libio/wmemstream.c

   1 /* Copyright (C) 1995-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include "libioP.h"
  19 #include "strfile.h"
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <wchar.h>
  23
  24
  25 struct _IO_FILE_wmemstream
  26 {
  27   _IO_strfile _sf;
  28   wchar_t **bufloc;
  29   size_t *sizeloc;
  30 };
  31
  32
  33 static int _IO_wmem_sync (FILE* fp) __THROW;
  34 static void _IO_wmem_finish (FILE* fp, int) __THROW;
  35
  36
  37 static const struct _IO_jump_t _IO_wmem_jumps libio_vtable =
  38 {
  39   JUMP_INIT_DUMMY,
  40   JUMP_INIT (finish, _IO_wmem_finish),
  41   JUMP_INIT (overflow, (_IO_overflow_t) _IO_wstr_overflow),
  42   JUMP_INIT (underflow, (_IO_underflow_t) _IO_wstr_underflow),
  43   JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
  44   JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
  45   JUMP_INIT (xsputn, _IO_wdefault_xsputn),
  46   JUMP_INIT (xsgetn, _IO_wdefault_xsgetn),
  47   JUMP_INIT (seekoff, _IO_wstr_seekoff),
  48   JUMP_INIT (seekpos, _IO_default_seekpos),
  49   JUMP_INIT (setbuf, _IO_default_setbuf),
  50   JUMP_INIT (sync, _IO_wmem_sync),
  51   JUMP_INIT (doallocate, _IO_wdefault_doallocate),
  52   JUMP_INIT (read, _IO_default_read),
  53   JUMP_INIT (write, _IO_default_write),
  54   JUMP_INIT (seek, _IO_default_seek),
  55   JUMP_INIT (close, _IO_default_close),
  56   JUMP_INIT (stat, _IO_default_stat),
  57   JUMP_INIT (showmanyc, _IO_default_showmanyc),
  58   JUMP_INIT (imbue, _IO_default_imbue)
  59 };
  60
  61 /* Open a stream that writes into a malloc'd buffer that is expanded as
  62    necessary.  *BUFLOC and *SIZELOC are updated with the buffer's location
  63    and the number of characters written on fflush or fclose.  */
  64 FILE *
  65 open_wmemstream (wchar_t **bufloc, size_t *sizeloc)
  66 {
  67   struct locked_FILE
  68   {
  69     struct _IO_FILE_wmemstream fp;
  70 #ifdef _IO_MTSAFE_IO
  71     _IO_lock_t lock;
  72 #endif
  73     struct _IO_wide_data wd;
  74   } *new_f;
  75   wchar_t *buf;
  76
  77   new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
  78   if (new_f == NULL)
  79     return NULL;
  80 #ifdef _IO_MTSAFE_IO
  81   new_f->fp._sf._sbf._f._lock = &new_f->lock;
  82 #endif
  83
  84   buf = calloc (1, BUFSIZ);
  85   if (buf == NULL)
  86     {
  87       free (new_f);
  88       return NULL;
  89     }
  90   _IO_no_init (&new_f->fp._sf._sbf._f, 0, 0, &new_f->wd, &_IO_wmem_jumps);
  91   _IO_fwide (&new_f->fp._sf._sbf._f, 1);
  92   _IO_wstr_init_static (&new_f->fp._sf._sbf._f, buf,
  93                         BUFSIZ / sizeof (wchar_t), buf);
  94   new_f->fp._sf._sbf._f._flags2 &= ~_IO_FLAGS2_USER_WBUF;
  95   new_f->fp._sf._s._allocate_buffer_unused = (_IO_alloc_type) malloc;
  96   new_f->fp._sf._s._free_buffer_unused = (_IO_free_type) free;
  97
  98   new_f->fp.bufloc = bufloc;
  99   new_f->fp.sizeloc = sizeloc;
 100
 101   /* Disable single thread optimization.  BZ 21735.  */
 102   new_f->fp._sf._sbf._f._flags2 |= _IO_FLAGS2_NEED_LOCK;
 103
 104   return (FILE *) &new_f->fp._sf._sbf;
 105 }
 106
 107
 108 static int
 109 _IO_wmem_sync (FILE *fp)
 110 {
 111   struct _IO_FILE_wmemstream *mp = (struct _IO_FILE_wmemstream *) fp;
 112
 113   if (fp->_wide_data->_IO_write_ptr == fp->_wide_data->_IO_write_end)
 114     {
 115       _IO_wstr_overflow (fp, '\0');
 116       --fp->_wide_data->_IO_write_ptr;
 117     }
 118
 119   *mp->bufloc = fp->_wide_data->_IO_write_base;
 120   *mp->sizeloc = (fp->_wide_data->_IO_write_ptr
 121                   - fp->_wide_data->_IO_write_base);
 122
 123   return 0;
 124 }
 125
 126
 127 static void
 128 _IO_wmem_finish (FILE *fp, int dummy)
 129 {
 130   struct _IO_FILE_wmemstream *mp = (struct _IO_FILE_wmemstream *) fp;
 131
 132   *mp->bufloc = (wchar_t *) realloc (fp->_wide_data->_IO_write_base,
 133                                      (fp->_wide_data->_IO_write_ptr
 134                                       - fp->_wide_data->_IO_write_base + 1)
 135                                      * sizeof (wchar_t));
 136   if (*mp->bufloc != NULL)
 137     {
 138       size_t len = (fp->_wide_data->_IO_write_ptr
 139                     - fp->_wide_data->_IO_write_base);
 140       (*mp->bufloc)[len] = '\0';
 141       *mp->sizeloc = len;
 142
 143       fp->_wide_data->_IO_buf_base = NULL;
 144     }
 145
 146   _IO_wstr_finish (fp, 0);
 147 }