src/include/utils/timestamp.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * timestamp.h
   4  *        Definitions for the SQL92 "timestamp" and "interval" types.
   5  *
   6  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  * $PostgreSQL$
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #ifndef TIMESTAMP_H
  14 #define TIMESTAMP_H
  15
  16 #include <math.h>
  17 #include <limits.h>
  18 #include <float.h>
  19
  20 #include "fmgr.h"
  21 #include "pgtime.h"
  22 #ifdef HAVE_INT64_TIMESTAMP
  23 #include "utils/int8.h"
  24 #endif
  25
  26 /*
  27  * Timestamp represents absolute time.
  28  *
  29  * Interval represents delta time. Keep track of months (and years), days,
  30  * and hours/minutes/seconds separately since the elapsed time spanned is
  31  * unknown until instantiated relative to an absolute time.
  32  *
  33  * Note that Postgres uses "time interval" to mean a bounded interval,
  34  * consisting of a beginning and ending time, not a time span - thomas 97/03/20
  35  *
  36  * We have two implementations, one that uses int64 values with units of
  37  * microseconds, and one that uses double values with units of seconds.
  38  *
  39  * TimeOffset and fsec_t are convenience typedefs for temporary variables
  40  * that are of different types in the two cases.  Do not use fsec_t in values
  41  * stored on-disk, since it is not the same size in both implementations.
  42  */
  43
  44 #ifdef HAVE_INT64_TIMESTAMP
  45
  46 typedef int64 Timestamp;
  47 typedef int64 TimestampTz;
  48 typedef int64 TimeOffset;
  49 typedef int32 fsec_t;                   /* fractional seconds (in microseconds) */
  50
  51 #else
  52
  53 typedef double Timestamp;
  54 typedef double TimestampTz;
  55 typedef double TimeOffset;
  56 typedef double fsec_t;                  /* fractional seconds (in seconds) */
  57
  58 #endif
  59
  60 typedef struct
  61 {
  62         TimeOffset      time;                   /* all time units other than days, months and
  63                                                                  * years */
  64         int32           day;                    /* days, after time for alignment */
  65         int32           month;                  /* months and years, after time for alignment */
  66 } Interval;
  67
  68
  69 #define MAX_TIMESTAMP_PRECISION 6
  70 #define MAX_INTERVAL_PRECISION 6
  71
  72 /* in both timestamp.h and ecpg/dt.h */
  73 #define DAYS_PER_YEAR   365.25  /* assumes leap year every four years */
  74 #define MONTHS_PER_YEAR 12
  75 /*
  76  *      DAYS_PER_MONTH is very imprecise.  The more accurate value is
  77  *      365.2425/12 = 30.436875, or '30 days 10:29:06'.  Right now we only
  78  *      return an integral number of days, but someday perhaps we should
  79  *      also return a 'time' value to be used as well.  ISO 8601 suggests
  80  *      30 days.
  81  */
  82 #define DAYS_PER_MONTH  30              /* assumes exactly 30 days per month */
  83 #define HOURS_PER_DAY   24              /* assume no daylight savings time changes */
  84
  85 /*
  86  *      This doesn't adjust for uneven daylight savings time intervals or leap
  87  *      seconds, and it crudely estimates leap years.  A more accurate value
  88  *      for days per years is 365.2422.
  89  */
  90 #define SECS_PER_YEAR   (36525 * 864)   /* avoid floating-point computation */
  91 #define SECS_PER_DAY    86400
  92 #define SECS_PER_HOUR   3600
  93 #define SECS_PER_MINUTE 60
  94 #define MINS_PER_HOUR   60
  95
  96 #ifdef HAVE_INT64_TIMESTAMP
  97 #define USECS_PER_DAY   INT64CONST(86400000000)
  98 #define USECS_PER_HOUR  INT64CONST(3600000000)
  99 #define USECS_PER_MINUTE INT64CONST(60000000)
 100 #define USECS_PER_SEC   INT64CONST(1000000)
 101 #endif
 102
 103 /*
 104  * Macros for fmgr-callable functions.
 105  *
 106  * For Timestamp, we make use of the same support routines as for int64
 107  * or float8.  Therefore Timestamp is pass-by-reference if and only if
 108  * int64 or float8 is!
 109  */
 110 #ifdef HAVE_INT64_TIMESTAMP
 111
 112 #define DatumGetTimestamp(X)  ((Timestamp) DatumGetInt64(X))
 113 #define DatumGetTimestampTz(X)  ((TimestampTz) DatumGetInt64(X))
 114 #define DatumGetIntervalP(X)  ((Interval *) DatumGetPointer(X))
 115
 116 #define TimestampGetDatum(X) Int64GetDatum(X)
 117 #define TimestampTzGetDatum(X) Int64GetDatum(X)
 118 #define IntervalPGetDatum(X) PointerGetDatum(X)
 119
 120 #define PG_GETARG_TIMESTAMP(n) DatumGetTimestamp(PG_GETARG_DATUM(n))
 121 #define PG_GETARG_TIMESTAMPTZ(n) DatumGetTimestampTz(PG_GETARG_DATUM(n))
 122 #define PG_GETARG_INTERVAL_P(n) DatumGetIntervalP(PG_GETARG_DATUM(n))
 123
 124 #define PG_RETURN_TIMESTAMP(x) return TimestampGetDatum(x)
 125 #define PG_RETURN_TIMESTAMPTZ(x) return TimestampTzGetDatum(x)
 126 #define PG_RETURN_INTERVAL_P(x) return IntervalPGetDatum(x)
 127
 128 #define DT_NOBEGIN              (-INT64CONST(0x7fffffffffffffff) - 1)
 129 #define DT_NOEND                (INT64CONST(0x7fffffffffffffff))
 130
 131 #else  /* !HAVE_INT64_TIMESTAMP */
 132
 133 #define DatumGetTimestamp(X)  ((Timestamp) DatumGetFloat8(X))
 134 #define DatumGetTimestampTz(X)  ((TimestampTz) DatumGetFloat8(X))
 135 #define DatumGetIntervalP(X)  ((Interval *) DatumGetPointer(X))
 136
 137 #define TimestampGetDatum(X) Float8GetDatum(X)
 138 #define TimestampTzGetDatum(X) Float8GetDatum(X)
 139 #define IntervalPGetDatum(X) PointerGetDatum(X)
 140
 141 #define PG_GETARG_TIMESTAMP(n) DatumGetTimestamp(PG_GETARG_DATUM(n))
 142 #define PG_GETARG_TIMESTAMPTZ(n) DatumGetTimestampTz(PG_GETARG_DATUM(n))
 143 #define PG_GETARG_INTERVAL_P(n) DatumGetIntervalP(PG_GETARG_DATUM(n))
 144
 145 #define PG_RETURN_TIMESTAMP(x) return TimestampGetDatum(x)
 146 #define PG_RETURN_TIMESTAMPTZ(x) return TimestampTzGetDatum(x)
 147 #define PG_RETURN_INTERVAL_P(x) return IntervalPGetDatum(x)
 148
 149 #ifdef HUGE_VAL
 150 #define DT_NOBEGIN              (-HUGE_VAL)
 151 #define DT_NOEND                (HUGE_VAL)
 152 #else
 153 #define DT_NOBEGIN              (-DBL_MAX)
 154 #define DT_NOEND                (DBL_MAX)
 155 #endif
 156
 157 #endif   /* HAVE_INT64_TIMESTAMP */
 158
 159
 160 #define TIMESTAMP_NOBEGIN(j)    \
 161         do {(j) = DT_NOBEGIN;} while (0)
 162 #define TIMESTAMP_IS_NOBEGIN(j) ((j) == DT_NOBEGIN)
 163
 164 #define TIMESTAMP_NOEND(j)              \
 165         do {(j) = DT_NOEND;} while (0)
 166 #define TIMESTAMP_IS_NOEND(j)   ((j) == DT_NOEND)
 167
 168 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 169
 170 /*
 171  *      Round off to MAX_TIMESTAMP_PRECISION decimal places.
 172  *      Note: this is also used for rounding off intervals.
 173  */
 174 #define TS_PREC_INV 1000000.0
 175 #define TSROUND(j) (rint(((double) (j)) * TS_PREC_INV) / TS_PREC_INV)
 176
 177 #define TIMESTAMP_MASK(b) (1 << (b))
 178 #define INTERVAL_MASK(b) (1 << (b))
 179
 180 /* Macros to handle packing and unpacking the typmod field for intervals */
 181 #define INTERVAL_FULL_RANGE (0x7FFF)
 182 #define INTERVAL_RANGE_MASK (0x7FFF)
 183 #define INTERVAL_FULL_PRECISION (0xFFFF)
 184 #define INTERVAL_PRECISION_MASK (0xFFFF)
 185 #define INTERVAL_TYPMOD(p,r) ((((r) & INTERVAL_RANGE_MASK) << 16) | ((p) & INTERVAL_PRECISION_MASK))
 186 #define INTERVAL_PRECISION(t) ((t) & INTERVAL_PRECISION_MASK)
 187 #define INTERVAL_RANGE(t) (((t) >> 16) & INTERVAL_RANGE_MASK)
 188
 189 #ifdef HAVE_INT64_TIMESTAMP
 190 #define TimestampTzPlusMilliseconds(tz,ms) ((tz) + ((ms) * (int64) 1000))
 191 #else
 192 #define TimestampTzPlusMilliseconds(tz,ms) ((tz) + ((ms) / 1000.0))
 193 #endif
 194
 195
 196 /* Set at postmaster start */
 197 extern TimestampTz PgStartTime;
 198 /* Set at configuration reload */
 199 extern TimestampTz PgReloadTime;
 200
 201
 202 /*
 203  * timestamp.c prototypes
 204  */
 205
 206 extern Datum timestamp_in(PG_FUNCTION_ARGS);
 207 extern Datum timestamp_out(PG_FUNCTION_ARGS);
 208 extern Datum timestamp_recv(PG_FUNCTION_ARGS);
 209 extern Datum timestamp_send(PG_FUNCTION_ARGS);
 210 extern Datum timestamptypmodin(PG_FUNCTION_ARGS);
 211 extern Datum timestamptypmodout(PG_FUNCTION_ARGS);
 212 extern Datum timestamp_scale(PG_FUNCTION_ARGS);
 213 extern Datum timestamp_eq(PG_FUNCTION_ARGS);
 214 extern Datum timestamp_ne(PG_FUNCTION_ARGS);
 215 extern Datum timestamp_lt(PG_FUNCTION_ARGS);
 216 extern Datum timestamp_le(PG_FUNCTION_ARGS);
 217 extern Datum timestamp_ge(PG_FUNCTION_ARGS);
 218 extern Datum timestamp_gt(PG_FUNCTION_ARGS);
 219 extern Datum timestamp_finite(PG_FUNCTION_ARGS);
 220 extern Datum timestamp_cmp(PG_FUNCTION_ARGS);
 221 extern Datum timestamp_hash(PG_FUNCTION_ARGS);
 222 extern Datum timestamp_smaller(PG_FUNCTION_ARGS);
 223 extern Datum timestamp_larger(PG_FUNCTION_ARGS);
 224
 225 extern Datum timestamp_eq_timestamptz(PG_FUNCTION_ARGS);
 226 extern Datum timestamp_ne_timestamptz(PG_FUNCTION_ARGS);
 227 extern Datum timestamp_lt_timestamptz(PG_FUNCTION_ARGS);
 228 extern Datum timestamp_le_timestamptz(PG_FUNCTION_ARGS);
 229 extern Datum timestamp_gt_timestamptz(PG_FUNCTION_ARGS);
 230 extern Datum timestamp_ge_timestamptz(PG_FUNCTION_ARGS);
 231 extern Datum timestamp_cmp_timestamptz(PG_FUNCTION_ARGS);
 232
 233 extern Datum timestamptz_eq_timestamp(PG_FUNCTION_ARGS);
 234 extern Datum timestamptz_ne_timestamp(PG_FUNCTION_ARGS);
 235 extern Datum timestamptz_lt_timestamp(PG_FUNCTION_ARGS);
 236 extern Datum timestamptz_le_timestamp(PG_FUNCTION_ARGS);
 237 extern Datum timestamptz_gt_timestamp(PG_FUNCTION_ARGS);
 238 extern Datum timestamptz_ge_timestamp(PG_FUNCTION_ARGS);
 239 extern Datum timestamptz_cmp_timestamp(PG_FUNCTION_ARGS);
 240
 241 extern Datum interval_in(PG_FUNCTION_ARGS);
 242 extern Datum interval_out(PG_FUNCTION_ARGS);
 243 extern Datum interval_recv(PG_FUNCTION_ARGS);
 244 extern Datum interval_send(PG_FUNCTION_ARGS);
 245 extern Datum intervaltypmodin(PG_FUNCTION_ARGS);
 246 extern Datum intervaltypmodout(PG_FUNCTION_ARGS);
 247 extern Datum interval_scale(PG_FUNCTION_ARGS);
 248 extern Datum interval_eq(PG_FUNCTION_ARGS);
 249 extern Datum interval_ne(PG_FUNCTION_ARGS);
 250 extern Datum interval_lt(PG_FUNCTION_ARGS);
 251 extern Datum interval_le(PG_FUNCTION_ARGS);
 252 extern Datum interval_ge(PG_FUNCTION_ARGS);
 253 extern Datum interval_gt(PG_FUNCTION_ARGS);
 254 extern Datum interval_finite(PG_FUNCTION_ARGS);
 255 extern Datum interval_cmp(PG_FUNCTION_ARGS);
 256 extern Datum interval_hash(PG_FUNCTION_ARGS);
 257 extern Datum interval_smaller(PG_FUNCTION_ARGS);
 258 extern Datum interval_larger(PG_FUNCTION_ARGS);
 259 extern Datum interval_justify_interval(PG_FUNCTION_ARGS);
 260 extern Datum interval_justify_hours(PG_FUNCTION_ARGS);
 261 extern Datum interval_justify_days(PG_FUNCTION_ARGS);
 262
 263 extern Datum timestamp_trunc(PG_FUNCTION_ARGS);
 264 extern Datum interval_trunc(PG_FUNCTION_ARGS);
 265 extern Datum timestamp_part(PG_FUNCTION_ARGS);
 266 extern Datum interval_part(PG_FUNCTION_ARGS);
 267 extern Datum timestamp_zone(PG_FUNCTION_ARGS);
 268 extern Datum timestamp_izone(PG_FUNCTION_ARGS);
 269 extern Datum timestamp_timestamptz(PG_FUNCTION_ARGS);
 270
 271 extern Datum timestamptz_in(PG_FUNCTION_ARGS);
 272 extern Datum timestamptz_out(PG_FUNCTION_ARGS);
 273 extern Datum timestamptz_recv(PG_FUNCTION_ARGS);
 274 extern Datum timestamptz_send(PG_FUNCTION_ARGS);
 275 extern Datum timestamptztypmodin(PG_FUNCTION_ARGS);
 276 extern Datum timestamptztypmodout(PG_FUNCTION_ARGS);
 277 extern Datum timestamptz_scale(PG_FUNCTION_ARGS);
 278 extern Datum timestamptz_timestamp(PG_FUNCTION_ARGS);
 279 extern Datum timestamptz_zone(PG_FUNCTION_ARGS);
 280 extern Datum timestamptz_izone(PG_FUNCTION_ARGS);
 281 extern Datum timestamptz_timestamptz(PG_FUNCTION_ARGS);
 282
 283 extern Datum interval_um(PG_FUNCTION_ARGS);
 284 extern Datum interval_pl(PG_FUNCTION_ARGS);
 285 extern Datum interval_mi(PG_FUNCTION_ARGS);
 286 extern Datum interval_mul(PG_FUNCTION_ARGS);
 287 extern Datum mul_d_interval(PG_FUNCTION_ARGS);
 288 extern Datum interval_div(PG_FUNCTION_ARGS);
 289 extern Datum interval_accum(PG_FUNCTION_ARGS);
 290 extern Datum interval_avg(PG_FUNCTION_ARGS);
 291
 292 extern Datum timestamp_mi(PG_FUNCTION_ARGS);
 293 extern Datum timestamp_pl_interval(PG_FUNCTION_ARGS);
 294 extern Datum timestamp_mi_interval(PG_FUNCTION_ARGS);
 295 extern Datum timestamp_age(PG_FUNCTION_ARGS);
 296 extern Datum overlaps_timestamp(PG_FUNCTION_ARGS);
 297
 298 extern Datum timestamptz_pl_interval(PG_FUNCTION_ARGS);
 299 extern Datum timestamptz_mi_interval(PG_FUNCTION_ARGS);
 300 extern Datum timestamptz_age(PG_FUNCTION_ARGS);
 301 extern Datum timestamptz_trunc(PG_FUNCTION_ARGS);
 302 extern Datum timestamptz_part(PG_FUNCTION_ARGS);
 303
 304 extern Datum now(PG_FUNCTION_ARGS);
 305 extern Datum statement_timestamp(PG_FUNCTION_ARGS);
 306 extern Datum clock_timestamp(PG_FUNCTION_ARGS);
 307
 308 extern Datum pg_postmaster_start_time(PG_FUNCTION_ARGS);
 309 extern Datum pg_conf_load_time(PG_FUNCTION_ARGS);
 310
 311 extern Datum generate_series_timestamp(PG_FUNCTION_ARGS);
 312 extern Datum generate_series_timestamptz(PG_FUNCTION_ARGS);
 313
 314 /* Internal routines (not fmgr-callable) */
 315
 316 extern TimestampTz GetCurrentTimestamp(void);
 317
 318 extern void TimestampDifference(TimestampTz start_time, TimestampTz stop_time,
 319                                         long *secs, int *microsecs);
 320 extern bool TimestampDifferenceExceeds(TimestampTz start_time,
 321                                                    TimestampTz stop_time,
 322                                                    int msec);
 323
 324 extern TimestampTz time_t_to_timestamptz(pg_time_t tm);
 325 extern pg_time_t timestamptz_to_time_t(TimestampTz t);
 326
 327 extern const char *timestamptz_to_str(TimestampTz t);
 328
 329 extern int      tm2timestamp(struct pg_tm * tm, fsec_t fsec, int *tzp, Timestamp *dt);
 330 extern int timestamp2tm(Timestamp dt, int *tzp, struct pg_tm * tm,
 331                          fsec_t *fsec, char **tzn, pg_tz *attimezone);
 332 extern void dt2time(Timestamp dt, int *hour, int *min, int *sec, fsec_t *fsec);
 333
 334 extern int      interval2tm(Interval span, struct pg_tm * tm, fsec_t *fsec);
 335 extern int      tm2interval(struct pg_tm * tm, fsec_t fsec, Interval *span);
 336
 337 extern Timestamp SetEpochTimestamp(void);
 338 extern void GetEpochTime(struct pg_tm * tm);
 339
 340 extern int      timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 341
 342 /* timestamp comparison works for timestamptz also */
 343 #define timestamptz_cmp_internal(dt1,dt2)       timestamp_cmp_internal(dt1, dt2)
 344
 345 extern int      isoweek2j(int year, int week);
 346 extern void isoweek2date(int woy, int *year, int *mon, int *mday);
 347 extern void isoweekdate2date(int isoweek, int isowday, int *year, int *mon, int *mday);
 348 extern int      date2isoweek(int year, int mon, int mday);
 349 extern int      date2isoyear(int year, int mon, int mday);
 350 extern int      date2isoyearday(int year, int mon, int mday);
 351
 352 #endif   /* TIMESTAMP_H */