1/* FILE * interface to a struct __wprintf_buffer. Wide 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__wprintf_buffer_as_file_commit (struct __wprintf_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->wide_stream._IO_write_ptr >= file->next->write_ptr);
31 assert (file->wide_stream._IO_write_ptr <= file->next->write_end);
32 assert (file->wide_stream._IO_write_base == file->next->write_base);
33 assert (file->wide_stream._IO_write_end == file->next->write_end);
34
35 file->next->write_ptr = file->wide_stream._IO_write_ptr;
36}
37
38/* Pointer the FILE * write buffer into the active struct __wprintf_buffer
39 area. */
40static void
41__wprintf_buffer_as_file_switch_to_buffer (struct __wprintf_buffer_as_file *file)
42{
43 file->wide_stream._IO_write_base = file->next->write_base;
44 file->wide_stream._IO_write_ptr = file->next->write_ptr;
45 file->wide_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
51wint_t
52__wprintf_buffer_as_file_overflow (FILE *fp, int ch)
53{
54 struct __wprintf_buffer_as_file *file
55 = (struct __wprintf_buffer_as_file *) fp;
56
57 __wprintf_buffer_as_file_commit (file);
58
59 /* EOF means only a flush is requested. */
60 if (ch != WEOF)
61 __wprintf_buffer_putc (file->next, ch);
62 else
63 ch = 0;
64
65 /* Ensure that flushing actually produces room. */
66 if (!__wprintf_buffer_has_failed (file->next)
67 && file->next->write_ptr == file->next->write_end)
68 __wprintf_buffer_flush (file->next);
69
70 __wprintf_buffer_as_file_switch_to_buffer (file);
71
72 if (!__wprintf_buffer_has_failed (file->next))
73 return (unsigned char) ch;
74 else
75 return WEOF;
76}
77
78size_t
79__wprintf_buffer_as_file_xsputn (FILE *fp, const void *buf, size_t len)
80{
81 struct __wprintf_buffer_as_file *file
82 = (struct __wprintf_buffer_as_file *) fp;
83
84 __wprintf_buffer_as_file_commit (file);
85
86 /* Copy the data. */
87 __wprintf_buffer_write (file->next, buf, len);
88
89 __wprintf_buffer_as_file_switch_to_buffer (file);
90
91 if (!__wprintf_buffer_has_failed (file->next))
92 return len;
93 else
94 /* We may actually have written something. But the stream is
95 corrupted in this case anyway, so try not to divine the write
96 count here. */
97 return 0;
98}
99
100void
101__wprintf_buffer_as_file_init (struct __wprintf_buffer_as_file *file,
102 struct __wprintf_buffer *next)
103{
104 file->stream._lock = NULL;
105 _IO_no_init (&file->stream, _IO_USER_LOCK, 0, &file->wide_stream,
106 &_IO_wprintf_buffer_as_file_jumps);
107 _IO_fwide (&file->stream, 1);
108
109 /* Set up the write buffer from the next buffer. */
110 file->next = next;
111 __wprintf_buffer_as_file_switch_to_buffer (file);
112
113 /* Mark the read area as inactive, by making all pointers equal. */
114 file->stream._IO_read_base = file->stream._IO_write_base;
115 file->stream._IO_read_ptr = file->stream._IO_write_base;
116 file->stream._IO_read_end = file->stream._IO_write_base;
117}
118
119bool
120__wprintf_buffer_as_file_terminate (struct __wprintf_buffer_as_file *file)
121{
122 if (file->stream._flags & _IO_ERR_SEEN)
123 return false;
124 else
125 {
126 __wprintf_buffer_as_file_commit (file);
127 return true;
128 }
129}
130