text: /****************************************************************************
   *
   *   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 "log_writer.h"
  #include "array.h"
  #include <px4.h>
  #include <drivers/drv_hrt.h>
  #include <uORB/Subscription.hpp>
  #include <version/version.h>
  #include <systemlib/git_version.h>
  #include <systemlib/param/param.h>
  
  extern "C" __EXPORT int logger_main(int argc, char *argv[]);
  
  #define TRY_SUBSCRIBE_INTERVAL 1000*1000	// interval in microseconds at which we try to subscribe to a topic
  // if we haven't succeeded before
  
  namespace px4
  {
  namespace logger
  {
  
  struct LoggerSubscription {
  	int fd[ORB_MULTI_MAX_INSTANCES];
  	uint16_t msg_ids[ORB_MULTI_MAX_INSTANCES];
  	uint64_t time_tried_subscribe;	// captures the time at which we checked last time if this instance existed
  	const orb_metadata *metadata = nullptr;
  
  	LoggerSubscription() {}
  
  	LoggerSubscription(int fd_, const orb_metadata *metadata_) :
  		metadata(metadata_)
  	{
  		fd[0] = fd_;
  		time_tried_subscribe = 0;
  
  		for (int i = 1; i < ORB_MULTI_MAX_INSTANCES; i++) {
  			fd[i] = -1;
  		}
  	}
  };
  
  class Logger
  {
  public:
  	Logger(size_t buffer_size, unsigned log_interval, bool log_on_start,
  	       bool log_until_shutdown, bool log_name_timestamp);
  
  	~Logger();
  
  	/**
  	 * Tell the logger that we're in replay mode. This must be called
  	 * before starting the logger.
  	 * @param file_name file name of the used log replay file. Will be copied.
  	 */
  	static void setReplayFile(const char *file_name);
  
  	/**
  	 * Add a topic to be logged. This must be called before start_log()
  	 * (because it does not write an ADD_LOGGED_MSG message).
  	 * @param name topic name
  	 * @param interval limit rate if >0, otherwise log as fast as the topic is updated.
  	 * @return 0 on success
  	 */
  	int add_topic(const char *name, unsigned interval);
  
  	/**
  	 * add a logged topic (called by add_topic() above)
  	 */
  	int add_topic(const orb_metadata *topic);
  
  	static int start(char *const *argv);
  
  	static void usage(const char *reason);
  
  	void status();
  	void print_statistics();
  
  	void set_arm_override(bool override) { _arm_override = override; }
  
  private:
  	static void run_trampoline(int argc, char *argv[]);
  
  	void run();
  
  	/**
  	 * Write an ADD_LOGGED_MSG to the log for a all current subscriptions and instances
  	 */
  	void write_all_add_logged_msg();
  
  	/**
  	 * Write an ADD_LOGGED_MSG to the log for a given subscription and instance.
  	 * _writer.lock() must be held when calling this.
  	 */
  	void write_add_logged_msg(LoggerSubscription &subscription, int instance);
  
  	/**
  	 * Create logging directory
  	 * @param tt if not null, use it for the directory name
  	 * @return 0 on success
  	 */
  	int create_log_dir(tm *tt);
  
  	static bool file_exist(const char *filename);
  
  	/**
  	 * Get log file name with directory (create it if necessary)
  	 */
  	int get_log_file_name(char *file_name, size_t file_name_size);
  
  	/**
  	 * Check if there is enough free space left on the SD Card
  	 * @return 0 on success, 1 if not enough space, <0 on error
  	 */
  	int check_free_space();
  
  	void start_log();
  
  	void stop_log();
  
  	/**
  	 * write the file header with file magic and timestamp.
  	 */
  	void write_header();
  
  	void write_formats();
  
  	void write_version();
  
  	void write_info(const char *name, const char *value);
  	void write_info(const char *name, int32_t value);
  
  	void write_parameters();
  
  	void write_changed_parameters();
  
  	bool copy_if_updated_multi(LoggerSubscription &sub, int multi_instance, void *buffer);
  
  	/**
  	 * Write data to the logger. Waits if buffer is full until all data is written.
  	 * Must be called with _writer.lock() held.
  	 */
  	bool write_wait(void *ptr, size_t size);
  
  	/**
  	 * Write data to the logger and handle dropouts.
  	 * Must be called with _writer.lock() held.
  	 * @return true if data written, false otherwise (on overflow)
  	 */
  	bool write(void *ptr, size_t size);
  
  	/**
  	 * Get the time for log file name
  	 * @param tt returned time
  	 * @param boot_time use time when booted instead of current time
  	 * @return true on success, false otherwise (eg. if no gps)
  	 */
  	bool get_log_time(struct tm *tt, bool boot_time = false);
  
  	/**
  	 * Parse a file containing a list of uORB topics to log, calling add_topic for each
  	 * @param fname name of file
  	 * @return number of topics added
  	 */
  	int add_topics_from_file(const char *fname);
  
  	void add_default_topics();
  
  	static constexpr size_t 	MAX_TOPICS_NUM = 64; /**< Maximum number of logged topics */
  	static constexpr unsigned	MAX_NO_LOGFOLDER = 999;	/**< Maximum number of log dirs */
  	static constexpr unsigned	MAX_NO_LOGFILE = 999;	/**< Maximum number of log files */
  #ifdef __PX4_POSIX_EAGLE
  	static constexpr const char	*LOG_ROOT = PX4_ROOTFSDIR"/log";
  #else
  	static constexpr const char 	*LOG_ROOT = PX4_ROOTFSDIR"/fs/microsd/log";
  #endif
  
  	uint8_t						*_msg_buffer = nullptr;
  	int						_msg_buffer_len = 0;
  	bool						_task_should_exit = true;
  	char 						_log_dir[64];
  	bool						_has_log_dir = false;
  	bool						_enabled = false;
  	bool						_was_armed = false;
  	bool						_arm_override;
  
  
  	// statistics
  	hrt_abstime					_start_time; ///< Time when logging started (not the logger thread)
  	hrt_abstime					_dropout_start = 0; ///< start of current dropout (0 = no dropout)
  	float						_max_dropout_duration = 0.f; ///< max duration of dropout [s]
  	size_t						_write_dropouts = 0; ///< failed buffer writes due to buffer overflow
  	size_t						_high_water = 0; ///< maximum used write buffer
  
  	const bool 					_log_on_start;
  	const bool 					_log_until_shutdown;
  	const bool					_log_name_timestamp;
  	Array<LoggerSubscription, MAX_TOPICS_NUM>	_subscriptions;
  	LogWriter					_writer;
  	uint32_t					_log_interval;
  	param_t						_log_utc_offset;
  	orb_advert_t					_mavlink_log_pub = nullptr;
  	uint16_t					_next_topic_id; ///< id of next subscribed topic
  
  	static char		*_replay_file_name;
  };
  
  } //namespace logger
  } //namespace px4
  