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
|
/* io.c -- Code for file and memory I/O.
Copyright (C) 2017 Jakob Tsar-Fox, All Rights Reserved.
This file is part of Nekopack.
Nekopack is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
Nekopack 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with Nekopack. If not, see <http://www.gnu.org/licenses/>. */
#include <stdint.h>
#include <string.h>
#include "io.h"
/* Allocates `len` bytes of memory and returns a new stream pointing to
it. The memory provided has not zeroed. */
struct stream *stream_new(size_t len) {
stream *new = malloc(sizeof(stream));
new->len = len;
new->_start = malloc(len);
new->_cur = new->_start;
new->_location = HEAP;
}
/* Called to free or unmap the memory chunk associated with the given
stream, as well as the stream structure itself. */
void stream_free(struct stream *s) {
switch (s->_loc) {
case HEAP:
free(s->_start);
}
free(s);
}
/* Copies `n` bytes from the given stream into the memory area specified
by `dest`. The stream is advanced appropriately. */
void stream_read(void *dest, struct stream *s, size_t n) {
memcpy(dest, s->_cur, n);
(char *) s->_cur += n;
}
/* Copies `n` bytes into the given stream from the memory area specified
by `src`. The stream is advanced appropriately. */
void stream_write(struct stream *s, void *src, size_t n) {
if (s->cur + n > s->start + s->len) {
ptrdiff_t dist = (uintptr_t) s->_cur - (uintptr_t) s->_start;
switch(s->_loc) {
case HEAP:
s->_start = realloc(s->_start, s->len * 2);
s->_cur = s->_start + dist;
}
}
memcpy(s->cur, src, n);
s->cur += n;
}
|
