1 files changed, 47 insertions, 0 deletions
diff --git a/kernel/collection/include/collection/rbuffer.h b/kernel/collection/include/collection/rbuffer.h
new file mode 100644
index 0000000..dbdd6ee
--- /dev/null
+++ b/kernel/collection/include/collection/rbuffer.h
@@ -0,0 +1,47 @@
+#ifndef RBUFFER_H
+#define RBUFFER_H
+
+#include <stddef.h>
+
+#define EEMPTY -1
+#define EFULL -2
+
+typedef char rbuffer_byte_t;
+
+struct rbuffer_t {
+  rbuffer_byte_t* address;
+  size_t size;
+  size_t head;
+  size_t tail;
+};
+
+#define RBUFFER_INIT(array, length) \
+  { \
+    .address = array, \
+    .size = length, \
+    .head=0, \
+    .tail=0 \
+  }
+
+void rbuffer_init(struct rbuffer_t* rb, rbuffer_byte_t* address, size_t size);
+
+/** Read data from ringbuffer. */
+static inline int rbuffer_read(struct rbuffer_t* const rb, rbuffer_byte_t* const data_out) {
+  if (rb->head == rb->tail) return EEMPTY;
+  *data_out = rb->address[rb->head];
+  rb->head = rb->head + 1;
+  if (rb->head >= rb->size) rb->head=0;
+  return 0;
+}
+
+static inline int rbuffer_write(struct rbuffer_t* const rb, rbuffer_byte_t data_in) {
+  size_t next_tail = rb->tail + 1;
+  if (next_tail >= rb->size) next_tail = 0;  
+  if (rb->head == next_tail) return EFULL;
+  
+  rb->address[rb->tail] = data_in;
+  rb->tail = next_tail;
+  return 0;
+}
+
+#endif