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/**
* @file datatop.c
* @brief Executes commands for application.
*
* Contains the main() function where program executes. Calls appropriate
* methods based on user's CLI commands. Executes parsing function to
* determine necessary output and handles errors which may arise during the
* parse. Initiliazes files for data collection. Will call functions designed
* to poll and print the data in understandable format.
*/

#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include "datatop_interface.h"
#include "datatop_linked_list.h"
#include "datatop_opt.h"
#include "datatop_fileops.h"
#include "datatop_polling.h"
#include "datatop_gen_poll.h"

struct dtop_linked_list *first_dpg_list;
struct cli_opts usr_cl_opts;

/**
 * @brief Prints the datapoint names and values to the terminal.
 *
 * @param dpg_list A pointer to the first node of a linked list which
 *                 contains all data_point_gatherer structs to print.
 */
void dtop_print_terminal(struct dtop_linked_list *dpg_list)
{
	struct dtop_linked_list *curr_ptr = dpg_list;
	struct dtop_data_point_gatherer *dpset;

	while (curr_ptr) {
		dpset = (struct dtop_data_point_gatherer *) curr_ptr->data;
		dtop_print_dpg(dpset);
		curr_ptr = curr_ptr->next_ptr;
	}
}

/**
 * @brief Polls the data periodically and prints to file specified by the user.
 *
 * Polls the data as often as specified by the user in their CLI arguments
 * and outputs the data to a file also specified in CLI arguments. Then prints
 * a snapshot of delta(dp_value) to the terminal.
 *
 * @param dpg_list A pointer to the first node of a linked list which contains
 *                 all data_point_gatherer structs to poll and print.
 * @param fw A pointer to the file which will be printed to.
 * @return FILE_ERROR - Writing to file was unsuccessful.
 * @return FILE_SUCCESS - Writing to file was successful.
 */
int dtop_poll_periodically(struct dtop_linked_list *dpg_list, FILE *fw)
{
	struct timeval tv, timeout;
	fd_set rfds;
	time_t curtime, endtime;
	int inp, quit = 0;
	struct dtop_linked_list *curr_ptr = dpg_list;
	struct dtop_data_point_gatherer *dpset;
	struct timeval ftime, itime, polltime;

	gettimeofday(&tv, NULL);
	curtime = tv.tv_sec;
	endtime = tv.tv_sec + usr_cl_opts.poll_time;

	/* print all of our datapoint names as column headers in csv format */
	if (fprintf(fw, "\"Time\",") < 0)
		return FILE_ERROR;

	while (curr_ptr) {
		dpset = (struct dtop_data_point_gatherer *) curr_ptr->data;
		if (dtop_print_dpg_names_csv(dpset, fw) == FILE_ERROR)
			return FILE_ERROR;
		curr_ptr = curr_ptr->next_ptr;
	}
	if (fprintf(fw, "\n") < 0)
		return FILE_ERROR;

	dtop_print_interactive_opts();
	gettimeofday(&itime, NULL);
	/* periodically poll the datapoints and print in csv format */
	while (curtime < endtime
		|| usr_cl_opts.poll_time == POLL_NOT_SPECIFIED) {
		FD_ZERO(&rfds);
		FD_SET(0, &rfds);
		timeout.tv_sec = usr_cl_opts.poll_per;
		timeout.tv_usec = 0;
		//ftime is right before timeout calculations for most acurate calculations
		gettimeofday(&ftime, NULL);
		timersub(&ftime, &itime, &polltime);
		timersub(&timeout,&polltime, &timeout);
		inp = select(1, &rfds, NULL, NULL, &timeout);
		gettimeofday(&itime, NULL);
		if (inp) {
			char s[4];
			scanf("%s", s);
			if (strcmp(s, "quit") == 0
			    || strcmp(s, "q") == 0) {
				quit = QUIT;
				break;
			}
			if (strcmp(s, "i") == 0) {
				dtop_print_snapshot_diff(first_dpg_list);
				dtop_reset_dp_initial_values(first_dpg_list);
			}
			if (strcmp(s, "l") == 0)
				dtop_print_snapshot_diff(first_dpg_list);
		}
		gettimeofday(&tv, NULL);
		curtime = tv.tv_sec;
		dtop_poll(dpg_list);
		printf("Polled at %ld.%06ld\n", tv.tv_sec, tv.tv_usec);
		if (dtop_print_time_at_poll(fw) == FILE_ERROR)
			return FILE_ERROR;
		if (dtop_write_pollingdata_csv(dpg_list, fw) == FILE_ERROR)
			return FILE_ERROR;
	}

	if (quit != QUIT)
		dtop_print_snapshot_diff(dpg_list);
	return FILE_SUCCESS;
}

static void dtop_set_niceness(int niceness)
{
	int pid, rc;
	pid = getpid();
	printf("Requesting nice %d\n", niceness);
	rc = setpriority(PRIO_PROCESS, pid, niceness);
	if (rc != 0)
		fprintf(stderr, "Error setting priority [%d]\n", errno);

	rc = getpriority(PRIO_PROCESS, pid);
	printf("Running with nice %d.\n", rc);
}

int main(int argc, char **argv)
{
	int parse_status;
	printf("DataTop - Version %s\n", VERSION);
	printf("(c)2014-2015 Linux Foundation\n");

	dtop_load_default_options(&usr_cl_opts);

	parse_status = dtop_parse_cli_opts(&usr_cl_opts, argc, argv);
	switch (parse_status) {
	case PARSE_SUCCESS:
		dtop_set_niceness(usr_cl_opts.priority);
	break;

	case PARSE_FORCE_EXIT:
		exit(EXIT_SUCCESS);
	break;

	case PARSE_FAILURE:
	default:
		printf("Failed to parse command line arguments.\n");
		exit(EXIT_FAILURE);
	break;
	}

	dtop_dual_line_init("/proc/net/netstat");
	dtop_dual_line_init("/proc/net/snmp");
	dtop_single_line_init("/proc/net/snmp6");
	dtop_gen_init("/proc/sys/net/");
	dtop_gen_init("/sys/module/rmnet_data/parameters/");
	dtop_gen_init("/sys/class/net/rmnet_mhi0/statistics/");
	dtop_gen_init("/sys/class/net/usb_rmnet0/statistics/");
	dtop_gen_init("/sys/class/net/rmnet_ipa0/statistics/");
	dtop_meminfo_init();
	dtop_dev_init();
	dtop_stat_init();
	dtop_cpu_stats_init();
	dtop_gen_init("/sys/kernel/debug/clk/bimc_clk/");
	dtop_gen_init("/sys/kernel/debug/clk/snoc_clk/");
	dtop_gen_init("/sys/kernel/debug/clk/pnoc_clk/");

	if (usr_cl_opts.print_cl == OPT_CHOSE) {
		dtop_poll(first_dpg_list);
		dtop_print_terminal(first_dpg_list);
	}

	if (usr_cl_opts.print_csv == OPT_CHOSE) {
		FILE *to_file = NULL;
		if ((dtop_open_writing_file(usr_cl_opts.file_name,
						&to_file)) == VALID) {
			printf("\nData being polled for %ld seconds.\n",
						usr_cl_opts.poll_time);
			if (dtop_poll_periodically(first_dpg_list, to_file)
			    == FILE_ERROR) {
				fprintf(stderr, "err=%d: %s\n", errno,
							strerror(errno));
				dtop_close_file(to_file);
				deconstruct_dpgs(first_dpg_list);
				dtop_rem_linked_list(first_dpg_list);
				exit(EXIT_FAILURE);
			}
			dtop_close_file(to_file);
		} else {
			printf("File Can Not Be Opened\n");
			exit(EXIT_FAILURE);
		}
	}

	if (usr_cl_opts.snapshot_file) {
		if (dtop_print_system_snapshot(usr_cl_opts.snapshot_file)
			    == FILE_ERROR) {
			fprintf(stderr, "err=%d: %s\n", errno,
						strerror(errno));
			deconstruct_dpgs(first_dpg_list);
			dtop_rem_linked_list(first_dpg_list);
			exit(EXIT_FAILURE);
		}
	}

	if (usr_cl_opts.print_cl == OPT_NOT_CHOSE &&
	    usr_cl_opts.print_csv == OPT_NOT_CHOSE) {
		if ((!usr_cl_opts.snapshot_file)
		   || usr_cl_opts.poll_time_selected == POLL_TIME_SELECTED) {
			printf("\nData will now be polled for %ld seconds.\n",
							usr_cl_opts.poll_time);
			dtop_poll(first_dpg_list);
			sleep(usr_cl_opts.poll_time);
			dtop_poll(first_dpg_list);
			dtop_print_snapshot_diff(first_dpg_list);
		}
	}

	deconstruct_dpgs(first_dpg_list);
	dtop_rem_linked_list(first_dpg_list);
	return 0;
}

/**
 * @brief Adds each dpg as a node to a linked list.
 *
 * Called when a dpg is initialized.
 *
 * @param dpg A pointer to a data_point_gatherer struct which is to be added to the linked list.
 */
void dtop_register(struct dtop_data_point_gatherer *dpg)
{
	if (dpg)
		first_dpg_list = dtop_add_linked_list(dpg, first_dpg_list);
}