source: SVN/rincon/u-boot/common/circbuf.c @ 55

Last change on this file since 55 was 55, checked in by Tim Harvey, 2 years ago

rincon: added latest u-boot source

restored form server backup

Signed-off-by: Tim Harvey <tharvey@…>

File size: 2.3 KB
Line 
1/*
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}
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