interval.c

postgresql8.3.4源码,开源数据库

	 * is_nonzero when determining the signs of hour/minute/seconds fields.
	 */
	switch (style)
	{
			/* compatible with ISO date formats */
		case USE_ISO_DATES:
			if (tm->tm_year != 0)
			{
				sprintf(cp, "%d year%s",
						tm->tm_year, (tm->tm_year != 1) ? "s" : "");
				cp += strlen(cp);
				is_before = (tm->tm_year < 0);
				is_nonzero = TRUE;
			}

			if (tm->tm_mon != 0)
			{
				sprintf(cp, "%s%s%d mon%s", is_nonzero ? " " : "",
						(is_before && tm->tm_mon > 0) ? "+" : "",
						tm->tm_mon, (tm->tm_mon != 1) ? "s" : "");
				cp += strlen(cp);
				is_before = (tm->tm_mon < 0);
				is_nonzero = TRUE;
			}

			if (tm->tm_mday != 0)
			{
				sprintf(cp, "%s%s%d day%s", is_nonzero ? " " : "",
						(is_before && tm->tm_mday > 0) ? "+" : "",
						tm->tm_mday, (tm->tm_mday != 1) ? "s" : "");
				cp += strlen(cp);
				is_before = (tm->tm_mday < 0);
				is_nonzero = TRUE;
			}
			if (!is_nonzero || tm->tm_hour != 0 || tm->tm_min != 0 ||
				tm->tm_sec != 0 || fsec != 0)
			{
				int			minus = tm->tm_hour < 0 || tm->tm_min < 0 ||
				tm->tm_sec < 0 || fsec < 0;

				sprintf(cp, "%s%s%02d:%02d", (is_nonzero ? " " : ""),
						(minus ? "-" : (is_before ? "+" : "")),
						abs(tm->tm_hour), abs(tm->tm_min));
				cp += strlen(cp);
				/* Mark as "non-zero" since the fields are now filled in */
				is_nonzero = TRUE;

				/* fractional seconds? */
				if (fsec != 0)
				{
#ifdef HAVE_INT64_TIMESTAMP
					sprintf(cp, ":%02d", abs(tm->tm_sec));
					cp += strlen(cp);
					sprintf(cp, ".%06d", Abs(fsec));
#else
					fsec += tm->tm_sec;
					sprintf(cp, ":%012.9f", fabs(fsec));
#endif
					TrimTrailingZeros(cp);
					cp += strlen(cp);
					is_nonzero = TRUE;
				}
				/* otherwise, integer seconds only? */
				else if (tm->tm_sec != 0)
				{
					sprintf(cp, ":%02d", abs(tm->tm_sec));
					cp += strlen(cp);
					is_nonzero = TRUE;
				}
			}
			break;

		case USE_POSTGRES_DATES:
		default:
			strcpy(cp, "@ ");
			cp += strlen(cp);

			if (tm->tm_year != 0)
			{
				int			year = tm->tm_year;

				if (tm->tm_year < 0)
					year = -year;

				sprintf(cp, "%d year%s", year,
						(year != 1) ? "s" : "");
				cp += strlen(cp);
				is_before = (tm->tm_year < 0);
				is_nonzero = TRUE;
			}

			if (tm->tm_mon != 0)
			{
				int			mon = tm->tm_mon;

				if (is_before || (!is_nonzero && tm->tm_mon < 0))
					mon = -mon;

				sprintf(cp, "%s%d mon%s", is_nonzero ? " " : "", mon,
						(mon != 1) ? "s" : "");
				cp += strlen(cp);
				if (!is_nonzero)
					is_before = (tm->tm_mon < 0);
				is_nonzero = TRUE;
			}

			if (tm->tm_mday != 0)
			{
				int			day = tm->tm_mday;

				if (is_before || (!is_nonzero && tm->tm_mday < 0))
					day = -day;

				sprintf(cp, "%s%d day%s", is_nonzero ? " " : "", day,
						(day != 1) ? "s" : "");
				cp += strlen(cp);
				if (!is_nonzero)
					is_before = (tm->tm_mday < 0);
				is_nonzero = TRUE;
			}
			if (tm->tm_hour != 0)
			{
				int			hour = tm->tm_hour;

				if (is_before || (!is_nonzero && tm->tm_hour < 0))
					hour = -hour;

				sprintf(cp, "%s%d hour%s", is_nonzero ? " " : "", hour,
						(hour != 1) ? "s" : "");
				cp += strlen(cp);
				if (!is_nonzero)
					is_before = (tm->tm_hour < 0);
				is_nonzero = TRUE;
			}

			if (tm->tm_min != 0)
			{
				int			min = tm->tm_min;

				if (is_before || (!is_nonzero && tm->tm_min < 0))
					min = -min;

				sprintf(cp, "%s%d min%s", is_nonzero ? " " : "", min,
						(min != 1) ? "s" : "");
				cp += strlen(cp);
				if (!is_nonzero)
					is_before = (tm->tm_min < 0);
				is_nonzero = TRUE;
			}

			/* fractional seconds? */
			if (fsec != 0)
			{
#ifdef HAVE_INT64_TIMESTAMP
				if (is_before || (!is_nonzero && tm->tm_sec < 0))
					tm->tm_sec = -tm->tm_sec;
				sprintf(cp, "%s%d.%02d secs", is_nonzero ? " " : "",
						tm->tm_sec, ((int) fsec) / 10000);
				cp += strlen(cp);
				if (!is_nonzero)
					is_before = (fsec < 0);
#else
				fsec_t		sec;

				fsec += tm->tm_sec;
				sec = fsec;
				if (is_before || (!is_nonzero && fsec < 0))
					sec = -sec;

				sprintf(cp, "%s%.2f secs", is_nonzero ? " " : "", sec);
				cp += strlen(cp);
				if (!is_nonzero)
					is_before = (fsec < 0);
#endif
				is_nonzero = TRUE;

				/* otherwise, integer seconds only? */
			}
			else if (tm->tm_sec != 0)
			{
				int			sec = tm->tm_sec;

				if (is_before || (!is_nonzero && tm->tm_sec < 0))
					sec = -sec;

				sprintf(cp, "%s%d sec%s", is_nonzero ? " " : "", sec,
						(sec != 1) ? "s" : "");
				cp += strlen(cp);
				if (!is_nonzero)
					is_before = (tm->tm_sec < 0);
				is_nonzero = TRUE;
			}
			break;
	}

	/* identically zero? then put in a unitless zero... */
	if (!is_nonzero)
	{
		strcat(cp, "0");
		cp += strlen(cp);
	}

	if (is_before && (style != USE_ISO_DATES))
	{
		strcat(cp, " ago");
		cp += strlen(cp);
	}

	return 0;
}	/* EncodeInterval() */

/* interval2tm()
 * Convert a interval data type to a tm structure.
 */
static int
interval2tm(interval span, struct tm * tm, fsec_t *fsec)
{
#ifdef HAVE_INT64_TIMESTAMP
	int64		time;
#else
	double		time;
#endif

	if (span.month != 0)
	{
		tm->tm_year = span.month / MONTHS_PER_YEAR;
		tm->tm_mon = span.month % MONTHS_PER_YEAR;

	}
	else
	{
		tm->tm_year = 0;
		tm->tm_mon = 0;
	}

	time = span.time;

#ifdef HAVE_INT64_TIMESTAMP
	tm->tm_mday = time / USECS_PER_DAY;
	time -= tm->tm_mday * USECS_PER_DAY;
	tm->tm_hour = time / USECS_PER_HOUR;
	time -= tm->tm_hour * USECS_PER_HOUR;
	tm->tm_min = time / USECS_PER_MINUTE;
	time -= tm->tm_min * USECS_PER_MINUTE;
	tm->tm_sec = time / USECS_PER_SEC;
	*fsec = time - (tm->tm_sec * USECS_PER_SEC);
#else
recalc:
	TMODULO(time, tm->tm_mday, (double) SECS_PER_DAY);
	TMODULO(time, tm->tm_hour, (double) SECS_PER_HOUR);
	TMODULO(time, tm->tm_min, (double) SECS_PER_MINUTE);
	TMODULO(time, tm->tm_sec, 1.0);
	time = TSROUND(time);
	/* roundoff may need to propagate to higher-order fields */
	if (time >= 1.0)
	{
		time = ceil(span.time);
		goto recalc;
	}
	*fsec = time;
#endif

	return 0;
}	/* interval2tm() */

static int
tm2interval(struct tm * tm, fsec_t fsec, interval * span)
{
	span->month = tm->tm_year * MONTHS_PER_YEAR + tm->tm_mon;
#ifdef HAVE_INT64_TIMESTAMP
	span->time = (((((((tm->tm_mday * INT64CONST(24)) +
					   tm->tm_hour) * INT64CONST(60)) +
					 tm->tm_min) * INT64CONST(60)) +
				   tm->tm_sec) * USECS_PER_SEC) + fsec;
#else
	span->time = (((((tm->tm_mday * (double) HOURS_PER_DAY) +
					 tm->tm_hour) * (double) MINS_PER_HOUR) +
				   tm->tm_min) * (double) SECS_PER_MINUTE) +
		tm->tm_sec + fsec;
#endif

	return 0;
}	/* tm2interval() */

interval *
PGTYPESinterval_new(void)
{
	interval   *result;

	result = (interval *) pgtypes_alloc(sizeof(interval));
	/* result can be NULL if we run out of memory */
	return result;
}

void
PGTYPESinterval_free(interval * intvl)
{
	free(intvl);
}

interval *
PGTYPESinterval_from_asc(char *str, char **endptr)
{
	interval   *result = NULL;
	fsec_t		fsec;
	struct tm	tt,
			   *tm = &tt;
	int			dtype;
	int			nf;
	char	   *field[MAXDATEFIELDS];
	int			ftype[MAXDATEFIELDS];
	char		lowstr[MAXDATELEN + MAXDATEFIELDS];
	char	   *realptr;
	char	  **ptr = (endptr != NULL) ? endptr : &realptr;

	tm->tm_year = 0;
	tm->tm_mon = 0;
	tm->tm_mday = 0;
	tm->tm_hour = 0;
	tm->tm_min = 0;
	tm->tm_sec = 0;
	fsec = 0;

	if (strlen(str) >= sizeof(lowstr))
	{
		errno = PGTYPES_INTVL_BAD_INTERVAL;
		return NULL;
	}

	if (ParseDateTime(str, lowstr, field, ftype, MAXDATEFIELDS, &nf, ptr) != 0 ||
		DecodeInterval(field, ftype, nf, &dtype, tm, &fsec) != 0)
	{
		errno = PGTYPES_INTVL_BAD_INTERVAL;
		return NULL;
	}

	result = (interval *) pgtypes_alloc(sizeof(interval));
	if (!result)
		return NULL;

	if (dtype != DTK_DELTA)
	{
		errno = PGTYPES_INTVL_BAD_INTERVAL;
		free(result);
		return NULL;
	}

	if (tm2interval(tm, fsec, result) != 0)
	{
		errno = PGTYPES_INTVL_BAD_INTERVAL;
		free(result);
		return NULL;
	}

	errno = 0;
	return result;
}

char *
PGTYPESinterval_to_asc(interval * span)
{
	struct tm	tt,
			   *tm = &tt;
	fsec_t		fsec;
	char		buf[MAXDATELEN + 1];
	int			DateStyle = 0;

	if (interval2tm(*span, tm, &fsec) != 0)
	{
		errno = PGTYPES_INTVL_BAD_INTERVAL;
		return NULL;
	}

	if (EncodeInterval(tm, fsec, DateStyle, buf) != 0)
	{
		errno = PGTYPES_INTVL_BAD_INTERVAL;
		return NULL;
	}

	return pgtypes_strdup(buf);
}

int
PGTYPESinterval_copy(interval * intvlsrc, interval * intvldest)
{
	intvldest->time = intvlsrc->time;
	intvldest->month = intvlsrc->month;

	return 0;
}