1 | /**
|
---|
2 | * \file
|
---|
3 | * Ring Buffer library
|
---|
4 | */
|
---|
5 |
|
---|
6 | #include "ringbuf.h"
|
---|
7 |
|
---|
8 |
|
---|
9 | /**
|
---|
10 | * \brief init a RINGBUF object
|
---|
11 | * \param r pointer to a RINGBUF object
|
---|
12 | * \param buf pointer to a byte array
|
---|
13 | * \param size size of buf
|
---|
14 | * \return 0 if successfull, otherwise failed
|
---|
15 | */
|
---|
16 | int16_t RINGBUF_Init(RINGBUF *r, uint8_t* buf, int32_t size)
|
---|
17 | {
|
---|
18 | if(r == NULL || buf == NULL || size < 2) return -1;
|
---|
19 |
|
---|
20 | r->p_o = r->p_r = r->p_w = buf;
|
---|
21 | r->fill_cnt = 0;
|
---|
22 | r->size = size;
|
---|
23 |
|
---|
24 | return 0;
|
---|
25 | }
|
---|
26 | /**
|
---|
27 | * \brief put a character into ring buffer
|
---|
28 | * \param r pointer to a ringbuf object
|
---|
29 | * \param c character to be put
|
---|
30 | * \return 0 if successfull, otherwise failed
|
---|
31 | */
|
---|
32 | int16_t RINGBUF_Put(RINGBUF *r, uint8_t c)
|
---|
33 | {
|
---|
34 | if(r->fill_cnt>=r->size)return -1; // ring buffer is full, this should be atomic operation
|
---|
35 |
|
---|
36 |
|
---|
37 | r->fill_cnt++; // increase filled slots count, this should be atomic operation
|
---|
38 |
|
---|
39 |
|
---|
40 | *r->p_w++ = c; // put character into buffer
|
---|
41 |
|
---|
42 | if(r->p_w >= r->p_o + r->size) // rollback if write pointer go pass
|
---|
43 | r->p_w = r->p_o; // the physical boundary
|
---|
44 |
|
---|
45 | return 0;
|
---|
46 | }
|
---|
47 | /**
|
---|
48 | * \brief get a character from ring buffer
|
---|
49 | * \param r pointer to a ringbuf object
|
---|
50 | * \param c read character
|
---|
51 | * \return 0 if successfull, otherwise failed
|
---|
52 | */
|
---|
53 | int16_t RINGBUF_Get(RINGBUF *r, uint8_t* c)
|
---|
54 | {
|
---|
55 | if(r->fill_cnt<=0)return -1; // ring buffer is empty, this should be atomic operation
|
---|
56 |
|
---|
57 |
|
---|
58 | r->fill_cnt--; // decrease filled slots count
|
---|
59 |
|
---|
60 |
|
---|
61 | *c = *r->p_r++; // get the character out
|
---|
62 |
|
---|
63 | if(r->p_r >= r->p_o + r->size) // rollback if write pointer go pass
|
---|
64 | r->p_r = r->p_o; // the physical boundary
|
---|
65 |
|
---|
66 | return 0;
|
---|
67 | }
|
---|