Added typedef decimal_digits_t (uint16) for number of digits in most

aspects of decimals and integers

For fields and Item's uint8 should be good enough. After
discussions with Alexander Barkov we choose uint16 (for now)
as some format functions may accept +256 digits.

The reason for this patch was to make the usage and storage of decimal
digits simlar. Before this patch decimals was stored/used as uint8,
int and uint.  The lengths for numbers where also using a lot of
different types.

Changed most decimal variables and functions to use the new typedef.

squash! af7f09106b6c1dc20ae8c480bff6fd22d266b184

Use decimal_digits_t for all aspects of digits (total, precision
and scale), both for decimals and integers.

1 files changed, 50 insertions, 44 deletions

diff --git a/sql/sql_type.cc b/sql/sql_type.cc
index 6ee51b763e0..6a1ccbbbd22 100644
--- a/sql/sql_type.cc
+++ b/sql/sql_type.cc
@@ -1179,9 +1179,9 @@ Datetime_truncation_not_needed::Datetime_truncation_not_needed(THD *thd, Item *i
 
 /********************************************************************/
 
-uint Type_numeric_attributes::find_max_decimals(Item **item, uint nitems)
+decimal_digits_t Type_numeric_attributes::find_max_decimals(Item **item, uint nitems)
 {
-  uint res= 0;
+  decimal_digits_t res= 0;
   for (uint i= 0; i < nitems; i++)
     set_if_bigger(res, item[i]->decimals);
   return res;
@@ -1218,9 +1218,10 @@ uint32 Type_numeric_attributes::find_max_octet_length(Item **item, uint nitems)
 }
 
 
-int Type_numeric_attributes::find_max_decimal_int_part(Item **item, uint nitems)
+decimal_digits_t Type_numeric_attributes::
+find_max_decimal_int_part(Item **item, uint nitems)
 {
-  int max_int_part= 0;
+  decimal_digits_t max_int_part= 0;
   for (uint i=0 ; i < nitems ; i++)
     set_if_bigger(max_int_part, item[i]->decimal_int_part());
   return max_int_part;
@@ -1237,11 +1238,12 @@ Type_numeric_attributes::aggregate_numeric_attributes_decimal(Item **item,
                                                               uint nitems,
                                                               bool unsigned_arg)
 {
-  int max_int_part= find_max_decimal_int_part(item, nitems);
+  decimal_digits_t max_int_part= find_max_decimal_int_part(item, nitems);
   decimals= find_max_decimals(item, nitems);
-  int precision= MY_MIN(max_int_part + decimals, DECIMAL_MAX_PRECISION);
+  decimal_digits_t precision= (decimal_digits_t)
+    MY_MIN(max_int_part + decimals, DECIMAL_MAX_PRECISION);
   max_length= my_decimal_precision_to_length_no_truncation(precision,
-                                                           (uint8) decimals,
+                                                           decimals,
                                                            unsigned_flag);
 }
 
@@ -7030,20 +7032,20 @@ const Vers_type_handler* Type_handler_blob_common::vers() const
 
 /***************************************************************************/
 
-uint Type_handler::Item_time_precision(THD *thd, Item *item) const
+decimal_digits_t Type_handler::Item_time_precision(THD *thd, Item *item) const
 {
   return MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS);
 }
 
 
-uint Type_handler::Item_datetime_precision(THD *thd, Item *item) const
+decimal_digits_t Type_handler::Item_datetime_precision(THD *thd, Item *item) const
 {
   return MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS);
 }
 
 
-uint Type_handler_string_result::Item_temporal_precision(THD *thd, Item *item,
-                                                         bool is_time) const
+decimal_digits_t Type_handler_string_result::
+Item_temporal_precision(THD *thd, Item *item, bool is_time) const
 {
   StringBuffer<64> buf;
   String *tmp;
@@ -7059,34 +7061,34 @@ uint Type_handler_string_result::Item_temporal_precision(THD *thd, Item *item,
        Datetime(thd, &status, tmp->ptr(), tmp->length(), tmp->charset(),
                 Datetime::Options(TIME_FUZZY_DATES, TIME_FRAC_TRUNCATE)).
          is_valid_datetime()))
-    return MY_MIN(status.precision, TIME_SECOND_PART_DIGITS);
-  return MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS);
+    return (decimal_digits_t) MY_MIN(status.precision, TIME_SECOND_PART_DIGITS);
+  return (decimal_digits_t) MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS);
 }
 
 /***************************************************************************/
 
-uint Type_handler::Item_decimal_scale(const Item *item) const
+decimal_digits_t Type_handler::Item_decimal_scale(const Item *item) const
 {
-  return item->decimals < NOT_FIXED_DEC ?
-         item->decimals :
-         MY_MIN(item->max_length, DECIMAL_MAX_SCALE);
+  return (item->decimals < NOT_FIXED_DEC ?
+          item->decimals :
+          (decimal_digits_t) MY_MIN(item->max_length, DECIMAL_MAX_SCALE));
 }
 
-uint Type_handler_temporal_result::
-       Item_decimal_scale_with_seconds(const Item *item) const
+decimal_digits_t Type_handler_temporal_result::
+Item_decimal_scale_with_seconds(const Item *item) const
 {
-  return item->decimals < NOT_FIXED_DEC ?
-         item->decimals :
-         TIME_SECOND_PART_DIGITS;
+  return (item->decimals < NOT_FIXED_DEC ?
+          item->decimals :
+          TIME_SECOND_PART_DIGITS);
 }
 
-uint Type_handler::Item_divisor_precision_increment(const Item *item) const
+decimal_digits_t Type_handler::Item_divisor_precision_increment(const Item *item) const
 {
   return item->decimals;
 }
 
-uint Type_handler_temporal_result::
-       Item_divisor_precision_increment_with_seconds(const Item *item) const
+decimal_digits_t Type_handler_temporal_result::
+Item_divisor_precision_increment_with_seconds(const Item *item) const
 {
   return item->decimals <  NOT_FIXED_DEC ?
          item->decimals :
@@ -7095,7 +7097,7 @@ uint Type_handler_temporal_result::
 
 /***************************************************************************/
 
-uint Type_handler_string_result::Item_decimal_precision(const Item *item) const
+decimal_digits_t Type_handler_string_result::Item_decimal_precision(const Item *item) const
 {
   uint res= item->max_char_length();
   /*
@@ -7104,49 +7106,51 @@ uint Type_handler_string_result::Item_decimal_precision(const Item *item) const
     INT(0) or DECIMAL(0,0) when converting NULL or empty strings to INT/DECIMAL:
       CREATE TABLE t1 AS SELECT CONVERT(NULL,SIGNED) AS a;
   */
-  return res ? MY_MIN(res, DECIMAL_MAX_PRECISION) : 1;
+  return res ? (decimal_digits_t) MY_MIN(res, DECIMAL_MAX_PRECISION) : (decimal_digits_t) 1;
 }
 
-uint Type_handler_real_result::Item_decimal_precision(const Item *item) const
+decimal_digits_t Type_handler_real_result::Item_decimal_precision(const Item *item) const
 {
   uint res= item->max_char_length();
-  return res ? MY_MIN(res, DECIMAL_MAX_PRECISION) : 1;
+  return res ? (decimal_digits_t) MY_MIN(res, DECIMAL_MAX_PRECISION) : (decimal_digits_t) 1;
 }
 
-uint Type_handler_decimal_result::Item_decimal_precision(const Item *item) const
+decimal_digits_t Type_handler_decimal_result::Item_decimal_precision(const Item *item) const
 {
   uint prec= my_decimal_length_to_precision(item->max_char_length(),
                                             item->decimals,
                                             item->unsigned_flag);
-  return MY_MIN(prec, DECIMAL_MAX_PRECISION);
+  return (decimal_digits_t) MY_MIN(prec, DECIMAL_MAX_PRECISION);
 }
 
-uint Type_handler_int_result::Item_decimal_precision(const Item *item) const
+decimal_digits_t Type_handler_int_result::Item_decimal_precision(const Item *item) const
 {
  uint prec= my_decimal_length_to_precision(item->max_char_length(),
                                            item->decimals,
                                            item->unsigned_flag);
- return MY_MIN(prec, DECIMAL_MAX_PRECISION);
+ return (decimal_digits_t) MY_MIN(prec, DECIMAL_MAX_PRECISION);
 }
 
-uint Type_handler_time_common::Item_decimal_precision(const Item *item) const
+decimal_digits_t Type_handler_time_common::Item_decimal_precision(const Item *item) const
 {
-  return 7 + MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS);
+  return (decimal_digits_t) (7 + MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS));
 }
 
-uint Type_handler_date_common::Item_decimal_precision(const Item *item) const
+decimal_digits_t Type_handler_date_common::Item_decimal_precision(const Item *item) const
 {
   return 8;
 }
 
-uint Type_handler_datetime_common::Item_decimal_precision(const Item *item) const
+decimal_digits_t Type_handler_datetime_common::
+Item_decimal_precision(const Item *item) const
 {
-  return 14 + MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS);
+  return (decimal_digits_t) (14 + MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS));
 }
 
-uint Type_handler_timestamp_common::Item_decimal_precision(const Item *item) const
+decimal_digits_t Type_handler_timestamp_common::
+Item_decimal_precision(const Item *item) const
 {
-  return 14 + MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS);
+  return (decimal_digits_t) (14 + MY_MIN(item->decimals, TIME_SECOND_PART_DIGITS));
 }
 
 /***************************************************************************/
@@ -7681,7 +7685,7 @@ static void wrong_precision_error(uint errcode, Item *a,
 */
 
 bool get_length_and_scale(ulonglong length, ulonglong decimals,
-                          uint *out_length, uint *out_decimals,
+                          uint *out_length, decimal_digits_t *out_decimals,
                           uint max_precision, uint max_scale,
                           Item *a)
 {
@@ -7696,7 +7700,7 @@ bool get_length_and_scale(ulonglong length, ulonglong decimals,
     return 1;
   }
 
-  *out_decimals=  (uint) decimals;
+  *out_decimals=  (decimal_digits_t)  decimals;
   my_decimal_trim(&length, out_decimals);
   *out_length=  (uint) length;
   
@@ -7764,7 +7768,8 @@ Item *Type_handler_decimal_result::
         create_typecast_item(THD *thd, Item *item,
                              const Type_cast_attributes &attr) const
 {
-  uint len, dec;
+  uint len;
+  decimal_digits_t dec;
   if (get_length_and_scale(attr.length(), attr.decimals(), &len, &dec,
                            DECIMAL_MAX_PRECISION, DECIMAL_MAX_SCALE, item))
     return NULL;
@@ -7776,7 +7781,8 @@ Item *Type_handler_double::
         create_typecast_item(THD *thd, Item *item,
                              const Type_cast_attributes &attr) const
 {
-  uint len, dec;
+  uint len;
+  decimal_digits_t dec;
   if (!attr.length_specified())
     return new (thd->mem_root) Item_double_typecast(thd, item,
                                                     DBL_DIG + 7,