date.c

关系型数据库 Postgresql 6.5.2

}	/* intervalne() */

/*
 *		intervallt		- returns TRUE, iff interval i1 is less than interval i2
 *		Check length of intervals.
 */
bool
intervallt(TimeInterval i1, TimeInterval i2)
{
	AbsoluteTime t10,
				t11,
				t20,
				t21;

	if (i1->status == T_INTERVAL_INVAL || i2->status == T_INTERVAL_INVAL)
		return FALSE;			/* invalid interval */

	t10 = i1->data[0];
	t11 = i1->data[1];
	t20 = i2->data[0];
	t21 = i2->data[1];

	if ((t10 == INVALID_ABSTIME) || (t20 == INVALID_ABSTIME)
		|| (t20 == INVALID_ABSTIME) || (t21 == INVALID_ABSTIME))
		return FALSE;

	if (t10 == CURRENT_ABSTIME)
		t10 = GetCurrentTransactionStartTime();
	if (t11 == CURRENT_ABSTIME)
		t11 = GetCurrentTransactionStartTime();
	if (t20 == CURRENT_ABSTIME)
		t20 = GetCurrentTransactionStartTime();
	if (t21 == CURRENT_ABSTIME)
		t21 = GetCurrentTransactionStartTime();

	return (t11 - t10) < (t21 - t20);
}	/* intervallt() */

/*
 *		intervalle		- returns TRUE, iff interval i1 is less than or equal to interval i2
 *		Check length of intervals.
 */
bool
intervalle(TimeInterval i1, TimeInterval i2)
{
	AbsoluteTime t10,
				t11,
				t20,
				t21;

	if (i1->status == T_INTERVAL_INVAL || i2->status == T_INTERVAL_INVAL)
		return FALSE;			/* invalid interval */

	t10 = i1->data[0];
	t11 = i1->data[1];
	t20 = i2->data[0];
	t21 = i2->data[1];

	if ((t10 == INVALID_ABSTIME) || (t20 == INVALID_ABSTIME)
		|| (t20 == INVALID_ABSTIME) || (t21 == INVALID_ABSTIME))
		return FALSE;

	if (t10 == CURRENT_ABSTIME)
		t10 = GetCurrentTransactionStartTime();
	if (t11 == CURRENT_ABSTIME)
		t11 = GetCurrentTransactionStartTime();
	if (t20 == CURRENT_ABSTIME)
		t20 = GetCurrentTransactionStartTime();
	if (t21 == CURRENT_ABSTIME)
		t21 = GetCurrentTransactionStartTime();

	return (t11 - t10) <= (t21 - t20);
}	/* intervalle() */

/*
 *		intervalgt		- returns TRUE, iff interval i1 is less than interval i2
 *		Check length of intervals.
 */
bool
intervalgt(TimeInterval i1, TimeInterval i2)
{
	AbsoluteTime t10,
				t11,
				t20,
				t21;

	if (i1->status == T_INTERVAL_INVAL || i2->status == T_INTERVAL_INVAL)
		return FALSE;			/* invalid interval */

	t10 = i1->data[0];
	t11 = i1->data[1];
	t20 = i2->data[0];
	t21 = i2->data[1];

	if ((t10 == INVALID_ABSTIME) || (t20 == INVALID_ABSTIME)
		|| (t20 == INVALID_ABSTIME) || (t21 == INVALID_ABSTIME))
		return FALSE;

	if (t10 == CURRENT_ABSTIME)
		t10 = GetCurrentTransactionStartTime();
	if (t11 == CURRENT_ABSTIME)
		t11 = GetCurrentTransactionStartTime();
	if (t20 == CURRENT_ABSTIME)
		t20 = GetCurrentTransactionStartTime();
	if (t21 == CURRENT_ABSTIME)
		t21 = GetCurrentTransactionStartTime();

	return (t11 - t10) > (t21 - t20);
}	/* intervalgt() */

/*
 *		intervalge		- returns TRUE, iff interval i1 is less than or equal to interval i2
 *		Check length of intervals.
 */
bool
intervalge(TimeInterval i1, TimeInterval i2)
{
	AbsoluteTime t10,
				t11,
				t20,
				t21;

	if (i1->status == T_INTERVAL_INVAL || i2->status == T_INTERVAL_INVAL)
		return FALSE;			/* invalid interval */

	t10 = i1->data[0];
	t11 = i1->data[1];
	t20 = i2->data[0];
	t21 = i2->data[1];

	if ((t10 == INVALID_ABSTIME) || (t20 == INVALID_ABSTIME)
		|| (t20 == INVALID_ABSTIME) || (t21 == INVALID_ABSTIME))
		return FALSE;

	if (t10 == CURRENT_ABSTIME)
		t10 = GetCurrentTransactionStartTime();
	if (t11 == CURRENT_ABSTIME)
		t11 = GetCurrentTransactionStartTime();
	if (t20 == CURRENT_ABSTIME)
		t20 = GetCurrentTransactionStartTime();
	if (t21 == CURRENT_ABSTIME)
		t21 = GetCurrentTransactionStartTime();

	return (t11 - t10) >= (t21 - t20);
}	/* intervalge() */


/*
 *		intervalleneq	- returns 1, iff length of interval i is equal to
 *								reltime t
 */
bool
intervalleneq(TimeInterval i, RelativeTime t)
{
	RelativeTime rt;

	if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME))
		return 0;
	rt = intervalrel(i);
	return rt != INVALID_RELTIME && rt == t;
}

/*
 *		intervallenne	- returns 1, iff length of interval i is not equal
 *								to reltime t
 */
bool
intervallenne(TimeInterval i, RelativeTime t)
{
	RelativeTime rt;

	if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME))
		return 0;
	rt = intervalrel(i);
	return rt != INVALID_RELTIME && rt != t;
}

/*
 *		intervallenlt	- returns 1, iff length of interval i is less than
 *								reltime t
 */
bool
intervallenlt(TimeInterval i, RelativeTime t)
{
	RelativeTime rt;

	if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME))
		return 0;
	rt = intervalrel(i);
	return rt != INVALID_RELTIME && rt < t;
}

/*
 *		intervallengt	- returns 1, iff length of interval i is greater than
 *								reltime t
 */
bool
intervallengt(TimeInterval i, RelativeTime t)
{
	RelativeTime rt;

	if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME))
		return 0;
	rt = intervalrel(i);
	return rt != INVALID_RELTIME && rt > t;
}

/*
 *		intervallenle	- returns 1, iff length of interval i is less or equal
 *									than reltime t
 */
bool
intervallenle(TimeInterval i, RelativeTime t)
{
	RelativeTime rt;

	if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME))
		return 0;
	rt = intervalrel(i);
	return rt != INVALID_RELTIME && rt <= t;
}

/*
 *		intervallenge	- returns 1, iff length of interval i is greater or
 *								equal than reltime t
 */
bool
intervallenge(TimeInterval i, RelativeTime t)
{
	RelativeTime rt;

	if ((i->status == T_INTERVAL_INVAL) || (t == INVALID_RELTIME))
		return 0;
	rt = intervalrel(i);
	return rt != INVALID_RELTIME && rt >= t;
}

/*
 *		intervalct		- returns 1, iff interval i1 contains interval i2
 */
bool
intervalct(TimeInterval i1, TimeInterval i2)
{
	if (i1->status == T_INTERVAL_INVAL || i2->status == T_INTERVAL_INVAL)
		return 0;
	return (abstimele(i1->data[0], i2->data[0]) &&
			abstimege(i1->data[1], i2->data[1]));
}

/*
 *		intervalov		- returns 1, iff interval i1 (partially) overlaps i2
 */
bool
intervalov(TimeInterval i1, TimeInterval i2)
{
	if (i1->status == T_INTERVAL_INVAL || i2->status == T_INTERVAL_INVAL)
		return 0;
	return (!(abstimelt(i1->data[1], i2->data[0]) ||
			  abstimegt(i1->data[0], i2->data[1])));
}

/*
 *		intervalstart	- returns  the start of interval i
 */
AbsoluteTime
intervalstart(TimeInterval i)
{
	if (i->status == T_INTERVAL_INVAL)
		return INVALID_ABSTIME;
	return i->data[0];
}

/*
 *		intervalend		- returns  the end of interval i
 */
AbsoluteTime
intervalend(TimeInterval i)
{
	if (i->status == T_INTERVAL_INVAL)
		return INVALID_ABSTIME;
	return i->data[1];
}


/*****************************************************************************
 *	 PRIVATE ROUTINES														 *
 *****************************************************************************/

#ifdef NOT_USED
/*
 *		isreltime		- returns 1, iff datestring is of type reltime
 *								  2, iff datestring is 'invalid time' identifier
 *								  0, iff datestring contains a syntax error
 *		VALID time	less or equal +/-  `@ 68 years'
 *
 */
int
isreltime(char *str)
{
	struct tm	tt,
			   *tm = &tt;
	double		fsec;
	int			dtype;
	char	   *field[MAXDATEFIELDS];
	int			nf,
				ftype[MAXDATEFIELDS];
	char		lowstr[MAXDATELEN + 1];

	if (!PointerIsValid(str))
		return 0;

	if (strlen(str) > MAXDATELEN)
		return 0;

	if ((ParseDateTime(str, lowstr, field, ftype, MAXDATEFIELDS, &nf) != 0)
		|| (DecodeDateDelta(field, ftype, nf, &dtype, tm, &fsec) != 0))
		return 0;

	switch (dtype)
	{
		case (DTK_DELTA):
			return (abs(tm->tm_year) <= 68) ? 1 : 0;
			break;

		case (DTK_INVALID):
			return 2;
			break;

		default:
			return 0;
			break;
	}

	return 0;
}	/* isreltime() */

#endif

#ifdef NOT_USED
int
dummyfunc()
{
	char	   *p;
	char		c;
	int			i;
	char		unit[UNITMAXLEN];
	char		direction[DIRMAXLEN];
	int			localSign;
	int			localUnitNumber;
	long		localQuantity;

	if (!PointerIsValid(sign))
		sign = &localSign;

	if (!PointerIsValid(unitnr))
		unitnr = &localUnitNumber;

	if (!PointerIsValid(quantity))
		quantity = &localQuantity;

	unit[0] = '\0';
	direction[0] = '\0';
	p = timestring;
	/* skip leading blanks */
	while ((c = *p) != '\0')
	{
		if (c != ' ')
			break;
		p++;
	}

	/* Test whether 'invalid time' identifier or not */
	if (!strncmp(INVALID_RELTIME_STR, p, strlen(INVALID_RELTIME_STR) + 1))
		return 2;				/* correct 'invalid time' identifier found */

	/* handle label of relative time */
	if (c != RELTIME_LABEL)
		return 0;				/* syntax error */
	c = *++p;
	if (c != ' ')
		return 0;				/* syntax error */
	p++;
	/* handle the quantity */
	*quantity = 0;
	for (;;)
	{
		c = *p;
		if (isdigit(c))
		{
			*quantity = *quantity * 10 + (c - '0');
			p++;
		}
		else
		{
			if (c == ' ')
				break;			/* correct quantity found */
			else
				return 0;		/* syntax error */
		}
	}

	/* handle unit */
	p++;
	i = 0;
	for (;;)
	{
		c = *p;
		if (c >= 'a' && c <= 'z' && i <= (UNITMAXLEN - 1))
		{
			unit[i] = c;
			p++;
			i++;
		}
		else
		{
			if ((c == ' ' || c == '\0')
				&& correct_unit(unit, unitnr))
				break;			/* correct unit found */
			else
				return 0;		/* syntax error */
		}
	}

	/* handle optional direction */
	if (c == ' ')
		p++;
	i = 0;
	*sign = 1;
	for (;;)
	{
		c = *p;
		if (c >= 'a' && c <= 'z' && i <= (DIRMAXLEN - 1))
		{
			direction[i] = c;
			p++;
			i++;
		}
		else
		{
			if ((c == ' ' || c == '\0') && i == 0)
			{
				*sign = 1;
				break;			/* no direction specified */
			}
			if ((c == ' ' || c == '\0') && i != 0)
			{
				direction[i] = '\0';
				correct_dir(direction, sign);
				break;			/* correct direction found */
			}
			else
				return 0;		/* syntax error */
		}
	}

	return 1;
}

/*
 *		correct_unit	- returns 1, iff unit is a correct unit description
 *
 *		output parameter:
 *				unptr: points to an integer which is the appropriate unit number
 *					   (see function isreltime())
 */
static int
correct_unit(char *unit, int *unptr)
{
	int			j = 0;

	while (j < NUNITS)
	{
		if (strncmp(unit, unit_tab[j], strlen(unit_tab[j])) == 0)
		{
			*unptr = j;
			return 1;
		}
		j++;
	}
	return 0;					/* invalid unit descriptor */
}

/*
 *		correct_dir		- returns 1, iff direction is a correct identifier
 *
 *		output parameter:
 *				signptr: points to -1 if dir corresponds to past tense
 *						 else  to 1
 */
static int
correct_dir(char *direction, int *signptr)
{
	*signptr = 1;
	if (strncmp(RELTIME_PAST, direction, strlen(RELTIME_PAST) + 1) == 0)
	{
		*signptr = -1;
		return 1;
	}
	else
		return 0;				/* invalid direction descriptor */
}

#endif

/*
 *		istinterval		- returns 1, iff i_string is a valid interval descr.
 *								  0, iff i_string is NOT a valid interval desc.
 *								  2, iff any time is INVALID_ABSTIME
 *
 *		output parameter:
 *				i_start, i_end: interval margins
 *
 *		Time interval:
 *		`[' {` '} `'' <AbsTime> `'' {` '} `'' <AbsTime> `'' {` '} `]'
 *
 *		OR	`Undefined Range'	(see also INVALID_INTERVAL_STR)
 *
 *		where <AbsTime> satisfies the syntax of absolute time.
 *
 *		e.g.  [  '  Jan 18 1902'   'Jan 1 00:00:00 1970']
 */
static int
istinterval(char *i_string,
			AbsoluteTime *i_start,
			AbsoluteTime *i_end)
{
	char	   *p,
			   *p1;
	char		c;

	p = i_string;
	/* skip leading blanks up to '[' */
	while ((c = *p) != '\0')
	{
		if (IsSpace(c))
			p++;
		else if (c != '[')
			return 0;			/* syntax error */
		else
			break;
	}
	p++;
	/* skip leading blanks up to "'" */
	while ((c = *p) != '\0')
	{
		if (IsSpace(c))
			p++;
		else if (c != '"')
			return 0;			/* syntax error */
		else
			break;
	}
	p++;
	if (strncmp(INVALID_INTERVAL_STR, p, strlen(INVALID_INTERVAL_STR)) == 0)
		return 0;				/* undefined range, handled like a syntax
								 * err. */
	/* search for the end of the first date and change it to a NULL */
	p1 = p;
	while ((c = *p1) != '\0')
	{
		if (c == '"')
		{
			*p1 = '\0';
			break;
		}
		p1++;
	}
	/* get the first date */
	*i_start = nabstimein(p);	/* first absolute date */
	/* rechange NULL at the end of the first date to a "'" */
	*p1 = '"';
	p = ++p1;
	/* skip blanks up to "'", beginning of second date */
	while ((c = *p) != '\0')
	{
		if (IsSpace(c))
			p++;
		else if (c != '"')
			return 0;			/* syntax error */
		else
			break;
	}
	p++;
	/* search for the end of the second date and change it to a NULL */
	p1 = p;
	while ((c = *p1) != '\0')
	{
		if (c == '"')
		{
			*p1 = '\0';
			break;
		}
		p1++;
	}
	/* get the second date */
	*i_end = nabstimein(p);		/* second absolute date */
	/* rechange NULL at the end of the first date to a ''' */
	*p1 = '"';
	p = ++p1;
	/* skip blanks up to ']' */
	while ((c = *p) != '\0')
	{
		if (IsSpace(c))
			p++;
		else if (c != ']')
			return 0;			/* syntax error */
		else
			break;
	}
	p++;
	c = *p;
	if (c != '\0')
		return 0;				/* syntax error */
	/* it seems to be a valid interval */
	return 1;
}


/*****************************************************************************
 *
 *****************************************************************************/

/*
 * timeofday -
 *	   returns the current time as a text. similar to timenow() but returns
 *	   seconds with more precision (up to microsecs). (I need this to compare
 *	   the Wisconsin benchmark with Illustra whose TimeNow() shows current
 *	   time with precision up to microsecs.)			  - ay 3/95
 */
text *
timeofday(void)
{

	struct timeval tp;
	struct timezone tpz;
	char		templ[500];
	char		buf[500];
	text	   *tm;
	int			len = 0;

	gettimeofday(&tp, &tpz);
	strftime(templ, sizeof(templ), "%a %b %d %H:%M:%S.%%d %Y %Z",
			 localtime((time_t *) &tp.tv_sec));
	sprintf(buf, templ, tp.tv_usec);

	len = VARHDRSZ + strlen(buf);
	tm = (text *) palloc(len);
	VARSIZE(tm) = len;
	strncpy(VARDATA(tm), buf, strlen(buf));
	return tm;
}