datetime.c

来自「postgresql8.3.4源码,开源数据库」· C语言 代码 · 共 2,681 行 · 第 1/5 页

						return DTERR_FIELD_OVERFLOW;

					/*
					 * only a few kinds are allowed to have an embedded
					 * decimal
					 */
					if (*cp == '.')
						switch (ptype)
						{
							case DTK_JULIAN:
							case DTK_TIME:
							case DTK_SECOND:
								break;
							default:
								return DTERR_BAD_FORMAT;
								break;
						}
					else if (*cp != '\0')
						return DTERR_BAD_FORMAT;

					switch (ptype)
					{
						case DTK_YEAR:
							tm->tm_year = val;
							tmask = DTK_M(YEAR);
							break;

						case DTK_MONTH:

							/*
							 * already have a month and hour? then assume
							 * minutes
							 */
							if ((fmask & DTK_M(MONTH)) != 0 &&
								(fmask & DTK_M(HOUR)) != 0)
							{
								tm->tm_min = val;
								tmask = DTK_M(MINUTE);
							}
							else
							{
								tm->tm_mon = val;
								tmask = DTK_M(MONTH);
							}
							break;

						case DTK_DAY:
							tm->tm_mday = val;
							tmask = DTK_M(DAY);
							break;

						case DTK_HOUR:
							tm->tm_hour = val;
							tmask = DTK_M(HOUR);
							break;

						case DTK_MINUTE:
							tm->tm_min = val;
							tmask = DTK_M(MINUTE);
							break;

						case DTK_SECOND:
							tm->tm_sec = val;
							tmask = DTK_M(SECOND);
							if (*cp == '.')
							{
								double		frac;

								frac = strtod(cp, &cp);
								if (*cp != '\0')
									return DTERR_BAD_FORMAT;
#ifdef HAVE_INT64_TIMESTAMP
								*fsec = rint(frac * 1000000);
#else
								*fsec = frac;
#endif
								tmask = DTK_ALL_SECS_M;
							}
							break;

						case DTK_TZ:
							tmask = DTK_M(TZ);
							dterr = DecodeTimezone(field[i], tzp);
							if (dterr)
								return dterr;
							break;

						case DTK_JULIAN:
							/***
							 * previous field was a label for "julian date"?
							 ***/
							tmask = DTK_DATE_M;
							j2date(val, &tm->tm_year, &tm->tm_mon, &tm->tm_mday);
							if (*cp == '.')
							{
								double		time;

								time = strtod(cp, &cp);
								if (*cp != '\0')
									return DTERR_BAD_FORMAT;

								tmask |= DTK_TIME_M;
#ifdef HAVE_INT64_TIMESTAMP
								dt2time(time * USECS_PER_DAY,
								&tm->tm_hour, &tm->tm_min, &tm->tm_sec, fsec);
#else
								dt2time(time * SECS_PER_DAY,
								&tm->tm_hour, &tm->tm_min, &tm->tm_sec, fsec);
#endif
							}
							break;

						case DTK_TIME:
							/* previous field was "t" for ISO time */
							dterr = DecodeNumberField(strlen(field[i]), field[i],
													  (fmask | DTK_DATE_M),
													  &tmask, tm,
													  fsec, &is2digits);
							if (dterr < 0)
								return dterr;
							ftype[i] = dterr;

							if (tmask != DTK_TIME_M)
								return DTERR_BAD_FORMAT;
							break;

						default:
							return DTERR_BAD_FORMAT;
							break;
					}

					ptype = 0;
					*dtype = DTK_DATE;
				}
				else
				{
					char	   *cp;
					int			flen;

					flen = strlen(field[i]);
					cp = strchr(field[i], '.');

					/* Embedded decimal? */
					if (cp != NULL)
					{
						/*
						 * Under limited circumstances, we will accept a
						 * date...
						 */
						if (i == 0 && nf >= 2 && ftype[nf - 1] == DTK_DATE)
						{
							dterr = DecodeDate(field[i], fmask,
											   &tmask, &is2digits, tm);
							if (dterr)
								return dterr;
						}
						/* embedded decimal and several digits before? */
						else if (flen - strlen(cp) > 2)
						{
							/*
							 * Interpret as a concatenated date or time Set
							 * the type field to allow decoding other fields
							 * later. Example: 20011223 or 040506
							 */
							dterr = DecodeNumberField(flen, field[i],
													  (fmask | DTK_DATE_M),
													  &tmask, tm,
													  fsec, &is2digits);
							if (dterr < 0)
								return dterr;
							ftype[i] = dterr;
						}
						else
							return DTERR_BAD_FORMAT;
					}
					else if (flen > 4)
					{
						dterr = DecodeNumberField(flen, field[i],
												  (fmask | DTK_DATE_M),
												  &tmask, tm,
												  fsec, &is2digits);
						if (dterr < 0)
							return dterr;
						ftype[i] = dterr;
					}
					/* otherwise it is a single date/time field... */
					else
					{
						dterr = DecodeNumber(flen, field[i],
											 FALSE,
											 (fmask | DTK_DATE_M),
											 &tmask, tm,
											 fsec, &is2digits);
						if (dterr)
							return dterr;
					}
				}
				break;

			case DTK_STRING:
			case DTK_SPECIAL:
				type = DecodeSpecial(i, field[i], &val);
				if (type == IGNORE_DTF)
					continue;

				tmask = DTK_M(type);
				switch (type)
				{
					case RESERV:
						switch (val)
						{
							case DTK_CURRENT:
								ereport(ERROR,
									 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
									  errmsg("date/time value \"current\" is no longer supported")));
								return DTERR_BAD_FORMAT;
								break;

							case DTK_NOW:
								tmask = DTK_TIME_M;
								*dtype = DTK_TIME;
								GetCurrentTimeUsec(tm, fsec, NULL);
								break;

							case DTK_ZULU:
								tmask = (DTK_TIME_M | DTK_M(TZ));
								*dtype = DTK_TIME;
								tm->tm_hour = 0;
								tm->tm_min = 0;
								tm->tm_sec = 0;
								tm->tm_isdst = 0;
								break;

							default:
								return DTERR_BAD_FORMAT;
						}

						break;

					case DTZMOD:

						/*
						 * daylight savings time modifier (solves "MET DST"
						 * syntax)
						 */
						tmask |= DTK_M(DTZ);
						tm->tm_isdst = 1;
						if (tzp == NULL)
							return DTERR_BAD_FORMAT;
						*tzp += val * MINS_PER_HOUR;
						break;

					case DTZ:

						/*
						 * set mask for TZ here _or_ check for DTZ later when
						 * getting default timezone
						 */
						tmask |= DTK_M(TZ);
						tm->tm_isdst = 1;
						if (tzp == NULL)
							return DTERR_BAD_FORMAT;
						*tzp = val * MINS_PER_HOUR;
						ftype[i] = DTK_TZ;
						break;

					case TZ:
						tm->tm_isdst = 0;
						if (tzp == NULL)
							return DTERR_BAD_FORMAT;
						*tzp = val * MINS_PER_HOUR;
						ftype[i] = DTK_TZ;
						break;

					case IGNORE_DTF:
						break;

					case AMPM:
						mer = val;
						break;

					case ADBC:
						bc = (val == BC);
						break;

					case UNITS:
						tmask = 0;
						ptype = val;
						break;

					case ISOTIME:
						tmask = 0;

						/***
						 * We will need one of the following fields:
						 *	DTK_NUMBER should be hhmmss.fff
						 *	DTK_TIME should be hh:mm:ss.fff
						 *	DTK_DATE should be hhmmss-zz
						 ***/
						if (i >= nf - 1 ||
							(ftype[i + 1] != DTK_NUMBER &&
							 ftype[i + 1] != DTK_TIME &&
							 ftype[i + 1] != DTK_DATE))
							return DTERR_BAD_FORMAT;

						ptype = val;
						break;

					case UNKNOWN_FIELD:

						/*
						 * Before giving up and declaring error, check to see
						 * if it is an all-alpha timezone name.
						 */
						namedTz = pg_tzset(field[i]);
						if (!namedTz)
							return DTERR_BAD_FORMAT;
						/* we'll apply the zone setting below */
						tmask = DTK_M(TZ);
						break;

					default:
						return DTERR_BAD_FORMAT;
				}
				break;

			default:
				return DTERR_BAD_FORMAT;
		}

		if (tmask & fmask)
			return DTERR_BAD_FORMAT;
		fmask |= tmask;
	}				/* end loop over fields */

	/* do final checking/adjustment of Y/M/D fields */
	dterr = ValidateDate(fmask, is2digits, bc, tm);
	if (dterr)
		return dterr;

	/* handle AM/PM */
	if (mer != HR24 && tm->tm_hour > 12)
		return DTERR_FIELD_OVERFLOW;
	if (mer == AM && tm->tm_hour == 12)
		tm->tm_hour = 0;
	else if (mer == PM && tm->tm_hour != 12)
		tm->tm_hour += 12;

	if (tm->tm_hour < 0 || tm->tm_min < 0 || tm->tm_min > 59 ||
		tm->tm_sec < 0 || tm->tm_sec > 60 || tm->tm_hour > 24 ||
	/* test for > 24:00:00 */
#ifdef HAVE_INT64_TIMESTAMP
		(tm->tm_hour == 24 && (tm->tm_min > 0 || tm->tm_sec > 0 ||
							   *fsec > INT64CONST(0))) ||
		*fsec < INT64CONST(0) || *fsec >= USECS_PER_SEC
#else
		(tm->tm_hour == 24 && (tm->tm_min > 0 || tm->tm_sec > 0 ||
							   *fsec > 0)) ||
		*fsec < 0 || *fsec >= 1
#endif
		)
		return DTERR_FIELD_OVERFLOW;

	if ((fmask & DTK_TIME_M) != DTK_TIME_M)
		return DTERR_BAD_FORMAT;

	/*
	 * If we had a full timezone spec, compute the offset (we could not do it
	 * before, because we may need the date to resolve DST status).
	 */
	if (namedTz != NULL)
	{
		long int	gmtoff;

		/* daylight savings time modifier disallowed with full TZ */
		if (fmask & DTK_M(DTZMOD))
			return DTERR_BAD_FORMAT;

		/* if non-DST zone, we do not need to know the date */
		if (pg_get_timezone_offset(namedTz, &gmtoff))
		{
			*tzp = -(int) gmtoff;
		}
		else
		{
			/* a date has to be specified */
			if ((fmask & DTK_DATE_M) != DTK_DATE_M)
				return DTERR_BAD_FORMAT;
			*tzp = DetermineTimeZoneOffset(tm, namedTz);
		}
	}

	/* timezone not specified? then find local timezone if possible */
	if (tzp != NULL && !(fmask & DTK_M(TZ)))
	{
		struct pg_tm tt,
				   *tmp = &tt;

		/*
		 * daylight savings time modifier but no standard timezone? then error
		 */
		if (fmask & DTK_M(DTZMOD))
			return DTERR_BAD_FORMAT;

		if ((fmask & DTK_DATE_M) == 0)
			GetCurrentDateTime(tmp);
		else
		{
			tmp->tm_year = tm->tm_year;
			tmp->tm_mon = tm->tm_mon;
			tmp->tm_mday = tm->tm_mday;
		}
		tmp->tm_hour = tm->tm_hour;
		tmp->tm_min = tm->tm_min;
		tmp->tm_sec = tm->tm_sec;
		*tzp = DetermineTimeZoneOffset(tmp, session_timezone);
		tm->tm_isdst = tmp->tm_isdst;
	}

	return 0;
}

/* DecodeDate()
 * Decode date string which includes delimiters.
 * Return 0 if okay, a DTERR code if not.
 *
 *	str: field to be parsed
 *	fmask: bitmask for field types already seen
 *	*tmask: receives bitmask for fields found here
 *	*is2digits: set to TRUE if we find 2-digit year
 *	*tm: field values are stored into appropriate members of this struct
 */
static int
DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
		   struct pg_tm * tm)
{
	fsec_t		fsec;
	int			nf = 0;
	int			i,
				len;
	int			dterr;
	bool		haveTextMonth = FALSE;
	int			type,
				val,
				dmask = 0;
	char	   *field[MAXDATEFIELDS];

	*tmask = 0;

	/* parse this string... */
	while (*str != '\0' && nf < MAXDATEFIELDS)
	{
		/* skip field separators */
		while (!isalnum((unsigned char) *str))
			str++;

		field[nf] = str;
		if (isdigit((unsigned char) *str))
		{
			while (isdigit((unsigned char) *str))
				str++;
		}
		else if (isalpha((unsigned char) *str))
		{
			while (isalpha((unsigned char) *str))
				str++;
		}

		/* Just get rid of any non-digit, non-alpha characters... */
		if (*str != '\0')
			*str++ = '\0';
		nf++;
	}

	/* look first for text fields, since that will be unambiguous month */
	for (i = 0; i < nf; i++)
	{
		if (isalpha((unsigned char) *field[i]))
		{
			type = DecodeSpecial(i, field[i], &val);
			if (type == IGNORE_DTF)
				continue;

			dmask = DTK_M(type);
			switch (type)
			{
				case MONTH:
					tm->tm_mon = val;
					haveTextMonth = TRUE;
					break;

				default:
					return DTERR_BAD_FORMAT;
			}
			if (fmask & dmask)
				return DTERR_BAD_FORMAT;

			fmask |= dmask;
			*tmask |= dmask;

			/* mark this field as being completed */
			field[i] = NULL;
		}
	}

	/* now pick up remaining numeric fields */
	for (i = 0; i < nf; i++)
	{
		if (field[i] == NULL)
			continue;

		if ((len = strlen(field[i])) <= 0)
			return DTERR_BAD_FORMAT;

		dterr = DecodeNumber(len, field[i], haveTextMonth, fmask,
							 &dmask, tm,
							 &fsec, is2digits);
		if (dterr)
			return dterr;

		if (fmask & dmask)
			return DTERR_BAD_FORMAT;

		fmask |= dmask;
		*tmask |= dmask;
	}

	if ((fmask & ~(DTK_M(DOY) | DTK_M(TZ))) != DTK_DATE_M)
		return DTERR_BAD_FORMAT;

	/* validation of the field values must wait until ValidateDate() */

	return 0;
}

/* ValidateDate()
 * Check valid year/month/day values, handle BC and DOY cases