blob: d3f013c63e42779b9bd520d99b71a5d2c787a543 (
plain)
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
|
/*
* Copyright © 2016-2017 The TokTok team.
* Copyright © 2013 Tox project.
* Copyright © 2013 plutooo
*
* This file is part of Tox, the free peer to peer instant messenger.
* This file is donated to the Tox Project.
*
* Tox 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.
*
* Tox 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 Tox. If not, see <http://www.gnu.org/licenses/>.
*/
#include "ring_buffer.h"
#include "../toxcore/ccompat.h"
#include <stdlib.h>
struct RingBuffer {
uint16_t size; /* Max size */
uint16_t start;
uint16_t end;
void **data;
};
bool rb_full(const RingBuffer *b)
{
return (b->end + 1) % b->size == b->start;
}
bool rb_empty(const RingBuffer *b)
{
return b->end == b->start;
}
/*
* returns: NULL on success
* input value "p" on FAILURE -> caller can free on failed rb_write
*/
void *rb_write(RingBuffer *b, void *p)
{
void *rc = nullptr;
if ((b->end + 1) % b->size == b->start) { /* full */
rc = b->data[b->start];
}
b->data[b->end] = p;
b->end = (b->end + 1) % b->size;
if (b->end == b->start) {
b->start = (b->start + 1) % b->size;
}
return rc;
}
bool rb_read(RingBuffer *b, void **p)
{
if (b->end == b->start) { /* Empty */
*p = nullptr;
return false;
}
*p = b->data[b->start];
b->start = (b->start + 1) % b->size;
return true;
}
RingBuffer *rb_new(int size)
{
RingBuffer *buf = (RingBuffer *)calloc(sizeof(RingBuffer), 1);
if (!buf) {
return nullptr;
}
buf->size = size + 1; /* include empty elem */
if (!(buf->data = (void **)calloc(buf->size, sizeof(void *)))) {
free(buf);
return nullptr;
}
return buf;
}
void rb_kill(RingBuffer *b)
{
if (b) {
free(b->data);
free(b);
}
}
uint16_t rb_size(const RingBuffer *b)
{
if (rb_empty(b)) {
return 0;
}
return
b->end > b->start ?
b->end - b->start :
(b->size - b->start) + b->end;
}
uint16_t rb_data(const RingBuffer *b, void **dest)
{
uint16_t i = 0;
for (; i < rb_size(b); i++) {
dest[i] = b->data[(b->start + i) % b->size];
}
return i;
}
|
