Repository navigation
Expand file tree
/
Copy pathdate.c
More file actions
1357 lines (1306 loc) · 35.6 KB
/
Copy pathdate.c
File metadata and controls
1357 lines (1306 loc) · 35.6 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)>0 ){
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 non-zero then this
** routine will always fail. If bLocaltimeFault is nonzero and
** sqlite3GlobalConfig.xAltLocaltime is not NULL, then xAltLocaltime() is
** invoked in place of the OS-defined localtime() function.
**
** 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_MAIN);
#endif
sqlite3_mutex_enter(mutex);
pX = localtime(t);
#ifndef SQLITE_UNTESTABLE
if( sqlite3GlobalConfig.bLocaltimeFault ){
if( sqlite3GlobalConfig.xAltLocaltime!=0
&& 0==sqlite3GlobalConfig.xAltLocaltime((const void*)t,(void*)pTm)
){
pX = pTm;
}else{
pX = 0;
}
}
#endif
if( pX ) *pTm = *pX;
#if SQLITE_THREADSAFE>0
sqlite3_mutex_leave(mutex);
#endif
rc = pX==0;
#else
#ifndef SQLITE_UNTESTABLE
if( sqlite3GlobalConfig.bLocaltimeFault ){
if( sqlite3GlobalConfig.xAltLocaltime!=0 ){
return sqlite3GlobalConfig.xAltLocaltime((const void*)t,(void*)pTm);
}else{
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
/*
** Assuming the input DateTime is UTC, move it to its localtime equivalent.
*/
static int toLocaltime(
DateTime *p, /* Date at which to calculate offset */
sqlite3_context *pCtx /* Write error here if one occurs */
){
time_t t;
struct tm sLocal;
int iYearDiff;
/* Initialize the contents of sLocal to avoid a compiler warning. */
memset(&sLocal, 0, sizeof(sLocal));
computeJD(p);
if( p->iJD<2108667600*(i64)100000 /* 1970-01-01 */
|| p->iJD>2130141456*(i64)100000 /* 2038-01-18 */
){
/* 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.
*/
DateTime x = *p;
computeYMD_HMS(&x);
iYearDiff = (2000 + x.Y%4) - x.Y;
x.Y += iYearDiff;
x.validJD = 0;
computeJD(&x);
t = (time_t)(x.iJD/1000 - 21086676*(i64)10000);
}else{
iYearDiff = 0;
t = (time_t)(p->iJD/1000 - 21086676*(i64)10000);
}
if( osLocaltime(&t, &sLocal) ){
sqlite3_result_error(pCtx, "local time unavailable", -1);
return SQLITE_ERROR;
}
p->Y = sLocal.tm_year + 1900 - iYearDiff;
p->M = sLocal.tm_mon + 1;
p->D = sLocal.tm_mday;
p->h = sLocal.tm_hour;
p->m = sLocal.tm_min;
p->s = sLocal.tm_sec + (p->iJD%1000)*0.001;
p->validYMD = 1;
p->validHMS = 1;
p->validJD = 0;
p->rawS = 0;
p->validTZ = 0;
p->isError = 0;
return SQLITE_OK;
}
#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 nName; /* Length of the name */
char zName[7]; /* Name of the transformation */
float rLimit; /* Maximum NNN value for this transform */
float rXform; /* Constant used for this transform */
} aXformType[] = {
{ 6, "second", 4.6427e+14, 1.0 },
{ 6, "minute", 7.7379e+12, 60.0 },
{ 4, "hour", 1.2897e+11, 3600.0 },
{ 3, "day", 5373485.0, 86400.0 },
{ 5, "month", 176546.0, 2592000.0 },
{ 4, "year", 14713.0, 31536000.0 },
};
/*
** 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 idx /* Parameter index of the modifier */
){
int rc = 1;
double r;
switch(sqlite3UpperToLower[(u8)z[0]] ){
case 'a': {
/*
** auto
**
** If rawS is available, then interpret as a julian day number, or
** a unix timestamp, depending on its magnitude.
*/
if( sqlite3_stricmp(z, "auto")==0 ){
if( idx>1 ) return 1; /* IMP: R-33611-57934 */
if( !p->rawS || p->validJD ){
rc = 0;
p->rawS = 0;
}else if( p->s>=-21086676*(i64)10000 /* -4713-11-24 12:00:00 */
&& p->s<=(25340230*(i64)10000)+799 /* 9999-12-31 23:59:59 */
){
r = p->s*1000.0 + 210866760000000.0;
clearYMD_HMS_TZ(p);
p->iJD = (sqlite3_int64)(r + 0.5);
p->validJD = 1;
p->rawS = 0;
rc = 0;
}
}
break;
}
case 'j': {
/*
** julianday
**
** Always interpret the prior number as a julian-day value. If this
** is not the first modifier, or if the prior argument is not a numeric
** value in the allowed range of julian day numbers understood by
** SQLite (0..5373484.5) then the result will be NULL.
*/
if( sqlite3_stricmp(z, "julianday")==0 ){
if( idx>1 ) return 1; /* IMP: R-31176-64601 */
if( p->validJD && p->rawS ){
rc = 0;
p->rawS = 0;
}
}
break;
}
#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) ){
rc = toLocaltime(p, pCtx);
}
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 ){
if( idx>1 ) return 1; /* IMP: R-49255-55373 */
r = p->s*1000.0 + 210866760000000.0;
if( r>=0.0 && r<464269060800000.0 ){
clearYMD_HMS_TZ(p);
p->iJD = (sqlite3_int64)(r + 0.5);
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 ){
i64 iOrigJD; /* Original localtime */
i64 iGuess; /* Guess at the corresponding utc time */
int cnt = 0; /* Safety to prevent infinite loop */
int iErr; /* Guess is off by this much */
computeJD(p);
iGuess = iOrigJD = p->iJD;
iErr = 0;
do{
DateTime new;
memset(&new, 0, sizeof(new));
iGuess -= iErr;
new.iJD = iGuess;
new.validJD = 1;
rc = toLocaltime(&new, pCtx);
if( rc ) return rc;
computeJD(&new);
iErr = new.iJD - iOrigJD;
}while( iErr && cnt++<3 );
memset(p, 0, sizeof(*p));
p->iJD = iGuess;
p->validJD = 1;
p->tzSet = 1;
}
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)>0
&& (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)<=0 ){
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( i ){
case 4: { /* Special processing to add months */
int x;
assert( strcmp(aXformType[i].zName,"month")==0 );
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 5: { /* Special processing to add years */
int y = (int)r;
assert( strcmp(aXformType[i].zName,"year")==0 );
computeYMD_HMS(p);
p->Y += y;
p->validJD = 0;
r -= (int)r;
break;
}
}
computeJD(p);
p->iJD += (sqlite3_int64)(r*1000.0*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 ){
if( !sqlite3NotPureFunc(context) ) return 1;
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, i) ) 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);
}
}
/*
** unixepoch( TIMESTRING, MOD, MOD, ...)
**
** Return the number of seconds (including fractional seconds) since
** the unix epoch of 1970-01-01 00:00:00 GMT.
*/
static void unixepochFunc(
sqlite3_context *context,