CircularBuffer.h

/*
 CircularBuffer.h - Circular buffer library for Arduino.
 Copyright (c) 2017 Roberto Lo Giacco.  All right reserved.

 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 St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __CIRCULAR_BUFFER__
#define __CIRCULAR_BUFFER__
#include <inttypes.h>

#ifndef CIRCULAR_BUFFER_XS
#define __CB_ST__ uint16_t
#else
#define __CB_ST__ uint8_t
#endif

template<typename T, __CB_ST__ S> class CircularBuffer {
public:

	CircularBuffer();

	~CircularBuffer();

	/**
	 * Adds an element to the beginning of buffer: the operation returns `false` if the addition caused overwriting an existing element.
	 */
	bool unshift(T value);

	/**
	 * Adds an element to the end of buffer: the operation returns `false` if the addition caused overwriting an existing element.
	 */
	bool push(T value);

	/**
	 * Removes an element from the beginning of the buffer.
	 */
	T shift();

	/**
	 * Removes an element from the end of the buffer.
	 */
	T pop();

	/**
	 * Returns the element at the beginning of the buffer.
	 */
	T inline first();

	/**
	 * Returns the element at the end of the buffer.
	 */
	T inline last();

	/**
	 * Array-like access to buffer
	 */
	T operator [] (__CB_ST__ index);

	/**
	 * Returns how many elements are actually stored in the buffer.
	 */
	__CB_ST__ inline size();

	/**
	 * Returns how many elements can be safely pushed into the buffer.
	 */
	__CB_ST__ inline available();

	/**
	 * Returns `true` if no elements can be removed from the buffer.
	 */
	bool inline isEmpty();

	/**
	 * Returns `true` if no elements can be added to the buffer without overwriting existing elements.
	 */
	bool inline isFull();

	/**
	 * Resets the buffer to a clean status, dropping any reference to current elements
	 * and making all buffer positions available again.
	 */
	void inline clear();

private:
	T buffer[S];
	T *head;
	T *tail;
	uint16_t count;
};

#include <CircularBuffer.tpp>
#endif