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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 <drizzled/function/min_max.h>
#include <drizzled/item/cmpfunc.h>
namespace drizzled
{
void Item_func_min_max::fix_length_and_dec()
{
int max_int_part=0;
bool datetime_found= false;
decimals=0;
max_length=0;
maybe_null=0;
cmp_type=args[0]->result_type();
for (uint32_t i=0 ; i < arg_count ; i++)
{
set_if_bigger(max_length, args[i]->max_length);
set_if_bigger(decimals, args[i]->decimals);
set_if_bigger(max_int_part, args[i]->decimal_int_part());
if (args[i]->maybe_null)
maybe_null=1;
cmp_type=item_cmp_type(cmp_type,args[i]->result_type());
if (args[i]->result_type() != ROW_RESULT && args[i]->is_datetime())
{
datetime_found= true;
if (!datetime_item || args[i]->field_type() == DRIZZLE_TYPE_DATETIME)
datetime_item= args[i];
}
}
if (cmp_type == STRING_RESULT)
{
agg_arg_charsets(collation, args, arg_count, MY_COLL_CMP_CONV, 1);
if (datetime_found)
{
session= getSessionPtr();
compare_as_dates= true;
}
}
else if ((cmp_type == DECIMAL_RESULT) || (cmp_type == INT_RESULT))
max_length= my_decimal_precision_to_length(max_int_part+decimals, decimals,
unsigned_flag);
cached_field_type= agg_field_type(args, arg_count);
}
/*
Compare item arguments in the DATETIME context.
SYNOPSIS
cmp_datetimes()
value [out] found least/greatest DATE/DATETIME value
DESCRIPTION
Compare item arguments as DATETIME values and return the index of the
least/greatest argument in the arguments array.
The correct integer DATE/DATETIME value of the found argument is
stored to the value pointer, if latter is provided.
RETURN
0 If one of arguments is NULL or there was a execution error
# index of the least/greatest argument
*/
uint32_t Item_func_min_max::cmp_datetimes(uint64_t *value)
{
uint64_t min_max= 0;
uint32_t min_max_idx= 0;
for (uint32_t i=0; i < arg_count ; i++)
{
Item **arg= args + i;
bool is_null_unused;
uint64_t res= get_datetime_value(session, &arg, 0, datetime_item,
&is_null_unused);
/* Check if we need to stop (because of error or KILL) and stop the loop */
if (session->is_error())
{
null_value= 1;
return 0;
}
if ((null_value= args[i]->null_value))
return 0;
if (i == 0 || (res < min_max ? cmp_sign : -cmp_sign) > 0)
{
min_max= res;
min_max_idx= i;
}
}
if (value)
{
*value= min_max;
if (datetime_item->field_type() == DRIZZLE_TYPE_DATE)
*value/= 1000000L;
}
return min_max_idx;
}
String *Item_func_min_max::val_str(String *str)
{
assert(fixed == 1);
if (compare_as_dates)
{
String *str_res;
uint32_t min_max_idx= cmp_datetimes(NULL);
if (null_value)
return 0;
str_res= args[min_max_idx]->val_str(str);
if (args[min_max_idx]->null_value)
{
// check if the call to val_str() above returns a NULL value
null_value= 1;
return NULL;
}
str_res->set_charset(collation.collation);
return str_res;
}
switch (cmp_type) {
case INT_RESULT:
{
int64_t nr=val_int();
if (null_value)
return 0;
str->set_int(nr, unsigned_flag, &my_charset_bin);
return str;
}
case DECIMAL_RESULT:
{
my_decimal dec_buf, *dec_val= val_decimal(&dec_buf);
if (null_value)
return 0;
my_decimal2string(E_DEC_FATAL_ERROR, dec_val, 0, 0, 0, str);
return str;
}
case REAL_RESULT:
{
double nr= val_real();
if (null_value)
return 0;
str->set_real(nr,decimals,&my_charset_bin);
return str;
}
case STRING_RESULT:
{
String *res= NULL;
for (uint32_t i=0; i < arg_count ; i++)
{
if (i == 0)
res=args[i]->val_str(str);
else
{
String *res2;
res2= args[i]->val_str(res == str ? &tmp_value : str);
if (res2)
{
int cmp= sortcmp(res,res2,collation.collation);
if ((cmp_sign < 0 ? cmp : -cmp) < 0)
res=res2;
}
}
if ((null_value= args[i]->null_value))
return 0;
}
res->set_charset(collation.collation);
return res;
}
case ROW_RESULT:
// This case should never be chosen
assert(0);
return 0;
}
return 0; // Keep compiler happy
}
double Item_func_min_max::val_real()
{
assert(fixed == 1);
double value=0.0;
if (compare_as_dates)
{
uint64_t result= 0;
(void)cmp_datetimes(&result);
return (double)result;
}
for (uint32_t i=0; i < arg_count ; i++)
{
if (i == 0)
value= args[i]->val_real();
else
{
double tmp= args[i]->val_real();
if (!args[i]->null_value && (tmp < value ? cmp_sign : -cmp_sign) > 0)
value=tmp;
}
if ((null_value= args[i]->null_value))
break;
}
return value;
}
int64_t Item_func_min_max::val_int()
{
assert(fixed == 1);
int64_t value=0;
if (compare_as_dates)
{
uint64_t result= 0;
(void)cmp_datetimes(&result);
return (int64_t)result;
}
for (uint32_t i=0; i < arg_count ; i++)
{
if (i == 0)
value=args[i]->val_int();
else
{
int64_t tmp=args[i]->val_int();
if (!args[i]->null_value && (tmp < value ? cmp_sign : -cmp_sign) > 0)
value=tmp;
}
if ((null_value= args[i]->null_value))
break;
}
return value;
}
my_decimal *Item_func_min_max::val_decimal(my_decimal *dec)
{
assert(fixed == 1);
my_decimal tmp_buf, *tmp, *res= NULL;
if (compare_as_dates)
{
uint64_t value= 0;
(void)cmp_datetimes(&value);
uint64_t2decimal(value, dec);
return dec;
}
for (uint32_t i=0; i < arg_count ; i++)
{
if (i == 0)
res= args[i]->val_decimal(dec);
else
{
tmp= args[i]->val_decimal(&tmp_buf); // Zero if NULL
if (tmp && (my_decimal_cmp(tmp, res) * cmp_sign) < 0)
{
if (tmp == &tmp_buf)
{
/* Move value out of tmp_buf as this will be reused on next loop */
my_decimal2decimal(tmp, dec);
res= dec;
}
else
res= tmp;
}
}
if ((null_value= args[i]->null_value))
{
res= 0;
break;
}
}
return res;
}
} /* namespace drizzled */
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