Revision 0:f6f6750994d2, committed 2019-05-17

Comitter:

ivaariasga

Date:

Fri May 17 13:06:31 2019 +0000

Commit message:

Circular Buffer C implementation, must create an instance of the buffer structure and then allocate memory dinamically for the buffer.

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/circularBuff.cpp	Fri May 17 13:06:31 2019 +0000
@@ -0,0 +1,64 @@
+#include "circularBuff.h"
+
+int circ_buf_rst(circ_buf_t * cbuf) 
+{
+    int r = -1;
+
+    if(cbuf)
+    {
+        cbuf->head = 0;
+        cbuf->tail = 0;
+        r = 0;
+    }
+
+    return r;
+}
+
+bool circ_buf_empty(circ_buf_t cbuf)
+{
+    // We define empty as head == tail
+    return (cbuf.head == cbuf.tail);
+}
+
+bool circ_buf_full(circ_buf_t cbuf)
+{
+    // We determine "full" case by head being one position behind the tail
+    // Note that this means we are wasting one space in the buffer!
+    // Instead, you could have an "empty" flag and determine buffer full that way
+    return ((cbuf.head + 1) % cbuf.size) == cbuf.tail;
+}
+
+int circ_buf_put(circ_buf_t * cbuf, uint8_t data)
+{
+    int r = -1;
+
+    if(cbuf)
+    {
+        cbuf->buffer[cbuf->head] = data;
+        cbuf->head = (cbuf->head + 1) % cbuf->size;
+
+        if(cbuf->head == cbuf->tail)
+        {
+            cbuf->tail = (cbuf->tail + 1) % cbuf->size;
+        }
+
+        r = 0;
+    }
+
+    return r;
+}
+
+int circ_buf_get(circ_buf_t * cbuf, uint8_t * data)
+{
+    int r = -1;
+
+    if(cbuf && data && !circ_buf_empty(*cbuf))
+    {
+        *data = cbuf->buffer[cbuf->tail];
+        cbuf->tail = (cbuf->tail + 1) % cbuf->size;
+
+        r = 0;
+    }
+
+    return r;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/circularBuff.h	Fri May 17 13:06:31 2019 +0000
@@ -0,0 +1,19 @@
+#include "mbed.h"
+
+#ifndef CIRCULARBUFF_H
+#define CIRCULARBUF_H
+
+typedef struct {
+    uint8_t *buffer;
+    size_t head;
+    size_t tail;
+    size_t size; //of the buffer
+} circ_buf_t;
+
+int circ_buf_rst(circ_buf_t * cbuf);
+int circ_buf_put(circ_buf_t * cbuf, uint8_t data);
+int circ_buf_get(circ_buf_t * cbuf, uint8_t * data);
+bool circ_buf_empty(circ_buf_t cbuf);
+bool circ_buf_full(circ_buf_t cbuf);
+
+#endif
\ No newline at end of file