~drizzle-trunk/drizzle/development

/* Copyright (C) 2000 MySQL AB

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include <my_global.h>

#include "m_string.h"

/*

  _dig_vec arrays are public because they are used in several outer places.

*/

char _dig_vec_upper[] =

  "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

char _dig_vec_lower[] =

  "0123456789abcdefghijklmnopqrstuvwxyz";

/*

  Convert integer to its string representation in given scale of notation.

  SYNOPSIS

    int2str()

      val     - value to convert

      dst     - points to buffer where string representation should be stored

      radix   - radix of scale of notation

      upcase  - set to 1 if we should use upper-case digits

  DESCRIPTION

    Converts the (long) integer value to its character form and moves it to 

    the destination buffer followed by a terminating NUL. 

    If radix is -2..-36, val is taken to be SIGNED, if radix is  2..36, val is

    taken to be UNSIGNED. That is, val is signed if and only if radix is. 

    All other radixes treated as bad and nothing will be changed in this case.

    For conversion to decimal representation (radix is -10 or 10) one can use

    optimized int10_to_str() function.

  RETURN VALUE

    Pointer to ending NUL character or NullS if radix is bad.

*/

char *

int2str(register long int val, register char *dst, register int radix, 

        int upcase)

{

  char buffer[65];

  register char *p;

  long int new_val;

  char *dig_vec= upcase ? _dig_vec_upper : _dig_vec_lower;

  ulong uval= (ulong) val;

  if (radix < 0)

  {

    if (radix < -36 || radix > -2)

      return NullS;

    if (val < 0)

    {

      *dst++ = '-';

      /* Avoid integer overflow in (-val) for LONGLONG_MIN (BUG#31799). */

      uval = (ulong)0 - uval;

    }

    radix = -radix;

  }

  else if (radix > 36 || radix < 2)

    return NullS;

  /*

    The slightly contorted code which follows is due to the fact that

    few machines directly support unsigned long / and %.  Certainly

    the VAX C compiler generates a subroutine call.  In the interests

    of efficiency (hollow laugh) I let this happen for the first digit

    only; after that "val" will be in range so that signed integer

    division will do.  Sorry 'bout that.  CHECK THE CODE PRODUCED BY

    YOUR C COMPILER.  The first % and / should be unsigned, the second

    % and / signed, but C compilers tend to be extraordinarily

    sensitive to minor details of style.  This works on a VAX, that's

    all I claim for it.

  */

  p = &buffer[sizeof(buffer)-1];

  *p = '\0';

  new_val= uval / (ulong) radix;

  *--p = dig_vec[(uchar) (uval- (ulong) new_val*(ulong) radix)];

  val = new_val;

#ifdef HAVE_LDIV

  while (val != 0)

  {

    ldiv_t res;

    res=ldiv(val,radix);

    *--p = dig_vec[res.rem];

    val= res.quot;

  }

#else

  while (val != 0)

  {

    new_val=val/radix;

    *--p = dig_vec[(uchar) (val-new_val*radix)];

    val= new_val;

  }

#endif

  while ((*dst++ = *p++) != 0) ;

  return dst-1;

}

/*

  Converts integer to its string representation in decimal notation.

  SYNOPSIS

    int10_to_str()

      val     - value to convert

      dst     - points to buffer where string representation should be stored

      radix   - flag that shows whenever val should be taken as signed or not

  DESCRIPTION

    This is version of int2str() function which is optimized for normal case

    of radix 10/-10. It takes only sign of radix parameter into account and 

    not its absolute value.

  RETURN VALUE

    Pointer to ending NUL character.

*/

char *int10_to_str(long int val,char *dst,int radix)

{

  char buffer[65];

  register char *p;

  long int new_val;

  unsigned long int uval = (unsigned long int) val;

  if (radix < 0)				/* -10 */

  {

    if (val < 0)

    {

      *dst++ = '-';

      /* Avoid integer overflow in (-val) for LONGLONG_MIN (BUG#31799). */

      uval = (unsigned long int)0 - uval;

    }

  }

  p = &buffer[sizeof(buffer)-1];

  *p = '\0';

  new_val= (long) (uval / 10);

  *--p = '0'+ (char) (uval - (unsigned long) new_val * 10);

  val = new_val;

  while (val != 0)

  {

    new_val=val/10;

    *--p = '0' + (char) (val-new_val*10);

    val= new_val;

  }

  while ((*dst++ = *p++) != 0) ;

  return dst-1;

}