#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char* argv[]) {
	struct timeval time1, time2, time3, time4;
	double ftime1, ftime2, ftime3, ftime4;
	int repeat = 10000;
	int size = 10;
	void* buf;
	char* filename = "file";
	int fd;
	int i;
	char* option;
	char* arg;

	/* 引数の処理 */
	for ( i = 1 ; i < (argc-1) ; i+=2 ) {
		option = argv[i];
		arg = argv[i+1];
		if ( strcmp(option, "-repeat") == 0 ) {
			repeat = atoi(arg);
		} else if ( strcmp(option, "-size") == 0 ) {
			size = atoi(arg);
		} else if ( strcmp(option, "-filename") == 0 ) {
			filename = arg;
		} else {
			fprintf(stderr, "Unknown option: %s\n", option);
			exit(1);
		}
	}

	printf("repeat=%d\n", repeat);
	printf("size=%d\n", size);
	printf("filename=%s\n", filename);

	/* 大きさsizeのデータをrepeat回書き出す */
	buf = malloc(size);
	fd = open(filename, O_CREAT);
	gettimeofday(&time1, 0);
	for ( i=0 ; i < repeat ; i++ ) {
		write(fd, buf, size);
	}
	gettimeofday(&time2, 0);
	close(fd);
	free(buf);

	/* 大きさrepeatのデータをsize回書き出す */
	fd = open(filename, O_CREAT);
	buf = malloc(repeat);
	gettimeofday(&time3, 0);
	for ( i=0 ; i < size ; i++ ) {
		write(fd, buf, repeat);
	}
	gettimeofday(&time4, 0);
	close(fd);
	free(buf);

	// 結果の表示
	printf("time1=%d.%06d\n", time1.tv_sec, time1.tv_usec);
	printf("time2=%d.%06d\n", time2.tv_sec, time2.tv_usec);
	printf("time3=%d.%06d\n", time3.tv_sec, time3.tv_usec);
	printf("time4=%d.%06d\n", time4.tv_sec, time4.tv_usec);

	ftime1 = time1.tv_sec + (1e-6 * time1.tv_usec);
	ftime2 = time2.tv_sec + (1e-6 * time2.tv_usec);
	ftime3 = time3.tv_sec + (1e-6 * time3.tv_usec);
	ftime4 = time4.tv_sec + (1e-6 * time4.tv_usec);

	printf("サイズ %d のデータを %d 回書き出すためにかかった時間は %f 秒\n", size, repeat, ftime2-ftime1);
	printf("サイズ %d のデータを %d 回書き出すためにかかった時間は %f 秒\n", repeat, size, ftime4-ftime3);

}