kc3-lang/gnulib/lib/amemxfrm.c

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• Hash : d60f3b0c
  Author :
  Date : 2011-01-01T20:17:23
  

  maint: update almost all copyright ranges to include 2011
  
  Run the new "make update-copyright" rule.
  

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• lib/amemxfrm.c

• /* Locale dependent memory area transformation for comparison.
     Copyright (C) 2009-2011 Free Software Foundation, Inc.
     Written by Bruno Haible <bruno@clisp.org>, 2009.
  
     This program is free software: you can redistribute it and/or modify it
     under the terms of the GNU Lesser General Public License as published
     by the Free Software Foundation; either version 3 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
     Lesser General Public License for more details.
  
     You should have received a copy of the GNU Lesser General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  
  #include <config.h>
  
  /* Specification.  */
  #include "amemxfrm.h"
  
  #include <errno.h>
  #include <stdlib.h>
  #include <string.h>
  
  char *
  amemxfrm (char *s, size_t n, char *resultbuf, size_t *lengthp)
  {
    /* Result accumulator.  */
    char *result;
    size_t length;
    size_t allocated;
  
    char orig_sentinel;
  
    /* Initial memory allocation.  */
    if (resultbuf != NULL && *lengthp > 0)
      {
        result = resultbuf;
        allocated = *lengthp;
      }
    else
      {
        allocated = (n > 0 ? n : 1);
        result = (char *) malloc (allocated);
        if (result == NULL)
          goto out_of_memory_2;
      }
    length = 0;
  
    /* Add sentinel.byte.  */
    orig_sentinel = s[n];
    s[n] = '\0';
  
    /* Iterate through S, transforming each NUL terminated segment.
       Accumulate the resulting transformed segments in result, separated by
       NULs.  */
    {
      const char *p_end = s + n + 1;
      const char *p;
  
      p = s;
      for (;;)
        {
          /* Search next NUL byte.  */
          size_t l = strlen (p);
  
          for (;;)
            {
              size_t k;
  
              /* A call to strxfrm costs about 20 times more than a call to
                 strdup of the result.  Therefore it is worth to try to avoid
                 calling strxfrm more than once on a given string, by making
                 enough room before calling strxfrm.
                 The size of the strxfrm result, k, is likely to be between
                 l and 3 * l.  */
              if (3 * l >= allocated - length)
                {
                  /* Grow the result buffer.  */
                  size_t new_allocated;
                  char *new_result;
  
                  new_allocated = length + 3 * l + 1;
                  if (new_allocated < 2 * allocated)
                    new_allocated = 2 * allocated;
                  if (new_allocated < 64)
                    new_allocated = 64;
                  if (result == resultbuf)
                    new_result = (char *) malloc (new_allocated);
                  else
                    new_result = (char *) realloc (result, new_allocated);
                  if (new_result != NULL)
                    {
                      allocated = new_allocated;
                      result = new_result;
                    }
                }
  
              errno = 0;
              k = strxfrm (result + length, p, allocated - length);
              if (errno != 0)
                goto fail;
              if (k >= allocated - length)
                {
                  /* Grow the result buffer.  */
                  size_t new_allocated;
                  char *new_result;
  
                  new_allocated = length + k + 1;
                  if (new_allocated < 2 * allocated)
                    new_allocated = 2 * allocated;
                  if (new_allocated < 64)
                    new_allocated = 64;
                  if (result == resultbuf)
                    new_result = (char *) malloc (new_allocated);
                  else
                    new_result = (char *) realloc (result, new_allocated);
                  if (new_result == NULL)
                    goto out_of_memory_1;
                  allocated = new_allocated;
                  result = new_result;
                }
              else
                {
                  length += k;
                  break;
                }
            }
  
          p = p + l + 1;
          if (p == p_end)
            break;
          result[length] = '\0';
          length++;
        }
    }
  
    /* Shrink the allocated memory if possible.
       It is not worth calling realloc when length + 1 == allocated; it would
       save just one byte.  */
    if (result != resultbuf && length + 1 < allocated)
      {
        if ((length > 0 ? length : 1) <= *lengthp)
          {
            memcpy (resultbuf, result, length);
            free (result);
            result = resultbuf;
          }
        else
          {
            char *memory = (char *) realloc (result, length > 0 ? length : 1);
            if (memory != NULL)
              result = memory;
          }
      }
  
    s[n] = orig_sentinel;
    *lengthp = length;
    return result;
  
   fail:
    {
      int saved_errno = errno;
      if (result != resultbuf)
        free (result);
      s[n] = orig_sentinel;
      errno = saved_errno;
      return NULL;
    }
  
   out_of_memory_1:
    if (result != resultbuf)
      free (result);
    s[n] = orig_sentinel;
   out_of_memory_2:
    errno = ENOMEM;
    return NULL;
  }
  

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