/* -*- Mode: c; c-basic-offset: 2 -*-

 *

 * snprintf.c - Rasqal formatted numbers utilities

 *

 * Copyright (C) 2011, David Beckett http://www.dajobe.org/

 * 

 * This package is Free Software and part of Redland http://librdf.org/

 * 

 * It is licensed under the following three licenses as alternatives:

 *   1. GNU Lesser General Public License (LGPL) V2.1 or any newer version

 *   2. GNU General Public License (GPL) V2 or any newer version

 *   3. Apache License, V2.0 or any newer version

 * 

 * You may not use this file except in compliance with at least one of

 * the above three licenses.

 * 

 * See LICENSE.html or LICENSE.txt at the top of this package for the

 * complete terms and further detail along with the license texts for

 * the licenses in COPYING.LIB, COPYING and LICENSE-2.0.txt respectively.

 * 

 * 

 */

#ifdef HAVE_CONFIG_H

#include <rasqal_config.h>

#endif

#ifdef WIN32

#include <win32_rasqal_config.h>

#endif

#include <stdio.h>

#include <string.h>

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#include <stdarg.h>

#include "rasqal.h"

#include "rasqal_internal.h"

static const char digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";

/**

 * rasqal_format_integer:

 * @buffer: buffer (or NULL)

 * @bufsize: size of above (or 0)

 * @integer: integer value to format

 *

 * INTERNAL - Format an integer as a decimal into a buffer or

 * calculate the size needed.

 *

 * Works Like the C99 snprintf() but just for integers.

 *

 * If @buffer is NULL or the @bufsize is too small, the number of

 * bytes needed (excluding NUL) is returned and no formatting is done.

 *

 * Return value: number of bytes needed or written (excluding NUL) or 0 on failure

 */

size_t

rasqal_format_integer(char* buffer, size_t bufsize, int integer,

                      int width, char padding)

{

  size_t len = 1;

  char *p;

  unsigned int value;

  unsigned int base = 10;

  if(integer < 0) {

    value = RASQAL_GOOD_CAST(unsigned int, -integer);

    len++;

    width++;

  } else

    value = RASQAL_GOOD_CAST(unsigned int, integer);

  while(value /= base)

    len++;

  if(width > 0) {

    size_t width_l = RASQAL_GOOD_CAST(size_t, width);

    if(width_l > len)

      len = width_l;

  }

  if(!buffer || bufsize < (len + 1)) /* +1 for NUL */

    return len;

  if(!padding)

    padding = ' ';

  if(integer < 0)

    value = RASQAL_GOOD_CAST(unsigned int, -integer);

  else

    value = RASQAL_GOOD_CAST(unsigned int, integer);

  p = &buffer[len];

  *p-- = '\0';

  while(value  > 0 && p >= buffer) {

    *p-- = digits[value % base];

    value /= base;

  }

  while(p >= buffer)

    *p-- = padding;

  if(integer < 0)

    *buffer = '-';

  return len;

}