sampling_index.c

#include "sampling_index.h"

#define INTERVAL_BLOCK 100
#define INTERVAL_MIN_TIME 120
#define MIN_TIME_BETWEEN_INTERVALS 900 //240

typedef enum { false, true } bool;

long size_of_file(char *filename)
{
	FILE *f = fopen(filename, "r");
	fseek(f, 0L, SEEK_END);
	long sz = ftell(f);
	fclose(f);
	return sz;
}

void print_interval(interval *i, int n)
{
	fprintf(stderr, "INTERVAL %d %llu %llu\n", n, i->start_ts, i->end_ts);
}

interval *read_index(char *index_filename, char *original_file, unsigned long *inter_ctr)
{


	fprintf(stderr, "%s %s\n", index_filename, original_file);

	long original_file_size = size_of_file(original_file);

	unsigned long ctr = 0, interval_ctr = 0, byte_ctr = 0, avg_interval_size = 0, avg_packets_in_interval = 0;
	unsigned long intervals_max_size = INTERVAL_BLOCK;
	interval *intervals = calloc(INTERVAL_BLOCK, sizeof(interval));
	unsigned long last_interval_ts = 0;


	FILE *index_file = fopen(index_filename, "r");

	if (index_file == NULL) {
		perror("Error while opening the index file.\n");
		exit(EXIT_FAILURE);
	}

	//FOR EACH LINE IN FILE
	unsigned long long pkt, byte, ts, pps; //PPS = packets per second
	double average_pps;
	short one = 0;

	bool in_interval = false;

	while (fscanf(index_file, "%llu %hd %llu %llu %llu %lf", &pkt, &one, &byte, &ts, &pps, &average_pps) >= 6) {

		if (!in_interval) {
			//NEW INTERVAL
			//if((pps <= 10000 || pps >= average_pps) && (ts - last_interval_ts) > MIN_TIME_BETWEEN_INTERVALS){
			if (pps >= average_pps && (ts - last_interval_ts) > MIN_TIME_BETWEEN_INTERVALS) {
				in_interval = true;

				intervals[interval_ctr].start_packet = pkt;
				intervals[interval_ctr].start_byte   = byte;
				intervals[interval_ctr].start_ts	 = ts;

			}

		} else { //IN INTERVAL
			//END OF INTERVAL
			//if((pps >= 10000 && pps < average_pps) && ((ts - intervals[interval_ctr].start_ts) > INTERVAL_MIN_TIME)){
			if (pps < average_pps && ((ts - intervals[interval_ctr].start_ts) > INTERVAL_MIN_TIME)) {
				intervals[interval_ctr].end_packet = pkt;
				intervals[interval_ctr].end_byte   = byte;
				intervals[interval_ctr].end_ts	   = ts;
				print_interval(&intervals[interval_ctr], interval_ctr);

				//fprintf(stdout, "FROM %llu TO %llu BYTES: %llu\n", intervals[interval_ctr].start_ts, intervals[interval_ctr].end_ts, intervals[interval_ctr].end_byte - intervals[interval_ctr].start_byte);
				byte_ctr += (intervals[interval_ctr].end_byte - intervals[interval_ctr].start_byte);
				avg_interval_size += (intervals[interval_ctr].end_ts - intervals[interval_ctr].start_ts);
				avg_packets_in_interval += (intervals[interval_ctr].end_packet - intervals[interval_ctr].start_packet);
				interval_ctr++;
				in_interval = false;
				last_interval_ts = ts;

				if (interval_ctr == intervals_max_size) {
					intervals_max_size = intervals_max_size + intervals_max_size * 0.5;
					intervals = realloc(intervals, intervals_max_size * sizeof(interval));
				}
			}
		}

		ctr++;
	}

	fprintf(stderr, "INTERVALS:                   %lu\n", interval_ctr);
	fprintf(stderr, "AVERAGE SIZE OF INTERVAL:    %.2lf secs\n", avg_interval_size / ((double) interval_ctr));
	fprintf(stderr, "AVERAGE PACKETS IN INTERVAL: %.2lf pkts\n", avg_packets_in_interval / ((double) interval_ctr));
	fprintf(stderr, "%% A PROCESAR DEL FICHERO:    %lf%%\n", (byte_ctr / ((double) original_file_size)) * 100);

	*inter_ctr = interval_ctr;
	fclose(index_file);
	return intervals;

}

// int main(){

// 	interval *intervals = read_index("indice.txt", "/Users/carlosvega/samples/merge_http.pcap");
// 	free(intervals);

// 	return 0;
// }