File.h

/**
 * \file File.h
 * \author Lukas Hutak <xhutak01@stud.fit.vutbr.cz>
 * \brief File output (header file)
 *
 * Copyright (C) 2015 CESNET, z.s.p.o.
 *
 * 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 of the Company nor the names of its contributors
 *    may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * ALTERNATIVELY, provided that this notice is retained in full, this
 * product may be distributed under the terms of the GNU General Public
 * License (GPL) version 2 or later, in which case the provisions
 * of the GPL apply INSTEAD OF those given above.
 *
 * This software is provided ``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 company 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.
 *
 */

#ifndef FILE_H
#define FILE_H

#include "json.h"

#include <string>
#include <ctime>
#include <cstdio>

#include <pthread.h>

/**
 * \brief The class for file output interface
 */
class File : public Output {
public:
	// Constructor & destructor
	File(const pugi::xpath_node &config);
	~File();

	// Store a record to the file
	void ProcessDataRecord(const std::string &record);

	// Get a directory path for a time window
	static int dir_name(const time_t &tm, const std::string &tmplt,
		std::string &dir);
	// Create a directory for a time window
	static int dir_create(const std::string &path);
	// Create a file for a time window
	static FILE *file_create(const std::string &tmplt, const std::string &prefix,
				const time_t &tm);
private:
	/** Minimal window size */
	const unsigned int _WINDOW_MIN_SIZE = 60; // seconds

	/** Configuration of a thread */
	typedef struct thread_ctx_s {
		pthread_t thread;            /**< Thread                     */
		pthread_mutex_t mutex;       /**< Data mutex                 */
		bool stop;                   /**< Stop flag for temination   */

		unsigned int window_size;    /**< Size of a time window      */
		time_t window_time;          /**< Current time window        */
		std::string storage_path;    /**< Storage path (template)    */
		std::string file_prefix;     /**< File prefix                */

		FILE *new_file;              /**< New file                   */
		bool new_file_ready;         /**< New file flag              */
	} thread_ctx_t;

	/** File descritor */
	FILE *_file;
	/** Thread for changing time windows */
	thread_ctx_t *_thread;

	// Window changer
	static void *thread_window(void *context);
};

#endif // FILE_H