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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
/* Copyright (C) 2004 Manuel Novoa III <mjn3@codepoet.org>
*
* GNU Library General Public License (LGPL) version 2 or later.
*
* Dedicated to Toni. See uClibc/DEDICATION.mjn3 for details.
*/
#include "_stdio.h"
libc_hidden_proto(memcpy)
libc_hidden_proto(fopencookie)
#ifndef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__
#error no custom streams!
#endif
typedef struct {
size_t pos;
size_t len;
size_t eof;
int dynbuf;
unsigned char *buf;
FILE *fp;
} __fmo_cookie;
#define COOKIE ((__fmo_cookie *) cookie)
static ssize_t fmo_read(register void *cookie, char *buf, size_t bufsize)
{
size_t count = COOKIE->len - COOKIE->pos;
/* Note: 0 < bufsize < SSIZE_MAX because of _stdio_READ. */
if (!count) { /* EOF! */
return 0;
}
if (bufsize > count) {
bufsize = count;
}
memcpy(buf, COOKIE->buf + COOKIE->pos, bufsize);
COOKIE->pos += bufsize;
return bufsize;
}
static ssize_t fmo_write(register void *cookie, const char *buf, size_t bufsize)
{
size_t count;
/* Note: bufsize < SSIZE_MAX because of _stdio_WRITE. */
/* If appending, need to seek to end of file!!!! */
if (COOKIE->fp->__modeflags & __FLAG_APPEND) {
COOKIE->pos = COOKIE->eof;
}
count = COOKIE->len - COOKIE->pos;
if (bufsize > count) {
bufsize = count;
if (count == 0) { /* We're at the end of the buffer... */
__set_errno(EFBIG);
return -1;
}
}
memcpy(COOKIE->buf + COOKIE->pos, buf, bufsize);
COOKIE->pos += bufsize;
if (COOKIE->pos > COOKIE->eof) {
COOKIE->eof = COOKIE->pos;
if (bufsize < count) { /* New eof and still room in buffer? */
*(COOKIE->buf + COOKIE->pos) = 0;
}
}
return bufsize;
}
/* glibc doesn't allow seeking, but it has in-buffer seeks... we don't. */
static int fmo_seek(register void *cookie, __offmax_t *pos, int whence)
{
__offmax_t p = *pos;
/* Note: fseek already checks that whence is legal, so don't check here
* unless debugging. */
assert(((unsigned int) whence) <= 2);
if (whence != SEEK_SET) {
p += (whence == SEEK_CUR) ? COOKIE->pos : /* SEEK_END */ COOKIE->eof;
}
/* Note: glibc only allows seeking in the buffer. We'll actually restrict
* to the data. */
/* Check for offset < 0, offset > eof, or offset overflow... */
if (((uintmax_t) p) > COOKIE->eof) {
return -1;
}
COOKIE->pos = *pos = p;
return 0;
}
static int fmo_close(register void *cookie)
{
if (COOKIE->dynbuf) {
free(COOKIE->buf);
}
free(cookie);
return 0;
}
#undef COOKIE
static const cookie_io_functions_t _fmo_io_funcs = {
fmo_read, fmo_write, fmo_seek, fmo_close
};
/* TODO: If we have buffers enabled, it might be worthwile to add a pointer
* to the FILE in the cookie and have read, write, and seek operate directly
* on the buffer itself (ie replace the FILE buffer with the cookie buffer
* and update FILE bufstart, etc. whenever we seek). */
FILE *fmemopen(void *s, size_t len, const char *modes)
{
FILE *fp;
register __fmo_cookie *cookie;
size_t i;
if ((cookie = malloc(sizeof(__fmo_cookie))) != NULL) {
cookie->len = len;
cookie->eof = cookie->pos = 0; /* pos and eof adjusted below. */
cookie->dynbuf = 0;
if (((cookie->buf = s) == NULL) && (len > 0)) {
if ((cookie->buf = malloc(len)) == NULL) {
goto EXIT_cookie;
}
cookie->dynbuf = 1;
*cookie->buf = 0; /* If we're appending, treat as empty file. */
}
#ifndef __BCC__
fp = fopencookie(cookie, modes, _fmo_io_funcs);
#else
fp = fopencookie(cookie, modes, &_fmo_io_funcs);
#endif
/* Note: We don't need to worry about locking fp in the thread case
* as the only possible access would be a close or flush with
* nothing currently in the FILE's write buffer. */
if (fp != NULL) {
cookie->fp = fp;
if (fp->__modeflags & __FLAG_READONLY) {
cookie->eof = len;
}
if ((fp->__modeflags & __FLAG_APPEND) && (len > 0)) {
for (i = 0 ; i < len ; i++) {
if (cookie->buf[i] == 0) {
break;
}
}
cookie->eof = cookie->pos = i; /* Adjust eof and pos. */
}
__STDIO_STREAM_VALIDATE(fp);
return fp;
}
}
if (!s) {
free(cookie->buf);
}
EXIT_cookie:
free(cookie);
return NULL;
}
|
