nabstime.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

/* timestamptz_abstime()
 * Convert timestamp with time zone to abstime.
 */
Datum
timestamptz_abstime(PG_FUNCTION_ARGS)
{
	TimestampTz timestamp = PG_GETARG_TIMESTAMP(0);
	AbsoluteTime result;
	fsec_t		fsec;
	struct pg_tm tt,
			   *tm = &tt;

	if (TIMESTAMP_IS_NOBEGIN(timestamp))
		result = NOSTART_ABSTIME;
	else if (TIMESTAMP_IS_NOEND(timestamp))
		result = NOEND_ABSTIME;
	else if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) == 0)
		result = tm2abstime(tm, 0);
	else
	{
		ereport(ERROR,
				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
				 errmsg("timestamp out of range")));
		result = INVALID_ABSTIME;
	}

	PG_RETURN_ABSOLUTETIME(result);
}

/* 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")));
			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")));
			break;
	};

	PG_RETURN_TIMESTAMP(result);
}


/*****************************************************************************
 *	 USER I/O ROUTINES														 *
 *****************************************************************************/

/*
 *		reltimein		- converts a reltime string in an internal format
 */
Datum
reltimein(PG_FUNCTION_ARGS)
{
	char	   *str = PG_GETARG_CSTRING(0);
	RelativeTime result;
	struct pg_tm tt,
			   *tm = &tt;
	fsec_t		fsec;
	int			dtype;
	int			dterr;
	char	   *field[MAXDATEFIELDS];
	int			nf,
				ftype[MAXDATEFIELDS];
	char		workbuf[MAXDATELEN + 1];

	dterr = ParseDateTime(str, workbuf, sizeof(workbuf),
						  field, ftype, MAXDATEFIELDS, &nf);
	if (dterr == 0)
		dterr = DecodeInterval(field, ftype, nf, &dtype, tm, &fsec);
	if (dterr != 0)
	{
		if (dterr == DTERR_FIELD_OVERFLOW)
			dterr = DTERR_INTERVAL_OVERFLOW;
		DateTimeParseError(dterr, str, "reltime");
	}

	switch (dtype)
	{
		case DTK_DELTA:
			result = ((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec;
			result += tm->tm_year * SECS_PER_YEAR + ((tm->tm_mon * DAYS_PER_MONTH) + tm->tm_mday) * SECS_PER_DAY;
			break;

		default:
			elog(ERROR, "unexpected dtype %d while parsing reltime \"%s\"",
				 dtype, str);
			result = INVALID_RELTIME;
			break;
	}

	PG_RETURN_RELATIVETIME(result);
}

/*
 *		reltimeout		- converts the internal format to a reltime string
 */
Datum
reltimeout(PG_FUNCTION_ARGS)
{
	RelativeTime time = PG_GETARG_RELATIVETIME(0);
	char	   *result;
	struct pg_tm tt,
			   *tm = &tt;
	char		buf[MAXDATELEN + 1];

	reltime2tm(time, tm);
	EncodeInterval(tm, 0, DateStyle, buf);

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

/*
 *		reltimerecv			- converts external binary format to reltime
 */
Datum
reltimerecv(PG_FUNCTION_ARGS)
{
	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);

	PG_RETURN_RELATIVETIME((RelativeTime) pq_getmsgint(buf, sizeof(RelativeTime)));
}

/*
 *		reltimesend			- converts reltime to binary format
 */
Datum
reltimesend(PG_FUNCTION_ARGS)
{
	RelativeTime time = PG_GETARG_RELATIVETIME(0);
	StringInfoData buf;

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


static void
reltime2tm(RelativeTime time, struct pg_tm * tm)
{
	double		dtime = time;

	FMODULO(dtime, tm->tm_year, 31557600);
	FMODULO(dtime, tm->tm_mon, 2592000);
	FMODULO(dtime, tm->tm_mday, SECS_PER_DAY);
	FMODULO(dtime, tm->tm_hour, SECS_PER_HOUR);
	FMODULO(dtime, tm->tm_min, SECS_PER_MINUTE);
	FMODULO(dtime, tm->tm_sec, 1);
}


/*
 *		tintervalin		- converts an tinterval string to internal format
 */
Datum
tintervalin(PG_FUNCTION_ARGS)
{
	char	   *tintervalstr = PG_GETARG_CSTRING(0);
	TimeInterval tinterval;
	AbsoluteTime i_start,
				i_end,
				t1,
				t2;

	parsetinterval(tintervalstr, &t1, &t2);

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

	if (t1 == INVALID_ABSTIME || t2 == INVALID_ABSTIME)
		tinterval->status = T_INTERVAL_INVAL;	/* undefined  */
	else
		tinterval->status = T_INTERVAL_VALID;

	i_start = ABSTIMEMIN(t1, t2);
	i_end = ABSTIMEMAX(t1, t2);
	tinterval->data[0] = i_start;
	tinterval->data[1] = i_end;

	PG_RETURN_TIMEINTERVAL(tinterval);
}


/*
 *		tintervalout	- converts an internal tinterval format to a string
 */
Datum
tintervalout(PG_FUNCTION_ARGS)
{
	TimeInterval tinterval = PG_GETARG_TIMEINTERVAL(0);
	char	   *i_str,
			   *p;

	i_str = (char *) palloc(T_INTERVAL_LEN);	/* ["..." "..."] */
	strcpy(i_str, "[\"");
	if (tinterval->status == T_INTERVAL_INVAL)
		strcat(i_str, INVALID_INTERVAL_STR);
	else
	{
		p = DatumGetCString(DirectFunctionCall1(abstimeout,
								  AbsoluteTimeGetDatum(tinterval->data[0])));
		strcat(i_str, p);
		pfree(p);
		strcat(i_str, "\" \"");
		p = DatumGetCString(DirectFunctionCall1(abstimeout,
								  AbsoluteTimeGetDatum(tinterval->data[1])));
		strcat(i_str, p);
		pfree(p);
	}
	strcat(i_str, "\"]");
	PG_RETURN_CSTRING(i_str);
}

/*
 *		tintervalrecv			- converts external binary format to tinterval
 */
Datum
tintervalrecv(PG_FUNCTION_ARGS)
{
	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
	TimeInterval tinterval;

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

	tinterval->status = pq_getmsgint(buf, sizeof(tinterval->status));

	if (!(tinterval->status == T_INTERVAL_INVAL ||
		  tinterval->status == T_INTERVAL_VALID))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
				 errmsg("invalid status in external \"tinterval\" value")));

	tinterval->data[0] = pq_getmsgint(buf, sizeof(tinterval->data[0]));
	tinterval->data[1] = pq_getmsgint(buf, sizeof(tinterval->data[1]));

	PG_RETURN_TIMEINTERVAL(tinterval);
}

/*
 *		tintervalsend			- converts tinterval to binary format
 */
Datum
tintervalsend(PG_FUNCTION_ARGS)
{
	TimeInterval tinterval = PG_GETARG_TIMEINTERVAL(0);
	StringInfoData buf;

	pq_begintypsend(&buf);
	pq_sendint(&buf, tinterval->status, sizeof(tinterval->status));
	pq_sendint(&buf, tinterval->data[0], sizeof(tinterval->data[0]));
	pq_sendint(&buf, tinterval->data[1], sizeof(tinterval->data[1]));
	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}


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

Datum
interval_reltime(PG_FUNCTION_ARGS)
{
	Interval   *interval = PG_GETARG_INTERVAL_P(0);
	RelativeTime time;
	int			year,
				month,
				day;

#ifdef HAVE_INT64_TIMESTAMP
	int64		span;
#else
	double		span;
#endif

	year = interval->month / MONTHS_PER_YEAR;
	month = interval->month % MONTHS_PER_YEAR;
	day = interval->day;

#ifdef HAVE_INT64_TIMESTAMP
	span = ((INT64CONST(365250000) * year + INT64CONST(30000000) * month +
			 INT64CONST(1000000) * day) * INT64CONST(86400)) +
		interval->time;
	span /= USECS_PER_SEC;
#else
	span = (DAYS_PER_YEAR * year + (double) DAYS_PER_MONTH * month + day) * SECS_PER_DAY + interval->time;
#endif

	if (span < INT_MIN || span > INT_MAX)
		time = INVALID_RELTIME;
	else
		time = span;

	PG_RETURN_RELATIVETIME(time);
}


Datum
reltime_interval(PG_FUNCTION_ARGS)
{
	RelativeTime reltime = PG_GETARG_RELATIVETIME(0);
	Interval   *result;
	int			year,
				month,
				day;

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

	switch (reltime)
	{
		case INVALID_RELTIME:
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				  errmsg("cannot convert reltime \"invalid\" to interval")));
			result->time = 0;
			result->day = 0;
			result->month = 0;
			break;

		default:
#ifdef HAVE_INT64_TIMESTAMP
			year = reltime / SECS_PER_YEAR;
			reltime -= year * SECS_PER_YEAR;
			month = reltime / (DAYS_PER_MONTH * SECS_PER_DAY);
			reltime -= month * (DAYS_PER_MONTH * SECS_PER_DAY);
			day = reltime / SECS_PER_DAY;
			reltime -= day * SECS_PER_DAY;

			result->time = (reltime * USECS_PER_SEC);
#else
			TMODULO(reltime, year, SECS_PER_YEAR);
			TMODULO(reltime, month, DAYS_PER_MONTH * SECS_PER_DAY);
			TMODULO(reltime, day, SECS_PER_DAY);

			result->time = reltime;
#endif
			result->month = MONTHS_PER_YEAR * year + month;
			result->day = day;
			break;
	}

	PG_RETURN_INTERVAL_P(result);
}


/*
 *		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);
}

/*
 *		timepl, timemi and abstimemi use the formula
 *				abstime + reltime = abstime
 *		so		abstime - reltime = abstime
 *		and		abstime - abstime = reltime
 */

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

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

	PG_RETURN_ABSOLUTETIME(INVALID_ABSTIME);
}


/*
 *		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);
}


/*
 *		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);
}

/*
 *		tintervalrel		- returns  relative time corresponding to tinterval
 */
Datum
tintervalrel(PG_FUNCTION_ARGS)
{
	TimeInterval tinterval = PG_GETARG_TIMEINTERVAL(0);
	AbsoluteTime t1 = tinterval->data[0];
	AbsoluteTime t2 = tinterval->data[1];

	if (tinterval->status != T_INTERVAL_VALID)
		PG_RETURN_RELATIVETIME(INVALID_RELTIME);

	if (AbsoluteTimeIsReal(t1) &&
		AbsoluteTimeIsReal(t2))
		PG_RETURN_RELATIVETIME(t2 - t1);

	PG_RETURN_RELATIVETIME(INVALID_RELTIME);
}


/*
 *		timenow			- returns  time "now", internal format
 *
 *		Now AbsoluteTime is time since Jan 1 1970 -mer 7 Feb 1992
 */
Datum
timenow(PG_FUNCTION_ARGS)
{
	time_t		sec;

	if (time(&sec) < 0)
		PG_RETURN_ABSOLUTETIME(INVALID_ABSTIME);

	PG_RETURN_ABSOLUTETIME((AbsoluteTime) sec);
}

/*
 * reltime comparison routines
 */
static int
reltime_cmp_internal(RelativeTime a, RelativeTime b)
{
	/*
	 * We consider all INVALIDs to be equal and larger than any non-INVALID.
	 * This is somewhat arbitrary; the important thing is to have a consistent
	 * sort order.
	 */
	if (a == INVALID_RELTIME)
	{
		if (b == INVALID_RELTIME)
			return 0;			/* INVALID = INVALID */
		else
			return 1;			/* INVALID > non-INVALID */
	}

	if (b == INVALID_RELTIME)
		return -1;				/* non-INVALID < INVALID */

	if (a > b)
		return 1;
	else if (a == b)
		return 0;
	else
		return -1;
}