ekf2: move EKF out of ecl

src/modules/ekf2/EKF/RingBuffer.h

@@ -0,0 +1,166 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2015 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file RingBuffer.h
+ * @author Roman Bapst <bapstroman@gmail.com>
+ * Template RingBuffer.
+ */
+
+#include <inttypes.h>
+#include <cstdio>
+#include <cstring>
+
+template <typename data_type>
+class RingBuffer
+{
+public:
+	explicit RingBuffer(size_t size) { allocate(size); }
+	RingBuffer() { allocate(1); }
+	~RingBuffer() { delete[] _buffer; }
+
+	// no copy, assignment, move, move assignment
+	RingBuffer(const RingBuffer &) = delete;
+	RingBuffer &operator=(const RingBuffer &) = delete;
+	RingBuffer(RingBuffer &&) = delete;
+	RingBuffer &operator=(RingBuffer &&) = delete;
+
+	bool allocate(uint8_t size)
+	{
+		if (valid() && (size == _size)) {
+			// no change
+			return true;
+		}
+
+		if (size == 0) {
+			return false;
+		}
+
+		if (_buffer != nullptr) {
+			delete[] _buffer;
+		}
+
+		_buffer = new data_type[size] {};
+
+		if (_buffer == nullptr) {
+			return false;
+		}
+
+		_size = size;
+
+		_head = 0;
+		_tail = 0;
+
+		_first_write = true;
+
+		return true;
+	}
+
+	bool valid() const { return (_buffer != nullptr) && (_size > 0); }
+
+	void push(const data_type &sample)
+	{
+		uint8_t head_new = _head;
+
+		if (!_first_write) {
+			head_new = (_head + 1) % _size;
+		}
+
+		_buffer[head_new] = sample;
+		_head = head_new;
+
+		// move tail if we overwrite it
+		if (_head == _tail && !_first_write) {
+			_tail = (_tail + 1) % _size;
+
+		} else {
+			_first_write = false;
+		}
+	}
+
+	uint8_t get_length() const { return _size; }
+
+	data_type &operator[](const uint8_t index) { return _buffer[index]; }
+
+	const data_type &get_newest() const { return _buffer[_head]; }
+	const data_type &get_oldest() const { return _buffer[_tail]; }
+
+	uint8_t get_oldest_index() const { return _tail; }
+
+	bool pop_first_older_than(const uint64_t &timestamp, data_type *sample)
+	{
+		// start looking from newest observation data
+		for (uint8_t i = 0; i < _size; i++) {
+			int index = (_head - i);
+			index = index < 0 ? _size + index : index;
+
+			if (timestamp >= _buffer[index].time_us && timestamp < _buffer[index].time_us + (uint64_t)1e5) {
+				*sample = _buffer[index];
+
+				// Now we can set the tail to the item which
+				// comes after the one we removed since we don't
+				// want to have any older data in the buffer
+				if (index == _head) {
+					_tail = _head;
+					_first_write = true;
+
+				} else {
+					_tail = (index + 1) % _size;
+				}
+
+				_buffer[index].time_us = 0;
+
+				return true;
+			}
+
+			if (index == _tail) {
+				// we have reached the tail and haven't got a
+				// match
+				return false;
+			}
+		}
+
+		return false;
+	}
+
+	int get_total_size() const { return sizeof(*this) + sizeof(data_type) * _size; }
+
+private:
+	data_type *_buffer{nullptr};
+
+	uint8_t _head{0};
+	uint8_t _tail{0};
+	uint8_t _size{0};
+
+	bool _first_write{true};
+};