date.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

Datum
timetz_gt(PG_FUNCTION_ARGS)
{
	TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
	TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

	PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) > 0);
}

Datum
timetz_ge(PG_FUNCTION_ARGS)
{
	TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
	TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

	PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) >= 0);
}

Datum
timetz_cmp(PG_FUNCTION_ARGS)
{
	TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
	TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

	PG_RETURN_INT32(timetz_cmp_internal(time1, time2));
}

/*
 * timetz, being an unusual size, needs a specialized hash function.
 */
Datum
timetz_hash(PG_FUNCTION_ARGS)
{
	TimeTzADT  *key = PG_GETARG_TIMETZADT_P(0);

	/*
	 * Specify hash length as sizeof(double) + sizeof(int4), not as
	 * sizeof(TimeTzADT), 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->zone));
}

Datum
timetz_larger(PG_FUNCTION_ARGS)
{
	TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
	TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
	TimeTzADT  *result;

	if (timetz_cmp_internal(time1, time2) > 0)
		result = time1;
	else
		result = time2;
	PG_RETURN_TIMETZADT_P(result);
}

Datum
timetz_smaller(PG_FUNCTION_ARGS)
{
	TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
	TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
	TimeTzADT  *result;

	if (timetz_cmp_internal(time1, time2) < 0)
		result = time1;
	else
		result = time2;
	PG_RETURN_TIMETZADT_P(result);
}

/* timetz_pl_interval()
 * Add interval to timetz.
 */
Datum
timetz_pl_interval(PG_FUNCTION_ARGS)
{
	TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
	Interval   *span = PG_GETARG_INTERVAL_P(1);
	TimeTzADT  *result;

#ifndef HAVE_INT64_TIMESTAMP
	TimeTzADT	time1;
#endif

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

#ifdef HAVE_INT64_TIMESTAMP
	result->time = time->time + span->time;
	result->time -= result->time / USECS_PER_DAY * USECS_PER_DAY;
	if (result->time < INT64CONST(0))
		result->time += USECS_PER_DAY;
#else
	result->time = time->time + span->time;
	TMODULO(result->time, time1.time, (double) SECS_PER_DAY);
	if (result->time < 0)
		result->time += SECS_PER_DAY;
#endif

	result->zone = time->zone;

	PG_RETURN_TIMETZADT_P(result);
}

/* timetz_mi_interval()
 * Subtract interval from timetz.
 */
Datum
timetz_mi_interval(PG_FUNCTION_ARGS)
{
	TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
	Interval   *span = PG_GETARG_INTERVAL_P(1);
	TimeTzADT  *result;

#ifndef HAVE_INT64_TIMESTAMP
	TimeTzADT	time1;
#endif

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

#ifdef HAVE_INT64_TIMESTAMP
	result->time = time->time - span->time;
	result->time -= result->time / USECS_PER_DAY * USECS_PER_DAY;
	if (result->time < INT64CONST(0))
		result->time += USECS_PER_DAY;
#else
	result->time = time->time - span->time;
	TMODULO(result->time, time1.time, (double) SECS_PER_DAY);
	if (result->time < 0)
		result->time += SECS_PER_DAY;
#endif

	result->zone = time->zone;

	PG_RETURN_TIMETZADT_P(result);
}

/* overlaps_timetz() --- 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_timetz(PG_FUNCTION_ARGS)
{
	/*
	 * The arguments are TimeTzADT *, but we leave them as generic Datums for
	 * convenience of notation --- and to avoid dereferencing nulls.
	 */
	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 TIMETZ_GT(t1,t2) \
	DatumGetBool(DirectFunctionCall2(timetz_gt,t1,t2))
#define TIMETZ_LT(t1,t2) \
	DatumGetBool(DirectFunctionCall2(timetz_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 (TIMETZ_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 (TIMETZ_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 (TIMETZ_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 (TIMETZ_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 (TIMETZ_LT(ts1, ts2))
	{
		/* This case is ts2 < te1 OR te2 < te1 */
		if (te1IsNull)
			PG_RETURN_NULL();
		if (TIMETZ_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 TIMETZ_GT
#undef TIMETZ_LT
}


Datum
timetz_time(PG_FUNCTION_ARGS)
{
	TimeTzADT  *timetz = PG_GETARG_TIMETZADT_P(0);
	TimeADT		result;

	/* swallow the time zone and just return the time */
	result = timetz->time;

	PG_RETURN_TIMEADT(result);
}


Datum
time_timetz(PG_FUNCTION_ARGS)
{
	TimeADT		time = PG_GETARG_TIMEADT(0);
	TimeTzADT  *result;
	struct pg_tm tt,
			   *tm = &tt;
	fsec_t		fsec;
	int			tz;

	GetCurrentDateTime(tm);
	time2tm(time, tm, &fsec);
	tz = DetermineTimeZoneOffset(tm, global_timezone);

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

	result->time = time;
	result->zone = tz;

	PG_RETURN_TIMETZADT_P(result);
}


/* timestamptz_timetz()
 * Convert timestamp to timetz data type.
 */
Datum
timestamptz_timetz(PG_FUNCTION_ARGS)
{
	TimestampTz timestamp = PG_GETARG_TIMESTAMP(0);
	TimeTzADT  *result;
	struct pg_tm tt,
			   *tm = &tt;
	int			tz;
	fsec_t		fsec;
	char	   *tzn;

	if (TIMESTAMP_NOT_FINITE(timestamp))
		PG_RETURN_NULL();

	if (timestamp2tm(timestamp, &tz, tm, &fsec, &tzn, NULL) != 0)
		ereport(ERROR,
				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
				 errmsg("timestamp out of range")));

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

	tm2timetz(tm, fsec, tz, result);

	PG_RETURN_TIMETZADT_P(result);
}


/* datetimetz_timestamptz()
 * Convert date and timetz to timestamp with time zone data type.
 * Timestamp is stored in GMT, so add the time zone
 * stored with the timetz to the result.
 * - thomas 2000-03-10
 */
Datum
datetimetz_timestamptz(PG_FUNCTION_ARGS)
{
	DateADT		date = PG_GETARG_DATEADT(0);
	TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
	TimestampTz result;

#ifdef HAVE_INT64_TIMESTAMP
	result = date * USECS_PER_DAY + time->time + time->zone * USECS_PER_SEC;
#else
	result = date * (double) SECS_PER_DAY + time->time + time->zone;
#endif

	PG_RETURN_TIMESTAMP(result);
}


/* timetz_text()
 * Convert timetz to text data type.
 */
Datum
timetz_text(PG_FUNCTION_ARGS)
{
	/* Input is a Timetz, but may as well leave it in Datum form */
	Datum		timetz = PG_GETARG_DATUM(0);
	text	   *result;
	char	   *str;
	int			len;

	str = DatumGetCString(DirectFunctionCall1(timetz_out, timetz));

	len = strlen(str) + VARHDRSZ;

	result = palloc(len);

	VARATT_SIZEP(result) = len;
	memmove(VARDATA(result), str, (len - VARHDRSZ));

	pfree(str);

	PG_RETURN_TEXT_P(result);
}


/* text_timetz()
 * Convert text string to timetz.
 * Text type is not null terminated, so use temporary string
 *	then call the standard input routine.
 */
Datum
text_timetz(PG_FUNCTION_ARGS)
{
	text	   *str = PG_GETARG_TEXT_P(0);
	int			i;
	char	   *sp,
			   *dp,
				dstr[MAXDATELEN + 1];

	if (VARSIZE(str) - VARHDRSZ > MAXDATELEN)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_DATETIME_FORMAT),
		  errmsg("invalid input syntax for type time with time zone: \"%s\"",
				 VARDATA(str))));

	sp = VARDATA(str);
	dp = dstr;
	for (i = 0; i < (VARSIZE(str) - VARHDRSZ); i++)
		*dp++ = *sp++;
	*dp = '\0';

	return DirectFunctionCall3(timetz_in,
							   CStringGetDatum(dstr),
							   ObjectIdGetDatum(InvalidOid),
							   Int32GetDatum(-1));
}

/* timetz_part()
 * Extract specified field from time type.
 */
Datum
timetz_part(PG_FUNCTION_ARGS)
{
	text	   *units = PG_GETARG_TEXT_P(0);
	TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
	float8		result;
	int			type,
				val;
	char	   *lowunits;

	lowunits = downcase_truncate_identifier(VARDATA(units),
											VARSIZE(units) - VARHDRSZ,
											false);

	type = DecodeUnits(0, lowunits, &val);
	if (type == UNKNOWN_FIELD)
		type = DecodeSpecial(0, lowunits, &val);

	if (type == UNITS)
	{
		double		dummy;
		int			tz;
		fsec_t		fsec;
		struct pg_tm tt,
				   *tm = &tt;

		timetz2tm(time, tm, &fsec, &tz);

		switch (val)
		{
			case DTK_TZ:
				result = -tz;
				break;

			case DTK_TZ_MINUTE:
				result = -tz;
				result /= SECS_PER_MINUTE;
				FMODULO(result, dummy, (double) SECS_PER_MINUTE);
				break;

			case DTK_TZ_HOUR:
				dummy = -tz;
				FMODULO(dummy, result, (double) SECS_PER_HOUR);
				break;

			case DTK_MICROSEC:
#ifdef HAVE_INT64_TIMESTAMP
				result = tm->tm_sec * USECS_PER_SEC + fsec;
#else
				result = (tm->tm_sec + fsec) * 1000000;
#endif
				break;

			case DTK_MILLISEC:
#ifdef HAVE_INT64_TIMESTAMP
				result = tm->tm_sec * INT64CONST(1000) + fsec / INT64CONST(1000);
#else
				result = (tm->tm_sec + fsec) * 1000;
#endif
				break;

			case DTK_SECOND:
#ifdef HAVE_INT64_TIMESTAMP
				result = tm->tm_sec + fsec / USECS_PER_SEC;
#else
				result = tm->tm_sec + fsec;
#endif
				break;

			case DTK_MINUTE:
				result = tm->tm_min;
				break;

			case DTK_HOUR:
				result = tm->tm_hour;
				break;

			case DTK_DAY:
			case DTK_MONTH:
			case DTK_QUARTER:
			case DTK_YEAR:
			case DTK_DECADE:
			case DTK_CENTURY:
			case DTK_MILLENNIUM:
			default:
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				errmsg("\"time with time zone\" units \"%s\" not recognized",
					   DatumGetCString(DirectFunctionCall1(textout,
												 PointerGetDatum(units))))));

				result = 0;
		}
	}
	else if (type == RESERV && val == DTK_EPOCH)
	{
#ifdef HAVE_INT64_TIMESTAMP
		result = time->time / 1000000.0 + time->zone;
#else
		result = time->time + time->zone;
#endif
	}
	else
	{
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("\"time with time zone\" units \"%s\" not recognized",
						DatumGetCString(DirectFunctionCall1(textout,
												 PointerGetDatum(units))))));

		result = 0;
	}

	PG_RETURN_FLOAT8(result);
}

/* timetz_zone()
 * Encode time with time zone type with specified time zone.
 * Applies DST rules as of the current date.
 */
Datum
timetz_zone(PG_FUNCTION_ARGS)
{
	text	   *zone = PG_GETARG_TEXT_P(0);
	TimeTzADT  *t = PG_GETARG_TIMETZADT_P(1);
	TimeTzADT  *result;
	int			tz;
	char		tzname[TZ_STRLEN_MAX + 1];
	int			len;
	pg_tz	   *tzp;

	/*
	 * Look up the requested timezone.	First we look in the timezone database
	 * (to handle cases like "America/New_York"), and if that fails, we look
	 * in the date token table (to handle cases like "EST").
	 */
	len = Min(VARSIZE(zone) - VARHDRSZ, TZ_STRLEN_MAX);
	memcpy(tzname, VARDATA(zone), len);
	tzname[len] = '\0';
	tzp = pg_tzset(tzname);
	if (tzp)
	{
		/* Get the offset-from-GMT that is valid today for the selected zone */
		pg_time_t	now;
		struct pg_tm *tm;

		now = time(NULL);
		tm = pg_localtime(&now, tzp);
		tz = -tm->tm_gmtoff;
	}
	else
	{
		char	   *lowzone;
		int			type,
					val;

		lowzone = downcase_truncate_identifier(VARDATA(zone),
											   VARSIZE(zone) - VARHDRSZ,
											   false);
		type = DecodeSpecial(0, lowzone, &val);

		if (type == TZ || type == DTZ)
			tz = val * 60;
		else
		{
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
					 errmsg("time zone \"%s\" not recognized", tzname)));
			tz = 0;				/* keep compiler quiet */
		}
	}

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

#ifdef HAVE_INT64_TIMESTAMP
	result->time = t->time + (t->zone - tz) * USECS_PER_SEC;
	while (result->time < INT64CONST(0))
		result->time += USECS_PER_DAY;
	while (result->time >= USECS_PER_DAY)
		result->time -= USECS_PER_DAY;
#else
	result->time = t->time + (t->zone - tz);
	while (result->time < 0)
		result->time += SECS_PER_DAY;
	while (result->time >= SECS_PER_DAY)
		result->time -= SECS_PER_DAY;
#endif

	result->zone = tz;

	PG_RETURN_TIMETZADT_P(result);
}

/* timetz_izone()
 * Encode time with time zone type with specified time interval as time zone.
 */
Datum
timetz_izone(PG_FUNCTION_ARGS)
{
	Interval   *zone = PG_GETARG_INTERVAL_P(0);
	TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
	TimeTzADT  *result;
	int			tz;

	if (zone->month != 0)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("\"interval\" time zone \"%s\" not valid",
						DatumGetCString(DirectFunctionCall1(interval_out,
												  PointerGetDatum(zone))))));

#ifdef HAVE_INT64_TIMESTAMP
	tz = -(zone->time / USECS_PER_SEC);
#else
	tz = -(zone->time);
#endif

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

#ifdef HAVE_INT64_TIMESTAMP
	result->time = time->time + (time->zone - tz) * USECS_PER_SEC;
	while (result->time < INT64CONST(0))
		result->time += USECS_PER_DAY;
	while (result->time >= USECS_PER_DAY)
		result->time -= USECS_PER_DAY;
#else
	result->time = time->time + (time->zone - tz);
	while (result->time < 0)
		result->time += SECS_PER_DAY;
	while (result->time >= SECS_PER_DAY)
		result->time -= SECS_PER_DAY;
#endif

	result->zone = tz;

	PG_RETURN_TIMETZADT_P(result);
}