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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#include <float.h>
#include <algorithm>
#include <drizzled/error.h>
#include <drizzled/function/func.h>
#include <drizzled/item/sum.h>
#include <drizzled/item/type_holder.h>
#include <drizzled/field/enum.h>
using namespace std;
namespace drizzled {
Item_type_holder::Item_type_holder(Session *session, Item *item)
:Item(session, item), enum_set_typelib(0), fld_type(get_real_type(item))
{
assert(item->fixed);
maybe_null= item->maybe_null;
collation.set(item->collation);
get_full_info(item);
/* fix variable decimals which always is NOT_FIXED_DEC */
if (Field::result_merge_type(fld_type) == INT_RESULT)
decimals= 0;
prev_decimal_int_part= item->decimal_int_part();
}
Item_result Item_type_holder::result_type() const
{
return Field::result_merge_type(fld_type);
}
enum_field_types Item_type_holder::get_real_type(Item *item)
{
switch(item->type())
{
case FIELD_ITEM:
{
/*
Item_fields::field_type ask Field_type() but sometimes field return
a different type, like for enum/set, so we need to ask real type.
*/
Field *field= ((Item_field *) item)->field;
enum_field_types type= field->real_type();
if (field->is_created_from_null_item)
return DRIZZLE_TYPE_NULL;
return type;
}
case SUM_FUNC_ITEM:
{
/*
Argument of aggregate function sometimes should be asked about field
type
*/
Item_sum *item_sum= (Item_sum *) item;
if (item_sum->keep_field_type())
return get_real_type(item_sum->args[0]);
break;
}
case FUNC_ITEM:
if (((Item_func *) item)->functype() == Item_func::GUSERVAR_FUNC)
{
/*
There are work around of problem with changing variable type on the
fly and variable always report "string" as field type to get
acceptable information for client in send_field, so we make field
type from expression type.
*/
switch (item->result_type()) {
case STRING_RESULT:
return DRIZZLE_TYPE_VARCHAR;
case INT_RESULT:
return DRIZZLE_TYPE_LONGLONG;
case REAL_RESULT:
return DRIZZLE_TYPE_DOUBLE;
case DECIMAL_RESULT:
return DRIZZLE_TYPE_DECIMAL;
case ROW_RESULT:
assert(0);
return DRIZZLE_TYPE_VARCHAR;
}
}
break;
default:
break;
}
return item->field_type();
}
bool Item_type_holder::join_types(Session *, Item *item)
{
uint32_t max_length_orig= max_length;
uint32_t decimals_orig= decimals;
fld_type= Field::field_type_merge(fld_type, get_real_type(item));
{
int item_decimals= item->decimals;
/* fix variable decimals which always is NOT_FIXED_DEC */
if (Field::result_merge_type(fld_type) == INT_RESULT)
item_decimals= 0;
decimals= max((int)decimals, item_decimals);
}
if (Field::result_merge_type(fld_type) == DECIMAL_RESULT)
{
decimals= min((int)max(decimals, item->decimals), DECIMAL_MAX_SCALE);
int precision= min(max(prev_decimal_int_part, item->decimal_int_part())
+ decimals, DECIMAL_MAX_PRECISION);
unsigned_flag&= item->unsigned_flag;
max_length= class_decimal_precision_to_length(precision, decimals,
unsigned_flag);
}
switch (Field::result_merge_type(fld_type))
{
case STRING_RESULT:
{
const char *old_cs, *old_derivation;
uint32_t old_max_chars= max_length / collation.collation->mbmaxlen;
old_cs= collation.collation->name;
old_derivation= collation.derivation_name();
if (collation.aggregate(item->collation, MY_COLL_ALLOW_CONV))
{
my_error(ER_CANT_AGGREGATE_2COLLATIONS, MYF(0),
old_cs, old_derivation,
item->collation.collation->name,
item->collation.derivation_name(),
"UNION");
return true;
}
/*
To figure out max_length, we have to take into account possible
expansion of the size of the values because of character set
conversions.
*/
if (collation.collation != &my_charset_bin)
{
max_length= max(old_max_chars * collation.collation->mbmaxlen,
display_length(item) /
item->collation.collation->mbmaxlen *
collation.collation->mbmaxlen);
}
else
set_if_bigger(max_length, display_length(item));
break;
}
case REAL_RESULT:
{
if (decimals != NOT_FIXED_DEC)
{
int delta1= max_length_orig - decimals_orig;
int delta2= item->max_length - item->decimals;
max_length= max(delta1, delta2) + decimals;
if (fld_type == DRIZZLE_TYPE_DOUBLE && max_length > DBL_DIG + 2)
{
max_length= DBL_DIG + 7;
decimals= NOT_FIXED_DEC;
}
}
else
max_length= DBL_DIG+7;
break;
}
case INT_RESULT:
case DECIMAL_RESULT:
case ROW_RESULT:
max_length= max(max_length, display_length(item));
};
maybe_null|= item->maybe_null;
get_full_info(item);
/* Remember decimal integer part to be used in DECIMAL_RESULT handleng */
prev_decimal_int_part= decimal_int_part();
return false;
}
uint32_t Item_type_holder::display_length(Item *item)
{
if (item->type() == Item::FIELD_ITEM)
return ((Item_field *)item)->max_disp_length();
switch (item->field_type())
{
case DRIZZLE_TYPE_TIME:
case DRIZZLE_TYPE_BOOLEAN:
case DRIZZLE_TYPE_UUID:
case DRIZZLE_TYPE_IPV6:
case DRIZZLE_TYPE_MICROTIME:
case DRIZZLE_TYPE_TIMESTAMP:
case DRIZZLE_TYPE_DATETIME:
case DRIZZLE_TYPE_DATE:
case DRIZZLE_TYPE_VARCHAR:
case DRIZZLE_TYPE_DECIMAL:
case DRIZZLE_TYPE_ENUM:
case DRIZZLE_TYPE_BLOB:
return item->max_length;
case DRIZZLE_TYPE_LONG:
return MY_INT32_NUM_DECIMAL_DIGITS;
case DRIZZLE_TYPE_DOUBLE:
return 53;
case DRIZZLE_TYPE_NULL:
return 0;
case DRIZZLE_TYPE_LONGLONG:
return 20;
}
assert(0);
abort();
}
Field *Item_type_holder::make_field_by_type(Table *table)
{
/*
The field functions defines a field to be not null if null_ptr is not 0
*/
unsigned char *null_ptr= maybe_null ? (unsigned char*) "" : 0;
Field *field;
switch (fld_type) {
case DRIZZLE_TYPE_ENUM:
assert(enum_set_typelib);
field= new Field_enum((unsigned char *) 0,
max_length,
null_ptr,
0,
name,
enum_set_typelib,
collation.collation);
if (field)
field->init(table);
return field;
case DRIZZLE_TYPE_NULL:
return make_string_field(table);
default:
break;
}
return tmp_table_field_from_field_type(table, 0);
}
void Item_type_holder::get_full_info(Item *item)
{
if (fld_type == DRIZZLE_TYPE_ENUM)
{
if (item->type() == Item::SUM_FUNC_ITEM &&
(((Item_sum*)item)->sum_func() == Item_sum::MAX_FUNC ||
((Item_sum*)item)->sum_func() == Item_sum::MIN_FUNC))
item = ((Item_sum*)item)->args[0];
/*
We can have enum/set type after merging only if we have one enum|set
field (or MIN|MAX(enum|set field)) and number of NULL fields
*/
assert((enum_set_typelib &&
get_real_type(item) == DRIZZLE_TYPE_NULL) ||
(!enum_set_typelib &&
item->type() == Item::FIELD_ITEM &&
(get_real_type(item) == DRIZZLE_TYPE_ENUM) &&
((Field_enum*)((Item_field *) item)->field)->typelib));
if (!enum_set_typelib)
{
enum_set_typelib= ((Field_enum*)((Item_field *) item)->field)->typelib;
}
}
}
double Item_type_holder::val_real()
{
assert(0); // should never be called
return 0.0;
}
int64_t Item_type_holder::val_int()
{
assert(0); // should never be called
return 0;
}
type::Decimal *Item_type_holder::val_decimal(type::Decimal *)
{
assert(0); // should never be called
return 0;
}
String *Item_type_holder::val_str(String*)
{
assert(0); // should never be called
return 0;
}
void Item_result_field::cleanup()
{
Item::cleanup();
result_field= 0;
return;
}
} /* namespace drizzled */
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