replay: add replay module, build for sitl_default, but do not load on startup

This adds a new module that does:
- read an parse an ULog file, given via ENV variable 'replay'
- apply all parameters from the log file
- read and apply user-defined override parameters from a file
- publish all messages in 'real-time' from the log file and add a constant
  offset to the timestamp to match the system time.
- apply changed parameters in the log (which are not overridden)

src/modules/replay/replay.hpp

@@ -0,0 +1,152 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2016 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.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+#include <fstream>
+#include <map>
+#include <vector>
+#include <set>
+#include <string>
+
+#include "definitions.hpp"
+
+#include <uORB/uORBTopics.h>
+
+namespace px4
+{
+
+/**
+ * @class Replay
+ * Parses an ULog file and replays it in 'real-time'. The timestamp of each replayed message is offset
+ * to match the starting time of replay. It keeps a stream for each subscription to find the next message
+ * to replay. This is necessary because data messages from different subscriptions don't need to be in
+ * monotonic increasing order.
+ */
+class Replay
+{
+public:
+	Replay();
+
+	/// Destructor, also waits for task exit
+	~Replay();
+
+	/// Start task.
+	/// @param quiet silently fail if no log file found
+	/// @return		OK on success.
+	static int		start(bool quiet);
+
+	static void	task_main_trampoline(int argc, char *argv[]);
+
+	void		task_main();
+
+	/**
+	 * Tell the replay module that we want to use replay mode.
+	 * After that, only 'replay start' must be executed (typically the last step after startup).
+	 * @param file_name file name of the used log replay file. Will be copied.
+	 */
+	static void setupReplayFile(const char *file_name);
+
+	static bool isSetup() { return _replay_file; }
+private:
+	bool _task_should_exit = false;
+	std::set<std::string> _overridden_params;
+	std::map<std::string, std::string> _file_formats; ///< all formats we read from the file
+
+	uint64_t _file_start_time;
+	uint64_t _replay_start_time;
+	std::streampos _data_section_start; ///< first ADD_LOGGED_MSG message
+	std::vector<uint8_t> _read_buffer;
+
+	struct Subscription {
+
+		const orb_metadata *orb_meta = nullptr; ///< if nullptr, this subscription is invalid
+		orb_advert_t orb_advert = nullptr;
+		uint8_t multi_id;
+		int timestamp_offset; ///< marks the field of the timestamp
+
+		std::streampos next_read_pos;
+		uint64_t next_timestamp; ///< timestamp of the file
+	};
+	std::vector<Subscription> _subscriptions;
+
+	/** keep track of file position to avoid adding a subscription multiple times. */
+	std::streampos _subscription_file_pos = 0;
+
+	bool readFileHeader(std::ifstream &file);
+
+	/**
+	 * Read definitions section: check formats, apply parameters and store
+	 * the start of the data section.
+	 * @return true on success
+	 */
+	bool readFileDefinitions(std::ifstream &file);
+
+	///file parsing methods. They return false, when further parsing should be aborted.
+	bool readFormat(std::ifstream &file, uint16_t msg_size);
+	bool readAndAddSubscription(std::ifstream &file, uint16_t msg_size);
+
+	/**
+	 * Read and handle additional messages starting at current file position, while position < end_position.
+	 * This handles dropout and parameter update messages.
+	 * We need to handle these separately, because they have no timestamp. We look at the file position instead.
+	 * @return false on file error
+	 */
+	bool readAndHandleAdditionalMessages(std::ifstream &file, std::streampos end_position);
+	bool readDropout(std::ifstream &file, uint16_t msg_size);
+	bool readAndApplyParameter(std::ifstream &file, uint16_t msg_size);
+
+	/**
+	 * Find next data message for this subscription, starting with the stored file offset.
+	 * Skip the first message, and if found, read the timestamp and store the new file offset.
+	 * This also takes care of new subscriptions and parameter updates. When reaching EOF,
+	 * the subscription is set to invalid.
+	 * File seek position is arbitrary after this call.
+	 * @return false on file error
+	 */
+	bool nextDataMessage(std::ifstream &file, Subscription &subscription, int msg_id);
+
+	static const orb_metadata *findTopic(const std::string &name);
+	/** get the array size from a type. eg. float[3] -> return float */
+	static std::string extractArraySize(const std::string &type_name_full, int &array_size);
+	/** get the size of a type that is not an array */
+	static size_t sizeOfType(const std::string &type_name);
+	/** get the size of a type that can be an array */
+	static size_t sizeOfFullType(const std::string &type_name_full);
+
+	void setUserParams(const char *filename);
+
+	static char *_replay_file;
+};
+
+} //namespace px4