libio/wmemstream.c

   1 /* Copyright (C) 1995-2023 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 /* Open a stream that writes into a malloc'd buffer that is expanded as
  34    necessary.  *BUFLOC and *SIZELOC are updated with the buffer's location
  35    and the number of characters written on fflush or fclose.  */
  36 FILE *
  37 open_wmemstream (wchar_t **bufloc, size_t *sizeloc)
  38 {
  39   struct locked_FILE
  40   {
  41     struct _IO_FILE_wmemstream fp;
  42 #ifdef _IO_MTSAFE_IO
  43     _IO_lock_t lock;
  44 #endif
  45     struct _IO_wide_data wd;
  46   } *new_f;
  47   wchar_t *buf;
  48
  49   new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
  50   if (new_f == NULL)
  51     return NULL;
  52 #ifdef _IO_MTSAFE_IO
  53   new_f->fp._sf._sbf._f._lock = &new_f->lock;
  54 #endif
  55
  56   buf = calloc (1, BUFSIZ);
  57   if (buf == NULL)
  58     {
  59       free (new_f);
  60       return NULL;
  61     }
  62   _IO_no_init (&new_f->fp._sf._sbf._f, 0, 0, &new_f->wd, &_IO_wmem_jumps);
  63   _IO_fwide (&new_f->fp._sf._sbf._f, 1);
  64   _IO_wstr_init_static (&new_f->fp._sf._sbf._f, buf,
  65                         BUFSIZ / sizeof (wchar_t), buf);
  66   new_f->fp._sf._sbf._f._flags2 &= ~_IO_FLAGS2_USER_WBUF;
  67   new_f->fp._sf._s._allocate_buffer_unused = (_IO_alloc_type) malloc;
  68   new_f->fp._sf._s._free_buffer_unused = (_IO_free_type) free;
  69
  70   new_f->fp.bufloc = bufloc;
  71   new_f->fp.sizeloc = sizeloc;
  72
  73   /* Disable single thread optimization.  BZ 21735.  */
  74   new_f->fp._sf._sbf._f._flags2 |= _IO_FLAGS2_NEED_LOCK;
  75
  76   return (FILE *) &new_f->fp._sf._sbf;
  77 }
  78
  79
  80 int
  81 _IO_wmem_sync (FILE *fp)
  82 {
  83   struct _IO_FILE_wmemstream *mp = (struct _IO_FILE_wmemstream *) fp;
  84
  85   if (fp->_wide_data->_IO_write_ptr == fp->_wide_data->_IO_write_end)
  86     {
  87       _IO_wstr_overflow (fp, '\0');
  88       --fp->_wide_data->_IO_write_ptr;
  89     }
  90
  91   *mp->bufloc = fp->_wide_data->_IO_write_base;
  92   *mp->sizeloc = (fp->_wide_data->_IO_write_ptr
  93                   - fp->_wide_data->_IO_write_base);
  94
  95   return 0;
  96 }
  97
  98
  99 void
 100 _IO_wmem_finish (FILE *fp, int dummy)
 101 {
 102   struct _IO_FILE_wmemstream *mp = (struct _IO_FILE_wmemstream *) fp;
 103
 104   *mp->bufloc = (wchar_t *) realloc (fp->_wide_data->_IO_write_base,
 105                                      (fp->_wide_data->_IO_write_ptr
 106                                       - fp->_wide_data->_IO_write_base + 1)
 107                                      * sizeof (wchar_t));
 108   if (*mp->bufloc != NULL)
 109     {
 110       size_t len = (fp->_wide_data->_IO_write_ptr
 111                     - fp->_wide_data->_IO_write_base);
 112       (*mp->bufloc)[len] = '\0';
 113       *mp->sizeloc = len;
 114
 115       fp->_wide_data->_IO_buf_base = NULL;
 116     }
 117
 118   _IO_wstr_finish (fp, 0);
 119 }