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
|
/*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "file.h"
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
#if HAVE_MMAP
#include <sys/mman.h>
#endif
typedef struct {
const AVClass *class;
int log_offset;
void *log_ctx;
} FileLogContext;
static const AVClass file_log_ctx_class = {
"FILE", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT,
offsetof(FileLogContext, log_offset), offsetof(FileLogContext, log_ctx)
};
int av_file_map(const char *filename, uint8_t **bufptr, size_t *size,
int log_offset, void *log_ctx)
{
FileLogContext file_log_ctx = { &file_log_ctx_class, log_offset, log_ctx };
int err, fd = open(filename, O_RDONLY);
struct stat st;
av_unused void *ptr;
off_t off_size;
char errbuf[128];
size_t max_size = HAVE_MMAP ? SIZE_MAX : FF_INTERNAL_MEM_TYPE_MAX_VALUE;
*bufptr = NULL;
if (fd < 0) {
err = AVERROR(errno);
av_strerror(err, errbuf, sizeof(errbuf));
av_log(&file_log_ctx, AV_LOG_ERROR, "Cannot read file '%s': %s\n", filename, errbuf);
return err;
}
if (lstat(filename, &st) < 0) {
err = AVERROR(errno);
av_strerror(err, errbuf, sizeof(errbuf));
av_log(&file_log_ctx, AV_LOG_ERROR, "Error occurred in lstat(): %s\n", errbuf);
close(fd);
return err;
}
off_size = st.st_size;
if (off_size > max_size) {
av_log(&file_log_ctx, AV_LOG_ERROR,
"File size for file '%s' is too big\n", filename);
close(fd);
return AVERROR(EINVAL);
}
*size = off_size;
#if HAVE_MMAP
ptr = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
if ((int)(ptr) == -1) {
err = AVERROR(errno);
av_strerror(err, errbuf, sizeof(errbuf));
av_log(&file_log_ctx, AV_LOG_ERROR, "Error occurred in mmap(): %s\n", errbuf);
close(fd);
return err;
}
*bufptr = ptr;
#else
*bufptr = av_malloc(*size);
if (!*bufptr) {
av_log(&file_log_ctx, AV_LOG_ERROR, "Memory allocation error occurred\n");
close(fd);
return AVERROR(ENOMEM);
}
read(fd, *bufptr, *size);
#endif
close(fd);
return 0;
}
void av_file_unmap(uint8_t *bufptr, size_t size)
{
#if HAVE_MMAP
munmap(bufptr, size);
#else
av_free(bufptr);
#endif
}
#ifdef TEST
#undef printf
int main(void)
{
uint8_t *buf;
size_t size;
if (av_file_map("file.c", &buf, &size, 0, NULL) < 0)
return 1;
buf[0] = 's';
printf("%s", buf);
av_file_unmap(buf, size);
return 0;
}
#endif
|
