timestamp.c

PostgreSQL7.4.6 for Linux

}


/* interval2tm()
 * Convert a interval data type to a tm structure.
 */
int
interval2tm(Interval span, struct tm * tm, fsec_t *fsec)
{
#ifdef HAVE_INT64_TIMESTAMP
	int64		time;

#else
	double		time;
#endif

	if (span.month != 0)
	{
		tm->tm_year = span.month / 12;
		tm->tm_mon = span.month % 12;

	}
	else
	{
		tm->tm_year = 0;
		tm->tm_mon = 0;
	}

	time = span.time;

#ifdef HAVE_INT64_TIMESTAMP
	tm->tm_mday = (time / INT64CONST(86400000000));
	time -= (tm->tm_mday * INT64CONST(86400000000));
	tm->tm_hour = (time / INT64CONST(3600000000));
	time -= (tm->tm_hour * INT64CONST(3600000000));
	tm->tm_min = (time / INT64CONST(60000000));
	time -= (tm->tm_min * INT64CONST(60000000));
	tm->tm_sec = (time / INT64CONST(1000000));
	*fsec = (time - (tm->tm_sec * INT64CONST(1000000)));
#else
	TMODULO(time, tm->tm_mday, 86400e0);
	TMODULO(time, tm->tm_hour, 3600e0);
	TMODULO(time, tm->tm_min, 60e0);
	TMODULO(time, tm->tm_sec, 1e0);
	*fsec = time;
#endif

	return 0;
}

int
tm2interval(struct tm * tm, fsec_t fsec, Interval *span)
{
	span->month = ((tm->tm_year * 12) + tm->tm_mon);
#ifdef HAVE_INT64_TIMESTAMP
	span->time = ((((((((tm->tm_mday * INT64CONST(24))
						+ tm->tm_hour) * INT64CONST(60))
					  + tm->tm_min) * INT64CONST(60))
					+ tm->tm_sec) * INT64CONST(1000000)) + fsec);
#else
	span->time = ((((((tm->tm_mday * 24.0)
					  + tm->tm_hour) * 60.0)
					+ tm->tm_min) * 60.0)
				  + tm->tm_sec);
	span->time = JROUND(span->time + fsec);
#endif

	return 0;
}

#ifdef HAVE_INT64_TIMESTAMP
static int64
time2t(const int hour, const int min, const int sec, const fsec_t fsec)
{
	return ((((((hour * 60) + min) * 60) + sec) * INT64CONST(1000000)) + fsec);
}	/* time2t() */

#else
static double
time2t(const int hour, const int min, const int sec, const fsec_t fsec)
{
	return ((((hour * 60) + min) * 60) + sec + fsec);
}	/* time2t() */
#endif

static Timestamp
dt2local(Timestamp dt, int tz)
{
#ifdef HAVE_INT64_TIMESTAMP
	dt -= (tz * INT64CONST(1000000));
#else
	dt -= tz;
	dt = JROUND(dt);
#endif
	return dt;
}	/* dt2local() */


/*****************************************************************************
 *	 PUBLIC ROUTINES														 *
 *****************************************************************************/


Datum
timestamp_finite(PG_FUNCTION_ARGS)
{
	Timestamp	timestamp = PG_GETARG_TIMESTAMP(0);

	PG_RETURN_BOOL(!TIMESTAMP_NOT_FINITE(timestamp));
}

Datum
interval_finite(PG_FUNCTION_ARGS)
{
	PG_RETURN_BOOL(true);
}


/*----------------------------------------------------------
 *	Relational operators for timestamp.
 *---------------------------------------------------------*/

void
GetEpochTime(struct tm * tm)
{
	struct tm  *t0;
	time_t		epoch = 0;

	t0 = gmtime(&epoch);

	tm->tm_year = t0->tm_year;
	tm->tm_mon = t0->tm_mon;
	tm->tm_mday = t0->tm_mday;
	tm->tm_hour = t0->tm_hour;
	tm->tm_min = t0->tm_min;
	tm->tm_sec = t0->tm_sec;

	if (tm->tm_year < 1900)
		tm->tm_year += 1900;
	tm->tm_mon++;

	return;
}	/* GetEpochTime() */

Timestamp
SetEpochTimestamp(void)
{
	Timestamp	dt;
	struct tm	tt,
			   *tm = &tt;

	GetEpochTime(tm);
	/* we don't bother to test for failure ... */
	tm2timestamp(tm, 0, NULL, &dt);

	return dt;
}	/* SetEpochTimestamp() */

/*
 * We are currently sharing some code between timestamp and timestamptz.
 * The comparison functions are among them. - thomas 2001-09-25
 *
 *		timestamp_relop - is timestamp1 relop timestamp2
 *
 *		collate invalid timestamp at the end
 */
static int
timestamp_cmp_internal(Timestamp dt1, Timestamp dt2)
{
#ifdef HAVE_INT64_TIMESTAMP
	return ((dt1 < dt2) ? -1 : ((dt1 > dt2) ? 1 : 0));
#else

	/*
	 * When using float representation, we have to be wary of NaNs.
	 *
	 * We consider all NANs to be equal and larger than any non-NAN. This is
	 * somewhat arbitrary; the important thing is to have a consistent
	 * sort order.
	 */
	if (isnan(dt1))
	{
		if (isnan(dt2))
			return 0;			/* NAN = NAN */
		else
			return 1;			/* NAN > non-NAN */
	}
	else if (isnan(dt2))
	{
		return -1;				/* non-NAN < NAN */
	}
	else
	{
		if (dt1 > dt2)
			return 1;
		else if (dt1 < dt2)
			return -1;
		else
			return 0;
	}
#endif
}

Datum
timestamp_eq(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);

	PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) == 0);
}

Datum
timestamp_ne(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);

	PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) != 0);
}

Datum
timestamp_lt(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);

	PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) < 0);
}

Datum
timestamp_gt(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);

	PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) > 0);
}

Datum
timestamp_le(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);

	PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) <= 0);
}

Datum
timestamp_ge(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);

	PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) >= 0);
}

Datum
timestamp_cmp(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);

	PG_RETURN_INT32(timestamp_cmp_internal(dt1, dt2));
}


/*
 *		interval_relop	- is interval1 relop interval2
 *
 *		collate invalid interval at the end
 */
static int
interval_cmp_internal(Interval *interval1, Interval *interval2)
{
#ifdef HAVE_INT64_TIMESTAMP
	int64		span1,
				span2;

#else
	double		span1,
				span2;
#endif

	span1 = interval1->time;
	span2 = interval2->time;

#ifdef HAVE_INT64_TIMESTAMP
	if (interval1->month != 0)
		span1 += ((interval1->month * INT64CONST(30) * INT64CONST(86400000000)));
	if (interval2->month != 0)
		span2 += ((interval2->month * INT64CONST(30) * INT64CONST(86400000000)));
#else
	if (interval1->month != 0)
		span1 += (interval1->month * (30.0 * 86400));
	if (interval2->month != 0)
		span2 += (interval2->month * (30.0 * 86400));
#endif

	return ((span1 < span2) ? -1 : (span1 > span2) ? 1 : 0);
}

Datum
interval_eq(PG_FUNCTION_ARGS)
{
	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
	Interval   *interval2 = PG_GETARG_INTERVAL_P(1);

	PG_RETURN_BOOL(interval_cmp_internal(interval1, interval2) == 0);
}

Datum
interval_ne(PG_FUNCTION_ARGS)
{
	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
	Interval   *interval2 = PG_GETARG_INTERVAL_P(1);

	PG_RETURN_BOOL(interval_cmp_internal(interval1, interval2) != 0);
}

Datum
interval_lt(PG_FUNCTION_ARGS)
{
	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
	Interval   *interval2 = PG_GETARG_INTERVAL_P(1);

	PG_RETURN_BOOL(interval_cmp_internal(interval1, interval2) < 0);
}

Datum
interval_gt(PG_FUNCTION_ARGS)
{
	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
	Interval   *interval2 = PG_GETARG_INTERVAL_P(1);

	PG_RETURN_BOOL(interval_cmp_internal(interval1, interval2) > 0);
}

Datum
interval_le(PG_FUNCTION_ARGS)
{
	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
	Interval   *interval2 = PG_GETARG_INTERVAL_P(1);

	PG_RETURN_BOOL(interval_cmp_internal(interval1, interval2) <= 0);
}

Datum
interval_ge(PG_FUNCTION_ARGS)
{
	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
	Interval   *interval2 = PG_GETARG_INTERVAL_P(1);

	PG_RETURN_BOOL(interval_cmp_internal(interval1, interval2) >= 0);
}

Datum
interval_cmp(PG_FUNCTION_ARGS)
{
	Interval   *interval1 = PG_GETARG_INTERVAL_P(0);
	Interval   *interval2 = PG_GETARG_INTERVAL_P(1);

	PG_RETURN_INT32(interval_cmp_internal(interval1, interval2));
}

/*
 * interval, being an unusual size, needs a specialized hash function.
 */
Datum
interval_hash(PG_FUNCTION_ARGS)
{
	Interval   *key = PG_GETARG_INTERVAL_P(0);

	/*
	 * Specify hash length as sizeof(double) + sizeof(int4), not as
	 * sizeof(Interval), so that any garbage pad bytes in the structure
	 * won't be included in the hash!
	 */
	return hash_any((unsigned char *) key, sizeof(key->time) + sizeof(key->month));
}

/* overlaps_timestamp() --- implements the SQL92 OVERLAPS operator.
 *
 * Algorithm is per SQL92 spec.  This is much harder than you'd think
 * because the spec requires us to deliver a non-null answer in some cases
 * where some of the inputs are null.
 */
Datum
overlaps_timestamp(PG_FUNCTION_ARGS)
{
	/*
	 * The arguments are Timestamps, but we leave them as generic Datums
	 * to avoid unnecessary conversions between value and reference forms
	 * --- not to mention possible dereferences of null pointers.
	 */
	Datum		ts1 = PG_GETARG_DATUM(0);
	Datum		te1 = PG_GETARG_DATUM(1);
	Datum		ts2 = PG_GETARG_DATUM(2);
	Datum		te2 = PG_GETARG_DATUM(3);
	bool		ts1IsNull = PG_ARGISNULL(0);
	bool		te1IsNull = PG_ARGISNULL(1);
	bool		ts2IsNull = PG_ARGISNULL(2);
	bool		te2IsNull = PG_ARGISNULL(3);

#define TIMESTAMP_GT(t1,t2) \
	DatumGetBool(DirectFunctionCall2(timestamp_gt,t1,t2))
#define TIMESTAMP_LT(t1,t2) \
	DatumGetBool(DirectFunctionCall2(timestamp_lt,t1,t2))

	/*
	 * If both endpoints of interval 1 are null, the result is null
	 * (unknown). If just one endpoint is null, take ts1 as the non-null
	 * one. Otherwise, take ts1 as the lesser endpoint.
	 */
	if (ts1IsNull)
	{
		if (te1IsNull)
			PG_RETURN_NULL();
		/* swap null for non-null */
		ts1 = te1;
		te1IsNull = true;
	}
	else if (!te1IsNull)
	{
		if (TIMESTAMP_GT(ts1, te1))
		{
			Datum		tt = ts1;

			ts1 = te1;
			te1 = tt;
		}
	}

	/* Likewise for interval 2. */
	if (ts2IsNull)
	{
		if (te2IsNull)
			PG_RETURN_NULL();
		/* swap null for non-null */
		ts2 = te2;
		te2IsNull = true;
	}
	else if (!te2IsNull)
	{
		if (TIMESTAMP_GT(ts2, te2))
		{
			Datum		tt = ts2;

			ts2 = te2;
			te2 = tt;
		}
	}

	/*
	 * At this point neither ts1 nor ts2 is null, so we can consider three
	 * cases: ts1 > ts2, ts1 < ts2, ts1 = ts2
	 */
	if (TIMESTAMP_GT(ts1, ts2))
	{
		/*
		 * This case is ts1 < te2 OR te1 < te2, which may look redundant
		 * but in the presence of nulls it's not quite completely so.
		 */
		if (te2IsNull)
			PG_RETURN_NULL();
		if (TIMESTAMP_LT(ts1, te2))
			PG_RETURN_BOOL(true);
		if (te1IsNull)
			PG_RETURN_NULL();

		/*
		 * If te1 is not null then we had ts1 <= te1 above, and we just
		 * found ts1 >= te2, hence te1 >= te2.
		 */
		PG_RETURN_BOOL(false);
	}
	else if (TIMESTAMP_LT(ts1, ts2))
	{
		/* This case is ts2 < te1 OR te2 < te1 */
		if (te1IsNull)
			PG_RETURN_NULL();
		if (TIMESTAMP_LT(ts2, te1))
			PG_RETURN_BOOL(true);
		if (te2IsNull)
			PG_RETURN_NULL();

		/*
		 * If te2 is not null then we had ts2 <= te2 above, and we just
		 * found ts2 >= te1, hence te2 >= te1.
		 */
		PG_RETURN_BOOL(false);
	}
	else
	{
		/*
		 * For ts1 = ts2 the spec says te1 <> te2 OR te1 = te2, which is a
		 * rather silly way of saying "true if both are nonnull, else
		 * null".
		 */
		if (te1IsNull || te2IsNull)
			PG_RETURN_NULL();
		PG_RETURN_BOOL(true);
	}

#undef TIMESTAMP_GT
#undef TIMESTAMP_LT
}


/*----------------------------------------------------------
 *	"Arithmetic" operators on date/times.
 *---------------------------------------------------------*/

Datum
timestamp_smaller(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);
	Timestamp	result;

	/* use timestamp_cmp_internal to be sure this agrees with comparisons */
	if (timestamp_cmp_internal(dt1, dt2) < 0)
		result = dt1;
	else
		result = dt2;
	PG_RETURN_TIMESTAMP(result);
}

Datum
timestamp_larger(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);
	Timestamp	result;

	if (timestamp_cmp_internal(dt1, dt2) > 0)
		result = dt1;
	else
		result = dt2;
	PG_RETURN_TIMESTAMP(result);
}


Datum
timestamp_mi(PG_FUNCTION_ARGS)
{
	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);
	Interval   *result;

	result = (Interval *) palloc(sizeof(Interval));

	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
	{
		ereport(ERROR,
				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
				 errmsg("cannot subtract infinite timestamps")));

		result->time = 0;
	}
	else
#ifdef HAVE_INT64_TIMESTAMP
		result->time = (dt1 - dt2);
#else
		result->time = JROUND(dt1 - dt2);
#endif

	result->month = 0;