#include <stdio.h>
#include <stdlib.h>

int main(int argc, char ** argv)
{
	int x, y;
	FILE *fd;
	int HZ;
	unsigned long base_time, current_jiffies;
	unsigned long time;
	int RW;
	long read=0, write=0, total=0;
	if (argc == 1 || argc >=4)
	{
		printf("usage:\n");
		printf("(1)	./statistic <int: last x seconds>\n");
		printf("(2)	./statistic <int: from x seconds> <int: to y seconds>\n");
		return 0;
	}
	if (argc == 2 || argc ==3)
	{
		fd=fopen("/proc/jiffies", "r");
		fscanf(fd, "HZ=%d\nbase_time=%lu\ncurrent_jiffies=%lu\n", &HZ, &base_time, &current_jiffies);
		fclose(fd);
		printf("HZ=%d\nbase_time=%lu\ncurrent_jiffies=%lu\n\n", HZ, base_time, current_jiffies);
		if (argc == 2)
		{
			x = atoi(argv[1]);
			fd=fopen("/proc/statistic", "r");
			while (1)
			{
				if(fscanf(fd, "struct bio:\ntime: %lu\nRead or Write %d\n\n", &time, &RW)==EOF)
				{
					printf("To the End\n\n");
					break;
				}
				if ((current_jiffies-base_time-time) < x*HZ)
				{
					printf("struct bio:\ntime=%lu\nRW=%d\n\n", time, RW);
					if (RW)
						write++;
					else
						read++;
					total++;
				}
				else
					break;
			}
			fclose(fd);
			printf("Read bio: %ld\nWrite bio: %ld\nTotal bio: %ld\n", read, write, total);
		}
		if (argc == 3)
		{
			x = atoi(argv[1]);
			y = atoi(argv[2]);
			//printf("x=%d, y=%d\n", x, y);
			fd=fopen("/proc/statistic", "r");
			while (1)
			{
				if(fscanf(fd, "struct bio:\ntime: %lu\nRead or Write %d\n\n", &time, &RW)==EOF)	
				{
					printf("To the End\n\n");
					break;
				}
				if (time>x*HZ && time<y*HZ)
				{
					printf("struct bio:\ntime=%lu\nRW=%d\n\n", time, RW);
					if (RW)
						write++;
					else
						read++;
					total++;
				}
			}
			fclose(fd);
			printf("Read bio: %ld\nWrite bio: %ld\nTotal bio: %ld\n", read, write, total);
			
		}
	}
	return 0;
	
}