datatop/src/datatop_value_only_poll.c

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/**
 * @file datatop_value_only_poll.c
 * @brief Adds ability for data collection from files with only values
 *
 * File contains methods for searching and polling data from
 * value_only files, meaning a file with a single line, containing
 * only values.
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "datatop_interface.h"
#include "datatop_fileops.h"
#include "datatop_str.h"

#define DTOP_SINGLE_SIZE 8192
#define DTOP_SINGLE_LINE (DTOP_SINGLE_SIZE>>2)

/**
 * @brief Stores the data collected from a value_only files.
 *
 * @param dpg Struct that polled data is added to.
 * @return DTOP_POLL_IO_ERR - Poll of dpg unsuccessful.
 * @return DTOP_POLL_OK - Poll of dpg successful.
 */
int dtop_value_only_poll(struct dtop_data_point_gatherer *dpg)
{
	char *data;
	int line_len;
	char line[DTOP_SINGLE_LINE];
	int read;
	struct dt_procdict dict;
	int j;
	FILE *check = fopen(dpg->file, "r");
	if (check) {
		fclose(check);
		read = dt_read_file(dpg->file, &data, DTOP_SINGLE_SIZE);
	} else {
		return DTOP_POLL_IO_ERR;
	}

	if (read == 0 || data == 0)
		return DTOP_POLL_IO_ERR;

	line_len = dt_read_line(line, DTOP_SINGLE_LINE, data,
					   DTOP_SINGLE_SIZE, 0);

	/* Stores dp values in dictionary */
	dt_single_line_parse(line, line_len, &dict);

	/* Assigns the dp value to the dp struct */
	for (j = 0; j < dpg->data_points_len; j++)
		dtop_store_dp(&(dpg->data_points[j]), dict.val[j]);

	dt_free(&data);
	return DTOP_POLL_OK;
}

/**
 * @brief Frees dynamically allocated single line dpg.
 *
 * Frees the memory of the dpg along with it's data_points
 * and other malloc'd memory no longer needed.
 *
 * @param dpg Dpg to deconstruct and deallocate memory for.
 */
void dtop_value_only_dpg_deconstructor
			(struct dtop_data_point_gatherer *dpset)
{
	int i;
	for (i = 0; i < dpset->data_points_len; i++)
		free(dpset->data_points[i].name);
	free(dpset->data_points);
	free(dpset->file);
	free(dpset);
}

/**
 * @brief Creates a dpg for a single line file.
 *
 * Dynamically allocates memory for dpg which is then added to a linked list
 * via the dtop_register(dpg) function call.
 *
 * @param name Name of file dpg represents.
 * @param data_points dtop_data_point struct that dpg points to.
 * @param dp_count Number of data_points in data_points array
 */
static void construct_value_only_dpg(char *name, struct dtop_data_point
		*data_points, int dp_count)
{
	struct dtop_data_point_gatherer *dpg = malloc
		(sizeof(struct dtop_data_point_gatherer));
	dpg->prefix = name;
	dpg->file = name;
	dpg->poll = dtop_value_only_poll;
	dpg->data_points = data_points;
	dpg->data_points_len = dp_count;
	dpg->deconstruct = dtop_value_only_dpg_deconstructor;

	dtop_register(dpg);
}

/**
 * @brief Scans a single line file in order to autodetect dps.
 *
 * Searches through a file that contains a single line and only
 * values in order to detect and create dp's/
 *
 * @param name Name of file to scan.
 */
int dtop_value_only_search(char *name)
{
	int i;
	char *data;
	char line[DTOP_SINGLE_LINE];
	int line_len;
	int read;
	struct dt_procdict dict;
	struct dtop_data_point *data_points;


	read = dt_read_file(name, &data, DTOP_SINGLE_SIZE);
	if (read == 0 || data == 0) {
		free(name);
		return DTOP_POLL_IO_ERR;
	}

	line_len = dt_read_line(line,
				DTOP_SINGLE_LINE, data,
				DTOP_SINGLE_SIZE, 0);

	/* Stores dp values in dictionary */
	dt_single_line_parse(line, line_len, &dict);

	data_points = malloc(dict.max * sizeof(struct dtop_data_point));

	/* Creates a dtop_data_point struct for each dp found in the file */
	for (i = 0; i < dict.max; i++) {
		char *newname = malloc(sizeof(10));
		if (dict.val[i][0] == '-')
			data_points[i].type = DTOP_LONG;
		else
			data_points[i].type = DTOP_ULONG;
		data_points[i].name = malloc(sizeof(10));
		if (dict.max > 1)
			snprintf(newname, sizeof(10), "[%d]:", i);
		else
			strlcpy(newname, "", sizeof(10));
		strlcpy(data_points[i].name, newname, sizeof(10));
		free(newname);
		data_points[i].prefix = NULL;
		data_points[i].skip = DO_NOT_SKIP;
		data_points[i].initial_data_populated = NOT_POPULATED;
	}

	/* Calls dpg constructor, dpg will point to the dp struct */
	construct_value_only_dpg(name, data_points, dict.max);

	dt_free(&data);
	return DTOP_POLL_OK;
}

/**
 * @brief Calls dtop_search for files with a single line and only values.
 */
void dtop_value_only_init(char *name)
{
	char *file = malloc(strlen(name) + 1);
	strlcpy(file, name, strlen(name) + 1);
	dtop_value_only_search(file);
}