date.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 2,274 行 · 第 1/4 页

	if (dterr == 0)
		dterr = DecodeTimeOnly(field, ftype, nf, &dtype, tm, &fsec, &tz);
	if (dterr != 0)
		DateTimeParseError(dterr, str, "time");

	tm2time(tm, fsec, &result);
	AdjustTimeForTypmod(&result, typmod);

	PG_RETURN_TIMEADT(result);
}

/* tm2time()
 * Convert a tm structure to a time data type.
 */
static int
tm2time(struct tm * tm, fsec_t fsec, TimeADT *result)
{
#ifdef HAVE_INT64_TIMESTAMP
	*result = ((((((tm->tm_hour * 60) + tm->tm_min) * 60) + tm->tm_sec)
				* INT64CONST(1000000)) + fsec);
#else
	*result = ((((tm->tm_hour * 60) + tm->tm_min) * 60) + tm->tm_sec + fsec);
#endif
	return 0;
}

/* time2tm()
 * Convert time data type to POSIX time structure.
 * For dates within the system-supported time_t range, convert to the
 *	local time zone. If out of this range, leave as GMT. - tgl 97/05/27
 */
static int
time2tm(TimeADT time, struct tm * tm, fsec_t *fsec)
{
#ifdef HAVE_INT64_TIMESTAMP
	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));
	time -= (tm->tm_sec * INT64CONST(1000000));
	*fsec = time;
#else
	double		trem;

	trem = time;
	TMODULO(trem, tm->tm_hour, 3600e0);
	TMODULO(trem, tm->tm_min, 60e0);
	TMODULO(trem, tm->tm_sec, 1e0);
	*fsec = trem;
#endif

	return 0;
}

Datum
time_out(PG_FUNCTION_ARGS)
{
	TimeADT		time = PG_GETARG_TIMEADT(0);
	char	   *result;
	struct tm	tt,
			   *tm = &tt;
	fsec_t		fsec;
	char		buf[MAXDATELEN + 1];

	time2tm(time, tm, &fsec);
	EncodeTimeOnly(tm, fsec, NULL, DateStyle, buf);

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

/*
 *		time_recv			- converts external binary format to time
 *
 * We make no attempt to provide compatibility between int and float
 * time representations ...
 */
Datum
time_recv(PG_FUNCTION_ARGS)
{
	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);

#ifdef HAVE_INT64_TIMESTAMP
	PG_RETURN_TIMEADT((TimeADT) pq_getmsgint64(buf));
#else
	PG_RETURN_TIMEADT((TimeADT) pq_getmsgfloat8(buf));
#endif
}

/*
 *		time_send			- converts time to binary format
 */
Datum
time_send(PG_FUNCTION_ARGS)
{
	TimeADT		time = PG_GETARG_TIMEADT(0);
	StringInfoData buf;

	pq_begintypsend(&buf);
#ifdef HAVE_INT64_TIMESTAMP
	pq_sendint64(&buf, time);
#else
	pq_sendfloat8(&buf, time);
#endif
	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}


/* time_scale()
 * Adjust time type for specified scale factor.
 * Used by PostgreSQL type system to stuff columns.
 */
Datum
time_scale(PG_FUNCTION_ARGS)
{
	TimeADT		time = PG_GETARG_TIMEADT(0);
	int32		typmod = PG_GETARG_INT32(1);
	TimeADT		result;

	result = time;
	AdjustTimeForTypmod(&result, typmod);

	PG_RETURN_TIMEADT(result);
}

/* AdjustTimeForTypmod()
 * Force the precision of the time value to a specified value.
 * Uses *exactly* the same code as in AdjustTimestampForTypemod()
 * but we make a separate copy because those types do not
 * have a fundamental tie together but rather a coincidence of
 * implementation. - thomas
 */
static void
AdjustTimeForTypmod(TimeADT *time, int32 typmod)
{
#ifdef HAVE_INT64_TIMESTAMP
	static const int64 TimeScales[MAX_TIME_PRECISION + 1] = {
		INT64CONST(1000000),
		INT64CONST(100000),
		INT64CONST(10000),
		INT64CONST(1000),
		INT64CONST(100),
		INT64CONST(10),
		INT64CONST(1)
	};

	static const int64 TimeOffsets[MAX_TIME_PRECISION + 1] = {
		INT64CONST(500000),
		INT64CONST(50000),
		INT64CONST(5000),
		INT64CONST(500),
		INT64CONST(50),
		INT64CONST(5),
		INT64CONST(0)
	};

#else
	/* note MAX_TIME_PRECISION differs in this case */
	static const double TimeScales[MAX_TIME_PRECISION + 1] = {
		1.0,
		10.0,
		100.0,
		1000.0,
		10000.0,
		100000.0,
		1000000.0,
		10000000.0,
		100000000.0,
		1000000000.0,
		10000000000.0
	};
#endif

	if ((typmod >= 0) && (typmod <= MAX_TIME_PRECISION))
	{
		/*
		 * Note: this round-to-nearest code is not completely consistent
		 * about rounding values that are exactly halfway between integral
		 * values.	On most platforms, rint() will implement
		 * round-to-nearest-even, but the integer code always rounds up
		 * (away from zero).  Is it worth trying to be consistent?
		 */
#ifdef HAVE_INT64_TIMESTAMP
		if (*time >= INT64CONST(0))
		{
			*time = (((*time + TimeOffsets[typmod]) / TimeScales[typmod])
					 * TimeScales[typmod]);
		}
		else
		{
			*time = -((((-*time) + TimeOffsets[typmod]) / TimeScales[typmod])
					  * TimeScales[typmod]);
		}
#else
		*time = (rint(((double) *time) * TimeScales[typmod])
				 / TimeScales[typmod]);
#endif
	}
}


Datum
time_eq(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);

	PG_RETURN_BOOL(time1 == time2);
}

Datum
time_ne(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);

	PG_RETURN_BOOL(time1 != time2);
}

Datum
time_lt(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);

	PG_RETURN_BOOL(time1 < time2);
}

Datum
time_le(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);

	PG_RETURN_BOOL(time1 <= time2);
}

Datum
time_gt(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);

	PG_RETURN_BOOL(time1 > time2);
}

Datum
time_ge(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);

	PG_RETURN_BOOL(time1 >= time2);
}

Datum
time_cmp(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);

	if (time1 < time2)
		PG_RETURN_INT32(-1);
	if (time1 > time2)
		PG_RETURN_INT32(1);
	PG_RETURN_INT32(0);
}

Datum
time_larger(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);

	PG_RETURN_TIMEADT((time1 > time2) ? time1 : time2);
}

Datum
time_smaller(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);

	PG_RETURN_TIMEADT((time1 < time2) ? time1 : time2);
}

/* overlaps_time() --- 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_time(PG_FUNCTION_ARGS)
{
	/*
	 * The arguments are TimeADT, but we leave them as generic Datums to
	 * avoid dereferencing nulls (TimeADT is pass-by-reference!)
	 */
	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 TIMEADT_GT(t1,t2) \
	(DatumGetTimeADT(t1) > DatumGetTimeADT(t2))
#define TIMEADT_LT(t1,t2) \
	(DatumGetTimeADT(t1) < DatumGetTimeADT(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 (TIMEADT_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 (TIMEADT_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 (TIMEADT_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 (TIMEADT_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 (TIMEADT_LT(ts1, ts2))
	{
		/* This case is ts2 < te1 OR te2 < te1 */
		if (te1IsNull)
			PG_RETURN_NULL();
		if (TIMEADT_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 TIMEADT_GT
#undef TIMEADT_LT
}

/* timestamp_time()
 * Convert timestamp to time data type.
 */
Datum
timestamp_time(PG_FUNCTION_ARGS)
{
	Timestamp	timestamp = PG_GETARG_TIMESTAMP(0);
	TimeADT		result;
	struct tm	tt,
			   *tm = &tt;
	fsec_t		fsec;

	if (TIMESTAMP_NOT_FINITE(timestamp))
		PG_RETURN_NULL();

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

#ifdef HAVE_INT64_TIMESTAMP

	/*
	 * Could also do this with time = (timestamp / 86400000000 *
	 * 86400000000) - timestamp;
	 */
	result = ((((((tm->tm_hour * 60) + tm->tm_min) * 60) + tm->tm_sec)
			   * INT64CONST(1000000)) + fsec);
#else
	result = ((((tm->tm_hour * 60) + tm->tm_min) * 60) + tm->tm_sec + fsec);
#endif

	PG_RETURN_TIMEADT(result);
}

/* timestamptz_time()
 * Convert timestamptz to time data type.
 */
Datum
timestamptz_time(PG_FUNCTION_ARGS)
{
	TimestampTz timestamp = PG_GETARG_TIMESTAMP(0);
	TimeADT		result;
	struct 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) != 0)
		ereport(ERROR,
				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
				 errmsg("timestamp out of range")));

#ifdef HAVE_INT64_TIMESTAMP

	/*
	 * Could also do this with time = (timestamp / 86400000000 *
	 * 86400000000) - timestamp;
	 */
	result = ((((((tm->tm_hour * 60) + tm->tm_min) * 60) + tm->tm_sec)
			   * INT64CONST(1000000)) + fsec);
#else
	result = ((((tm->tm_hour * 60) + tm->tm_min) * 60) + tm->tm_sec + fsec);
#endif

	PG_RETURN_TIMEADT(result);
}

/* datetime_timestamp()
 * Convert date and time to timestamp data type.
 */
Datum
datetime_timestamp(PG_FUNCTION_ARGS)
{
	DateADT		date = PG_GETARG_DATEADT(0);
	TimeADT		time = PG_GETARG_TIMEADT(1);
	Timestamp	result;

	result = DatumGetTimestamp(DirectFunctionCall1(date_timestamp,
												 DateADTGetDatum(date)));
	result += time;

	PG_RETURN_TIMESTAMP(result);
}

/* time_interval()
 * Convert time to interval data type.
 */
Datum
time_interval(PG_FUNCTION_ARGS)
{
	TimeADT		time = PG_GETARG_TIMEADT(0);
	Interval   *result;

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

	result->time = time;
	result->month = 0;

	PG_RETURN_INTERVAL_P(result);
}

/* interval_time()
 * Convert interval to time data type.
 *
 * This is defined as producing the fractional-day portion of the interval.
 * Therefore, we can just ignore the months field.	It is not real clear
 * what to do with negative intervals, but we choose to subtract the floor,
 * so that, say, '-2 hours' becomes '22:00:00'.
 */
Datum
interval_time(PG_FUNCTION_ARGS)
{
	Interval   *span = PG_GETARG_INTERVAL_P(0);
	TimeADT		result;

#ifdef HAVE_INT64_TIMESTAMP
	int64		days;

	result = span->time;
	if (result >= INT64CONST(86400000000))
	{
		days = result / INT64CONST(86400000000);
		result -= days * INT64CONST(86400000000);
	}
	else if (result < 0)
	{
		days = (-result + INT64CONST(86400000000) - 1) / INT64CONST(86400000000);
		result += days * INT64CONST(86400000000);
	}
#else
	result = span->time;
	if (result >= 86400e0 || result < 0)
		result -= floor(result / 86400e0) * 86400e0;
#endif

	PG_RETURN_TIMEADT(result);
}

/* time_mi_time()
 * Subtract two times to produce an interval.
 */
Datum
time_mi_time(PG_FUNCTION_ARGS)
{
	TimeADT		time1 = PG_GETARG_TIMEADT(0);
	TimeADT		time2 = PG_GETARG_TIMEADT(1);
	Interval   *result;

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

	result->time = (time1 - time2);