VILLASnode/include/villas/nodes/file.hpp

/** Node type: File
 *
 * @file
 * @author Steffen Vogel <post@steffenvogel.de>
 * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
 * @license Apache 2.0
 *********************************************************************************/

#pragma once

#include <cstdio>

#include <villas/format.hpp>
#include <villas/task.hpp>

namespace villas {
namespace node {

/* Forward declarations */
class NodeCompat;

#define FILE_MAX_PATHLEN	512

struct file {
	Format *formatter;
	FILE *stream_in;
	FILE *stream_out;

	char *uri_tmpl;			/**< Format string for file name. */
	char *uri;			/**< Real file name. */

	unsigned skip_lines;		/**< Skip the first n-th lines/samples of the file. */
	int flush;			/**< Flush / upload file contents after each write. */
	struct Task task;		/**< Timer file descriptor. Blocks until 1 / rate seconds are elapsed. */
	double rate;			/**< The read rate. */
	size_t buffer_size_out;		/**< Defines size of output stream buffer. No buffer is created if value is set to zero. */
	size_t buffer_size_in;		/**< Defines size of input stream buffer. No buffer is created if value is set to zero. */

	enum class EpochMode {
		DIRECT,
		WAIT,
		RELATIVE,
		ABSOLUTE,
		ORIGINAL
	} epoch_mode;			/**< Specifies how file::offset is calculated. */

	enum class EOFBehaviour {
		STOP,			/**< Terminate when EOF is reached. */
		REWIND,			/**< Rewind the file when EOF is reached. */
		SUSPEND			/**< Blocking wait when EOF is reached. */
	} eof_mode;

	struct timespec first;		/**< The first timestamp in the file file::{read,write}::uri */
	struct timespec epoch;		/**< The epoch timestamp from the configuration. */
	struct timespec offset;		/**< An offset between the timestamp in the input file and the current time */
};

char * file_print(NodeCompat *n);

int file_parse(NodeCompat *n, json_t *json);

int file_start(NodeCompat *n);

int file_stop(NodeCompat *n);

int file_init(NodeCompat *n);

int file_destroy(NodeCompat *n);

int file_poll_fds(NodeCompat *n, int fds[]);

int file_read(NodeCompat *n, struct Sample * const smps[], unsigned cnt);

int file_write(NodeCompat *n, struct Sample * const smps[], unsigned cnt);

} // namespace node
} // namespace villas