src/include/utils/datetime.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * datetime.h
   4  *        Definitions for the date/time and other date/time support code.
   5  *        The support code is shared with other date data types,
   6  *         including abstime, reltime, date, and time.
   7  *
   8  *
   9  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  10  * Portions Copyright (c) 1994, Regents of the University of California
  11  *
  12  * $PostgreSQL$
  13  *
  14  *-------------------------------------------------------------------------
  15  */
  16 #ifndef DATETIME_H
  17 #define DATETIME_H
  18
  19 #include <limits.h>
  20 #include <math.h>
  21
  22 #include "utils/timestamp.h"
  23 #include "utils/tzparser.h"
  24
  25
  26 /* ----------------------------------------------------------------
  27  *                              time types + support macros
  28  *
  29  * String definitions for standard time quantities.
  30  *
  31  * These strings are the defaults used to form output time strings.
  32  * Other alternative forms are hardcoded into token tables in datetime.c.
  33  * ----------------------------------------------------------------
  34  */
  35
  36 #define DAGO                    "ago"
  37 #define DCURRENT                "current"
  38 #define EPOCH                   "epoch"
  39 #define INVALID                 "invalid"
  40 #define EARLY                   "-infinity"
  41 #define LATE                    "infinity"
  42 #define NOW                             "now"
  43 #define TODAY                   "today"
  44 #define TOMORROW                "tomorrow"
  45 #define YESTERDAY               "yesterday"
  46 #define ZULU                    "zulu"
  47
  48 #define DMICROSEC               "usecond"
  49 #define DMILLISEC               "msecond"
  50 #define DSECOND                 "second"
  51 #define DMINUTE                 "minute"
  52 #define DHOUR                   "hour"
  53 #define DDAY                    "day"
  54 #define DWEEK                   "week"
  55 #define DMONTH                  "month"
  56 #define DQUARTER                "quarter"
  57 #define DYEAR                   "year"
  58 #define DDECADE                 "decade"
  59 #define DCENTURY                "century"
  60 #define DMILLENNIUM             "millennium"
  61 #define DA_D                    "ad"
  62 #define DB_C                    "bc"
  63 #define DTIMEZONE               "timezone"
  64
  65 /*
  66  * Fundamental time field definitions for parsing.
  67  *
  68  *      Meridian:  am, pm, or 24-hour style.
  69  *      Millennium: ad, bc
  70  */
  71
  72 #define AM              0
  73 #define PM              1
  74 #define HR24    2
  75
  76 #define AD              0
  77 #define BC              1
  78
  79 /*
  80  * Fields for time decoding.
  81  *
  82  * Can't have more of these than there are bits in an unsigned int
  83  * since these are turned into bit masks during parsing and decoding.
  84  *
  85  * Furthermore, the values for YEAR, MONTH, DAY, HOUR, MINUTE, SECOND
  86  * must be in the range 0..14 so that the associated bitmasks can fit
  87  * into the left half of an INTERVAL's typmod value.  Since those bits
  88  * are stored in typmods, you can't change them without initdb!
  89  */
  90
  91 #define RESERV  0
  92 #define MONTH   1
  93 #define YEAR    2
  94 #define DAY             3
  95 #define JULIAN  4
  96 #define TZ              5
  97 #define DTZ             6
  98 #define DTZMOD  7
  99 #define IGNORE_DTF      8
 100 #define AMPM    9
 101 #define HOUR    10
 102 #define MINUTE  11
 103 #define SECOND  12
 104 #define MILLISECOND 13
 105 #define MICROSECOND 14
 106 #define DOY             15
 107 #define DOW             16
 108 #define UNITS   17
 109 #define ADBC    18
 110 /* these are only for relative dates */
 111 #define AGO             19
 112 #define ABS_BEFORE              20
 113 #define ABS_AFTER               21
 114 /* generic fields to help with parsing */
 115 #define ISODATE 22
 116 #define ISOTIME 23
 117 /* these are only for parsing intervals */
 118 #define WEEK            24
 119 #define DECADE          25
 120 #define CENTURY         26
 121 #define MILLENNIUM      27
 122 /* reserved for unrecognized string values */
 123 #define UNKNOWN_FIELD   31
 124
 125 /*
 126  * Token field definitions for time parsing and decoding.
 127  * These need to fit into the datetkn table type.
 128  * At the moment, that means keep them within [-127,127].
 129  * These are also used for bit masks in DecodeDateDelta()
 130  *      so actually restrict them to within [0,31] for now.
 131  * - thomas 97/06/19
 132  * Not all of these fields are used for masks in DecodeDateDelta
 133  *      so allow some larger than 31. - thomas 1997-11-17
 134  */
 135
 136 #define DTK_NUMBER              0
 137 #define DTK_STRING              1
 138
 139 #define DTK_DATE                2
 140 #define DTK_TIME                3
 141 #define DTK_TZ                  4
 142 #define DTK_AGO                 5
 143
 144 #define DTK_SPECIAL             6
 145 #define DTK_INVALID             7
 146 #define DTK_CURRENT             8
 147 #define DTK_EARLY               9
 148 #define DTK_LATE                10
 149 #define DTK_EPOCH               11
 150 #define DTK_NOW                 12
 151 #define DTK_YESTERDAY   13
 152 #define DTK_TODAY               14
 153 #define DTK_TOMORROW    15
 154 #define DTK_ZULU                16
 155
 156 #define DTK_DELTA               17
 157 #define DTK_SECOND              18
 158 #define DTK_MINUTE              19
 159 #define DTK_HOUR                20
 160 #define DTK_DAY                 21
 161 #define DTK_WEEK                22
 162 #define DTK_MONTH               23
 163 #define DTK_QUARTER             24
 164 #define DTK_YEAR                25
 165 #define DTK_DECADE              26
 166 #define DTK_CENTURY             27
 167 #define DTK_MILLENNIUM  28
 168 #define DTK_MILLISEC    29
 169 #define DTK_MICROSEC    30
 170 #define DTK_JULIAN              31
 171
 172 #define DTK_DOW                 32
 173 #define DTK_DOY                 33
 174 #define DTK_TZ_HOUR             34
 175 #define DTK_TZ_MINUTE   35
 176 #define DTK_ISOYEAR             36
 177 #define DTK_ISODOW              37
 178
 179
 180 /*
 181  * Bit mask definitions for time parsing.
 182  */
 183
 184 #define DTK_M(t)                (0x01 << (t))
 185
 186 /* Convenience: a second, plus any fractional component */
 187 #define DTK_ALL_SECS_M  (DTK_M(SECOND) | DTK_M(MILLISECOND) | DTK_M(MICROSECOND))
 188 #define DTK_DATE_M              (DTK_M(YEAR) | DTK_M(MONTH) | DTK_M(DAY))
 189 #define DTK_TIME_M              (DTK_M(HOUR) | DTK_M(MINUTE) | DTK_ALL_SECS_M)
 190
 191 #define MAXDATELEN              63              /* maximum possible length of an input date
 192                                                                  * string (not counting tr. null) */
 193 #define MAXDATEFIELDS   25              /* maximum possible number of fields in a date
 194                                                                  * string */
 195 #define TOKMAXLEN               10              /* only this many chars are stored in
 196                                                                  * datetktbl */
 197
 198 /* keep this struct small; it gets used a lot */
 199 typedef struct
 200 {
 201         char            token[TOKMAXLEN];
 202         char            type;
 203         char            value;                  /* this may be unsigned, alas */
 204 } datetkn;
 205
 206
 207 /* FMODULO()
 208  * Macro to replace modf(), which is broken on some platforms.
 209  * t = input and remainder
 210  * q = integer part
 211  * u = divisor
 212  */
 213 #define FMODULO(t,q,u) \
 214 do { \
 215         (q) = (((t) < 0) ? ceil((t) / (u)) : floor((t) / (u))); \
 216         if ((q) != 0) (t) -= rint((q) * (u)); \
 217 } while(0)
 218
 219 /* TMODULO()
 220  * Like FMODULO(), but work on the timestamp datatype (either int64 or float8).
 221  * We assume that int64 follows the C99 semantics for division (negative
 222  * quotients truncate towards zero).
 223  */
 224 #ifdef HAVE_INT64_TIMESTAMP
 225 #define TMODULO(t,q,u) \
 226 do { \
 227         (q) = ((t) / (u)); \
 228         if ((q) != 0) (t) -= ((q) * (u)); \
 229 } while(0)
 230 #else
 231 #define TMODULO(t,q,u) \
 232 do { \
 233         (q) = (((t) < 0) ? ceil((t) / (u)) : floor((t) / (u))); \
 234         if ((q) != 0) (t) -= rint((q) * (u)); \
 235 } while(0)
 236 #endif
 237
 238 /*
 239  * Date/time validation
 240  * Include check for leap year.
 241  */
 242
 243 extern const int day_tab[2][13];
 244
 245 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
 246
 247
 248 /* Julian date support for date2j() and j2date()
 249  *
 250  * IS_VALID_JULIAN checks the minimum date exactly, but is a bit sloppy
 251  * about the maximum, since it's far enough out to not be especially
 252  * interesting.
 253  */
 254
 255 #define JULIAN_MINYEAR (-4713)
 256 #define JULIAN_MINMONTH (11)
 257 #define JULIAN_MINDAY (24)
 258 #define JULIAN_MAXYEAR (5874898)
 259
 260 #define IS_VALID_JULIAN(y,m,d) ((((y) > JULIAN_MINYEAR) \
 261   || (((y) == JULIAN_MINYEAR) && (((m) > JULIAN_MINMONTH) \
 262   || (((m) == JULIAN_MINMONTH) && ((d) >= JULIAN_MINDAY))))) \
 263  && ((y) < JULIAN_MAXYEAR))
 264
 265 /* Julian-date equivalents of Day 0 in Unix and Postgres reckoning */
 266 #define UNIX_EPOCH_JDATE                2440588 /* == date2j(1970, 1, 1) */
 267 #define POSTGRES_EPOCH_JDATE    2451545 /* == date2j(2000, 1, 1) */
 268
 269
 270 /*
 271  * Datetime input parsing routines (ParseDateTime, DecodeDateTime, etc)
 272  * return zero or a positive value on success.  On failure, they return
 273  * one of these negative code values.  DateTimeParseError may be used to
 274  * produce a correct ereport.
 275  */
 276 #define DTERR_BAD_FORMAT                (-1)
 277 #define DTERR_FIELD_OVERFLOW    (-2)
 278 #define DTERR_MD_FIELD_OVERFLOW (-3)    /* triggers hint about DateStyle */
 279 #define DTERR_INTERVAL_OVERFLOW (-4)
 280 #define DTERR_TZDISP_OVERFLOW   (-5)
 281
 282
 283 extern void GetCurrentDateTime(struct pg_tm * tm);
 284 extern void GetCurrentTimeUsec(struct pg_tm * tm, fsec_t *fsec, int *tzp);
 285 extern void j2date(int jd, int *year, int *month, int *day);
 286 extern int      date2j(int year, int month, int day);
 287
 288 extern int ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 289                           char **field, int *ftype,
 290                           int maxfields, int *numfields);
 291 extern int DecodeDateTime(char **field, int *ftype,
 292                            int nf, int *dtype,
 293                            struct pg_tm * tm, fsec_t *fsec, int *tzp);
 294 extern int DecodeTimeOnly(char **field, int *ftype,
 295                            int nf, int *dtype,
 296                            struct pg_tm * tm, fsec_t *fsec, int *tzp);
 297 extern int DecodeInterval(char **field, int *ftype, int nf, int range,
 298                            int *dtype, struct pg_tm * tm, fsec_t *fsec);
 299 extern int DecodeISO8601Interval(char *str,
 300                                           int *dtype, struct pg_tm * tm, fsec_t *fsec);
 301
 302 extern void DateTimeParseError(int dterr, const char *str,
 303                                    const char *datatype);
 304
 305 extern int      DetermineTimeZoneOffset(struct pg_tm * tm, pg_tz *tzp);
 306
 307 extern void EncodeDateOnly(struct pg_tm * tm, int style, char *str);
 308 extern void EncodeTimeOnly(struct pg_tm * tm, fsec_t fsec, int *tzp, int style, char *str);
 309 extern void EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char **tzn, int style, char *str);
 310 extern void EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str);
 311
 312 extern int      DecodeSpecial(int field, char *lowtoken, int *val);
 313 extern int      DecodeUnits(int field, char *lowtoken, int *val);
 314
 315 extern int      j2day(int jd);
 316
 317 extern bool CheckDateTokenTables(void);
 318 extern void InstallTimeZoneAbbrevs(tzEntry *abbrevs, int n);
 319
 320 extern Datum pg_timezone_abbrevs(PG_FUNCTION_ARGS);
 321 extern Datum pg_timezone_names(PG_FUNCTION_ARGS);
 322
 323 #endif   /* DATETIME_H */