xref: /aosp_15_r20/external/cronet/third_party/icu/source/i18n/rbtz.cpp (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 *******************************************************************************
5 * Copyright (C) 2007-2013, International Business Machines Corporation and
6 * others. All Rights Reserved.
7 *******************************************************************************
8 */
9 
10 #include "utypeinfo.h"  // for 'typeid' to work
11 
12 #include "unicode/utypes.h"
13 
14 #if !UCONFIG_NO_FORMATTING
15 
16 #include "unicode/rbtz.h"
17 #include "unicode/gregocal.h"
18 #include "uvector.h"
19 #include "gregoimp.h"
20 #include "cmemory.h"
21 #include "umutex.h"
22 
23 U_NAMESPACE_BEGIN
24 
25 /**
26  * A struct representing a time zone transition
27  */
28 struct Transition : public UMemory {
29     UDate time;
30     TimeZoneRule* from;
31     TimeZoneRule* to;
32 };
33 
34 U_CDECL_BEGIN
35 static void U_CALLCONV
deleteTransition(void * obj)36 deleteTransition(void* obj) {
37     delete static_cast<Transition *>(obj);
38 }
39 U_CDECL_END
40 
compareRules(UVector * rules1,UVector * rules2)41 static UBool compareRules(UVector* rules1, UVector* rules2) {
42     if (rules1 == nullptr && rules2 == nullptr) {
43         return true;
44     } else if (rules1 == nullptr || rules2 == nullptr) {
45         return false;
46     }
47     int32_t size = rules1->size();
48     if (size != rules2->size()) {
49         return false;
50     }
51     for (int32_t i = 0; i < size; i++) {
52         TimeZoneRule *r1 = (TimeZoneRule*)rules1->elementAt(i);
53         TimeZoneRule *r2 = (TimeZoneRule*)rules2->elementAt(i);
54         if (*r1 != *r2) {
55             return false;
56         }
57     }
58     return true;
59 }
60 
UOBJECT_DEFINE_RTTI_IMPLEMENTATION(RuleBasedTimeZone)61 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(RuleBasedTimeZone)
62 
63 RuleBasedTimeZone::RuleBasedTimeZone(const UnicodeString& id, InitialTimeZoneRule* initialRule)
64 : BasicTimeZone(id), fInitialRule(initialRule), fHistoricRules(nullptr), fFinalRules(nullptr),
65   fHistoricTransitions(nullptr), fUpToDate(false) {
66 }
67 
RuleBasedTimeZone(const RuleBasedTimeZone & source)68 RuleBasedTimeZone::RuleBasedTimeZone(const RuleBasedTimeZone& source)
69 : BasicTimeZone(source), fInitialRule(source.fInitialRule->clone()),
70   fHistoricTransitions(nullptr), fUpToDate(false) {
71     fHistoricRules = copyRules(source.fHistoricRules);
72     fFinalRules = copyRules(source.fFinalRules);
73     if (source.fUpToDate) {
74         UErrorCode status = U_ZERO_ERROR;
75         complete(status);
76     }
77 }
78 
~RuleBasedTimeZone()79 RuleBasedTimeZone::~RuleBasedTimeZone() {
80     deleteTransitions();
81     deleteRules();
82 }
83 
84 RuleBasedTimeZone&
operator =(const RuleBasedTimeZone & right)85 RuleBasedTimeZone::operator=(const RuleBasedTimeZone& right) {
86     if (*this != right) {
87         BasicTimeZone::operator=(right);
88         deleteRules();
89         fInitialRule = right.fInitialRule->clone();
90         fHistoricRules = copyRules(right.fHistoricRules);
91         fFinalRules = copyRules(right.fFinalRules);
92         deleteTransitions();
93         fUpToDate = false;
94     }
95     return *this;
96 }
97 
98 bool
operator ==(const TimeZone & that) const99 RuleBasedTimeZone::operator==(const TimeZone& that) const {
100     if (this == &that) {
101         return true;
102     }
103     if (typeid(*this) != typeid(that) || !BasicTimeZone::operator==(that)) {
104         return false;
105     }
106     RuleBasedTimeZone *rbtz = (RuleBasedTimeZone*)&that;
107     if (*fInitialRule != *(rbtz->fInitialRule)) {
108         return false;
109     }
110     if (compareRules(fHistoricRules, rbtz->fHistoricRules)
111         && compareRules(fFinalRules, rbtz->fFinalRules)) {
112         return true;
113     }
114     return false;
115 }
116 
117 bool
operator !=(const TimeZone & that) const118 RuleBasedTimeZone::operator!=(const TimeZone& that) const {
119     return !operator==(that);
120 }
121 
122 void
addTransitionRule(TimeZoneRule * rule,UErrorCode & status)123 RuleBasedTimeZone::addTransitionRule(TimeZoneRule* rule, UErrorCode& status) {
124     LocalPointer<TimeZoneRule>lpRule(rule);
125     if (U_FAILURE(status)) {
126         return;
127     }
128     AnnualTimeZoneRule* atzrule = dynamic_cast<AnnualTimeZoneRule*>(rule);
129     if (atzrule != nullptr && atzrule->getEndYear() == AnnualTimeZoneRule::MAX_YEAR) {
130         // A final rule
131         if (fFinalRules == nullptr) {
132             LocalPointer<UVector> lpFinalRules(new UVector(uprv_deleteUObject, nullptr, status), status);
133             if (U_FAILURE(status)) {
134                 return;
135             }
136             fFinalRules = lpFinalRules.orphan();
137         } else if (fFinalRules->size() >= 2) {
138             // Cannot handle more than two final rules
139             status = U_INVALID_STATE_ERROR;
140             return;
141         }
142         fFinalRules->adoptElement(lpRule.orphan(), status);
143     } else {
144         // Non-final rule
145         if (fHistoricRules == nullptr) {
146             LocalPointer<UVector> lpHistoricRules(new UVector(uprv_deleteUObject, nullptr, status), status);
147             if (U_FAILURE(status)) {
148                 return;
149             }
150             fHistoricRules = lpHistoricRules.orphan();
151         }
152         fHistoricRules->adoptElement(lpRule.orphan(), status);
153     }
154     // Mark dirty, so transitions are recalculated at next complete() call
155     fUpToDate = false;
156 }
157 
158 
159 void
completeConst(UErrorCode & status) const160 RuleBasedTimeZone::completeConst(UErrorCode& status) const {
161     static UMutex gLock;
162     if (U_FAILURE(status)) {
163         return;
164     }
165     umtx_lock(&gLock);
166     if (!fUpToDate) {
167         RuleBasedTimeZone *ncThis = const_cast<RuleBasedTimeZone*>(this);
168         ncThis->complete(status);
169     }
170     umtx_unlock(&gLock);
171 }
172 
173 void
complete(UErrorCode & status)174 RuleBasedTimeZone::complete(UErrorCode& status) {
175     if (U_FAILURE(status)) {
176         return;
177     }
178     if (fUpToDate) {
179         return;
180     }
181     // Make sure either no final rules or a pair of AnnualTimeZoneRules
182     // are available.
183     if (fFinalRules != nullptr && fFinalRules->size() != 2) {
184         status = U_INVALID_STATE_ERROR;
185         return;
186     }
187 
188     // Create a TimezoneTransition and add to the list
189     if (fHistoricRules != nullptr || fFinalRules != nullptr) {
190         TimeZoneRule *curRule = fInitialRule;
191         UDate lastTransitionTime = MIN_MILLIS;
192 
193         // Build the transition array which represents historical time zone
194         // transitions.
195         if (fHistoricRules != nullptr && fHistoricRules->size() > 0) {
196             int32_t i;
197             int32_t historicCount = fHistoricRules->size();
198             LocalMemory<bool> done((bool *)uprv_malloc(sizeof(bool) * historicCount));
199             if (done == nullptr) {
200                 status = U_MEMORY_ALLOCATION_ERROR;
201                 goto cleanup;
202             }
203             for (i = 0; i < historicCount; i++) {
204                 done[i] = false;
205             }
206             while (true) {
207                 int32_t curStdOffset = curRule->getRawOffset();
208                 int32_t curDstSavings = curRule->getDSTSavings();
209                 UDate nextTransitionTime = MAX_MILLIS;
210                 TimeZoneRule *nextRule = nullptr;
211                 TimeZoneRule *r = nullptr;
212                 UBool avail;
213                 UDate tt;
214                 UnicodeString curName, name;
215                 curRule->getName(curName);
216 
217                 for (i = 0; i < historicCount; i++) {
218                     if (done[i]) {
219                         continue;
220                     }
221                     r = (TimeZoneRule*)fHistoricRules->elementAt(i);
222                     avail = r->getNextStart(lastTransitionTime, curStdOffset, curDstSavings, false, tt);
223                     if (!avail) {
224                         // No more transitions from this rule - skip this rule next time
225                         done[i] = true;
226                     } else {
227                         r->getName(name);
228                         if (*r == *curRule ||
229                             (name == curName && r->getRawOffset() == curRule->getRawOffset()
230                             && r->getDSTSavings() == curRule->getDSTSavings())) {
231                             continue;
232                         }
233                         if (tt < nextTransitionTime) {
234                             nextTransitionTime = tt;
235                             nextRule = r;
236                         }
237                     }
238                 }
239 
240                 if (nextRule ==  nullptr) {
241                     // Check if all historic rules are done
242                     UBool bDoneAll = true;
243                     for (int32_t j = 0; j < historicCount; j++) {
244                         if (!done[j]) {
245                             bDoneAll = false;
246                             break;
247                         }
248                     }
249                     if (bDoneAll) {
250                         break;
251                     }
252                 }
253 
254                 if (fFinalRules != nullptr) {
255                     // Check if one of final rules has earlier transition date
256                     for (i = 0; i < 2 /* fFinalRules->size() */; i++) {
257                         TimeZoneRule *fr = (TimeZoneRule*)fFinalRules->elementAt(i);
258                         if (*fr == *curRule) {
259                             continue;
260                         }
261                         r = (TimeZoneRule*)fFinalRules->elementAt(i);
262                         avail = r->getNextStart(lastTransitionTime, curStdOffset, curDstSavings, false, tt);
263                         if (avail) {
264                             if (tt < nextTransitionTime) {
265                                 nextTransitionTime = tt;
266                                 nextRule = r;
267                             }
268                         }
269                     }
270                 }
271 
272                 if (nextRule == nullptr) {
273                     // Nothing more
274                     break;
275                 }
276 
277                 if (fHistoricTransitions == nullptr) {
278                     LocalPointer<UVector> lpHistoricTransitions(
279                         new UVector(deleteTransition, nullptr, status), status);
280                     if (U_FAILURE(status)) {
281                         goto cleanup;
282                     }
283                     fHistoricTransitions = lpHistoricTransitions.orphan();
284                 }
285                 LocalPointer<Transition> trst(new Transition, status);
286                 if (U_FAILURE(status)) {
287                     goto cleanup;
288                 }
289                 trst->time = nextTransitionTime;
290                 trst->from = curRule;
291                 trst->to = nextRule;
292                 fHistoricTransitions->adoptElement(trst.orphan(), status);
293                 if (U_FAILURE(status)) {
294                     goto cleanup;
295                 }
296                 lastTransitionTime = nextTransitionTime;
297                 curRule = nextRule;
298             }
299         }
300         if (fFinalRules != nullptr) {
301             if (fHistoricTransitions == nullptr) {
302                 LocalPointer<UVector> lpHistoricTransitions(
303                     new UVector(deleteTransition, nullptr, status), status);
304                 if (U_FAILURE(status)) {
305                     goto cleanup;
306                 }
307                 fHistoricTransitions = lpHistoricTransitions.orphan();
308             }
309             // Append the first transition for each
310             TimeZoneRule *rule0 = (TimeZoneRule*)fFinalRules->elementAt(0);
311             TimeZoneRule *rule1 = (TimeZoneRule*)fFinalRules->elementAt(1);
312             UDate tt0, tt1;
313             UBool avail0 = rule0->getNextStart(lastTransitionTime, curRule->getRawOffset(), curRule->getDSTSavings(), false, tt0);
314             UBool avail1 = rule1->getNextStart(lastTransitionTime, curRule->getRawOffset(), curRule->getDSTSavings(), false, tt1);
315             if (!avail0 || !avail1) {
316                 // Should not happen, because both rules are permanent
317                 status = U_INVALID_STATE_ERROR;
318                 goto cleanup;
319             }
320             LocalPointer<Transition> final0(new Transition, status);
321             LocalPointer<Transition> final1(new Transition, status);
322             if (U_FAILURE(status)) {
323                goto cleanup;
324             }
325             if (tt0 < tt1) {
326                 final0->time = tt0;
327                 final0->from = curRule;
328                 final0->to = rule0;
329                 rule1->getNextStart(tt0, rule0->getRawOffset(), rule0->getDSTSavings(), false, final1->time);
330                 final1->from = rule0;
331                 final1->to = rule1;
332             } else {
333                 final0->time = tt1;
334                 final0->from = curRule;
335                 final0->to = rule1;
336                 rule0->getNextStart(tt1, rule1->getRawOffset(), rule1->getDSTSavings(), false, final1->time);
337                 final1->from = rule1;
338                 final1->to = rule0;
339             }
340             fHistoricTransitions->adoptElement(final0.orphan(), status);
341             fHistoricTransitions->adoptElement(final1.orphan(), status);
342             if (U_FAILURE(status)) {
343                 goto cleanup;
344             }
345         }
346     }
347     fUpToDate = true;
348     return;
349 
350 cleanup:
351     deleteTransitions();
352     fUpToDate = false;
353 }
354 
355 RuleBasedTimeZone*
clone() const356 RuleBasedTimeZone::clone() const {
357     return new RuleBasedTimeZone(*this);
358 }
359 
360 int32_t
getOffset(uint8_t era,int32_t year,int32_t month,int32_t day,uint8_t dayOfWeek,int32_t millis,UErrorCode & status) const361 RuleBasedTimeZone::getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
362                              uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const {
363     if (U_FAILURE(status)) {
364         return 0;
365     }
366     if (month < UCAL_JANUARY || month > UCAL_DECEMBER) {
367         status = U_ILLEGAL_ARGUMENT_ERROR;
368         return 0;
369     } else {
370         return getOffset(era, year, month, day, dayOfWeek, millis,
371                          Grego::monthLength(year, month), status);
372     }
373 }
374 
375 int32_t
getOffset(uint8_t era,int32_t year,int32_t month,int32_t day,uint8_t,int32_t millis,int32_t,UErrorCode & status) const376 RuleBasedTimeZone::getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
377                              uint8_t /*dayOfWeek*/, int32_t millis,
378                              int32_t /*monthLength*/, UErrorCode& status) const {
379     // dayOfWeek and monthLength are unused
380     if (U_FAILURE(status)) {
381         return 0;
382     }
383     if (era == GregorianCalendar::BC) {
384         // Convert to extended year
385         year = 1 - year;
386     }
387     int32_t rawOffset, dstOffset;
388     UDate time = (UDate)Grego::fieldsToDay(year, month, day) * U_MILLIS_PER_DAY + millis;
389     getOffsetInternal(time, true, kDaylight, kStandard, rawOffset, dstOffset, status);
390     if (U_FAILURE(status)) {
391         return 0;
392     }
393     return (rawOffset + dstOffset);
394 }
395 
396 void
getOffset(UDate date,UBool local,int32_t & rawOffset,int32_t & dstOffset,UErrorCode & status) const397 RuleBasedTimeZone::getOffset(UDate date, UBool local, int32_t& rawOffset,
398                              int32_t& dstOffset, UErrorCode& status) const {
399     getOffsetInternal(date, local, kFormer, kLatter, rawOffset, dstOffset, status);
400 }
401 
getOffsetFromLocal(UDate date,UTimeZoneLocalOption nonExistingTimeOpt,UTimeZoneLocalOption duplicatedTimeOpt,int32_t & rawOffset,int32_t & dstOffset,UErrorCode & status) const402 void RuleBasedTimeZone::getOffsetFromLocal(UDate date, UTimeZoneLocalOption nonExistingTimeOpt,
403                                            UTimeZoneLocalOption duplicatedTimeOpt,
404                                            int32_t& rawOffset, int32_t& dstOffset, UErrorCode& status) const {
405     getOffsetInternal(date, true, nonExistingTimeOpt, duplicatedTimeOpt, rawOffset, dstOffset, status);
406 }
407 
408 
409 /*
410  * The internal getOffset implementation
411  */
412 void
getOffsetInternal(UDate date,UBool local,int32_t NonExistingTimeOpt,int32_t DuplicatedTimeOpt,int32_t & rawOffset,int32_t & dstOffset,UErrorCode & status) const413 RuleBasedTimeZone::getOffsetInternal(UDate date, UBool local,
414                                      int32_t NonExistingTimeOpt, int32_t DuplicatedTimeOpt,
415                                      int32_t& rawOffset, int32_t& dstOffset,
416                                      UErrorCode& status) const {
417     rawOffset = 0;
418     dstOffset = 0;
419 
420     if (U_FAILURE(status)) {
421         return;
422     }
423     if (!fUpToDate) {
424         // Transitions are not yet resolved.  We cannot do it here
425         // because this method is const.  Thus, do nothing and return
426         // error status.
427         status = U_INVALID_STATE_ERROR;
428         return;
429     }
430     const TimeZoneRule *rule = nullptr;
431     if (fHistoricTransitions == nullptr) {
432         rule = fInitialRule;
433     } else {
434         UDate tstart = getTransitionTime((Transition*)fHistoricTransitions->elementAt(0),
435             local, NonExistingTimeOpt, DuplicatedTimeOpt);
436         if (date < tstart) {
437             rule = fInitialRule;
438         } else {
439             int32_t idx = fHistoricTransitions->size() - 1;
440             UDate tend = getTransitionTime((Transition*)fHistoricTransitions->elementAt(idx),
441                 local, NonExistingTimeOpt, DuplicatedTimeOpt);
442             if (date > tend) {
443                 if (fFinalRules != nullptr) {
444                     rule = findRuleInFinal(date, local, NonExistingTimeOpt, DuplicatedTimeOpt);
445                 }
446                 if (rule == nullptr) {
447                     // no final rules or the given time is before the first transition
448                     // specified by the final rules -> use the last rule
449                     rule = ((Transition*)fHistoricTransitions->elementAt(idx))->to;
450                 }
451             } else {
452                 // Find a historical transition
453                 while (idx >= 0) {
454                     if (date >= getTransitionTime((Transition*)fHistoricTransitions->elementAt(idx),
455                         local, NonExistingTimeOpt, DuplicatedTimeOpt)) {
456                         break;
457                     }
458                     idx--;
459                 }
460                 rule = ((Transition*)fHistoricTransitions->elementAt(idx))->to;
461             }
462         }
463     }
464     if (rule != nullptr) {
465         rawOffset = rule->getRawOffset();
466         dstOffset = rule->getDSTSavings();
467     }
468 }
469 
470 void
setRawOffset(int32_t)471 RuleBasedTimeZone::setRawOffset(int32_t /*offsetMillis*/) {
472     // We don't support this operation at this moment.
473     // Nothing to do!
474 }
475 
476 int32_t
getRawOffset() const477 RuleBasedTimeZone::getRawOffset() const {
478     // Note: This implementation returns standard GMT offset
479     // as of current time.
480     UErrorCode status = U_ZERO_ERROR;
481     int32_t raw, dst;
482     getOffset(uprv_getUTCtime(), false, raw, dst, status);
483     return raw;
484 }
485 
486 UBool
useDaylightTime() const487 RuleBasedTimeZone::useDaylightTime() const {
488     // Note: This implementation returns true when
489     // daylight saving time is used as of now or
490     // after the next transition.
491     UErrorCode status = U_ZERO_ERROR;
492     UDate now = uprv_getUTCtime();
493     int32_t raw, dst;
494     getOffset(now, false, raw, dst, status);
495     if (dst != 0) {
496         return true;
497     }
498     // If DST is not used now, check if DST is used after the next transition
499     UDate time;
500     TimeZoneRule *from, *to;
501     UBool avail = findNext(now, false, time, from, to);
502     if (avail && to->getDSTSavings() != 0) {
503         return true;
504     }
505     return false;
506 }
507 
508 UBool
inDaylightTime(UDate date,UErrorCode & status) const509 RuleBasedTimeZone::inDaylightTime(UDate date, UErrorCode& status) const {
510     if (U_FAILURE(status)) {
511         return false;
512     }
513     int32_t raw, dst;
514     getOffset(date, false, raw, dst, status);
515     if (dst != 0) {
516         return true;
517     }
518     return false;
519 }
520 
521 UBool
hasSameRules(const TimeZone & other) const522 RuleBasedTimeZone::hasSameRules(const TimeZone& other) const {
523     if (this == &other) {
524         return true;
525     }
526     if (typeid(*this) != typeid(other)) {
527         return false;
528     }
529     const RuleBasedTimeZone& that = static_cast<const RuleBasedTimeZone&>(other);
530     if (*fInitialRule != *(that.fInitialRule)) {
531         return false;
532     }
533     if (compareRules(fHistoricRules, that.fHistoricRules)
534         && compareRules(fFinalRules, that.fFinalRules)) {
535         return true;
536     }
537     return false;
538 }
539 
540 UBool
getNextTransition(UDate base,UBool inclusive,TimeZoneTransition & result) const541 RuleBasedTimeZone::getNextTransition(UDate base, UBool inclusive, TimeZoneTransition& result) const {
542     UErrorCode status = U_ZERO_ERROR;
543     completeConst(status);
544     if (U_FAILURE(status)) {
545         return false;
546     }
547     UDate transitionTime;
548     TimeZoneRule *fromRule, *toRule;
549     UBool found = findNext(base, inclusive, transitionTime, fromRule, toRule);
550     if (found) {
551         result.setTime(transitionTime);
552         result.setFrom(*fromRule);
553         result.setTo(*toRule);
554         return true;
555     }
556     return false;
557 }
558 
559 UBool
getPreviousTransition(UDate base,UBool inclusive,TimeZoneTransition & result) const560 RuleBasedTimeZone::getPreviousTransition(UDate base, UBool inclusive, TimeZoneTransition& result) const {
561     UErrorCode status = U_ZERO_ERROR;
562     completeConst(status);
563     if (U_FAILURE(status)) {
564         return false;
565     }
566     UDate transitionTime;
567     TimeZoneRule *fromRule, *toRule;
568     UBool found = findPrev(base, inclusive, transitionTime, fromRule, toRule);
569     if (found) {
570         result.setTime(transitionTime);
571         result.setFrom(*fromRule);
572         result.setTo(*toRule);
573         return true;
574     }
575     return false;
576 }
577 
578 int32_t
countTransitionRules(UErrorCode &) const579 RuleBasedTimeZone::countTransitionRules(UErrorCode& /*status*/) const {
580     int32_t count = 0;
581     if (fHistoricRules != nullptr) {
582         count += fHistoricRules->size();
583     }
584     if (fFinalRules != nullptr) {
585         count += fFinalRules->size();
586     }
587     return count;
588 }
589 
590 void
getTimeZoneRules(const InitialTimeZoneRule * & initial,const TimeZoneRule * trsrules[],int32_t & trscount,UErrorCode & status) const591 RuleBasedTimeZone::getTimeZoneRules(const InitialTimeZoneRule*& initial,
592                                     const TimeZoneRule* trsrules[],
593                                     int32_t& trscount,
594                                     UErrorCode& status) const {
595     if (U_FAILURE(status)) {
596         return;
597     }
598     // Initial rule
599     initial = fInitialRule;
600 
601     // Transition rules
602     int32_t cnt = 0;
603     int32_t idx;
604     if (fHistoricRules != nullptr && cnt < trscount) {
605         int32_t historicCount = fHistoricRules->size();
606         idx = 0;
607         while (cnt < trscount && idx < historicCount) {
608             trsrules[cnt++] = (const TimeZoneRule*)fHistoricRules->elementAt(idx++);
609         }
610     }
611     if (fFinalRules != nullptr && cnt < trscount) {
612         int32_t finalCount = fFinalRules->size();
613         idx = 0;
614         while (cnt < trscount && idx < finalCount) {
615             trsrules[cnt++] = (const TimeZoneRule*)fFinalRules->elementAt(idx++);
616         }
617     }
618     // Set the result length
619     trscount = cnt;
620 }
621 
622 void
deleteRules()623 RuleBasedTimeZone::deleteRules() {
624     delete fInitialRule;
625     fInitialRule = nullptr;
626     if (fHistoricRules != nullptr) {
627         delete fHistoricRules;
628         fHistoricRules = nullptr;
629     }
630     if (fFinalRules != nullptr) {
631         delete fFinalRules;
632         fFinalRules = nullptr;
633     }
634 }
635 
636 void
deleteTransitions()637 RuleBasedTimeZone::deleteTransitions() {
638     if (fHistoricTransitions != nullptr) {
639         delete fHistoricTransitions;
640     }
641     fHistoricTransitions = nullptr;
642 }
643 
644 UVector*
copyRules(UVector * source)645 RuleBasedTimeZone::copyRules(UVector* source) {
646     if (source == nullptr) {
647         return nullptr;
648     }
649     UErrorCode ec = U_ZERO_ERROR;
650     int32_t size = source->size();
651     LocalPointer<UVector> rules(new UVector(uprv_deleteUObject, nullptr, size, ec), ec);
652     if (U_FAILURE(ec)) {
653         return nullptr;
654     }
655     int32_t i;
656     for (i = 0; i < size; i++) {
657         LocalPointer<TimeZoneRule> rule(((TimeZoneRule*)source->elementAt(i))->clone(), ec);
658         rules->adoptElement(rule.orphan(), ec);
659         if (U_FAILURE(ec)) {
660             return nullptr;
661         }
662     }
663     return rules.orphan();
664 }
665 
666 TimeZoneRule*
findRuleInFinal(UDate date,UBool local,int32_t NonExistingTimeOpt,int32_t DuplicatedTimeOpt) const667 RuleBasedTimeZone::findRuleInFinal(UDate date, UBool local,
668                                    int32_t NonExistingTimeOpt, int32_t DuplicatedTimeOpt) const {
669     if (fFinalRules == nullptr) {
670         return nullptr;
671     }
672 
673     AnnualTimeZoneRule* fr0 = (AnnualTimeZoneRule*)fFinalRules->elementAt(0);
674     AnnualTimeZoneRule* fr1 = (AnnualTimeZoneRule*)fFinalRules->elementAt(1);
675     if (fr0 == nullptr || fr1 == nullptr) {
676         return nullptr;
677     }
678 
679     UDate start0, start1;
680     UDate base;
681     int32_t localDelta;
682 
683     base = date;
684     if (local) {
685         localDelta = getLocalDelta(fr1->getRawOffset(), fr1->getDSTSavings(),
686                                    fr0->getRawOffset(), fr0->getDSTSavings(),
687                                    NonExistingTimeOpt, DuplicatedTimeOpt);
688         base -= localDelta;
689     }
690     UBool avail0 = fr0->getPreviousStart(base, fr1->getRawOffset(), fr1->getDSTSavings(), true, start0);
691 
692     base = date;
693     if (local) {
694         localDelta = getLocalDelta(fr0->getRawOffset(), fr0->getDSTSavings(),
695                                    fr1->getRawOffset(), fr1->getDSTSavings(),
696                                    NonExistingTimeOpt, DuplicatedTimeOpt);
697         base -= localDelta;
698     }
699     UBool avail1 = fr1->getPreviousStart(base, fr0->getRawOffset(), fr0->getDSTSavings(), true, start1);
700 
701     if (!avail0 || !avail1) {
702         if (avail0) {
703             return fr0;
704         } else if (avail1) {
705             return fr1;
706         }
707         // Both rules take effect after the given time
708         return nullptr;
709     }
710 
711     return (start0 > start1) ? fr0 : fr1;
712 }
713 
714 UBool
findNext(UDate base,UBool inclusive,UDate & transitionTime,TimeZoneRule * & fromRule,TimeZoneRule * & toRule) const715 RuleBasedTimeZone::findNext(UDate base, UBool inclusive, UDate& transitionTime,
716                             TimeZoneRule*& fromRule, TimeZoneRule*& toRule) const {
717     if (fHistoricTransitions == nullptr) {
718         return false;
719     }
720     UBool isFinal = false;
721     UBool found = false;
722     Transition result;
723     Transition *tzt = (Transition*)fHistoricTransitions->elementAt(0);
724     UDate tt = tzt->time;
725     if (tt > base || (inclusive && tt == base)) {
726         result = *tzt;
727         found = true;
728     } else {
729         int32_t idx = fHistoricTransitions->size() - 1;
730         tzt = (Transition*)fHistoricTransitions->elementAt(idx);
731         tt = tzt->time;
732         if (inclusive && tt == base) {
733             result = *tzt;
734             found = true;
735         } else if (tt <= base) {
736             if (fFinalRules != nullptr) {
737                 // Find a transion time with finalRules
738                 TimeZoneRule *r0 = (TimeZoneRule*)fFinalRules->elementAt(0);
739                 TimeZoneRule *r1 = (TimeZoneRule*)fFinalRules->elementAt(1);
740                 UDate start0, start1;
741                 UBool avail0 = r0->getNextStart(base, r1->getRawOffset(), r1->getDSTSavings(), inclusive, start0);
742                 UBool avail1 = r1->getNextStart(base, r0->getRawOffset(), r0->getDSTSavings(), inclusive, start1);
743                 //  avail0/avail1 should be always true
744                 if (!avail0 && !avail1) {
745                     return false;
746                 }
747                 if (!avail1 || start0 < start1) {
748                     result.time = start0;
749                     result.from = r1;
750                     result.to = r0;
751                 } else {
752                     result.time = start1;
753                     result.from = r0;
754                     result.to = r1;
755                 }
756                 isFinal = true;
757                 found = true;
758             }
759         } else {
760             // Find a transition within the historic transitions
761             idx--;
762             Transition *prev = tzt;
763             while (idx > 0) {
764                 tzt = (Transition*)fHistoricTransitions->elementAt(idx);
765                 tt = tzt->time;
766                 if (tt < base || (!inclusive && tt == base)) {
767                     break;
768                 }
769                 idx--;
770                 prev = tzt;
771             }
772             result.time = prev->time;
773             result.from = prev->from;
774             result.to = prev->to;
775             found = true;
776         }
777     }
778     if (found) {
779         // For now, this implementation ignore transitions with only zone name changes.
780         if (result.from->getRawOffset() == result.to->getRawOffset()
781             && result.from->getDSTSavings() == result.to->getDSTSavings()) {
782             if (isFinal) {
783                 return false;
784             } else {
785                 // No offset changes.  Try next one if not final
786                 return findNext(result.time, false /* always exclusive */,
787                     transitionTime, fromRule, toRule);
788             }
789         }
790         transitionTime = result.time;
791         fromRule = result.from;
792         toRule = result.to;
793         return true;
794     }
795     return false;
796 }
797 
798 UBool
findPrev(UDate base,UBool inclusive,UDate & transitionTime,TimeZoneRule * & fromRule,TimeZoneRule * & toRule) const799 RuleBasedTimeZone::findPrev(UDate base, UBool inclusive, UDate& transitionTime,
800                             TimeZoneRule*& fromRule, TimeZoneRule*& toRule) const {
801     if (fHistoricTransitions == nullptr) {
802         return false;
803     }
804     UBool found = false;
805     Transition result;
806     Transition *tzt = (Transition*)fHistoricTransitions->elementAt(0);
807     UDate tt = tzt->time;
808     if (inclusive && tt == base) {
809         result = *tzt;
810         found = true;
811     } else if (tt < base) {
812         int32_t idx = fHistoricTransitions->size() - 1;
813         tzt = (Transition*)fHistoricTransitions->elementAt(idx);
814         tt = tzt->time;
815         if (inclusive && tt == base) {
816             result = *tzt;
817             found = true;
818         } else if (tt < base) {
819             if (fFinalRules != nullptr) {
820                 // Find a transion time with finalRules
821                 TimeZoneRule *r0 = (TimeZoneRule*)fFinalRules->elementAt(0);
822                 TimeZoneRule *r1 = (TimeZoneRule*)fFinalRules->elementAt(1);
823                 UDate start0, start1;
824                 UBool avail0 = r0->getPreviousStart(base, r1->getRawOffset(), r1->getDSTSavings(), inclusive, start0);
825                 UBool avail1 = r1->getPreviousStart(base, r0->getRawOffset(), r0->getDSTSavings(), inclusive, start1);
826                 //  avail0/avail1 should be always true
827                 if (!avail0 && !avail1) {
828                     return false;
829                 }
830                 if (!avail1 || start0 > start1) {
831                     result.time = start0;
832                     result.from = r1;
833                     result.to = r0;
834                 } else {
835                     result.time = start1;
836                     result.from = r0;
837                     result.to = r1;
838                 }
839             } else {
840                 result = *tzt;
841             }
842             found = true;
843         } else {
844             // Find a transition within the historic transitions
845             idx--;
846             while (idx >= 0) {
847                 tzt = (Transition*)fHistoricTransitions->elementAt(idx);
848                 tt = tzt->time;
849                 if (tt < base || (inclusive && tt == base)) {
850                     break;
851                 }
852                 idx--;
853             }
854             result = *tzt;
855             found = true;
856         }
857     }
858     if (found) {
859         // For now, this implementation ignore transitions with only zone name changes.
860         if (result.from->getRawOffset() == result.to->getRawOffset()
861             && result.from->getDSTSavings() == result.to->getDSTSavings()) {
862             // No offset changes.  Try next one if not final
863             return findPrev(result.time, false /* always exclusive */,
864                 transitionTime, fromRule, toRule);
865         }
866         transitionTime = result.time;
867         fromRule = result.from;
868         toRule = result.to;
869         return true;
870     }
871     return false;
872 }
873 
874 UDate
getTransitionTime(Transition * transition,UBool local,int32_t NonExistingTimeOpt,int32_t DuplicatedTimeOpt) const875 RuleBasedTimeZone::getTransitionTime(Transition* transition, UBool local,
876                                      int32_t NonExistingTimeOpt, int32_t DuplicatedTimeOpt) const {
877     UDate time = transition->time;
878     if (local) {
879         time += getLocalDelta(transition->from->getRawOffset(), transition->from->getDSTSavings(),
880                               transition->to->getRawOffset(), transition->to->getDSTSavings(),
881                               NonExistingTimeOpt, DuplicatedTimeOpt);
882     }
883     return time;
884 }
885 
886 int32_t
getLocalDelta(int32_t rawBefore,int32_t dstBefore,int32_t rawAfter,int32_t dstAfter,int32_t NonExistingTimeOpt,int32_t DuplicatedTimeOpt) const887 RuleBasedTimeZone::getLocalDelta(int32_t rawBefore, int32_t dstBefore, int32_t rawAfter, int32_t dstAfter,
888                              int32_t NonExistingTimeOpt, int32_t DuplicatedTimeOpt) const {
889     int32_t delta = 0;
890 
891     int32_t offsetBefore = rawBefore + dstBefore;
892     int32_t offsetAfter = rawAfter + dstAfter;
893 
894     UBool dstToStd = (dstBefore != 0) && (dstAfter == 0);
895     UBool stdToDst = (dstBefore == 0) && (dstAfter != 0);
896 
897     if (offsetAfter - offsetBefore >= 0) {
898         // Positive transition, which makes a non-existing local time range
899         if (((NonExistingTimeOpt & kStdDstMask) == kStandard && dstToStd)
900                 || ((NonExistingTimeOpt & kStdDstMask) == kDaylight && stdToDst)) {
901             delta = offsetBefore;
902         } else if (((NonExistingTimeOpt & kStdDstMask) == kStandard && stdToDst)
903                 || ((NonExistingTimeOpt & kStdDstMask) == kDaylight && dstToStd)) {
904             delta = offsetAfter;
905         } else if ((NonExistingTimeOpt & kFormerLatterMask) == kLatter) {
906             delta = offsetBefore;
907         } else {
908             // Interprets the time with rule before the transition,
909             // default for non-existing time range
910             delta = offsetAfter;
911         }
912     } else {
913         // Negative transition, which makes a duplicated local time range
914         if (((DuplicatedTimeOpt & kStdDstMask) == kStandard && dstToStd)
915                 || ((DuplicatedTimeOpt & kStdDstMask) == kDaylight && stdToDst)) {
916             delta = offsetAfter;
917         } else if (((DuplicatedTimeOpt & kStdDstMask) == kStandard && stdToDst)
918                 || ((DuplicatedTimeOpt & kStdDstMask) == kDaylight && dstToStd)) {
919             delta = offsetBefore;
920         } else if ((DuplicatedTimeOpt & kFormerLatterMask) == kFormer) {
921             delta = offsetBefore;
922         } else {
923             // Interprets the time with rule after the transition,
924             // default for duplicated local time range
925             delta = offsetAfter;
926         }
927     }
928     return delta;
929 }
930 
931 U_NAMESPACE_END
932 
933 #endif /* #if !UCONFIG_NO_FORMATTING */
934 
935 //eof
936 
937