-add queue

- add ping timer
- add subscribe function

ringbuf.c

@@ -0,0 +1,106 @@
+/**
+* \file
+*   Ring Buffer library
+*/
+#include <stdio.h>
+#include <string.h>
+#include "ringbuf.h"
+
+/**
+* \brief init a RINGBUF object
+* \param r pointer to a RINGBUF object
+* \param buf pointer to a byte array
+* \param size size of buf
+* \param block_size is size of data as block
+* \return 0 if successfull, otherwise failed
+*/
+int32_t rb_init(RINGBUF *r, uint8_t* buf, int32_t size, int32_t block_size)
+{
+    if (r == 0 || buf == 0 || size < 2) return -1;
+
+    if (size % block_size != 0) return -1;
+
+    r->p_o = r->p_r = r->p_w = buf;
+    r->fill_cnt = 0;
+    r->size = size;
+    r->block_size = block_size;
+    return 0;
+}
+/**
+* \brief put a character into ring buffer
+* \param r pointer to a ringbuf object
+* \param c character to be put
+* \return 0 if successfull, otherwise failed
+*/
+int32_t rb_put(RINGBUF *r, uint8_t *c)
+{
+    int32_t i;
+    uint8_t *data = c;
+    if (r->fill_cnt >= r->size)
+        return -1; // ring buffer is full, this should be atomic operation
+
+
+    r->fill_cnt += r->block_size;             // increase filled slots count, this should be atomic operation
+
+    for (i = 0; i < r->block_size; i++) {
+        *r->p_w = *data;              // put character into buffer
+
+        r->p_w ++;
+        data ++;
+    }
+
+    if (r->p_w >= r->p_o + r->size)     // rollback if write pointer go pass
+        r->p_w = r->p_o;          // the physical boundary
+
+    return 0;
+}
+/**
+* \brief get a character from ring buffer
+* \param r pointer to a ringbuf object
+* \param c read character
+* \return 0 if successfull, otherwise failed
+*/
+int32_t rb_get(RINGBUF *r, uint8_t *c)
+{
+    int32_t i;
+    uint8_t *data = c;
+    if (r->fill_cnt <= 0)return -1;     // ring buffer is empty, this should be atomic operation
+
+    r->fill_cnt -= r->block_size;              // decrease filled slots count
+
+    for (i = 0; i < r->block_size; i++)
+        *data++ = *r->p_r++;               // get the character out
+
+    if (r->p_r >= r->p_o + r->size)       // rollback if write pointer go pass
+        r->p_r = r->p_o;            // the physical boundary
+
+    return 0;
+}
+
+int32_t rb_available(RINGBUF *r)
+{
+    return (r->size - r->fill_cnt);
+}
+
+uint32_t rb_read(RINGBUF *r, uint8_t *buf, int len)
+{
+    int n = 0;
+    uint8_t data;
+    while (len > 0) {
+        while (rb_get(r, &data) != 0);
+        *buf++ = data;
+        n ++;
+        len --;
+    }
+
+    return n;
+}
+
+uint32_t rb_write(RINGBUF *r, uint8_t *buf, int len)
+{
+    uint32_t wi;
+    for (wi = 0; wi < len; wi++) {
+        while (rb_put(r, &buf[wi]) != 0);
+    }
+    return 0;
+}