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
|
/* Copyright (C) 1991, 92, 94, 95, 96 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
struct memstream_info
{
char **buffer;
size_t *bufsize;
};
/* Enlarge STREAM's buffer. */
static void
enlarge_buffer (register FILE *stream, int c)
{
struct memstream_info *info = (struct memstream_info *) stream->__cookie;
size_t need;
if (stream->__put_limit != stream->__buffer)
/* Record how much has actually been written into the buffer. */
*info->bufsize = stream->__bufp - stream->__buffer;
if (stream->__target != -1
&& stream->__target > *info->bufsize)
/* Our target (where the buffer maps to) is always zero except when
the user just did a SEEK_END fseek. If he sought within the
buffer, we need do nothing and will zero the target below. If he
sought past the end of the object, grow and zero-fill the buffer
up to the target address. */
need = stream->__target;
else
need = *info->bufsize;
/* We always need an extra character in the buffer. Either we are
writing C, or we are flushing and need to write a NUL terminator. */
++need;
if (stream->__bufsize < need)
{
/* Enlarge the buffer. */
char *newbuf;
size_t newsize;
if (stream->__bufsize * 2 < need)
newsize = need;
else
newsize = stream->__bufsize * 2;
newbuf = (char *) realloc ((void *) stream->__buffer, newsize);
if (newbuf == NULL)
{
stream->__error = 1;
return;
}
*info->buffer = stream->__buffer = newbuf;
stream->__bufsize = newsize;
}
stream->__target = stream->__offset = 0;
stream->__get_limit = stream->__bufp = stream->__buffer + *info->bufsize;
stream->__put_limit = stream->__buffer + stream->__bufsize;
need -= stream->__bufp - stream->__buffer + 1;
if (need > 0)
{
/* We are extending the buffer after an fseek; zero-fill new space. */
memset (stream->__bufp, '\0', need);
stream->__bufp += need;
}
if (c != EOF)
*stream->__bufp++ = (unsigned char) c;
else
*stream->__bufp = '\0';
}
/* Seek function for memstreams.
There is no external state to munge. */
static int
seek (void *cookie, fpos_t *pos, int whence)
{
switch (whence)
{
case SEEK_SET:
case SEEK_CUR:
return 0;
case SEEK_END:
/* Return the position relative to the end of the object.
fseek has just flushed us, so the info is consistent. */
*pos += *((struct memstream_info *) cookie)->bufsize;
return 0;
default:
__libc_fatal ("memstream::seek called with bogus WHENCE\n");
return -1;
}
}
static int
free_info (void *cookie)
{
#if 0
struct memstream_info *info = (struct memstream_info *) cookie;
char *buf;
buf = (char *) realloc ((PTR) *info->buffer, *info->bufsize);
if (buf != NULL)
*info->buffer = buf;
#endif
free (cookie);
return 0;
}
/* Open a stream that writes into a malloc'd buffer that is expanded as
necessary. *BUFLOC and *SIZELOC are updated with the buffer's location
and the number of characters written on fflush or fclose. */
FILE *
open_memstream (bufloc, sizeloc)
char **bufloc;
size_t *sizeloc;
{
FILE *stream;
struct memstream_info *info;
if (bufloc == NULL || sizeloc == NULL)
{
__set_errno (EINVAL);
return NULL;
}
stream = fmemopen ((char *) NULL, BUFSIZ, "w+");
if (stream == NULL)
return NULL;
info = (struct memstream_info *) malloc (sizeof (struct memstream_info));
if (info == NULL)
{
int save = errno;
(void) fclose (stream);
__set_errno (save);
return NULL;
}
stream->__room_funcs.__output = enlarge_buffer;
stream->__io_funcs.__seek = seek;
stream->__io_funcs.__close = free_info;
stream->__cookie = (void *) info;
stream->__userbuf = 1;
info->buffer = bufloc;
info->bufsize = sizeloc;
*bufloc = stream->__buffer;
return stream;
}
|
GitWeb