iconv/gconv_open.c

   1 /* Find matching transformation algorithms and initialize steps.
   2    Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <errno.h>
  22 #include <stdlib.h>
  23
  24 #include <gconv_int.h>
  25
  26
  27 int
  28 internal_function
  29 __gconv_open (const char *toset, const char *fromset, gconv_t *handle)
  30 {
  31   struct gconv_step *steps;
  32   size_t nsteps;
  33   gconv_t result = NULL;
  34   size_t cnt = 0;
  35   int res;
  36
  37   res = __gconv_find_transform (toset, fromset, &steps, &nsteps);
  38   if (res == GCONV_OK)
  39     {
  40       /* Allocate room for handle.  */
  41       result = (gconv_t) malloc (sizeof (struct gconv_info)
  42                                  + nsteps * sizeof (struct gconv_step_data));
  43       if (result == NULL)
  44         res = GCONV_NOMEM;
  45       else
  46         {
  47           /* Remember the list of steps.  */
  48           result->steps = steps;
  49           result->nsteps = nsteps;
  50
  51           /* Clear the array for the step data.  */
  52           memset (result->data, '\0',
  53                   nsteps * sizeof (struct gconv_step_data));
  54
  55           /* Call all initialization functions for the transformation
  56              step implemenations.  */
  57           for (cnt = 0; cnt < nsteps; ++cnt)
  58             {
  59               /* If this is the last step we must not allocate an
  60                  output buffer.  */
  61               result->data[cnt].is_last = cnt == nsteps - 1;
  62
  63               /* Reset the counter.  */
  64               result->data[cnt].invocation_counter = 0;
  65
  66               /* It's a regular use.  */
  67               result->data[cnt].internal_use = 0;
  68
  69               /* We use the `mbstate_t' member in DATA.  */
  70               result->data[cnt].statep = &result->data[cnt].__state;
  71
  72               /* Allocate the buffer.  */
  73               if (!result->data[cnt].is_last)
  74                 {
  75                   size_t size = (GCONV_NCHAR_GOAL
  76                                  * steps[cnt].max_needed_to);
  77
  78                   result->data[cnt].outbuf = (char *) malloc (size);
  79                   if (result->data[cnt].outbuf == NULL)
  80                     {
  81                       res = GCONV_NOMEM;
  82                       break;
  83                     }
  84                   result->data[cnt].outbufend = (result->data[cnt].outbuf
  85                                                  + size);
  86                 }
  87             }
  88         }
  89     }
  90
  91   if (res != GCONV_OK)
  92     {
  93       /* Something went wrong.  Free all the resources.  */
  94       int serrno = errno;
  95
  96       if (result != NULL)
  97         {
  98           while (cnt-- > 0)
  99             free (result->data[cnt].outbuf);
 100
 101           free (result);
 102           result = NULL;
 103         }
 104
 105       __gconv_close_transform (steps, nsteps);
 106
 107       __set_errno (serrno);
 108     }
 109
 110   *handle = result;
 111   return res;
 112 }