1/* FILE * interface to a struct __printf_buffer. Multibyte version.
2 Copyright (C) 2022-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <printf_buffer_as_file.h>
20
21#include <assert.h>
22#include <printf_buffer.h>
23
24/* Commit the data directly written through the stdio stream. */
25static void
26__printf_buffer_as_file_commit (struct __printf_buffer_as_file *file)
27{
28 /* Check that the write pointers in the file stream are consistent
29 with the next buffer. */
30 assert (file->stream._IO_write_ptr >= file->next->write_ptr);
31 assert (file->stream._IO_write_ptr <= file->next->write_end);
32 assert (file->stream._IO_write_base == file->next->write_base);
33 assert (file->stream._IO_write_end == file->next->write_end);
34
35 file->next->write_ptr = file->stream._IO_write_ptr;
36}
37
38/* Pointer the FILE * write buffer into the active printf_buffer
39 area. */
40static void
41__printf_buffer_as_file_switch_to_buffer (struct __printf_buffer_as_file *file)
42{
43 file->stream._IO_write_base = file->next->write_base;
44 file->stream._IO_write_ptr = file->next->write_ptr;
45 file->stream._IO_write_end = file->next->write_end;
46}
47
48/* Only a small subset of the vtable functions is implemented here,
49 following _IO_obstack_jumps. */
50
51int
52__printf_buffer_as_file_overflow (FILE *fp, int ch)
53{
54 struct __printf_buffer_as_file *file = (struct __printf_buffer_as_file *) fp;
55
56 __printf_buffer_as_file_commit (file);
57
58 /* EOF means only a flush is requested. */
59 if (ch != EOF)
60 __printf_buffer_putc (file->next, ch);
61
62 /* Ensure that flushing actually produces room. */
63 if (!__printf_buffer_has_failed (file->next)
64 && file->next->write_ptr == file->next->write_end)
65 __printf_buffer_flush (file->next);
66
67 __printf_buffer_as_file_switch_to_buffer (file);
68
69 if (!__printf_buffer_has_failed (file->next))
70 return (unsigned char) ch;
71 else
72 return EOF;
73}
74
75size_t
76__printf_buffer_as_file_xsputn (FILE *fp, const void *buf, size_t len)
77{
78 struct __printf_buffer_as_file *file = (struct __printf_buffer_as_file *) fp;
79
80 __printf_buffer_as_file_commit (file);
81
82 /* Copy the data. */
83 __printf_buffer_write (file->next, buf, len);
84
85 __printf_buffer_as_file_switch_to_buffer (file);
86
87 if (!__printf_buffer_has_failed (file->next))
88 return len;
89 else
90 /* We may actually have written something. But the stream is
91 corrupted in this case anyway, so try not to divine the write
92 count here. */
93 return 0;
94}
95
96void
97__printf_buffer_as_file_init (struct __printf_buffer_as_file *file,
98 struct __printf_buffer *next)
99{
100 file->stream._lock = NULL;
101 _IO_no_init (&file->stream, _IO_USER_LOCK, -1, NULL, NULL);
102 file->vtable = &_IO_printf_buffer_as_file_jumps;
103
104 /* Set up the write buffer from the next buffer. */
105 file->next = next;
106 __printf_buffer_as_file_switch_to_buffer (file);
107
108 /* Mark the read area as inactive, by making all pointers equal. */
109 file->stream._IO_read_base = file->stream._IO_write_base;
110 file->stream._IO_read_ptr = file->stream._IO_write_base;
111 file->stream._IO_read_end = file->stream._IO_write_base;
112}
113
114bool
115__printf_buffer_as_file_terminate (struct __printf_buffer_as_file *file)
116{
117 if (file->stream._flags & _IO_ERR_SEEN)
118 return false;
119 else
120 {
121 __printf_buffer_as_file_commit (file);
122 return true;
123 }
124}
125