#include <sys/time.h>

struct timeval *
uc_tvadd(struct timeval *dst, const struct timeval *a, const struct timeval *b)
{
	dst->tv_sec = a->tv_sec + b->tv_sec;
	dst->tv_usec = a->tv_usec + b->tv_usec;

	if (dst->tv_usec >= 1000000) {
		dst->tv_sec++;
        dst->tv_usec -= 1000000;
    }

	return dst;
}

struct timeval *
uc_tvsub(struct timeval *dst, const struct timeval *a, const struct timeval *b)
{
	dst->tv_sec = a->tv_sec - b->tv_sec;
	dst->tv_usec = a->tv_usec - b->tv_usec;

	if (dst->tv_usec < 0) {
		dst->tv_sec--;
        dst->tv_usec += 1000000;
    }

	return dst;
}

int 
uc_tvcmp(const struct timeval *a, const struct timeval *b)
{
    if (a->tv_sec < b->tv_sec)
        return -1;
    else if (a->tv_sec > b->tv_sec)
        return 1;

	if (a->tv_usec < b->tv_usec)
		return -1;
	else if (a->tv_usec > b->tv_usec)
        return 1;

    return 0;
}

struct timeval *
uc_ms2tv(struct timeval *dst, unsigned long long ms)
{
	dst->tv_sec = ms / 1000;
	dst->tv_usec = ms % 1000 * 1000;

	return dst;
}