MDEV-9215 Detect cmp_type() and result_type() from field_type()

Part5: Derive Item_param from Type_handler_hybrid_field_type

sql/item.cc

@@ -2977,13 +2977,12 @@ default_set_param_func(Item_param *param,
 
 
 Item_param::Item_param(THD *thd, uint pos_in_query_arg):
+  Type_handler_hybrid_field_type(MYSQL_TYPE_VARCHAR),
   Item_basic_value(thd),
   Rewritable_query_parameter(pos_in_query_arg, 1),
   state(NO_VALUE),
-  item_result_type(STRING_RESULT),
   /* Don't pretend to be a literal unless value for this item is set. */
   item_type(PARAM_ITEM),
-  param_type(MYSQL_TYPE_VARCHAR),
   set_param_func(default_set_param_func),
   m_out_param_info(NULL)
 {
@@ -3183,25 +3182,25 @@ bool Item_param::set_from_user_var(THD *thd, const user_var_entry *entry)
   DBUG_ENTER("Item_param::set_from_user_var");
   if (entry && entry->value)
   {
-    item_result_type= entry->type;
     unsigned_flag= entry->unsigned_flag;
     if (limit_clause_param)
     {
       bool unused;
       set_int(entry->val_int(&unused), MY_INT64_NUM_DECIMAL_DIGITS);
       item_type= Item::INT_ITEM;
+      set_handler_by_result_type(entry->type);
       DBUG_RETURN(!unsigned_flag && value.integer < 0 ? 1 : 0);
     }
-    switch (item_result_type) {
+    switch (entry->type) {
     case REAL_RESULT:
       set_double(*(double*)entry->value);
       item_type= Item::REAL_ITEM;
-      param_type= MYSQL_TYPE_DOUBLE;
+      set_handler_by_field_type(MYSQL_TYPE_DOUBLE);
       break;
     case INT_RESULT:
       set_int(*(longlong*)entry->value, MY_INT64_NUM_DECIMAL_DIGITS);
       item_type= Item::INT_ITEM;
-      param_type= MYSQL_TYPE_LONGLONG;
+      set_handler_by_field_type(MYSQL_TYPE_LONGLONG);
       break;
     case STRING_RESULT:
     {
@@ -3224,7 +3223,7 @@ bool Item_param::set_from_user_var(THD *thd, const user_var_entry *entry)
         charset of connection, so we have to set it later.
       */
       item_type= Item::STRING_ITEM;
-      param_type= MYSQL_TYPE_VARCHAR;
+      set_handler_by_field_type(MYSQL_TYPE_VARCHAR);
 
       if (set_str((const char *)entry->value, entry->length))
         DBUG_RETURN(1);
@@ -3240,7 +3239,7 @@ bool Item_param::set_from_user_var(THD *thd, const user_var_entry *entry)
         my_decimal_precision_to_length_no_truncation(ent_value->precision(),
                                                      decimals, unsigned_flag);
       item_type= Item::DECIMAL_ITEM;
-      param_type= MYSQL_TYPE_NEWDECIMAL;
+      set_handler_by_field_type(MYSQL_TYPE_NEWDECIMAL);
       break;
     }
     case ROW_RESULT:
@@ -3665,10 +3664,9 @@ void
 Item_param::set_param_type_and_swap_value(Item_param *src)
 {
   Type_std_attributes::set(src);
-  param_type= src->param_type;
+  set_handler(src->type_handler());
   set_param_func= src->set_param_func;
   item_type= src->item_type;
-  item_result_type= src->item_result_type;
 
   maybe_null= src->maybe_null;
   null_value= src->null_value;
@@ -3756,7 +3754,7 @@ Item_param::set_value(THD *thd, sp_rcontext *ctx, Item **it)
     return FALSE;
   }
 
-  item_result_type= arg->result_type();
+  set_handler_by_result_type(arg->result_type());
   item_type= arg->type();
   return FALSE;
 }
@@ -3775,7 +3773,7 @@ void
 Item_param::set_out_param_info(Send_field *info)
 {
   m_out_param_info= info;
-  param_type= m_out_param_info->type;
+  set_handler_by_field_type(m_out_param_info->type);
 }
 
 

sql/item.h

@@ -2594,11 +2594,22 @@ class Item_null_result :public Item_null
   }
 };
 
-/* Item represents one placeholder ('?') of prepared statement */
+/*
+  Item represents one placeholder ('?') of prepared statement
+
+  Notes:
+  Item_param::field_type() is used when this item is in a temporary table.
+  This is NOT placeholder metadata sent to client, as this value
+  is assigned after sending metadata (in setup_one_conversion_function).
+  For example in case of 'SELECT ?' you'll get MYSQL_TYPE_STRING both
+  in result set and placeholders metadata, no matter what type you will
+  supply for this placeholder in mysql_stmt_execute.
+*/
 
 class Item_param :public Item_basic_value,
                   private Settable_routine_parameter,
-                  public Rewritable_query_parameter
+                  public Rewritable_query_parameter,
+                  public Type_handler_hybrid_field_type
 {
 public:
   enum enum_item_param_state
@@ -2645,25 +2656,18 @@ class Item_param :public Item_basic_value,
     MYSQL_TIME     time;
   } value;
 
-  /* Cached values for virtual methods to save us one switch.  */
-  enum Item_result item_result_type;
   enum Type item_type;
 
-  /*
-    Used when this item is used in a temporary table.
-    This is NOT placeholder metadata sent to client, as this value
-    is assigned after sending metadata (in setup_one_conversion_function).
-    For example in case of 'SELECT ?' you'll get MYSQL_TYPE_STRING both
-    in result set and placeholders metadata, no matter what type you will
-    supply for this placeholder in mysql_stmt_execute.
-  */
-  enum enum_field_types param_type;
+  enum_field_types field_type() const
+  { return Type_handler_hybrid_field_type::field_type(); }
+  enum Item_result result_type () const
+  { return Type_handler_hybrid_field_type::result_type(); }
+  enum Item_result cmp_type () const
+  { return Type_handler_hybrid_field_type::cmp_type(); }
 
   Item_param(THD *thd, uint pos_in_query_arg);
 
-  enum Item_result result_type () const { return item_result_type; }
   enum Type type() const { return item_type; }
-  enum_field_types field_type() const { return param_type; }
 
   double val_real();
   longlong val_int();

sql/sql_prepare.cc

@@ -718,54 +718,44 @@ static void setup_one_conversion_function(THD *thd, Item_param *param,
   case MYSQL_TYPE_TINY:
     param->set_param_func= set_param_tiny;
     param->item_type= Item::INT_ITEM;
-    param->item_result_type= INT_RESULT;
     break;
   case MYSQL_TYPE_SHORT:
     param->set_param_func= set_param_short;
     param->item_type= Item::INT_ITEM;
-    param->item_result_type= INT_RESULT;
     break;
   case MYSQL_TYPE_LONG:
     param->set_param_func= set_param_int32;
     param->item_type= Item::INT_ITEM;
-    param->item_result_type= INT_RESULT;
     break;
   case MYSQL_TYPE_LONGLONG:
     param->set_param_func= set_param_int64;
     param->item_type= Item::INT_ITEM;
-    param->item_result_type= INT_RESULT;
     break;
   case MYSQL_TYPE_FLOAT:
     param->set_param_func= set_param_float;
     param->item_type= Item::REAL_ITEM;
-    param->item_result_type= REAL_RESULT;
     break;
   case MYSQL_TYPE_DOUBLE:
     param->set_param_func= set_param_double;
     param->item_type= Item::REAL_ITEM;
-    param->item_result_type= REAL_RESULT;
     break;
   case MYSQL_TYPE_DECIMAL:
   case MYSQL_TYPE_NEWDECIMAL:
     param->set_param_func= set_param_decimal;
     param->item_type= Item::DECIMAL_ITEM;
-    param->item_result_type= DECIMAL_RESULT;
     break;
   case MYSQL_TYPE_TIME:
     param->set_param_func= set_param_time;
     param->item_type= Item::STRING_ITEM;
-    param->item_result_type= STRING_RESULT;
     break;
   case MYSQL_TYPE_DATE:
     param->set_param_func= set_param_date;
     param->item_type= Item::STRING_ITEM;
-    param->item_result_type= STRING_RESULT;
     break;
   case MYSQL_TYPE_DATETIME:
   case MYSQL_TYPE_TIMESTAMP:
     param->set_param_func= set_param_datetime;
     param->item_type= Item::STRING_ITEM;
-    param->item_result_type= STRING_RESULT;
     break;
   case MYSQL_TYPE_TINY_BLOB:
   case MYSQL_TYPE_MEDIUM_BLOB:
@@ -778,7 +768,6 @@ static void setup_one_conversion_function(THD *thd, Item_param *param,
     DBUG_ASSERT(thd->variables.character_set_client);
     param->value.cs_info.final_character_set_of_str_value= &my_charset_bin;
     param->item_type= Item::STRING_ITEM;
-    param->item_result_type= STRING_RESULT;
     break;
   default:
     /*
@@ -808,10 +797,9 @@ static void setup_one_conversion_function(THD *thd, Item_param *param,
         charset of connection, so we have to set it later.
       */
       param->item_type= Item::STRING_ITEM;
-      param->item_result_type= STRING_RESULT;
     }
   }
-  param->param_type= (enum enum_field_types) param_type;
+  param->set_handler_by_field_type((enum enum_field_types) param_type);
 }
 
 #ifndef EMBEDDED_LIBRARY
@@ -823,8 +811,8 @@ static void setup_one_conversion_function(THD *thd, Item_param *param,
 */
 inline bool is_param_long_data_type(Item_param *param)
 {
-  return ((param->param_type >= MYSQL_TYPE_TINY_BLOB) &&
-          (param->param_type <= MYSQL_TYPE_STRING));
+  return ((param->field_type() >= MYSQL_TYPE_TINY_BLOB) &&
+          (param->field_type() <= MYSQL_TYPE_STRING));
 }
 
 
@@ -1213,7 +1201,7 @@ static bool insert_params_from_vars_with_log(Prepared_statement *stmt,
       the parameter's members that might be needed further
       (e.g. value.cs_info.character_set_client is used in the query_val_str()).
     */
-    setup_one_conversion_function(thd, param, param->param_type);
+    setup_one_conversion_function(thd, param, param->field_type());
     if (param->set_from_user_var(thd, entry))
       DBUG_RETURN(1);
 

sql/sql_type.h

@@ -318,6 +318,10 @@ class Type_handler_hybrid_field_type: public Type_handler
   enum_field_types field_type() const { return m_type_handler->field_type(); }
   Item_result result_type() const { return m_type_handler->result_type(); }
   Item_result cmp_type() const { return m_type_handler->cmp_type(); }
+  void set_handler(const Type_handler *other)
+  {
+    m_type_handler= other;
+  }
   const Type_handler *set_handler_by_result_type(Item_result type)
   {
     return (m_type_handler= get_handler_by_result_type(type));