Datum
btabstimecmp(PG_FUNCTION_ARGS)
{
	AbsoluteTime t1 = PG_GETARG_ABSOLUTETIME(0);
	AbsoluteTime t2 = PG_GETARG_ABSOLUTETIME(1);

	PG_RETURN_INT32(abstime_cmp_internal(t1, t2));
}

Datum
abstimege(PG_FUNCTION_ARGS)
{
	AbsoluteTime t1 = PG_GETARG_ABSOLUTETIME(0);
	AbsoluteTime t2 = PG_GETARG_ABSOLUTETIME(1);

	PG_RETURN_BOOL(abstime_cmp_internal(t1, t2) >= 0);
}

/* abstime_finite()
 */
Datum
abstime_finite(PG_FUNCTION_ARGS)
{
	AbsoluteTime abstime = PG_GETARG_ABSOLUTETIME(0);

	PG_RETURN_BOOL(abstime != INVALID_ABSTIME &&
				   abstime != NOSTART_ABSTIME &&
				   abstime != NOEND_ABSTIME);
}

/*
 *		abstimesend			- converts abstime to binary format
 */
Datum
abstimesend(PG_FUNCTION_ARGS)
{
	AbsoluteTime time = PG_GETARG_ABSOLUTETIME(0);
	StringInfoData buf;

	pq_begintypsend(&buf);
	pq_sendint(&buf, time, sizeof(time));
	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}

/*
 *		timemi			- returns the value of (abstime t1 - reltime t2)
 */
Datum
timemi(PG_FUNCTION_ARGS)
{
	AbsoluteTime t1 = PG_GETARG_ABSOLUTETIME(0);
	RelativeTime t2 = PG_GETARG_RELATIVETIME(1);

	if (AbsoluteTimeIsReal(t1) &&
		RelativeTimeIsValid(t2) &&
		((t2 > 0 && t1 > NOSTART_ABSTIME + t2) ||
		 (t2 <= 0 && t1 < NOEND_ABSTIME + t2))) /* prevent overflow */
		PG_RETURN_ABSOLUTETIME(t1 - t2);

	PG_RETURN_ABSOLUTETIME(INVALID_ABSTIME);
}

/*
 *		mktinterval		- creates a time interval with endpoints t1 and t2
 */
Datum
mktinterval(PG_FUNCTION_ARGS)
{
	AbsoluteTime t1 = PG_GETARG_ABSOLUTETIME(0);
	AbsoluteTime t2 = PG_GETARG_ABSOLUTETIME(1);
	AbsoluteTime tstart = ABSTIMEMIN(t1, t2);
	AbsoluteTime tend = ABSTIMEMAX(t1, t2);
	TimeInterval tinterval;

	tinterval = (TimeInterval) palloc(sizeof(TimeIntervalData));

	if (t1 == INVALID_ABSTIME || t2 == INVALID_ABSTIME)
		tinterval->status = T_INTERVAL_INVAL;

	else
	{
		tinterval->status = T_INTERVAL_VALID;
		tinterval->data[0] = tstart;
		tinterval->data[1] = tend;
	}

	PG_RETURN_TIMEINTERVAL(tinterval);
}

/*
 *		intinterval		- returns true iff absolute date is in the tinterval
 */
Datum
intinterval(PG_FUNCTION_ARGS)
{
	AbsoluteTime t = PG_GETARG_ABSOLUTETIME(0);
	TimeInterval tinterval = PG_GETARG_TIMEINTERVAL(1);

	if (tinterval->status == T_INTERVAL_VALID && t != INVALID_ABSTIME)
	{
		if (DatumGetBool(DirectFunctionCall2(abstimege,
											 AbsoluteTimeGetDatum(t),
								AbsoluteTimeGetDatum(tinterval->data[0]))) &&
			DatumGetBool(DirectFunctionCall2(abstimele,
											 AbsoluteTimeGetDatum(t),
								  AbsoluteTimeGetDatum(tinterval->data[1]))))
			PG_RETURN_BOOL(true);
	}
	PG_RETURN_BOOL(false);
}

/* abstime_timestamptz()
 * Convert abstime to timestamp with time zone.
 */
Datum
abstime_timestamptz(PG_FUNCTION_ARGS)
{
	AbsoluteTime abstime = PG_GETARG_ABSOLUTETIME(0);
	TimestampTz result;
	struct pg_tm tt,
			   *tm = &tt;
	int			tz;
	char		zone[MAXDATELEN + 1],
			   *tzn = zone;

	switch (abstime)
	{
		case INVALID_ABSTIME:
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("cannot convert abstime \"invalid\" to timestamp"),
						   errOmitLocation(true)));
			TIMESTAMP_NOBEGIN(result);
			break;

		case NOSTART_ABSTIME:
			TIMESTAMP_NOBEGIN(result);
			break;

		case NOEND_ABSTIME:
			TIMESTAMP_NOEND(result);
			break;

		default:
			abstime2tm(abstime, &tz, tm, &tzn);
			if (tm2timestamp(tm, 0, &tz, &result) != 0)
				ereport(ERROR,
						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
						 errmsg("timestamp out of range"),
								   errOmitLocation(true)));
			break;
	};

	PG_RETURN_TIMESTAMP(result);
}

/* abstimeout()
 * Given an AbsoluteTime return the English text version of the date
 */
Datum
abstimeout(PG_FUNCTION_ARGS)
{
	AbsoluteTime time = PG_GETARG_ABSOLUTETIME(0);
	char	   *result;
	int			tz;
	double		fsec = 0;
	struct pg_tm tt,
			   *tm = &tt;
	char		buf[MAXDATELEN + 1];
	char		zone[MAXDATELEN + 1],
			   *tzn = zone;

	switch (time)
	{
			/*
			 * Note that timestamp no longer supports 'invalid'. Retain
			 * 'invalid' for abstime for now, but dump it someday.
			 */
		case INVALID_ABSTIME:
			strcpy(buf, INVALID);
			break;
		case NOEND_ABSTIME:
			strcpy(buf, LATE);
			break;
		case NOSTART_ABSTIME:
			strcpy(buf, EARLY);
			break;
		default:
			abstime2tm(time, &tz, tm, &tzn);
			EncodeDateTime(tm, fsec, &tz, &tzn, DateStyle, buf);
			break;
	}

	result = pstrdup(buf);
	PG_RETURN_CSTRING(result);
}