1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * (C) Copyright 2003
4 * Gerry Hamel, geh@ti.com, Texas Instruments
5 */
6
7#include <log.h>
8#include <malloc.h>
9
10#include <circbuf.h>
11
12
13int 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
29int 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
40int 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
69int 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