blob: 2332c63717d898488d74ba5056d36c79970404a3 [file] [log] [blame]
wdenk232c1502004-03-12 00:14:09 +00001/*
2 * (C) Copyright 2003
3 * Gerry Hamel, geh@ti.com, Texas Instruments
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 */
20
21#include <common.h>
22#include <malloc.h>
23
24#include <circbuf.h>
25
26
27int buf_init (circbuf_t * buf, unsigned int size)
28{
29 assert (buf != NULL);
30
31 buf->size = 0;
32 buf->totalsize = size;
33 buf->data = (char *) malloc (sizeof (char) * size);
34 assert (buf->data != NULL);
35
36 buf->top = buf->data;
37 buf->tail = buf->data;
38 buf->end = &(buf->data[size]);
39
40 return 1;
41}
42
43int buf_free (circbuf_t * buf)
44{
45 assert (buf != NULL);
46 assert (buf->data != NULL);
47
48 free (buf->data);
49 memset (buf, 0, sizeof (circbuf_t));
50
51 return 1;
52}
53
54int buf_pop (circbuf_t * buf, char *dest, unsigned int len)
55{
56 unsigned int i;
57 char *p = buf->top;
58
59 assert (buf != NULL);
60 assert (dest != NULL);
61
62 /* Cap to number of bytes in buffer */
63 if (len > buf->size)
64 len = buf->size;
65
66 for (i = 0; i < len; i++) {
67 dest[i] = *p++;
68 /* Bounds check. */
69 if (p == buf->end) {
70 p = buf->data;
71 }
72 }
73
74 /* Update 'top' pointer */
75 buf->top = p;
76 buf->size -= len;
77
78 return len;
79}
80
81int buf_push (circbuf_t * buf, const char *src, unsigned int len)
82{
83 /* NOTE: this function allows push to overwrite old data. */
84 unsigned int i;
85 char *p = buf->tail;
86
87 assert (buf != NULL);
88 assert (src != NULL);
89
90 for (i = 0; i < len; i++) {
91 *p++ = src[i];
92 if (p == buf->end) {
93 p = buf->data;
94 }
95 /* Make sure pushing too much data just replaces old data */
96 if (buf->size < buf->totalsize) {
97 buf->size++;
98 } else {
99 buf->top++;
100 if (buf->top == buf->end) {
101 buf->top = buf->data;
102 }
103 }
104 }
105
106 /* Update 'tail' pointer */
107 buf->tail = p;
108
109 return len;
110}