From 82de9a951b1a43c4abc71425be03877a43063584 Mon Sep 17 00:00:00 2001
From: Leonard Kugis <leonard@kug.is>
Date: Wed, 15 May 2024 19:01:15 +0200
Subject: Added first version

---
 circular_buffer.h | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 circular_buffer.h

(limited to 'circular_buffer.h')

diff --git a/circular_buffer.h b/circular_buffer.h
new file mode 100644
index 0000000..a12bbbc
--- /dev/null
+++ b/circular_buffer.h
@@ -0,0 +1,82 @@
+/*
+ * ------------------------------------------------------------
+ * "THE BEERWARE LICENSE" (Revision 42):
+ * diegohamilton26@gmail.com wrote this code. As long as you retain this 
+ * notice, you can do whatever you want with this stuff. If we
+ * meet someday, and you think this stuff is worth it, you can
+ * buy me a beer in return,
+ * Diego Hamilton.
+ * ------------------------------------------------------------
+ */
+
+#ifndef _CIRCULAR_BUFFER_H
+#define _CIRCULAR_BUFFER_H
+
+#include <stddef.h>
+
+/*
+*   BUF must be a pointer of any buffer with type 'NAME' defined.
+*   ELEM must be a element (NOT A POINTER) of type T defined.
+*/
+
+#define circular_buffer_struct(T, SIZE)    \
+    struct {    \
+        size_t occup;   \
+        size_t size;    \
+        size_t head, tail;  \
+        T data[SIZE];    \
+    }
+
+#define cb_init(BUF, SIZE)  \
+    do {    \
+        (BUF).size = SIZE;   \
+        (BUF).occup = 0;   \
+        (BUF).head = 0;      \
+        (BUF).tail = 0;      \
+    } while(0)
+
+#define cb_size(BUF) ((BUF).size)
+#define cb_full(BUF) ((BUF).occup == (BUF).size)
+#define cb_empty(BUF) ((BUF).occup == 0)
+#define cb_occupation(BUF) ((BUF).occup)
+#define cb_reset(BUF)   \
+    do {    \
+        (BUF).head = 0;  \
+        (BUF).tail = 0;  \
+        (BUF).occup = 0;  \
+    } while(0)
+
+/* TODO: replace occup by calculations w/ head and tail? */
+#define cb_push(BUF, ELEM)  \
+    do {    \
+        ((BUF).data)[(BUF).tail] = (ELEM);   \
+        if ((BUF).tail == cb_size(BUF) - 1) {  \
+            (BUF).tail = 0;    \
+        } else {    \
+            (BUF).tail = ((BUF).tail + 1);    \
+        }   \
+        if (cb_full((BUF))) {   \
+            if ((BUF).head == cb_size(BUF) - 1) {  \
+                (BUF).head = 0;  \
+            } else {    \
+                (BUF).head = ((BUF).head + 1);          \
+            }   \
+        } else {    \
+            (BUF).occup = (BUF).occup + 1; \
+        }   \
+    } while(0)
+
+#define cb_pop(BUF, ELEM)                                   \
+    do {                                                        \
+        if(!cb_empty((BUF))) {                                    \
+            (ELEM) = (BUF).data[(BUF).head];                   \
+            if ((BUF).head == cb_size(BUF) - 1) {  \
+                (BUF).head = 0;  \
+            } else {    \
+                (BUF).head = ((BUF).head + 1);          \
+            }   \
+            (BUF).occup -= 1;                                    \
+        }                                                       \
+    } while(0)
+
+#endif
-- 
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