~drizzle-trunk/drizzle/development

/* - mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 MySQL

 *

 *  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; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  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/field/real.h>

#include <drizzled/error.h>

#include <drizzled/table.h>

#include <math.h>

#include <limits>

using namespace std;

namespace drizzled

{

extern const double log_10[309];

/*

  Floating-point numbers

 */

unsigned char *

Field_real::pack(unsigned char *to, const unsigned char *from,

                 uint32_t max_length, bool low_byte_first)

{

  assert(max_length >= pack_length());

#ifdef WORDS_BIGENDIAN

  if (low_byte_first != getTable()->getShare()->db_low_byte_first)

  {

    const unsigned char *dptr= from + pack_length();

    while (dptr-- > from)

      *to++ = *dptr;

    return(to);

  }

  else

#endif

    return(Field::pack(to, from, max_length, low_byte_first));

}

const unsigned char *

Field_real::unpack(unsigned char *to, const unsigned char *from,

                   uint32_t param_data, bool low_byte_first)

{

#ifdef WORDS_BIGENDIAN

  if (low_byte_first != getTable()->getShare()->db_low_byte_first)

  {

    const unsigned char *dptr= from + pack_length();

    while (dptr-- > from)

      *to++ = *dptr;

    return(from + pack_length());

  }

  else

#endif

    return(Field::unpack(to, from, param_data, low_byte_first));

}

/*

  If a field has fixed length, truncate the double argument pointed to by 'nr'

  appropriately.

  Also ensure that the argument is within [-max_value; max_value] range.

*/

int Field_real::truncate(double *nr, double max_value)

{

  int error= 1;

  double res= *nr;

  if (res == numeric_limits<double>::quiet_NaN())

  {

    res= 0;

    set_null();

    set_warning(DRIZZLE_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_OUT_OF_RANGE, 1);

    goto end;

  }

  if (!not_fixed)

  {

    uint32_t order= field_length - dec;

    uint32_t step= array_elements(log_10) - 1;

    max_value= 1.0;

    for (; order > step; order-= step)

      max_value*= log_10[step];

    max_value*= log_10[order];

    max_value-= 1.0 / log_10[dec];

    /* Check for infinity so we don't get NaN in calculations */

    if (res != numeric_limits<double>::infinity())

    {

      double tmp= rint((res - floor(res)) * log_10[dec]) / log_10[dec];

      res= floor(res) + tmp;

    }

  }

  if (res < -max_value)

  {

   res= -max_value;

   set_warning(DRIZZLE_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_OUT_OF_RANGE, 1);

  }

  else if (res > max_value)

  {

    res= max_value;

    set_warning(DRIZZLE_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_OUT_OF_RANGE, 1);

  }

  else

    error= 0;

end:

  *nr= res;

  return error;

}

int Field_real::store_decimal(const my_decimal *dm)

{

  double dbl;

  my_decimal2double(E_DEC_FATAL_ERROR, dm, &dbl);

  return store(dbl);

}

my_decimal *Field_real::val_decimal(my_decimal *decimal_value)

{

  ASSERT_COLUMN_MARKED_FOR_READ;

  double2my_decimal(E_DEC_FATAL_ERROR, val_real(), decimal_value);

  return decimal_value;

}

} /* namespace drizzled */