Providing templated circular buffer with size configurable at run-time (heavily borrowed from api::RingBufferN

Author: aentinger

src/threading/CircularBuffer.hpp

@@ -0,0 +1,118 @@
+/*
+ * This file is part of the Arduino_ThreadsafeIO library.
+ * Copyright (c) 2021 Arduino SA.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef ARDUINO_THREADS_RINGBUFFER_HPP_
+#define ARDUINO_THREADS_RINGBUFFER_HPP_
+
+/**************************************************************************************
+ * INCLUDE
+ **************************************************************************************/
+
+#include <SharedPtr.h>
+
+/**************************************************************************************
+ * CLASS DECLARATION
+ **************************************************************************************/
+
+template <typename T>
+class CircularBuffer
+{
+public:
+
+  CircularBuffer(size_t const size);
+
+  void store(T const data);
+  T read();
+  bool isFull() const;
+  bool isEmpty() const;
+
+
+private:
+
+  mbed::SharedPtr<T> _data;
+  size_t const _size;
+  size_t _head, _tail, _num_elems;
+
+  size_t next(size_t const idx);
+};
+
+/**************************************************************************************
+ * CTOR/DTOR
+ **************************************************************************************/
+
+template <typename T>
+CircularBuffer<T>::CircularBuffer(size_t const size)
+: _data{new T[size]}
+, _size{size}
+, _head{0}
+, _tail{0}
+, _num_elems{0}
+{
+}
+
+/**************************************************************************************
+ * PUBLIC MEMBER FUNCTIONS
+ **************************************************************************************/
+
+template <typename T>
+void CircularBuffer<T>::store(T const data)
+{
+  if (!isFull())
+  {
+    _data.get()[_head] = data;
+    _head = next(_head);
+    _num_elems++;
+  }
+}
+
+template <typename T>
+T CircularBuffer<T>::read()
+{
+  if (isEmpty())
+    return T{0};
+
+  T const value = _data.get()[_tail];
+  _tail = next(_tail);
+  _num_elems--;
+
+  return value;
+}
+
+template <typename T>
+bool CircularBuffer<T>::isFull() const
+{
+  return (_num_elems == _size);
+}
+
+template <typename T>
+bool CircularBuffer<T>::isEmpty() const
+{
+  return (_num_elems == 0);
+}
+
+/**************************************************************************************
+ * PRIVATE MEMBER FUNCTIONS
+ **************************************************************************************/
+
+template <typename T>
+size_t CircularBuffer<T>::next(size_t const idx)
+{
+  return ((idx + 1) % _size);
+}
+
+#endif /* ARDUINO_THREADS_RINGBUFFER_HPP_ */