interval.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 831 行 · 第 1/2 页

	if (*fsec != 0)
	{
		int			sec;

#ifdef HAVE_INT64_TIMESTAMP
		sec = (*fsec / INT64CONST(1000000));
		*fsec -= (sec * INT64CONST(1000000));
#else
		TMODULO(*fsec, sec, 1e0);
#endif
		tm->tm_sec += sec;
	}

	if (is_before)
	{
		*fsec = -(*fsec);
		tm->tm_sec = -(tm->tm_sec);
		tm->tm_min = -(tm->tm_min);
		tm->tm_hour = -(tm->tm_hour);
		tm->tm_mday = -(tm->tm_mday);
		tm->tm_mon = -(tm->tm_mon);
		tm->tm_year = -(tm->tm_year);
	}

	/* ensure that at least one time field has been found */
	return (fmask != 0) ? 0 : -1;
}	/* DecodeInterval() */

/* EncodeInterval()
 * Interpret time structure as a delta time and convert to string.
 *
 * Support "traditional Postgres" and ISO-8601 styles.
 * Actually, afaik ISO does not address time interval formatting,
 *	but this looks similar to the spec for absolute date/time.
 * - thomas 1998-04-30
 */
int
EncodeInterval(struct tm * tm, fsec_t fsec, int style, char *str)
{
	int			is_before = FALSE;
	int			is_nonzero = FALSE;
	char	   *cp = str;

	/*
	 * The sign of year and month are guaranteed to match, since they are
	 * stored internally as "month". But we'll need to check for is_before
	 * and 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", ((fsec >= 0) ? fsec : -(fsec)));
#else
					fsec += tm->tm_sec;
					sprintf(cp, ":%013.10f", 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_POSTGRES_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 / 12;
		tm->tm_mon = span.month % 12;

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

	time = span.time;

#ifdef HAVE_INT64_TIMESTAMP
	tm->tm_mday = (time / INT64CONST(86400000000));
	time -= (tm->tm_mday * INT64CONST(86400000000));
	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));
	*fsec = (time - (tm->tm_sec * INT64CONST(1000000)));
#else
	TMODULO(time, tm->tm_mday, 86400e0);
	TMODULO(time, tm->tm_hour, 3600e0);
	TMODULO(time, tm->tm_min, 60e0);
	TMODULO(time, tm->tm_sec, 1e0);
	*fsec = time;
#endif

	return 0;
}	/* interval2tm() */

static int
tm2interval(struct tm * tm, fsec_t fsec, interval *span)
{
	span->month = ((tm->tm_year * 12) + 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) * INT64CONST(1000000)) + fsec);
#else
	span->time = ((((((tm->tm_mday * 24.0)
					  + tm->tm_hour) * 60.0)
					+ tm->tm_min) * 60.0)
				  + tm->tm_sec);
	span->time = JROUND(span->time + fsec);
#endif

	return 0;
}	/* tm2interval() */

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;
	}

	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 *intrcldest)
{
	intrcldest->time = intvlsrc->time;
	intrcldest->month = intvlsrc->month;

	return 0;
}