1 /* Copyright (C) 2010-2018 The RetroArch team
2 *
3 * ---------------------------------------------------------------------------------------
4 * The following license statement only applies to this file (fifo_queue.c).
5 * ---------------------------------------------------------------------------------------
6 *
7 * Permission is hereby granted, free of charge,
8 * to any person obtaining a copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation the rights to
10 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
11 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
16 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
19 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21 */
22
23 #include <stdlib.h>
24 #include <string.h>
25
26 #include <queues/fifo_queue.h>
27
fifo_new(size_t size)28 fifo_buffer_t *fifo_new(size_t size)
29 {
30 uint8_t *buffer = NULL;
31 fifo_buffer_t *buf = (fifo_buffer_t*)calloc(1, sizeof(*buf));
32
33 if (!buf)
34 return NULL;
35
36 buffer = (uint8_t*)calloc(1, size + 1);
37
38 if (!buffer)
39 {
40 free(buf);
41 return NULL;
42 }
43
44 buf->buffer = buffer;
45 buf->size = size + 1;
46
47 return buf;
48 }
49
fifo_write(fifo_buffer_t * buffer,const void * in_buf,size_t size)50 void fifo_write(fifo_buffer_t *buffer, const void *in_buf, size_t size)
51 {
52 size_t first_write = size;
53 size_t rest_write = 0;
54
55 if (buffer->end + size > buffer->size)
56 {
57 first_write = buffer->size - buffer->end;
58 rest_write = size - first_write;
59 }
60
61 memcpy(buffer->buffer + buffer->end, in_buf, first_write);
62 memcpy(buffer->buffer, (const uint8_t*)in_buf + first_write, rest_write);
63
64 buffer->end = (buffer->end + size) % buffer->size;
65 }
66
fifo_read(fifo_buffer_t * buffer,void * in_buf,size_t size)67 void fifo_read(fifo_buffer_t *buffer, void *in_buf, size_t size)
68 {
69 size_t first_read = size;
70 size_t rest_read = 0;
71
72 if (buffer->first + size > buffer->size)
73 {
74 first_read = buffer->size - buffer->first;
75 rest_read = size - first_read;
76 }
77
78 memcpy(in_buf, (const uint8_t*)buffer->buffer + buffer->first, first_read);
79 memcpy((uint8_t*)in_buf + first_read, buffer->buffer, rest_read);
80
81 buffer->first = (buffer->first + size) % buffer->size;
82 }
83