities &
 				    CLIENT_NO_SCHEMA ? NullS : $1.str),
                                    $3.str, $5.str);
 	};