timestamp.c

postgresql8.3.4源码,开源数据库

	PG_RETURN_BOOL(!TIMESTAMP_NOT_FINITE(timestamp));
}

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


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

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

	t0 = pg_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;

	tm->tm_year += 1900;
	tm->tm_mon++;
}

Timestamp
SetEpochTimestamp(void)
{
	Timestamp	dt;
	struct pg_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
 */
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));
}

Datum
timestamp_hash(PG_FUNCTION_ARGS)
{
	/* We can use either hashint8 or hashfloat8 directly */
#ifdef HAVE_INT64_TIMESTAMP
	return hashint8(fcinfo);
#else
	return hashfloat8(fcinfo);
#endif
}


/*
 * Crosstype comparison functions for timestamp vs timestamptz
 */

Datum
timestamp_eq_timestamptz(PG_FUNCTION_ARGS)
{
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(0);
	TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
	TimestampTz dt1;

	dt1 = timestamp2timestamptz(timestampVal);

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

Datum
timestamp_ne_timestamptz(PG_FUNCTION_ARGS)
{
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(0);
	TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
	TimestampTz dt1;

	dt1 = timestamp2timestamptz(timestampVal);

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

Datum
timestamp_lt_timestamptz(PG_FUNCTION_ARGS)
{
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(0);
	TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
	TimestampTz dt1;

	dt1 = timestamp2timestamptz(timestampVal);

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

Datum
timestamp_gt_timestamptz(PG_FUNCTION_ARGS)
{
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(0);
	TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
	TimestampTz dt1;

	dt1 = timestamp2timestamptz(timestampVal);

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

Datum
timestamp_le_timestamptz(PG_FUNCTION_ARGS)
{
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(0);
	TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
	TimestampTz dt1;

	dt1 = timestamp2timestamptz(timestampVal);

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

Datum
timestamp_ge_timestamptz(PG_FUNCTION_ARGS)
{
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(0);
	TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
	TimestampTz dt1;

	dt1 = timestamp2timestamptz(timestampVal);

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

Datum
timestamp_cmp_timestamptz(PG_FUNCTION_ARGS)
{
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(0);
	TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
	TimestampTz dt1;

	dt1 = timestamp2timestamptz(timestampVal);

	PG_RETURN_INT32(timestamp_cmp_internal(dt1, dt2));
}

Datum
timestamptz_eq_timestamp(PG_FUNCTION_ARGS)
{
	TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(1);
	TimestampTz dt2;

	dt2 = timestamp2timestamptz(timestampVal);

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

Datum
timestamptz_ne_timestamp(PG_FUNCTION_ARGS)
{
	TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(1);
	TimestampTz dt2;

	dt2 = timestamp2timestamptz(timestampVal);

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

Datum
timestamptz_lt_timestamp(PG_FUNCTION_ARGS)
{
	TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(1);
	TimestampTz dt2;

	dt2 = timestamp2timestamptz(timestampVal);

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

Datum
timestamptz_gt_timestamp(PG_FUNCTION_ARGS)
{
	TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(1);
	TimestampTz dt2;

	dt2 = timestamp2timestamptz(timestampVal);

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

Datum
timestamptz_le_timestamp(PG_FUNCTION_ARGS)
{
	TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(1);
	TimestampTz dt2;

	dt2 = timestamp2timestamptz(timestampVal);

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

Datum
timestamptz_ge_timestamp(PG_FUNCTION_ARGS)
{
	TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(1);
	TimestampTz dt2;

	dt2 = timestamp2timestamptz(timestampVal);

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

Datum
timestamptz_cmp_timestamp(PG_FUNCTION_ARGS)
{
	TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
	Timestamp	timestampVal = PG_GETARG_TIMESTAMP(1);
	TimestampTz dt2;

	dt2 = timestamp2timestamptz(timestampVal);

	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
	span1 += interval1->month * INT64CONST(30) * USECS_PER_DAY;
	span1 += interval1->day * INT64CONST(24) * USECS_PER_HOUR;
	span2 += interval2->month * INT64CONST(30) * USECS_PER_DAY;
	span2 += interval2->day * INT64CONST(24) * USECS_PER_HOUR;
#else
	span1 += interval1->month * ((double) DAYS_PER_MONTH * SECS_PER_DAY);
	span1 += interval1->day * ((double) HOURS_PER_DAY * SECS_PER_HOUR);
	span2 += interval2->month * ((double) DAYS_PER_MONTH * SECS_PER_DAY);
	span2 += interval2->day * ((double) HOURS_PER_DAY * SECS_PER_HOUR);
#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));
}

Datum
interval_hash(PG_FUNCTION_ARGS)
{
	Interval   *key = PG_GETARG_INTERVAL_P(0);
	uint32		thash;
	uint32		mhash;

	/*
	 * To avoid any problems with padding bytes in the struct, we figure the
	 * field hashes separately and XOR them.  This also provides a convenient
	 * framework for dealing with the fact that the time field might be either
	 * double or int64.
	 */
#ifdef HAVE_INT64_TIMESTAMP
	thash = DatumGetUInt32(DirectFunctionCall1(hashint8,
											   Int64GetDatumFast(key->time)));
#else
	thash = DatumGetUInt32(DirectFunctionCall1(hashfloat8,
											 Float8GetDatumFast(key->time)));
#endif
	thash ^= DatumGetUInt32(hash_uint32(key->day));
	/* Shift so "k days" and "k months" don't hash to the same thing */
	mhash = DatumGetUInt32(hash_uint32(key->month));
	thash ^= mhash << 24;
	thash ^= mhash >> 8;
	PG_RETURN_UINT32(thash);
}

/* 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))
	{