diff --git a/README.md b/README.md
index a5ff2ac..5ba23d7 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ The goal is to develop and test a distributed messaging application based on an
## Prerequisites
-This project was developed for execution on Raspberry Pi Zero W. The rabian image used during development and testing can be found in the repository [`./rasbian_image/`]() directory. Installation directions can be found in Raspberry's website [here](https://www.raspberrypi.org/documentation/installation/installing-images/linux.md).
+This project was developed for execution on Raspberry Pi Zero W. The rabian image used during development and testing can be found in the repository [`./rasbian_image/`](https://gitlab.com/apostolof-ece-auth-gr/authRTESFinalAssignment/tree/master/rasbian_image) directory. Installation directions can be found in Raspberry's website [here](https://www.raspberrypi.org/documentation/installation/installing-images/linux.md).
There are two ways of connecting to the system. By connecting to the port denoted "USB", a new network interface will appear, Raspberry's IP is 192.168.0.1/24 in that network, so you need to configure a static IP for your PC in the range 192.168.0.[2-254].
@@ -68,7 +68,7 @@ Reach out to me:
## License
-[](https://gitlab.com/apostolof-ece-auth-gr/authRTESTask1/blob/master/LICENSE.md)
+[](https://gitlab.com/apostolof-ece-auth-gr/authRTESFinalAssignment/blob/master/LICENSE.md)
---
-In Mesopotamian mythology, Zaqar is the messenger of the god Sin. He relays these messages to mortals through his power over their dreams and nightmares.
\ No newline at end of file
+In Mesopotamian mythology, Zaqar is the messenger of the god Sin. He relays these messages to mortals through his power over their dreams and nightmares.
\ No newline at end of file
diff --git a/lib/circ_buff.c b/lib/circ_buff.c
new file mode 100644
index 0000000..66a055c
--- /dev/null
+++ b/lib/circ_buff.c
@@ -0,0 +1,126 @@
+#include
+#include
+#include
+#include
+#include
+
+#include "circ_buff.h"
+
+// Defines the circular buffer structure
+struct circ_buf_t {
+ char** buffer;
+ size_t head;
+ size_t tail;
+ size_t max; // of the buffer
+ bool full;
+};
+
+// Private Functions
+
+static void advance_pointer(cbuf_handle_t cbuf) {
+ assert(cbuf);
+
+ if(cbuf->full) {
+ cbuf->tail = (cbuf->tail + 1) % cbuf->max;
+ }
+
+ cbuf->head = (cbuf->head + 1) % cbuf->max;
+
+ // We mark full because we will advance tail on the next time around
+ cbuf->full = (cbuf->head == cbuf->tail);
+}
+
+static void retreat_pointer(cbuf_handle_t cbuf) {
+ assert(cbuf);
+
+ cbuf->full = false;
+ cbuf->tail = (cbuf->tail + 1) % cbuf->max;
+}
+
+// APIs
+
+cbuf_handle_t circ_buf_init(char** buffer, size_t size) {
+ assert(buffer && size);
+
+ cbuf_handle_t cbuf = malloc(sizeof(circ_buf_t));
+ assert(cbuf);
+
+ cbuf->buffer = buffer;
+ cbuf->max = size;
+ circ_buf_reset(cbuf);
+
+ assert(circ_buf_empty(cbuf));
+
+ return cbuf;
+}
+
+void circ_buf_free(cbuf_handle_t cbuf) {
+ assert(cbuf);
+ free(cbuf);
+}
+
+void circ_buf_reset(cbuf_handle_t cbuf) {
+ assert(cbuf);
+
+ cbuf->head = 0;
+ cbuf->tail = 0;
+ cbuf->full = false;
+}
+
+size_t circ_buf_size(cbuf_handle_t cbuf) {
+ assert(cbuf);
+
+ size_t size = cbuf->max;
+
+ if(!cbuf->full) {
+ if(cbuf->head >= cbuf->tail) {
+ size = (cbuf->head - cbuf->tail);
+ }
+ else {
+ size = (cbuf->max + cbuf->head - cbuf->tail);
+ }
+ }
+
+ return size;
+}
+
+size_t circ_buf_capacity(cbuf_handle_t cbuf) {
+ assert(cbuf);
+
+ return cbuf->max;
+}
+
+void circ_buf_put(cbuf_handle_t cbuf, char data) {
+ assert(cbuf && cbuf->buffer);
+
+ strcpy(cbuf->buffer[cbuf->head], data);
+
+ advance_pointer(cbuf);
+}
+
+int circ_buf_get(cbuf_handle_t cbuf, char* data) {
+ assert(cbuf && data && cbuf->buffer);
+
+ int r = -1;
+
+ if(!circ_buf_empty(cbuf)) {
+ strcpy(data, cbuf->buffer[cbuf->tail]);
+ retreat_pointer(cbuf);
+
+ r = 0;
+ }
+
+ return r;
+}
+
+bool circ_buf_empty(cbuf_handle_t cbuf) {
+ assert(cbuf);
+
+ return (!cbuf->full && (cbuf->head == cbuf->tail));
+}
+
+bool circ_buf_full(cbuf_handle_t cbuf) {
+ assert(cbuf);
+
+ return cbuf->full;
+}
diff --git a/lib/circ_buff.h b/lib/circ_buff.h
new file mode 100644
index 0000000..b0f8a1f
--- /dev/null
+++ b/lib/circ_buff.h
@@ -0,0 +1,44 @@
+/*
+ * Implementation of a simple circular buffer data structure.
+ * Based on the example and guide found here:
+ * https://embeddedartistry.com/blog/2017/4/6/circular-buffers-in-cc
+*/
+#ifndef CIRC_BUFF_H_
+#define CIRC_BUFF_H_
+
+#include
+
+// Circular buffer structure
+typedef struct circ_buf_t circ_buf_t;
+// and handle type
+typedef circ_buf_t* cbuf_handle_t;
+
+// Initializes a circular buffer structure and returns the circular buffer handle.
+// Pass in a storage buffer and size.
+cbuf_handle_t circ_buf_init(char** buffer, size_t size);
+
+// Frees a circular buffer structure. Does not free data buffer!
+void circ_buf_free(cbuf_handle_t cbuf);
+
+// Resets the circular buffer to empty, head == tail. Data not cleared!
+void circ_buf_reset(cbuf_handle_t cbuf);
+
+// Adds data, even if the buffer is full. Old data is overwritten.
+void circ_buf_put(cbuf_handle_t cbuf, char data);
+
+// Retrieves a value from the buffer.
+int circ_buf_get(cbuf_handle_t cbuf, char* data);
+
+// Checks if the buffer is empty.
+bool circ_buf_empty(cbuf_handle_t cbuf);
+
+// Checks if the buffer is full.
+bool circ_buf_full(cbuf_handle_t cbuf);
+
+// Checks the capacity of the buffer.
+size_t circ_buf_capacity(cbuf_handle_t cbuf);
+
+// Checks the number of elements stored in the buffer.
+size_t circ_buf_size(cbuf_handle_t cbuf);
+
+#endif //CIRC_BUFF_H_