1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2003
4 * Gerry Hamel, geh@ti.com, Texas Instruments
5 */
6
7 #include <common.h>
8 #include <malloc.h>
9
10 #include <circbuf.h>
11
12
buf_init(circbuf_t * buf,unsigned int size)13 int buf_init (circbuf_t * buf, unsigned int size)
14 {
15 assert (buf != NULL);
16
17 buf->size = 0;
18 buf->totalsize = size;
19 buf->data = (char *) malloc (sizeof (char) * size);
20 assert (buf->data != NULL);
21
22 buf->top = buf->data;
23 buf->tail = buf->data;
24 buf->end = &(buf->data[size]);
25
26 return 1;
27 }
28
buf_free(circbuf_t * buf)29 int buf_free (circbuf_t * buf)
30 {
31 assert (buf != NULL);
32 assert (buf->data != NULL);
33
34 free (buf->data);
35 memset (buf, 0, sizeof (circbuf_t));
36
37 return 1;
38 }
39
buf_pop(circbuf_t * buf,char * dest,unsigned int len)40 int buf_pop (circbuf_t * buf, char *dest, unsigned int len)
41 {
42 unsigned int i;
43 char *p;
44
45 assert (buf != NULL);
46 assert (dest != NULL);
47
48 p = buf->top;
49
50 /* Cap to number of bytes in buffer */
51 if (len > buf->size)
52 len = buf->size;
53
54 for (i = 0; i < len; i++) {
55 dest[i] = *p++;
56 /* Bounds check. */
57 if (p == buf->end) {
58 p = buf->data;
59 }
60 }
61
62 /* Update 'top' pointer */
63 buf->top = p;
64 buf->size -= len;
65
66 return len;
67 }
68
buf_push(circbuf_t * buf,const char * src,unsigned int len)69 int buf_push (circbuf_t * buf, const char *src, unsigned int len)
70 {
71 /* NOTE: this function allows push to overwrite old data. */
72 unsigned int i;
73 char *p;
74
75 assert (buf != NULL);
76 assert (src != NULL);
77
78 p = buf->tail;
79
80 for (i = 0; i < len; i++) {
81 *p++ = src[i];
82 if (p == buf->end) {
83 p = buf->data;
84 }
85 /* Make sure pushing too much data just replaces old data */
86 if (buf->size < buf->totalsize) {
87 buf->size++;
88 } else {
89 buf->top++;
90 if (buf->top == buf->end) {
91 buf->top = buf->data;
92 }
93 }
94 }
95
96 /* Update 'tail' pointer */
97 buf->tail = p;
98
99 return len;
100 }
101