about summary refs log tree commit diff
path: root/stdio-common/wprintf_buffer_as_file.c
blob: cd48a7d42a368e777f5ac080872e20380d04841f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
/* FILE * interface to a struct __wprintf_buffer.  Wide version.
   Copyright (C) 2022 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library 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 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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 the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <printf_buffer_as_file.h>

#include <assert.h>
#include <printf_buffer.h>

/* Commit the data directly written through the stdio stream.  */
static void
__wprintf_buffer_as_file_commit (struct __wprintf_buffer_as_file *file)
{
  /* Check that the write pointers in the file stream are consistent
     with the next buffer.  */
  assert (file->wide_stream._IO_write_ptr >= file->next->write_ptr);
  assert (file->wide_stream._IO_write_ptr <= file->next->write_end);
  assert (file->wide_stream._IO_write_base == file->next->write_base);
  assert (file->wide_stream._IO_write_end == file->next->write_end);

  file->next->write_ptr = file->wide_stream._IO_write_ptr;
}

/* Pointer the FILE * write buffer into the active struct __wprintf_buffer
   area.  */
static void
__wprintf_buffer_as_file_switch_to_buffer (struct __wprintf_buffer_as_file *file)
{
  file->wide_stream._IO_write_base = file->next->write_base;
  file->wide_stream._IO_write_ptr = file->next->write_ptr;
  file->wide_stream._IO_write_end = file->next->write_end;
}

/* Only a small subset of the vtable functions is implemented here,
   following _IO_obstack_jumps.  */

static wint_t
__wprintf_buffer_as_file_overflow (FILE *fp, int ch)
{
  struct __wprintf_buffer_as_file *file
    = (struct __wprintf_buffer_as_file *) fp;

  __wprintf_buffer_as_file_commit (file);

  /* EOF means only a flush is requested.   */
  if (ch != WEOF)
    __wprintf_buffer_putc (file->next, ch);
  else
    ch = 0;

  /* Ensure that flushing actually produces room.  */
  if (!__wprintf_buffer_has_failed (file->next)
      && file->next->write_ptr == file->next->write_end)
    __wprintf_buffer_flush (file->next);

  __wprintf_buffer_as_file_switch_to_buffer (file);

  if (!__wprintf_buffer_has_failed (file->next))
    return (unsigned char) ch;
  else
    return WEOF;
}

static size_t
__wprintf_buffer_as_file_xsputn (FILE *fp, const void *buf, size_t len)
{
  struct __wprintf_buffer_as_file *file
    = (struct __wprintf_buffer_as_file *) fp;

  __wprintf_buffer_as_file_commit (file);

  /* Copy the data.  */
  __wprintf_buffer_write (file->next, buf, len);

  __wprintf_buffer_as_file_switch_to_buffer (file);

  if (!__wprintf_buffer_has_failed (file->next))
    return len;
  else
    /* We may actually have written something.  But the stream is
       corrupted in this case anyway, so try not to divine the write
       count here.  */
    return 0;
}

static const struct _IO_jump_t _IO_wprintf_buffer_as_file_jumps libio_vtable =
{
  JUMP_INIT_DUMMY,
  JUMP_INIT(finish, NULL),
  JUMP_INIT(overflow, (_IO_overflow_t) __wprintf_buffer_as_file_overflow),
  JUMP_INIT(underflow, NULL),
  JUMP_INIT(uflow, NULL),
  JUMP_INIT(pbackfail, NULL),
  JUMP_INIT(xsputn, __wprintf_buffer_as_file_xsputn),
  JUMP_INIT(xsgetn, NULL),
  JUMP_INIT(seekoff, NULL),
  JUMP_INIT(seekpos, NULL),
  JUMP_INIT(setbuf, NULL),
  JUMP_INIT(sync, NULL),
  JUMP_INIT(doallocate, NULL),
  JUMP_INIT(read, NULL),
  JUMP_INIT(write, NULL),
  JUMP_INIT(seek, NULL),
  JUMP_INIT(close, NULL),
  JUMP_INIT(stat, NULL),
  JUMP_INIT(showmanyc, NULL),
  JUMP_INIT(imbue, NULL)
};

void
__wprintf_buffer_as_file_init (struct __wprintf_buffer_as_file *file,
                               struct __wprintf_buffer *next)
{
  file->stream._lock = NULL;
  _IO_no_init (&file->stream, _IO_USER_LOCK, 0, &file->wide_stream,
               &_IO_wprintf_buffer_as_file_jumps);
  _IO_fwide (&file->stream, 1);

  /* Set up the write buffer from the next buffer.  */
  file->next = next;
  __wprintf_buffer_as_file_switch_to_buffer (file);

  /* Mark the read area as inactive, by making all pointers equal.  */
  file->stream._IO_read_base = file->stream._IO_write_base;
  file->stream._IO_read_ptr = file->stream._IO_write_base;
  file->stream._IO_read_end = file->stream._IO_write_base;
}

bool
__wprintf_buffer_as_file_terminate (struct __wprintf_buffer_as_file *file)
{
  if (file->stream._flags & _IO_ERR_SEEN)
    return false;
  else
    {
      __wprintf_buffer_as_file_commit (file);
      return true;
    }
}