~drizzle-trunk/drizzle/development

/* -*- 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 <math.h>

#include <drizzled/error.h>

#include <drizzled/field.h>

#include <drizzled/item/float.h>

#include <drizzled/item/num.h>

#include <drizzled/item/string.h>

namespace drizzled

{

extern const CHARSET_INFO *system_charset_info;

static uint32_t nr_of_decimals(const char *str, const char *end)

{

  const char *decimal_point;

  /* Find position for '.' */

  for (;;)

  {

    if (str == end)

      return 0;

    if (*str == 'e' || *str == 'E')

      return NOT_FIXED_DEC;

    if (*str++ == '.')

      break;

  }

  decimal_point= str;

  for (; my_isdigit(system_charset_info, *str) ; str++)

    ;

  if (*str == 'e' || *str == 'E')

    return NOT_FIXED_DEC;

  return (uint32_t) (str - decimal_point);

}

String *Item_float::val_str(String *str)

{

  // following assert is redundant, because fixed=1 assigned in constructor

  assert(fixed == 1);

  str->set_real(value,decimals,&my_charset_bin);

  return str;

}

int64_t Item_float::val_int()

{

  assert(fixed == 1);

  if (value <= (double) INT64_MIN)

  {

     return INT64_MIN;

  }

  else if (value >= (double) (uint64_t) INT64_MAX)

  {

    return INT64_MAX;

  }

  return (int64_t) rint(value);

}

type::Decimal *Item_float::val_decimal(type::Decimal *decimal_value)

{

  // following assert is redundant, because fixed=1 assigned in constructor

  assert(fixed == 1);

  double2_class_decimal(E_DEC_FATAL_ERROR, value, decimal_value);

  return (decimal_value);

}

/**

  This function is only called during parsing. We will signal an error if

  value is not a true double value (overflow)

*/

Item_float::Item_float(const char *str_arg, uint32_t length)

{

  int error;

  char *end_not_used;

  value= my_strntod(&my_charset_bin, (char*) str_arg, length, &end_not_used,

                    &error);

  if (error)

  {

    /*

      Note that we depend on that str_arg is null terminated, which is true

      when we are in the parser

    */

    assert(str_arg[length] == 0);

    my_error(ER_ILLEGAL_VALUE_FOR_TYPE, MYF(0), "double", (char*) str_arg);

  }

  presentation= name=(char*) str_arg;

  decimals=(uint8_t) nr_of_decimals(str_arg, str_arg+length);

  max_length=length;

  fixed= 1;

}

int Item_float::save_in_field(Field *field, bool)

{

  double nr= val_real();

  if (null_value)

    return set_field_to_null(field);

  field->set_notnull();

  return field->store(nr);

}

void Item_float::print(String *str)

{

  if (presentation)

  {

    str->append(presentation);

    return;

  }

  char buffer[20];

  String num(buffer, sizeof(buffer), &my_charset_bin);

  num.set_real(value, decimals, &my_charset_bin);

  str->append(num);

}

/*

  hex item

  In string context this is a binary string.

  In number context this is a int64_t value.

*/

bool Item_float::eq(const Item *arg, bool) const

{

  if (arg->basic_const_item() && arg->type() == type())

  {

    /*

      We need to cast off const to call val_int(). This should be OK for

      a basic constant.

    */

    Item *item= (Item*) arg;

    return item->val_real() == value;

  }

  return false;

}

Item *Item_static_float_func::safe_charset_converter(const CHARSET_INFO * const)

{

  Item_string *conv;

  char buf[64];

  String *s, tmp(buf, sizeof(buf), &my_charset_bin);

  s= val_str(&tmp);

  if ((conv= new Item_static_string_func(func_name, s->ptr(), s->length(),

                                         s->charset())))

  {

    conv->str_value.copy();

    conv->str_value.mark_as_const();

  }

  return conv;

}

} /* namespace drizzled */