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
|
/* ****************************************************************************
* stream/csum32.c -- built-in stream for making a 32-bit checksum.
* Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
*
* This file is part of libcasio.
* libcasio 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 3.0 of the License,
* or (at your option) any later version.
*
* libcasio 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 libcasio; if not, see <http://www.gnu.org/licenses/>.
* ************************************************************************* */
#include "stream.h"
/* ---
* Cookie structure.
* --- */
struct thecookie {
tio_stream_t *_stream;
casio_uint32_t *_checksum;
};
/* ---
* Callbacks.
* --- */
/**
* csum32_read:
* Read from this stream.
*
* @arg cookie the cookie.
* @arg data the data pointer.
* @arg size the data size.
* @arg timeout the timeout.
* @return the error code (0 if ok).
*/
CASIO_LOCAL int csum32_read(struct thecookie *cookie,
unsigned char *dest, size_t count)
{
int err;
/* Make the call. */
err = tio_read(cookie->_stream, dest, count);
if (err) return (err);
/* Make the checksum. */
*cookie->_checksum = casio_checksum32(dest, count, *cookie->_checksum);
return (0);
}
/**
* csum32_close:
* Close the stream.
*
* @arg cookie the cookie.
* @return the error code (0 if ok).
*/
CASIO_LOCAL void csum32_close(struct thecookie *cookie)
{
casio_free(cookie);
}
/* Callbacks. */
CASIO_LOCAL tio_functions_t const csum32_callbacks = {
(tio_close_t *)&csum32_close,
(tio_read_t *)&csum32_read,
NULL, NULL
};
/* ---
* Main functions.
* --- */
/**
* casio_open_csum32:
* Open a 32-bit checksum stream.
*
* @arg stream the stream to make.
* @arg original the original stream.
* @arg csum the checksum pointer.
* @return the error code (0 if ok).
*/
int CASIO_EXPORT casio_open_csum32(tio_stream_t **stream,
tio_stream_t *original, casio_uint32_t *csum)
{
struct thecookie *cookie = NULL;
unsigned int openmode;
if (!tio_isreadable(original))
return (casio_error_op);
/* Allocate the cookie. */
cookie = casio_alloc(1, sizeof(struct thecookie));
if (!cookie)
return (casio_error_alloc);
/* Fill the cookie. */
cookie->_stream = original;
cookie->_checksum = csum;
/* Initialize and return da stream. */
return (casio_tio_error(tio_open(stream, original, cookie,
TIO_OPENFLAG_READ, &csum32_callbacks, 0)));
}
|