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/**
 * @file datatop_interface.h
 * @brief Declares functions held within datatop.c and datatop_helpers.c
 *
 * Declares functions which are held within datatop.c and datatop_helpers.c.
 * Also defines data structures used for storing data gathered during polling
 * such as datapoint names, values, and prefixes along with other valuable
 * information.
 */

#ifndef DATATOP_INTERFACE_H
#define DATATOP_INTERFACE_H

#include <inttypes.h>
#include "datatop_linked_list.h"

#define DTOP_ULONG 0
#define DTOP_LONG  1
#define DTOP_UINT  2
#define DTOP_INT   3
#define DTOP_UCHAR 4
#define DTOP_CHAR  5
#define DTOP_STR   6

#define FILE_ERROR       -1
#define FILE_SUCCESS      0
#define SKIP              1
#define DO_NOT_SKIP       0
#define POPULATED         1
#define NOT_POPULATED     0

#define DTOP_POLL_OK      0
#define DTOP_POLL_IO_ERR  1
#define NOT_CHECKED       0

#define QUIT              1

#define DTOP_DP_MAX_STR_LEN 32

#define DTOP_DP_HFILL   .initial_data_populated = NOT_POPULATED, \
			.skip = 0

/**
 * @struct dtop_data_union
 * @brief Provides the type for dp value.
 */
union dtop_data_union {
	uint64_t d_ulong;
	int64_t d_long;
	uint32_t d_uint;
	int32_t d_int;
	uint8_t d_uchar;
	int8_t d_char;
	char d_str[DTOP_DP_MAX_STR_LEN];
};

/**
 * @struct dtop_data_point
 * @brief Individual datapoint in a file.
 *
 * @var dtop_data_point::name
 * Stores the datapoints name.
 * @var dtop_data_point::prefix
 * Stores the individual prefix for the dp.
 * @var dtop_data_point::type
 * Type dp value is, see definitions.
 * @var dtop_data_point::initial_data
 * Holds the initial value of the dp the first time it was polled.
 * @var dtop_data_point::initial_data_populated
 * Variable that is changed when initial_data is populated.
 * @var dtop_data_point::data
 * Value of the dp at the most recent poll.
 */
struct dtop_data_point {
	char *name;
	char *prefix;

	/* Results of polling */
	char type;
	union dtop_data_union initial_data;
	char initial_data_populated;
	union dtop_data_union data;

	/* Skip on subsequent polls */
	char skip;
};

/**
 * @struct dtop_data_point_gatherer
 * @brief Struct used to hold data about a set of collected data.
 *
 * @var dtop_data_point_gatherer::prefix
 * Name of directory which data is collected from.
 * @var dtop_data_point_gatherer::file
 * File path that data is collected from.
 * @var dtop_data_point_gatherer::poll
 * Poll function takes a dtop_data_point_gatherer as parameter.
 * int equals, DTOP_POLL_IO_ERR - Poll of dpg unsuccessful, or
 * DTOP_POLL_OK - Poll of dpg successful.
 * @var dtop_data_point_gatherer::data_points
 * Pointer to a dtop_data_point struct (dp).
 * @var dtop_data_point_gatherer::data_points_len
 * Number of elements in the array of dp's the dpg accesses.
 */
struct dtop_data_point_gatherer {
	char *prefix;
	char *file;
	int (*poll)(struct dtop_data_point_gatherer *dpg);
	void (*deconstruct)(struct dtop_data_point_gatherer *dpg);

	struct dtop_data_point *data_points;
	int data_points_len;

	/* Private data */
	void *priv;
};

void dtop_register(struct dtop_data_point_gatherer *dpg);
void dtop_store_dp(struct dtop_data_point *dp, const char *str);
void dtop_print_dpg(struct dtop_data_point_gatherer *dpg);
void get_snapshot_diff(struct dtop_linked_list *dpg_list);
void dtop_print_snapshot_diff(struct dtop_linked_list *dpg_list);
void dtop_poll(struct dtop_linked_list *dpg_list);
int dtop_print_time_at_poll(FILE *fw);
int dtop_print_dpg_names_csv(struct dtop_data_point_gatherer *dpg, FILE *fw);
int dtop_write_pollingdata_csv(struct dtop_linked_list *dpg_list, FILE *fw);
void dtop_reset_dp_initial_values(struct dtop_linked_list *dpg_list);
void deconstruct_dpgs(struct dtop_linked_list *dpg_list);
int dtop_print_system_snapshot(char *file);


#ifndef HAVE_STRL_FUNCTIONS
#define strlcpy(X,Y,Z) strcpy(X,Y)
#define strlcat(X,Y,Z) strcat(X,Y)
#endif /* HAVE_STRL_FUNCTIONS */

#endif /*  DATATOP_INTERFACE_H */