From 542f9183bbc593bec0cfdf121d087e4e073ca155 Mon Sep 17 00:00:00 2001
From: Christina Quast <chrysh.ng+git@gmail.com>
Date: Sat, 11 Apr 2015 09:31:15 +0200
Subject: [PATCH] basic ringbuffer implementation

---
 firmware/src_simtrace/ringbuffer.c | 34 ++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 firmware/src_simtrace/ringbuffer.c

diff --git a/firmware/src_simtrace/ringbuffer.c b/firmware/src_simtrace/ringbuffer.c
new file mode 100644
index 00000000..85e39169
--- /dev/null
+++ b/firmware/src_simtrace/ringbuffer.c
@@ -0,0 +1,34 @@
+typedef struct ringbuf {
+    uint8_t buf[BUFLEN];
+    uint8_t *buf_end;
+    uint8_t *reader;
+    uint8_t *writer;
+} ringbuf;
+
+void rbuf_init(ringbuf *rb)
+{
+    rb->buf_end = buf[BUFLEN-1];
+    rb->buf = {0};
+    rb->reader = rb->buf[0];
+    rb->writer = rb->buf[0];
+}
+
+uint8_t rbuf_read(ringbuf *rb)
+{
+    uint8_t val = *(rb->reader);
+    if (rb->reader == rb->buf_end) {
+        rb->reader = rb->buf;
+    } else{
+        rb->reader++;
+    }
+    return val;
+}
+
+void rbuf_write(ringbuf *rb, uint8_t item) {
+    *(rb->writer) = item;
+    if (rb->writer == rb->buf_end) {
+        rb->writer = rb->buf;
+    } else{
+        rb->writer++;
+    }
+}