From 729f2a2c3ebfb2612d873caf453a1d7ca02180d9 Mon Sep 17 00:00:00 2001
From: dmlunar <root@lunar.sh>
Date: Wed, 22 Jan 2025 16:47:21 +0200
Subject: varpa: initial public commit

---
 firmware/src/peripheral/ring.c | 115 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 firmware/src/peripheral/ring.c

(limited to 'firmware/src/peripheral/ring.c')

diff --git a/firmware/src/peripheral/ring.c b/firmware/src/peripheral/ring.c
new file mode 100644
index 0000000..eacb654
--- /dev/null
+++ b/firmware/src/peripheral/ring.c
@@ -0,0 +1,115 @@
+/**
+ * 
+ * Author: Dylan Muller
+ * Copyright (c) 2025 
+ * All rights reserved.
+ * 
+ * - Commercial/IP use prohibited.
+ * - Attribution required.
+ * See License.txt
+ *
+ */
+
+#include "peripheral/ring.h"
+
+#define RING_INC_ROLL_OVER(n, s, e) (((n)+1>=(e)) ? (s) : (n)+1)
+
+ring_t ring_init(
+    uint8_t *buf, 
+    size_t len
+)
+{
+    return RING_INIT(buf, len);
+}
+
+bool ring_is_empty(
+    ring_t ring
+)
+{
+    return ring.read == ring.write;
+}
+
+bool ring_is_full(
+    ring_t ring
+)
+{
+    return RING_INC_ROLL_OVER(ring.write, ring.buf, ring.end) == ring.read;
+}
+
+size_t ring_push_available(
+    ring_t ring
+)
+{
+    if(ring.write < ring.read)
+        return ring.read - ring.write - 1;
+    else
+        return (ring.end - ring.buf) - (ring.write - ring.read) - 1;
+}
+
+size_t ring_pop_available(
+    ring_t ring
+)
+{
+    if(ring.read <= ring.write)
+        return ring.write - ring.read;
+    else
+        return (ring.end - ring.buf) - (ring.read - ring.write);
+}
+
+bool ring_push(
+    ring_t *ring,
+    uint8_t data
+)
+{
+    if(ring_is_full(*ring))
+        return 1;
+    
+    *ring->write = data;
+    ring->write = RING_INC_ROLL_OVER(ring->write, ring->buf, ring->end);
+    
+    return 0;
+}
+
+bool ring_push_over(
+    ring_t *ring,
+    uint8_t data
+)
+{
+    *ring->write = data;
+    ring->write = RING_INC_ROLL_OVER(ring->write, ring->buf, ring->end);
+    
+    if(ring->read == ring->write)
+    {
+        ring->read = RING_INC_ROLL_OVER(ring->read, ring->buf, ring->end);
+        return 1;
+    }
+    
+    return 0;
+}
+
+bool ring_pop(
+    ring_t *ring,
+    uint8_t *data
+)
+{
+    if(ring_is_empty(*ring))
+        return 1;
+    
+    *data = *ring->read;
+    ring->read = RING_INC_ROLL_OVER(ring->read, ring->buf, ring->end);
+    
+    return 0;
+}
+
+bool ring_peek(
+    ring_t *ring,
+    uint8_t *data
+)
+{
+    if(ring_is_empty(*ring))
+        return 1;
+    
+    *data = *ring->read;
+    
+    return 0;
+}
-- 
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