datetime.c 13.4 KB
Newer Older
1 2 3 4 5 6 7 8 9
/*-------------------------------------------------------------------------
 *
 * datetime.c--
 *    implements DATE and TIME data types specified in SQL-92 standard
 *
 * Copyright (c) 1994-5, Regents of the University of California
 *
 *
 * IDENTIFICATION
10
 *    $Header: /cvsroot/pgsql/src/backend/utils/adt/datetime.c,v 1.10 1997/07/01 00:22:40 thomas Exp $
11 12 13 14 15
 *
 *-------------------------------------------------------------------------
 */
#include <stdio.h>		/* for sprintf() */
#include <string.h>
16
#include <limits.h>
17

18
#include "postgres.h"
Marc G. Fournier's avatar
Marc G. Fournier committed
19 20 21
#ifdef HAVE_FLOAT_H
#include <float.h>
#endif
22 23 24 25 26
#include "miscadmin.h"
#include "utils/builtins.h"
#include "utils/nabstime.h"
#include "utils/datetime.h"
#include "access/xact.h"
27 28 29 30 31 32 33

static int	day_tab[2][12] = {
	{31,28,31,30,31,30,31,31,30,31,30,31},
	{31,29,31,30,31,30,31,31,30,31,30,31}  };

#define isleap(y) (((y % 4) == 0 && (y % 100) != 0) || (y % 400) == 0)

34 35 36 37 38 39 40 41 42 43 44 45 46
#define UTIME_MINYEAR (1901)
#define UTIME_MINMONTH (12)
#define UTIME_MINDAY (14)
#define UTIME_MAXYEAR (2038)
#define UTIME_MAXMONTH (01)
#define UTIME_MAXDAY (18)

#define IS_VALID_UTIME(y,m,d) (((y > UTIME_MINYEAR) \
 || ((y == UTIME_MINYEAR) && ((m > UTIME_MINMONTH) \
  || ((m == UTIME_MINMONTH) && (d >= UTIME_MINDAY))))) \
 && ((y < UTIME_MAXYEAR) \
 || ((y == UTIME_MAXYEAR) && ((m < UTIME_MAXMONTH) \
  || ((m == UTIME_MAXMONTH) && (d <= UTIME_MAXDAY))))))
47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81

/*****************************************************************************
 *   Date ADT
 *****************************************************************************/


/* date_in()
 * Given date text string, convert to internal date format.
 */
DateADT
date_in(char *str)
{
    DateADT date;
    double fsec;
    struct tm tt, *tm = &tt;
    int tzp;
    int dtype;
    int nf;
    char *field[MAXDATEFIELDS];
    int ftype[MAXDATEFIELDS];
    char lowstr[MAXDATELEN+1];

    if (!PointerIsValid(str))
	elog(WARN,"Bad (null) date external representation",NULL);

#ifdef DATEDEBUG
printf( "date_in- input string is %s\n", str);
#endif
    if ((ParseDateTime( str, lowstr, field, ftype, MAXDATEFIELDS, &nf) != 0)
      || (DecodeDateTime( field, ftype, nf, &dtype, tm, &fsec, &tzp) != 0))
	elog(WARN,"Bad date external representation %s",str);

    switch (dtype) {
    case DTK_DATE:
	break;
82 83 84 85

    case DTK_CURRENT:
	GetCurrentTime(tm);
	break;
86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104

    case DTK_EPOCH:
	tm->tm_year = 1970;
	tm->tm_mon = 1;
	tm->tm_mday = 1;
	break;

    default:
	elog(WARN,"Unrecognized date external representation %s",str);
    };

    if (tm->tm_year < 0 || tm->tm_year > 32767)
	elog(WARN, "date_in: year must be limited to values 0 through 32767 in '%s'", str);
    if (tm->tm_mon < 1 || tm->tm_mon > 12)
	elog(WARN, "date_in: month must be limited to values 1 through 12 in '%s'", str);
    if (tm->tm_mday < 1 || tm->tm_mday > day_tab[isleap(tm->tm_year)][tm->tm_mon-1])
	elog(WARN, "date_in: day must be limited to values 1 through %d in '%s'",
	     day_tab[isleap(tm->tm_year)][tm->tm_mon-1], str);

105
    date = (date2j( tm->tm_year, tm->tm_mon, tm->tm_mday) - date2j(2000,1,1));
106 107 108 109 110 111 112 113 114 115 116

    return(date);
} /* date_in() */

/* date_out()
 * Given internal format date, convert to text string.
 */
char *
date_out(DateADT date)
{
    char *result;
117
    struct tm tt, *tm = &tt;
118
    char buf[MAXDATELEN+1];
119 120

#if FALSE
121
    int year, month, day;
122
#endif
123

124 125
    j2date( (date + date2j(2000,1,1)),
      &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
126

127 128 129
    EncodeDateOnly( tm, DateStyle, buf);

#if FALSE
130 131 132 133
    if (EuroDates == 1) /* Output European-format dates */
        sprintf(buf, "%02d-%02d-%04d", day, month, year);
    else
        sprintf(buf, "%02d-%02d-%04d", month, day, year);
134
#endif
135

136
    result = PALLOC(strlen(buf)+1);
137 138 139 140 141 142

    strcpy( result, buf);

    return(result);
} /* date_out() */

143 144
int date2tm(DateADT dateVal, int *tzp, struct tm *tm, double *fsec, char **tzn);

145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225
bool
date_eq(DateADT dateVal1, DateADT dateVal2)
{
    return(dateVal1 == dateVal2);
}

bool
date_ne(DateADT dateVal1, DateADT dateVal2)
{
    return(dateVal1 != dateVal2);
}

bool
date_lt(DateADT dateVal1, DateADT dateVal2)
{
    return(dateVal1 < dateVal2);
} /* date_lt() */

bool
date_le(DateADT dateVal1, DateADT dateVal2)
{
    return(dateVal1 <= dateVal2);
} /* date_le() */

bool
date_gt(DateADT dateVal1, DateADT dateVal2)
{
    return(dateVal1 > dateVal2);
} /* date_gt() */

bool
date_ge(DateADT dateVal1, DateADT dateVal2)
{
    return(dateVal1 >= dateVal2);
} /* date_ge() */

int
date_cmp(DateADT dateVal1, DateADT dateVal2)
{
    if (dateVal1 < dateVal2) {
	return -1;
    } else if (dateVal1 > dateVal2) {
	return 1;
    };
    return 0;
} /* date_cmp() */

DateADT
date_larger(DateADT dateVal1, DateADT dateVal2)
{
  return(date_gt(dateVal1, dateVal2) ? dateVal1 : dateVal2);
} /* date_larger() */

DateADT
date_smaller(DateADT dateVal1, DateADT dateVal2)
{
  return(date_lt(dateVal1, dateVal2) ? dateVal1 : dateVal2);
} /* date_smaller() */

/* Compute difference between two dates in days.  */
int4
date_mi(DateADT dateVal1, DateADT dateVal2)
{
    return(dateVal1-dateVal2);
} /* date_mi() */

/* Add a number of days to a date, giving a new date.
   Must handle both positive and negative numbers of days.  */
DateADT
date_pli(DateADT dateVal, int4 days)
{
    return(dateVal+days);
} /* date_pli() */

/* Subtract a number of days from a date, giving a new date.  */
DateADT
date_mii(DateADT dateVal, int4 days)
{
  return(date_pli(dateVal, -days));
} /* date_mii() */

226 227 228 229 230

/* date_datetime()
 * Convert date to datetime data type.
 */
DateTime *
231
date_datetime(DateADT dateVal)
232 233
{
    DateTime *result;
234 235 236 237
    struct tm tt, *tm = &tt;
    int tz;
    double fsec = 0;
    char *tzn;
238

239
    result = PALLOCTYPE(DateTime);
240

241 242 243 244 245
    if (date2tm( dateVal, &tz, tm, &fsec, &tzn) != 0)
	elog(WARN,"Unable to convert date to datetime",NULL);

#ifdef DATEDEBUG
printf( "date_datetime- date is %d.%02d.%02d\n", tm->tm_year, tm->tm_mon, tm->tm_mday);
246
printf( "date_datetime- time is %02d:%02d:%02d %.7f\n", tm->tm_hour, tm->tm_min, tm->tm_sec, fsec);
247 248 249 250
#endif

    if (tm2datetime( tm, fsec, &tz, result) != 0)
	elog(WARN,"Datetime out of range",NULL);
251 252 253 254 255 256 257 258 259 260 261 262

    return(result);
} /* date_datetime() */


/* datetime_date()
 * Convert datetime to date data type.
 */
DateADT
datetime_date(DateTime *datetime)
{
    DateADT result;
263 264 265 266
    struct tm tt, *tm = &tt;
    int tz;
    double fsec;
    char *tzn;
267 268 269 270

    if (!PointerIsValid(datetime))
	elog(WARN,"Unable to convert null datetime to date",NULL);

271 272 273 274 275 276 277 278 279 280 281 282 283 284 285
    if (DATETIME_NOT_FINITE(*datetime))
	elog(WARN,"Unable to convert datetime to date",NULL);

    if (DATETIME_IS_EPOCH(*datetime)) {
	datetime2tm( SetDateTime(*datetime), NULL, tm, &fsec, NULL);

    } else if (DATETIME_IS_CURRENT(*datetime)) {
	datetime2tm( SetDateTime(*datetime), &tz, tm, &fsec, &tzn);

    } else {
	if (datetime2tm( *datetime, &tz, tm, &fsec, &tzn) != 0)
	    elog(WARN,"Unable to convert datetime to date",NULL);
    };

    result = (date2j( tm->tm_year, tm->tm_mon, tm->tm_mday) - date2j( 2000, 1, 1));
286 287 288 289 290 291 292 293 294 295 296 297

    return(result);
} /* datetime_date() */


/* abstime_date()
 * Convert abstime to date data type.
 */
DateADT
abstime_date(AbsoluteTime abstime)
{
    DateADT result;
298 299
    struct tm tt, *tm = &tt;
    int tz;
300 301 302 303 304 305

    switch (abstime) {
    case INVALID_ABSTIME:
    case NOSTART_ABSTIME:
    case NOEND_ABSTIME:
	elog(WARN,"Unable to convert reserved abstime value to date",NULL);
306
	/* pretend to drop through to make compiler think that result will be set */
307 308 309 310 311 312 313

    case EPOCH_ABSTIME:
	result = date2j(1970,1,1) - date2j(2000,1,1);
	break;

    case CURRENT_ABSTIME:
	GetCurrentTime(tm);
314
	result = date2j( tm->tm_year, tm->tm_mon, tm->tm_mday) - date2j(2000,1,1);
315 316 317
	break;

    default:
318
	abstime2tm(abstime, &tz, tm, NULL);
319 320 321 322 323 324 325
	result = date2j(tm->tm_year,tm->tm_mon,tm->tm_mday) - date2j(2000,1,1);
	break;
    };

    return(result);
} /* abstime_date() */

326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355

/* date2tm()
 * Convert date to time structure.
 * Note that date is an implicit local time, but the system calls assume
 *  that everything is GMT. So, convert to GMT, rotate to local time,
 *  and then convert again to try to get the time zones correct.
 */
int
date2tm(DateADT dateVal, int *tzp, struct tm *tm, double *fsec, char **tzn)
{
    struct tm *tx;
    time_t utime;
    *fsec = 0;

    j2date( (dateVal + date2j( 2000, 1, 1)), &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
    tm->tm_hour = 0;
    tm->tm_min = 0;
    tm->tm_sec = 0;
    tm->tm_isdst = -1;

    if (IS_VALID_UTIME( tm->tm_year, tm->tm_mon, tm->tm_mday)) {

	/* convert to system time */
	utime = ((dateVal + (date2j(2000,1,1)-date2j(1970,1,1)))*86400);
	utime += (12*60*60);	/* rotate to noon to get the right day in time zone */

#ifdef USE_POSIX_TIME
	tx = localtime(&utime);

#ifdef DATEDEBUG
356
#ifdef HAVE_INT_TIMEZONE
357
printf( "date2tm- (localtime) %d.%02d.%02d %02d:%02d:%02.0f %s %s dst=%d\n",
358
 tx->tm_year, tx->tm_mon, tx->tm_mday, tx->tm_hour, tx->tm_min, (double) tm->tm_sec,
359
 tzname[0], tzname[1], tx->tm_isdst);
360
#endif
361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376
#endif
	tm->tm_year = tx->tm_year + 1900;
	tm->tm_mon = tx->tm_mon + 1;
	tm->tm_mday = tx->tm_mday;
#if FALSE
	tm->tm_hour = tx->tm_hour;
	tm->tm_min = tx->tm_min;
	tm->tm_sec = tx->tm_sec;
#endif
	tm->tm_isdst = tx->tm_isdst;

#ifdef HAVE_INT_TIMEZONE
	*tzp = (tm->tm_isdst? (timezone - 3600): timezone);
	if (tzn != NULL) *tzn = tzname[(tm->tm_isdst > 0)];

#else /* !HAVE_INT_TIMEZONE */
377 378 379
	tm->tm_gmtoff = tx->tm_gmtoff;
	tm->tm_zone = tx->tm_zone;

380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410
	*tzp = (tm->tm_isdst? (tm->tm_gmtoff - 3600): tm->tm_gmtoff); /* tm_gmtoff is Sun/DEC-ism */
	if (tzn != NULL) *tzn = tm->tm_zone;
#endif

#else /* !USE_POSIX_TIME */
	*tzp = CTimeZone;	/* V7 conventions; don't know timezone? */
	if (tzn != NULL) *tzn = CTZName;
#endif

    /* otherwise, outside of timezone range so convert to GMT... */
    } else {
#if FALSE
	j2date( (dateVal + date2j( 2000, 1, 1)), &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
	tm->tm_hour = 0;
	tm->tm_min = 0;
	tm->tm_sec = 0;
#endif

#ifdef DATEDEBUG
printf( "date2tm- convert %d-%d-%d %d:%d%d to datetime\n",
 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
#endif

	*tzp = 0;
	tm->tm_isdst = 0;
	if (tzn != NULL) *tzn = NULL;
    };

    return 0;
} /* date2tm() */

411

412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444
/*****************************************************************************
 *   Time ADT
 *****************************************************************************/


TimeADT *
time_in(char *str)
{
    TimeADT *time;

    double fsec;
    struct tm tt, *tm = &tt;

    int nf;
    char lowstr[MAXDATELEN+1];
    char *field[MAXDATEFIELDS];
    int dtype;
    int ftype[MAXDATEFIELDS];

    if (!PointerIsValid(str))
        elog(WARN,"Bad (null) time external representation",NULL);

    if ((ParseDateTime( str, lowstr, field, ftype, MAXDATEFIELDS, &nf) != 0)
     || (DecodeTimeOnly( field, ftype, nf, &dtype, tm, &fsec) != 0))
        elog(WARN,"Bad time external representation '%s'",str);

    if ((tm->tm_hour < 0) || (tm->tm_hour > 23))
	elog(WARN,"Hour must be limited to values 0 through 23 in '%s'",str);
    if ((tm->tm_min < 0) || (tm->tm_min > 59))
	elog(WARN,"Minute must be limited to values 0 through 59 in '%s'",str);
    if ((tm->tm_sec < 0) || ((tm->tm_sec + fsec) >= 60))
	elog(WARN,"Second must be limited to values 0 through < 60 in '%s'",str);

445
    time = PALLOCTYPE(TimeADT);
446 447 448 449 450 451 452 453 454 455 456

    *time = ((((tm->tm_hour*60)+tm->tm_min)*60)+tm->tm_sec+fsec);

    return(time);
} /* time_in() */


char *
time_out(TimeADT *time)
{
    char *result;
457 458
    struct tm tt, *tm = &tt;
#if FALSE
459
    int hour, min, sec;
460
#endif
461
    double fsec;
462
    char buf[MAXDATELEN+1];
463 464 465 466

    if (!PointerIsValid(time))
	return NULL;

467 468 469
    tm->tm_hour = (*time / (60*60));
    tm->tm_min = (((int) (*time / 60)) % 60);
    tm->tm_sec = (((int) *time) % 60);
470 471 472

    fsec = 0;

473 474 475
    EncodeTimeOnly( tm, fsec, DateStyle, buf);

#if FALSE
476 477 478 479 480 481 482 483 484 485
    if (sec == 0.0) {
	sprintf(buf, "%02d:%02d", hour, min);

    } else {
	if (fsec == 0) {
	    sprintf(buf, "%02d:%02d:%02d", hour, min, sec);
	} else {
	    sprintf(buf, "%02d:%02d:%05.2f", hour, min, (sec+fsec));
	};
    };
486
#endif
487 488

    result = PALLOC(strlen(buf)+1);
489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555

    strcpy( result, buf);

    return(result);
} /* time_out() */


bool
time_eq(TimeADT *time1, TimeADT *time2)
{
    if (!PointerIsValid(time1) || !PointerIsValid(time2))
	return(FALSE);

    return(*time1 == *time2);
} /* time_eq() */

bool
time_ne(TimeADT *time1, TimeADT *time2)
{
    if (!PointerIsValid(time1) || !PointerIsValid(time2))
	return(FALSE);

    return(*time1 != *time2);
} /* time_eq() */

bool
time_lt(TimeADT *time1, TimeADT *time2)
{
    if (!PointerIsValid(time1) || !PointerIsValid(time2))
	return(FALSE);

    return(*time1 < *time2);
} /* time_eq() */

bool
time_le(TimeADT *time1, TimeADT *time2)
{
    if (!PointerIsValid(time1) || !PointerIsValid(time2))
	return(FALSE);

    return(*time1 <= *time2);
} /* time_eq() */

bool
time_gt(TimeADT *time1, TimeADT *time2)
{
    if (!PointerIsValid(time1) || !PointerIsValid(time2))
	return(FALSE);

    return(*time1 > *time2);
} /* time_eq() */

bool
time_ge(TimeADT *time1, TimeADT *time2)
{
    if (!PointerIsValid(time1) || !PointerIsValid(time2))
	return(FALSE);

    return(*time1 >= *time2);
} /* time_eq() */

int
time_cmp(TimeADT *time1, TimeADT *time2)
{
    return((*time1 < *time2)? -1: (((*time1 < *time2)? 1: 0)));
} /* time_cmp() */

556 557 558 559 560 561 562 563 564 565

/* datetime_datetime()
 * Convert date and time to datetime data type.
 */
DateTime *
datetime_datetime(DateADT date, TimeADT *time)
{
    DateTime *result;

    if (!PointerIsValid(time)) {
566
	result = PALLOCTYPE(DateTime);
567 568 569 570 571 572 573 574 575 576
	DATETIME_INVALID(*result);

    } else {
	result = date_datetime(date);
	*result += *time;
    };

    return(result);
} /* datetime_datetime() */

577 578 579 580 581 582

int32   /* RelativeTime */
int42reltime(int32 timevalue)
{
    return(timevalue);
}