iconv/gconv_open.c

   1 /* Find matching transformation algorithms and initialize steps.
   2    Copyright (C) 1997, 1998, 1999, 2000 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 #include <string.h>
  24
  25 #include <gconv_int.h>
  26
  27
  28 int
  29 internal_function
  30 __gconv_open (const char *toset, const char *fromset, __gconv_t *handle,
  31               int flags)
  32 {
  33   struct __gconv_step *steps;
  34   size_t nsteps;
  35   __gconv_t result = NULL;
  36   size_t cnt = 0;
  37   int res;
  38
  39   res = __gconv_find_transform (toset, fromset, &steps, &nsteps, flags);
  40   if (res == __GCONV_OK)
  41     {
  42       /* Allocate room for handle.  */
  43       result = (__gconv_t) malloc (sizeof (struct __gconv_info)
  44                                    + (nsteps
  45                                       * sizeof (struct __gconv_step_data)));
  46       if (result == NULL)
  47         res = __GCONV_NOMEM;
  48       else
  49         {
  50           /* Remember the list of steps.  */
  51           result->__steps = steps;
  52           result->__nsteps = nsteps;
  53
  54           /* Clear the array for the step data.  */
  55           memset (result->__data, '\0',
  56                   nsteps * sizeof (struct __gconv_step_data));
  57
  58           /* Call all initialization functions for the transformation
  59              step implementations.  */
  60           for (cnt = 0; cnt < nsteps - 1; ++cnt)
  61             {
  62               size_t size;
  63
  64               /* If this is the last step we must not allocate an
  65                  output buffer.  */
  66               result->__data[cnt].__is_last = 0;
  67
  68               /* Reset the counter.  */
  69               result->__data[cnt].__invocation_counter = 0;
  70
  71               /* It's a regular use.  */
  72               result->__data[cnt].__internal_use = 0;
  73
  74               /* We use the `mbstate_t' member in DATA.  */
  75               result->__data[cnt].__statep = &result->__data[cnt].__state;
  76
  77               /* Allocate the buffer.  */
  78               size = (GCONV_NCHAR_GOAL * steps[cnt].__max_needed_to);
  79
  80               result->__data[cnt].__outbuf = (char *) malloc (size);
  81               if (result->__data[cnt].__outbuf == NULL)
  82                 {
  83                   res = __GCONV_NOMEM;
  84                   break;
  85                 }
  86               result->__data[cnt].__outbufend =
  87                 result->__data[cnt].__outbuf + size;
  88             }
  89
  90           /* Now handle the last entry.  */
  91           result->__data[cnt].__is_last = 1;
  92           result->__data[cnt].__invocation_counter = 0;
  93           result->__data[cnt].__internal_use = 0;
  94           result->__data[cnt].__statep = &result->__data[cnt].__state;
  95         }
  96     }
  97
  98   if (res != __GCONV_OK)
  99     {
 100       /* Something went wrong.  Free all the resources.  */
 101       int serrno = errno;
 102
 103       if (result != NULL)
 104         {
 105           while (cnt-- > 0)
 106             free (result->__data[cnt].__outbuf);
 107
 108           free (result);
 109           result = NULL;
 110         }
 111
 112       __gconv_close_transform (steps, nsteps);
 113
 114       __set_errno (serrno);
 115     }
 116
 117   *handle = result;
 118   return res;
 119 }