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

				}
				else
				{
					ftype[nf] = DTK_DATE;
					while (isalnum((unsigned char) *cp) || *cp == delim)
						APPEND_CHAR(bufp, bufend, pg_tolower((unsigned char) *cp++));
				}
			}

			/*
			 * otherwise, number only and will determine year, month, day, or
			 * concatenated fields later...
			 */
			else
				ftype[nf] = DTK_NUMBER;
		}
		/* Leading decimal point? Then fractional seconds... */
		else if (*cp == '.')
		{
			APPEND_CHAR(bufp, bufend, *cp++);
			while (isdigit((unsigned char) *cp))
				APPEND_CHAR(bufp, bufend, *cp++);

			ftype[nf] = DTK_NUMBER;
		}

		/*
		 * text? then date string, month, day of week, special, or timezone
		 */
		else if (isalpha((unsigned char) *cp))
		{
			bool		is_date;

			ftype[nf] = DTK_STRING;
			APPEND_CHAR(bufp, bufend, pg_tolower((unsigned char) *cp++));
			while (isalpha((unsigned char) *cp))
				APPEND_CHAR(bufp, bufend, pg_tolower((unsigned char) *cp++));

			/*
			 * Dates can have embedded '-', '/', or '.' separators.  It could
			 * also be a timezone name containing embedded '/', '+', '-', '_',
			 * or ':' (but '_' or ':' can't be the first punctuation). If the
			 * next character is a digit or '+', we need to check whether what
			 * we have so far is a recognized non-timezone keyword --- if so,
			 * don't believe that this is the start of a timezone.
			 */
			is_date = false;
			if (*cp == '-' || *cp == '/' || *cp == '.')
				is_date = true;
			else if (*cp == '+' || isdigit((unsigned char) *cp))
			{
				*bufp = '\0';	/* null-terminate current field value */
				/* we need search only the core token table, not TZ names */
				if (datebsearch(field[nf], datetktbl, szdatetktbl) == NULL)
					is_date = true;
			}
			if (is_date)
			{
				ftype[nf] = DTK_DATE;
				do
				{
					APPEND_CHAR(bufp, bufend, pg_tolower((unsigned char) *cp++));
				} while (*cp == '+' || *cp == '-' ||
						 *cp == '/' || *cp == '_' ||
						 *cp == '.' || *cp == ':' ||
						 isalnum((unsigned char) *cp));
			}
		}
		/* sign? then special or numeric timezone */
		else if (*cp == '+' || *cp == '-')
		{
			APPEND_CHAR(bufp, bufend, *cp++);
			/* soak up leading whitespace */
			while (isspace((unsigned char) *cp))
				cp++;
			/* numeric timezone? */
			if (isdigit((unsigned char) *cp))
			{
				ftype[nf] = DTK_TZ;
				APPEND_CHAR(bufp, bufend, *cp++);
				while (isdigit((unsigned char) *cp) ||
					   *cp == ':' || *cp == '.')
					APPEND_CHAR(bufp, bufend, *cp++);
			}
			/* special? */
			else if (isalpha((unsigned char) *cp))
			{
				ftype[nf] = DTK_SPECIAL;
				APPEND_CHAR(bufp, bufend, pg_tolower((unsigned char) *cp++));
				while (isalpha((unsigned char) *cp))
					APPEND_CHAR(bufp, bufend, pg_tolower((unsigned char) *cp++));
			}
			/* otherwise something wrong... */
			else
				return DTERR_BAD_FORMAT;
		}
		/* ignore other punctuation but use as delimiter */
		else if (ispunct((unsigned char) *cp))
		{
			cp++;
			continue;
		}
		/* otherwise, something is not right... */
		else
			return DTERR_BAD_FORMAT;

		/* force in a delimiter after each field */
		*bufp++ = '\0';
		nf++;
	}

	*numfields = nf;

	return 0;
}


/* DecodeDateTime()
 * Interpret previously parsed fields for general date and time.
 * Return 0 if full date, 1 if only time, and negative DTERR code if problems.
 * (Currently, all callers treat 1 as an error return too.)
 *
 *		External format(s):
 *				"<weekday> <month>-<day>-<year> <hour>:<minute>:<second>"
 *				"Fri Feb-7-1997 15:23:27"
 *				"Feb-7-1997 15:23:27"
 *				"2-7-1997 15:23:27"
 *				"1997-2-7 15:23:27"
 *				"1997.038 15:23:27"		(day of year 1-366)
 *		Also supports input in compact time:
 *				"970207 152327"
 *				"97038 152327"
 *				"20011225T040506.789-07"
 *
 * Use the system-provided functions to get the current time zone
 *	if not specified in the input string.
 * If the date is outside the time_t system-supported time range,
 *	then assume UTC time zone. - thomas 1997-05-27
 */
int
DecodeDateTime(char **field, int *ftype, int nf,
			   int *dtype, struct pg_tm * tm, fsec_t *fsec, int *tzp)
{
	int			fmask = 0,
				tmask,
				type;
	int			ptype = 0;		/* "prefix type" for ISO y2001m02d04 format */
	int			i;
	int			val;
	int			dterr;
	int			mer = HR24;
	bool		haveTextMonth = FALSE;
	bool		is2digits = FALSE;
	bool		bc = FALSE;
	pg_tz	   *namedTz = NULL;

	/*
	 * We'll insist on at least all of the date fields, but initialize the
	 * remaining fields in case they are not set later...
	 */
	*dtype = DTK_DATE;
	tm->tm_hour = 0;
	tm->tm_min = 0;
	tm->tm_sec = 0;
	*fsec = 0;
	/* don't know daylight savings time status apriori */
	tm->tm_isdst = -1;
	if (tzp != NULL)
		*tzp = 0;

	for (i = 0; i < nf; i++)
	{
		switch (ftype[i])
		{
			case DTK_DATE:
				/***
				 * Integral julian day with attached time zone?
				 * All other forms with JD will be separated into
				 * distinct fields, so we handle just this case here.
				 ***/
				if (ptype == DTK_JULIAN)
				{
					char	   *cp;
					int			val;

					if (tzp == NULL)
						return DTERR_BAD_FORMAT;

					errno = 0;
					val = strtoi(field[i], &cp, 10);
					if (errno == ERANGE)
						return DTERR_FIELD_OVERFLOW;

					j2date(val, &tm->tm_year, &tm->tm_mon, &tm->tm_mday);
					/* Get the time zone from the end of the string */
					dterr = DecodeTimezone(cp, tzp);
					if (dterr)
						return dterr;

					tmask = DTK_DATE_M | DTK_TIME_M | DTK_M(TZ);
					ptype = 0;
					break;
				}
				/***
				 * Already have a date? Then this might be a time zone name
				 * with embedded punctuation (e.g. "America/New_York") or a
				 * run-together time with trailing time zone (e.g. hhmmss-zz).
				 * - thomas 2001-12-25
				 *
				 * We consider it a time zone if we already have month & day.
				 * This is to allow the form "mmm dd hhmmss tz year", which
				 * we've historically accepted.
				 ***/
				else if (ptype != 0 ||
						 ((fmask & (DTK_M(MONTH) | DTK_M(DAY))) ==
						  (DTK_M(MONTH) | DTK_M(DAY))))
				{
					/* No time zone accepted? Then quit... */
					if (tzp == NULL)
						return DTERR_BAD_FORMAT;

					if (isdigit((unsigned char) *field[i]) || ptype != 0)
					{
						char	   *cp;

						if (ptype != 0)
						{
							/* Sanity check; should not fail this test */
							if (ptype != DTK_TIME)
								return DTERR_BAD_FORMAT;
							ptype = 0;
						}

						/*
						 * Starts with a digit but we already have a time
						 * field? Then we are in trouble with a date and time
						 * already...
						 */
						if ((fmask & DTK_TIME_M) == DTK_TIME_M)
							return DTERR_BAD_FORMAT;

						if ((cp = strchr(field[i], '-')) == NULL)
							return DTERR_BAD_FORMAT;

						/* Get the time zone from the end of the string */
						dterr = DecodeTimezone(cp, tzp);
						if (dterr)
							return dterr;
						*cp = '\0';

						/*
						 * Then read the rest of the field as a concatenated
						 * time
						 */
						dterr = DecodeNumberField(strlen(field[i]), field[i],
												  fmask,
												  &tmask, tm,
												  fsec, &is2digits);
						if (dterr < 0)
							return dterr;

						/*
						 * modify tmask after returning from
						 * DecodeNumberField()
						 */
						tmask |= DTK_M(TZ);
					}
					else
					{
						namedTz = pg_tzset(field[i]);
						if (!namedTz)
						{
							/*
							 * We should return an error code instead of
							 * ereport'ing directly, but then there is no way
							 * to report the bad time zone name.
							 */
							ereport(ERROR,
									(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
									 errmsg("time zone \"%s\" not recognized",
											field[i])));
						}
						/* we'll apply the zone setting below */
						tmask = DTK_M(TZ);
					}
				}
				else
				{
					dterr = DecodeDate(field[i], fmask,
									   &tmask, &is2digits, tm);
					if (dterr)
						return dterr;
				}
				break;

			case DTK_TIME:
				dterr = DecodeTime(field[i], fmask, &tmask, tm, fsec);
				if (dterr)
					return dterr;

				/*
				 * Check upper limit on hours; other limits checked in
				 * DecodeTime()
				 */
				/* test for > 24:00:00 */
				if (tm->tm_hour > 24 ||
					(tm->tm_hour == 24 && (tm->tm_min > 0 || tm->tm_sec > 0)))
					return DTERR_FIELD_OVERFLOW;
				break;

			case DTK_TZ:
				{
					int			tz;

					if (tzp == NULL)
						return DTERR_BAD_FORMAT;

					dterr = DecodeTimezone(field[i], &tz);
					if (dterr)
						return dterr;
					*tzp = tz;
					tmask = DTK_M(TZ);
				}
				break;

			case DTK_NUMBER:

				/*
				 * Was this an "ISO date" with embedded field labels? An
				 * example is "y2001m02d04" - thomas 2001-02-04
				 */
				if (ptype != 0)
				{
					char	   *cp;
					int			val;

					errno = 0;
					val = strtoi(field[i], &cp, 10);
					if (errno == ERANGE)
						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);
							/* fractional Julian Day? */
							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;
							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 and no date yet? */
					if (cp != NULL && !(fmask & DTK_DATE_M))
					{
						dterr = DecodeDate(field[i], fmask,
										   &tmask, &is2digits, tm);
						if (dterr)
							return dterr;
					}
					/* embedded decimal and several digits before? */
					else if (cp != NULL && 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,
												  &tmask, tm,
												  fsec, &is2digits);
						if (dterr < 0)
							return dterr;
					}
					else if (flen > 4)
					{
						dterr = DecodeNumberField(flen, field[i], fmask,
												  &tmask, tm,
												  fsec, &is2digits);
						if (dterr < 0)
							return dterr;
					}
					/* otherwise it is a single date/time field... */
					else
					{
						dterr = DecodeNumber(flen, field[i],
											 haveTextMonth, fmask,
											 &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: