Impl UART buffering (still not tested)

1 files changed, 50 insertions, 0 deletions

diff --git a/app/platform/stm32f0-gcc/ring_buffer.h b/app/platform/stm32f0-gcc/ring_buffer.h
new file mode 100644
index 0000000..1a065ef
--- /dev/null
+++ b/app/platform/stm32f0-gcc/ring_buffer.h
@@ -0,0 +1,50 @@
+#pragma once
+#include <cassert>
+#include <cstring>
+
+template <typename T>
+class RingBuffer
+{
+public:
+    using UnitType = T;
+    constexpr explicit RingBuffer(UnitType* buffer, size_t buffer_size)
+        : _buffer_size(buffer_size), _buffer(buffer)
+    {
+        assert(buffer_size);
+        assert(buffer);
+    }
+    constexpr void Push(UnitType item)
+    {
+        _buffer[_head] = item;
+        _head = (_head + 1) % _buffer_size;
+    }
+    constexpr void Push(const UnitType *items, size_t nitems)
+    {
+        if (items) for (; nitems; items++, nitems--) Push(*items);
+    }
+    constexpr UnitType Pop()
+    {
+        const auto item = _buffer[_tail];
+        _tail = (_tail + 1) % _buffer_size;
+        return item;
+    }
+    constexpr void Pop(UnitType* buf, size_t nitems)
+    {
+        if (buf) for (; nitems; nitems--, buf++) *buf = Pop();
+    }
+    constexpr size_t Free()
+    {
+        return Size() - Occupied();
+    }
+    constexpr size_t Occupied()
+    {
+        return _head - _tail + (_head >= _tail) ? 0 : _buffer_size;
+    }
+    constexpr bool IsEmpty() { return _head == _tail; }
+    constexpr bool IsFull() { return _tail + 1 == _head; }
+    constexpr size_t Size() { return _buffer_size - 1; }
+private:
+    size_t _buffer_size{};
+    UnitType *_buffer{};
+    size_t _head{}, _tail{};
+};