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GeezerVison is showing github.com — sqlcipher/src/date.c at master · wolfcon/sqlcipher Expand file tree/ Copy pathdate.cMore file actions 1249 lines (1203 loc) · 32.8 KB / Copy pathdate.cFile metadata and controls1249 lines (1203 loc) · 32.8 KB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 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 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 /* ** 2003 October 31 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the C functions that implement date and time ** functions for SQLite. ** ** There is only one exported symbol in this file - the function ** sqlite3RegisterDateTimeFunctions() found at the bottom of the file. ** All other code has file scope. ** ** SQLite processes all times and dates as julian day numbers. The ** dates and times are stored as the number of days since noon ** in Greenwich on November 24, 4714 B.C. according to the Gregorian ** calendar system. ** ** 1970-01-01 00:00:00 is JD 2440587.5 ** 2000-01-01 00:00:00 is JD 2451544.5 ** ** This implementation requires years to be expressed as a 4-digit number ** which means that only dates between 0000-01-01 and 9999-12-31 can ** be represented, even though julian day numbers allow a much wider ** range of dates. ** ** The Gregorian calendar system is used for all dates and times, ** even those that predate the Gregorian calendar. Historians usually ** use the julian calendar for dates prior to 1582-10-15 and for some ** dates afterwards, depending on locale. Beware of this difference. ** ** The conversion algorithms are implemented based on descriptions ** in the following text: ** ** Jean Meeus ** Astronomical Algorithms, 2nd Edition, 1998 ** ISBN 0-943396-61-1 ** Willmann-Bell, Inc ** Richmond, Virginia (USA) */ #include "sqliteInt.h" #include <stdlib.h> #include <assert.h> #include <time.h> #ifndef SQLITE_OMIT_DATETIME_FUNCS /* ** The MSVC CRT on Windows CE may not have a localtime() function. ** So declare a substitute. The substitute function itself is ** defined in "os_win.c". */ #if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \ (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API) struct tm *__cdecl localtime(const time_t *); #endif /* ** A structure for holding a single date and time. */ typedef struct DateTime DateTime; struct DateTime { sqlite3_int64 iJD; /* The julian day number times 86400000 */ int Y, M, D; /* Year, month, and day */ int h, m; /* Hour and minutes */ int tz; /* Timezone offset in minutes */ double s; /* Seconds */ char validJD; /* True (1) if iJD is valid */ char rawS; /* Raw numeric value stored in s */ char validYMD; /* True (1) if Y,M,D are valid */ char validHMS; /* True (1) if h,m,s are valid */ char validTZ; /* True (1) if tz is valid */ char tzSet; /* Timezone was set explicitly */ char isError; /* An overflow has occurred */ }; /* ** Convert zDate into one or more integers according to the conversion ** specifier zFormat. ** ** zFormat[] contains 4 characters for each integer converted, except for ** the last integer which is specified by three characters. The meaning ** of a four-character format specifiers ABCD is: ** ** A: number of digits to convert. Always "2" or "4". ** B: minimum value. Always "0" or "1". ** C: maximum value, decoded as: ** a: 12 ** b: 14 ** c: 24 ** d: 31 ** e: 59 ** f: 9999 ** D: the separator character, or \000 to indicate this is the ** last number to convert. ** ** Example: To translate an ISO-8601 date YYYY-MM-DD, the format would ** be "40f-21a-20c". The "40f-" indicates the 4-digit year followed by "-". ** The "21a-" indicates the 2-digit month followed by "-". The "20c" indicates ** the 2-digit day which is the last integer in the set. ** ** The function returns the number of successful conversions. */ static int getDigits(const char *zDate, const char *zFormat, ...){ /* The aMx[] array translates the 3rd character of each format ** spec into a max size: a b c d e f */ static const u16 aMx[] = { 12, 14, 24, 31, 59, 9999 }; va_list ap; int cnt = 0; char nextC; va_start(ap, zFormat); do{ char N = zFormat[0] - '0'; char min = zFormat[1] - '0'; int val = 0; u16 max; assert( zFormat[2]>='a' && zFormat[2]<='f' ); max = aMx[zFormat[2] - 'a']; nextC = zFormat[3]; val = 0; while( N-- ){ if( !sqlite3Isdigit(*zDate) ){ goto end_getDigits; } val = val*10 + *zDate - '0'; zDate++; } if( val<(int)min || val>(int)max || (nextC!=0 && nextC!=*zDate) ){ goto end_getDigits; } *va_arg(ap,int*) = val; zDate++; cnt++; zFormat += 4; }while( nextC ); end_getDigits: va_end(ap); return cnt; } /* ** Parse a timezone extension on the end of a date-time. ** The extension is of the form: ** ** (+/-)HH:MM ** ** Or the "zulu" notation: ** ** Z ** ** If the parse is successful, write the number of minutes ** of change in p->tz and return 0. If a parser error occurs, ** return non-zero. ** ** A missing specifier is not considered an error. */ static int parseTimezone(const char *zDate, DateTime *p){ int sgn = 0; int nHr, nMn; int c; while( sqlite3Isspace(*zDate) ){ zDate++; } p->tz = 0; c = *zDate; if( c=='-' ){ sgn = -1; }else if( c=='+' ){ sgn = +1; }else if( c=='Z' || c=='z' ){ zDate++; goto zulu_time; }else{ return c!=0; } zDate++; if( getDigits(zDate, "20b:20e", &nHr, &nMn)!=2 ){ return 1; } zDate += 5; p->tz = sgn*(nMn + nHr*60); zulu_time: while( sqlite3Isspace(*zDate) ){ zDate++; } p->tzSet = 1; return *zDate!=0; } /* ** Parse times of the form HH:MM or HH:MM:SS or HH:MM:SS.FFFF. ** The HH, MM, and SS must each be exactly 2 digits. The ** fractional seconds FFFF can be one or more digits. ** ** Return 1 if there is a parsing error and 0 on success. */ static int parseHhMmSs(const char *zDate, DateTime *p){ int h, m, s; double ms = 0.0; if( getDigits(zDate, "20c:20e", &h, &m)!=2 ){ return 1; } zDate += 5; if( *zDate==':' ){ zDate++; if( getDigits(zDate, "20e", &s)!=1 ){ return 1; } zDate += 2; if( *zDate=='.' && sqlite3Isdigit(zDate[1]) ){ double rScale = 1.0; zDate++; while( sqlite3Isdigit(*zDate) ){ ms = ms*10.0 + *zDate - '0'; rScale *= 10.0; zDate++; } ms /= rScale; } }else{ s = 0; } p->validJD = 0; p->rawS = 0; p->validHMS = 1; p->h = h; p->m = m; p->s = s + ms; if( parseTimezone(zDate, p) ) return 1; p->validTZ = (p->tz!=0)?1:0; return 0; } /* ** Put the DateTime object into its error state. */ static void datetimeError(DateTime *p){ memset(p, 0, sizeof(*p)); p->isError = 1; } /* ** Convert from YYYY-MM-DD HH:MM:SS to julian day. We always assume ** that the YYYY-MM-DD is according to the Gregorian calendar. ** ** Reference: Meeus page 61 */ static void computeJD(DateTime *p){ int Y, M, D, A, B, X1, X2; if( p->validJD ) return; if( p->validYMD ){ Y = p->Y; M = p->M; D = p->D; }else{ Y = 2000; /* If no YMD specified, assume 2000-Jan-01 */ M = 1; D = 1; } if( Y<-4713 || Y>9999 || p->rawS ){ datetimeError(p); return; } if( M<=2 ){ Y--; M += 12; } A = Y/100; B = 2 - A + (A/4); X1 = 36525*(Y+4716)/100; X2 = 306001*(M+1)/10000; p->iJD = (sqlite3_int64)((X1 + X2 + D + B - 1524.5 ) * 86400000); p->validJD = 1; if( p->validHMS ){ p->iJD += p->h*3600000 + p->m*60000 + (sqlite3_int64)(p->s*1000); if( p->validTZ ){ p->iJD -= p->tz*60000; p->validYMD = 0; p->validHMS = 0; p->validTZ = 0; } } } /* ** Parse dates of the form ** ** YYYY-MM-DD HH:MM:SS.FFF ** YYYY-MM-DD HH:MM:SS ** YYYY-MM-DD HH:MM ** YYYY-MM-DD ** ** Write the result into the DateTime structure and return 0 ** on success and 1 if the input string is not a well-formed ** date. */ static int parseYyyyMmDd(const char *zDate, DateTime *p){ int Y, M, D, neg; if( zDate[0]=='-' ){ zDate++; neg = 1; }else{ neg = 0; } if( getDigits(zDate, "40f-21a-21d", &Y, &M, &D)!=3 ){ return 1; } zDate += 10; while( sqlite3Isspace(*zDate) || 'T'==*(u8*)zDate ){ zDate++; } if( parseHhMmSs(zDate, p)==0 ){ /* We got the time */ }else if( *zDate==0 ){ p->validHMS = 0; }else{ return 1; } p->validJD = 0; p->validYMD = 1; p->Y = neg ? -Y : Y; p->M = M; p->D = D; if( p->validTZ ){ computeJD(p); } return 0; } /* ** Set the time to the current time reported by the VFS. ** ** Return the number of errors. */ static int setDateTimeToCurrent(sqlite3_context *context, DateTime *p){ p->iJD = sqlite3StmtCurrentTime(context); if( p->iJD>0 ){ p->validJD = 1; return 0; }else{ return 1; } } /* ** Input "r" is a numeric quantity which might be a julian day number, ** or the number of seconds since 1970. If the value if r is within ** range of a julian day number, install it as such and set validJD. ** If the value is a valid unix timestamp, put it in p->s and set p->rawS. */ static void setRawDateNumber(DateTime *p, double r){ p->s = r; p->rawS = 1; if( r>=0.0 && r<5373484.5 ){ p->iJD = (sqlite3_int64)(r*86400000.0 + 0.5); p->validJD = 1; } } /* ** Attempt to parse the given string into a julian day number. Return ** the number of errors. ** ** The following are acceptable forms for the input string: ** ** YYYY-MM-DD HH:MM:SS.FFF +/-HH:MM ** DDDD.DD ** now ** ** In the first form, the +/-HH:MM is always optional. The fractional ** seconds extension (the ".FFF") is optional. The seconds portion ** (":SS.FFF") is option. The year and date can be omitted as long ** as there is a time string. The time string can be omitted as long ** as there is a year and date. */ static int parseDateOrTime( sqlite3_context *context, const char *zDate, DateTime *p ){ double r; if( parseYyyyMmDd(zDate,p)==0 ){ return 0; }else if( parseHhMmSs(zDate, p)==0 ){ return 0; }else if( sqlite3StrICmp(zDate,"now")==0 && sqlite3NotPureFunc(context) ){ return setDateTimeToCurrent(context, p); }else if( sqlite3AtoF(zDate, &r, sqlite3Strlen30(zDate), SQLITE_UTF8) ){ setRawDateNumber(p, r); return 0; } return 1; } /* The julian day number for 9999-12-31 23:59:59.999 is 5373484.4999999. ** Multiplying this by 86400000 gives 464269060799999 as the maximum value ** for DateTime.iJD. ** ** But some older compilers (ex: gcc 4.2.1 on older Macs) cannot deal with ** such a large integer literal, so we have to encode it. */ #define INT_464269060799999 ((((i64)0x1a640)<<32)|0x1072fdff) /* ** Return TRUE if the given julian day number is within range. ** ** The input is the JulianDay times 86400000. */ static int validJulianDay(sqlite3_int64 iJD){ return iJD>=0 && iJD<=INT_464269060799999; } /* ** Compute the Year, Month, and Day from the julian day number. */ static void computeYMD(DateTime *p){ int Z, A, B, C, D, E, X1; if( p->validYMD ) return; if( !p->validJD ){ p->Y = 2000; p->M = 1; p->D = 1; }else if( !validJulianDay(p->iJD) ){ datetimeError(p); return; }else{ Z = (int)((p->iJD + 43200000)/86400000); A = (int)((Z - 1867216.25)/36524.25); A = Z + 1 + A - (A/4); B = A + 1524; C = (int)((B - 122.1)/365.25); D = (36525*(C&32767))/100; E = (int)((B-D)/30.6001); X1 = (int)(30.6001*E); p->D = B - D - X1; p->M = E<14 ? E-1 : E-13; p->Y = p->M>2 ? C - 4716 : C - 4715; } p->validYMD = 1; } /* ** Compute the Hour, Minute, and Seconds from the julian day number. */ static void computeHMS(DateTime *p){ int s; if( p->validHMS ) return; computeJD(p); s = (int)((p->iJD + 43200000) % 86400000); p->s = s/1000.0; s = (int)p->s; p->s -= s; p->h = s/3600; s -= p->h*3600; p->m = s/60; p->s += s - p->m*60; p->rawS = 0; p->validHMS = 1; } /* ** Compute both YMD and HMS */ static void computeYMD_HMS(DateTime *p){ computeYMD(p); computeHMS(p); } /* ** Clear the YMD and HMS and the TZ */ static void clearYMD_HMS_TZ(DateTime *p){ p->validYMD = 0; p->validHMS = 0; p->validTZ = 0; } #ifndef SQLITE_OMIT_LOCALTIME /* ** On recent Windows platforms, the localtime_s() function is available ** as part of the "Secure CRT". It is essentially equivalent to ** localtime_r() available under most POSIX platforms, except that the ** order of the parameters is reversed. ** ** See http://msdn.microsoft.com/en-us/library/a442x3ye(VS.80).aspx. ** ** If the user has not indicated to use localtime_r() or localtime_s() ** already, check for an MSVC build environment that provides ** localtime_s(). */ #if !HAVE_LOCALTIME_R && !HAVE_LOCALTIME_S \ && defined(_MSC_VER) && defined(_CRT_INSECURE_DEPRECATE) #undef HAVE_LOCALTIME_S #define HAVE_LOCALTIME_S 1 #endif /* ** The following routine implements the rough equivalent of localtime_r() ** using whatever operating-system specific localtime facility that ** is available. This routine returns 0 on success and ** non-zero on any kind of error. ** ** If the sqlite3GlobalConfig.bLocaltimeFault variable is true then this ** routine will always fail. ** ** EVIDENCE-OF: R-62172-00036 In this implementation, the standard C ** library function localtime_r() is used to assist in the calculation of ** local time. */ static int osLocaltime(time_t *t, struct tm *pTm){ int rc; #if !HAVE_LOCALTIME_R && !HAVE_LOCALTIME_S struct tm *pX; #if SQLITE_THREADSAFE>0 sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); #endif sqlite3_mutex_enter(mutex); pX = localtime(t); #ifndef SQLITE_UNTESTABLE if( sqlite3GlobalConfig.bLocaltimeFault ) pX = 0; #endif if( pX ) *pTm = *pX; sqlite3_mutex_leave(mutex); rc = pX==0; #else #ifndef SQLITE_UNTESTABLE if( sqlite3GlobalConfig.bLocaltimeFault ) return 1; #endif #if HAVE_LOCALTIME_R rc = localtime_r(t, pTm)==0; #else rc = localtime_s(pTm, t); #endif /* HAVE_LOCALTIME_R */ #endif /* HAVE_LOCALTIME_R || HAVE_LOCALTIME_S */ return rc; } #endif /* SQLITE_OMIT_LOCALTIME */ #ifndef SQLITE_OMIT_LOCALTIME /* ** Compute the difference (in milliseconds) between localtime and UTC ** (a.k.a. GMT) for the time value p where p is in UTC. If no error occurs, ** return this value and set *pRc to SQLITE_OK. ** ** Or, if an error does occur, set *pRc to SQLITE_ERROR. The returned value ** is undefined in this case. */ static sqlite3_int64 localtimeOffset( DateTime *p, /* Date at which to calculate offset */ sqlite3_context *pCtx, /* Write error here if one occurs */ int *pRc /* OUT: Error code. SQLITE_OK or ERROR */ ){ DateTime x, y; time_t t; struct tm sLocal; /* Initialize the contents of sLocal to avoid a compiler warning. */ memset(&sLocal, 0, sizeof(sLocal)); x = *p; computeYMD_HMS(&x); if( x.Y<1971 || x.Y>=2038 ){ /* EVIDENCE-OF: R-55269-29598 The localtime_r() C function normally only ** works for years between 1970 and 2037. For dates outside this range, ** SQLite attempts to map the year into an equivalent year within this ** range, do the calculation, then map the year back. */ x.Y = 2000; x.M = 1; x.D = 1; x.h = 0; x.m = 0; x.s = 0.0; } else { int s = (int)(x.s + 0.5); x.s = s; } x.tz = 0; x.validJD = 0; computeJD(&x); t = (time_t)(x.iJD/1000 - 21086676*(i64)10000); if( osLocaltime(&t, &sLocal) ){ sqlite3_result_error(pCtx, "local time unavailable", -1); *pRc = SQLITE_ERROR; return 0; } y.Y = sLocal.tm_year + 1900; y.M = sLocal.tm_mon + 1; y.D = sLocal.tm_mday; y.h = sLocal.tm_hour; y.m = sLocal.tm_min; y.s = sLocal.tm_sec; y.validYMD = 1; y.validHMS = 1; y.validJD = 0; y.rawS = 0; y.validTZ = 0; y.isError = 0; computeJD(&y); *pRc = SQLITE_OK; return y.iJD - x.iJD; } #endif /* SQLITE_OMIT_LOCALTIME */ /* ** The following table defines various date transformations of the form ** ** 'NNN days' ** ** Where NNN is an arbitrary floating-point number and "days" can be one ** of several units of time. */ static const struct { u8 eType; /* Transformation type code */ u8 nName; /* Length of th name */ char *zName; /* Name of the transformation */ double rLimit; /* Maximum NNN value for this transform */ double rXform; /* Constant used for this transform */ } aXformType[] = { { 0, 6, "second", 464269060800.0, 86400000.0/(24.0*60.0*60.0) }, { 0, 6, "minute", 7737817680.0, 86400000.0/(24.0*60.0) }, { 0, 4, "hour", 128963628.0, 86400000.0/24.0 }, { 0, 3, "day", 5373485.0, 86400000.0 }, { 1, 5, "month", 176546.0, 30.0*86400000.0 }, { 2, 4, "year", 14713.0, 365.0*86400000.0 }, }; /* ** Process a modifier to a date-time stamp. The modifiers are ** as follows: ** ** NNN days ** NNN hours ** NNN minutes ** NNN.NNNN seconds ** NNN months ** NNN years ** start of month ** start of year ** start of week ** start of day ** weekday N ** unixepoch ** localtime ** utc ** ** Return 0 on success and 1 if there is any kind of error. If the error ** is in a system call (i.e. localtime()), then an error message is written ** to context pCtx. If the error is an unrecognized modifier, no error is ** written to pCtx. */ static int parseModifier( sqlite3_context *pCtx, /* Function context */ const char *z, /* The text of the modifier */ int n, /* Length of zMod in bytes */ DateTime *p /* The date/time value to be modified */ ){ int rc = 1; double r; switch(sqlite3UpperToLower[(u8)z[0]] ){ #ifndef SQLITE_OMIT_LOCALTIME case 'l': { /* localtime ** ** Assuming the current time value is UTC (a.k.a. GMT), shift it to ** show local time. */ if( sqlite3_stricmp(z, "localtime")==0 && sqlite3NotPureFunc(pCtx) ){ computeJD(p); p->iJD += localtimeOffset(p, pCtx, &rc); clearYMD_HMS_TZ(p); } break; } #endif case 'u': { /* ** unixepoch ** ** Treat the current value of p->s as the number of ** seconds since 1970. Convert to a real julian day number. */ if( sqlite3_stricmp(z, "unixepoch")==0 && p->rawS ){ r = p->s*1000.0 + 210866760000000.0; if( r>=0.0 && r<464269060800000.0 ){ clearYMD_HMS_TZ(p); p->iJD = (sqlite3_int64)r; p->validJD = 1; p->rawS = 0; rc = 0; } } #ifndef SQLITE_OMIT_LOCALTIME else if( sqlite3_stricmp(z, "utc")==0 && sqlite3NotPureFunc(pCtx) ){ if( p->tzSet==0 ){ sqlite3_int64 c1; computeJD(p); c1 = localtimeOffset(p, pCtx, &rc); if( rc==SQLITE_OK ){ p->iJD -= c1; clearYMD_HMS_TZ(p); p->iJD += c1 - localtimeOffset(p, pCtx, &rc); } p->tzSet = 1; }else{ rc = SQLITE_OK; } } #endif break; } case 'w': { /* ** weekday N ** ** Move the date to the same time on the next occurrence of ** weekday N where 0==Sunday, 1==Monday, and so forth. If the ** date is already on the appropriate weekday, this is a no-op. */ if( sqlite3_strnicmp(z, "weekday ", 8)==0 && sqlite3AtoF(&z[8], &r, sqlite3Strlen30(&z[8]), SQLITE_UTF8) && (n=(int)r)==r && n>=0 && r<7 ){ sqlite3_int64 Z; computeYMD_HMS(p); p->validTZ = 0; p->validJD = 0; computeJD(p); Z = ((p->iJD + 129600000)/86400000) % 7; if( Z>n ) Z -= 7; p->iJD += (n - Z)*86400000; clearYMD_HMS_TZ(p); rc = 0; } break; } case 's': { /* ** start of TTTTT ** ** Move the date backwards to the beginning of the current day, ** or month or year. */ if( sqlite3_strnicmp(z, "start of ", 9)!=0 ) break; if( !p->validJD && !p->validYMD && !p->validHMS ) break; z += 9; computeYMD(p); p->validHMS = 1; p->h = p->m = 0; p->s = 0.0; p->rawS = 0; p->validTZ = 0; p->validJD = 0; if( sqlite3_stricmp(z,"month")==0 ){ p->D = 1; rc = 0; }else if( sqlite3_stricmp(z,"year")==0 ){ p->M = 1; p->D = 1; rc = 0; }else if( sqlite3_stricmp(z,"day")==0 ){ rc = 0; } break; } case '+': case '-': case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': { double rRounder; int i; for(n=1; z[n] && z[n]!=':' && !sqlite3Isspace(z[n]); n++){} if( !sqlite3AtoF(z, &r, n, SQLITE_UTF8) ){ rc = 1; break; } if( z[n]==':' ){ /* A modifier of the form (+|-)HH:MM:SS.FFF adds (or subtracts) the ** specified number of hours, minutes, seconds, and fractional seconds ** to the time. The ".FFF" may be omitted. The ":SS.FFF" may be ** omitted. */ const char *z2 = z; DateTime tx; sqlite3_int64 day; if( !sqlite3Isdigit(*z2) ) z2++; memset(&tx, 0, sizeof(tx)); if( parseHhMmSs(z2, &tx) ) break; computeJD(&tx); tx.iJD -= 43200000; day = tx.iJD/86400000; tx.iJD -= day*86400000; if( z[0]=='-' ) tx.iJD = -tx.iJD; computeJD(p); clearYMD_HMS_TZ(p); p->iJD += tx.iJD; rc = 0; break; } /* If control reaches this point, it means the transformation is ** one of the forms like "+NNN days". */ z += n; while( sqlite3Isspace(*z) ) z++; n = sqlite3Strlen30(z); if( n>10 || n<3 ) break; if( sqlite3UpperToLower[(u8)z[n-1]]=='s' ) n--; computeJD(p); rc = 1; rRounder = r<0 ? -0.5 : +0.5; for(i=0; i<ArraySize(aXformType); i++){ if( aXformType[i].nName==n && sqlite3_strnicmp(aXformType[i].zName, z, n)==0 && r>-aXformType[i].rLimit && r<aXformType[i].rLimit ){ switch( aXformType[i].eType ){ case 1: { /* Special processing to add months */ int x; computeYMD_HMS(p); p->M += (int)r; x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12; p->Y += x; p->M -= x*12; p->validJD = 0; r -= (int)r; break; } case 2: { /* Special processing to add years */ int y = (int)r; computeYMD_HMS(p); p->Y += y; p->validJD = 0; r -= (int)r; break; } } computeJD(p); p->iJD += (sqlite3_int64)(r*aXformType[i].rXform + rRounder); rc = 0; break; } } clearYMD_HMS_TZ(p); break; } default: { break; } } return rc; } /* ** Process time function arguments. argv[0] is a date-time stamp. ** argv[1] and following are modifiers. Parse them all and write ** the resulting time into the DateTime structure p. Return 0 ** on success and 1 if there are any errors. ** ** If there are zero parameters (if even argv[0] is undefined) ** then assume a default value of "now" for argv[0]. */ static int isDate( sqlite3_context *context, int argc, sqlite3_value **argv, DateTime *p ){ int i, n; const unsigned char *z; int eType; memset(p, 0, sizeof(*p)); if( argc==0 ){ return setDateTimeToCurrent(context, p); } if( (eType = sqlite3_value_type(argv[0]))==SQLITE_FLOAT || eType==SQLITE_INTEGER ){ setRawDateNumber(p, sqlite3_value_double(argv[0])); }else{ z = sqlite3_value_text(argv[0]); if( !z || parseDateOrTime(context, (char*)z, p) ){ return 1; } } for(i=1; i<argc; i++){ z = sqlite3_value_text(argv[i]); n = sqlite3_value_bytes(argv[i]); if( z==0 || parseModifier(context, (char*)z, n, p) ) return 1; } computeJD(p); if( p->isError || !validJulianDay(p->iJD) ) return 1; return 0; } /* ** The following routines implement the various date and time functions ** of SQLite. */ /* ** julianday( TIMESTRING, MOD, MOD, ...) ** ** Return the julian day number of the date specified in the arguments */ static void juliandayFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ DateTime x; if( isDate(context, argc, argv, &x)==0 ){ computeJD(&x); sqlite3_result_double(context, x.iJD/86400000.0); } } /* ** datetime( TIMESTRING, MOD, MOD, ...) ** ** Return YYYY-MM-DD HH:MM:SS */ static void datetimeFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ DateTime x; if( isDate(context, argc, argv, &x)==0 ){ char zBuf[100]; computeYMD_HMS(&x); sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d %02d:%02d:%02d", x.Y, x.M, x.D, x.h, x.m, (int)(x.s)); sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT); } } /* ** time( TIMESTRING, MOD, MOD, ...) ** ** Return HH:MM:SS */ static void timeFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ DateTime x; if( isDate(context, argc, argv, &x)==0 ){ char zBuf[100]; computeHMS(&x); sqlite3_snprintf(sizeof(zBuf), zBuf, "%02d:%02d:%02d", x.h, x.m, (int)x.s); sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT); } } /* ** date( TIMESTRING, MOD, MOD, ...) ** ** Return YYYY-MM-DD */ static void dateFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ DateTime x; if( isDate(context, argc, argv, &x)==0 ){ char zBuf[100]; computeYMD(&x); sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d", x.Y, x.M, x.D); sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT); } } /* ** strftime( FORMAT, TIMESTRING, MOD, MOD, ...) ** ** Return a string described by FORMAT. Conversions as follows: ** ** %d day of month ** %f ** fractional seconds SS.SSS ** %H hour 00-24 ** %j day of year 000-366 ** %J ** julian day number ** %m month 01-12 ** %M minute 00-59 ** %s seconds since 1970-01-01 ** %S seconds 00-59 ** %w day of week 0-6 sunday==0 |
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