Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 936 insertions, 0 deletions

diff --git a/intl/icu/source/i18n/rbtz.cpp b/intl/icu/source/i18n/rbtz.cpp
new file mode 100644
index 0000000000..e4d71436c5
--- /dev/null
+++ b/intl/icu/source/i18n/rbtz.cpp
@@ -0,0 +1,936 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+*******************************************************************************
+* Copyright (C) 2007-2013, International Business Machines Corporation and
+* others. All Rights Reserved.
+*******************************************************************************
+*/
+
+#include "utypeinfo.h"  // for 'typeid' to work
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "unicode/rbtz.h"
+#include "unicode/gregocal.h"
+#include "uvector.h"
+#include "gregoimp.h"
+#include "cmemory.h"
+#include "umutex.h"
+
+U_NAMESPACE_BEGIN
+
+/**
+ * A struct representing a time zone transition
+ */
+struct Transition : public UMemory {
+    UDate time;
+    TimeZoneRule* from;
+    TimeZoneRule* to;
+};
+
+U_CDECL_BEGIN
+static void U_CALLCONV
+deleteTransition(void* obj) {
+    delete static_cast<Transition *>(obj);
+}
+U_CDECL_END
+
+static UBool compareRules(UVector* rules1, UVector* rules2) {
+    if (rules1 == nullptr && rules2 == nullptr) {
+        return true;
+    } else if (rules1 == nullptr || rules2 == nullptr) {
+        return false;
+    }
+    int32_t size = rules1->size();
+    if (size != rules2->size()) {
+        return false;
+    }
+    for (int32_t i = 0; i < size; i++) {
+        TimeZoneRule *r1 = (TimeZoneRule*)rules1->elementAt(i);
+        TimeZoneRule *r2 = (TimeZoneRule*)rules2->elementAt(i);
+        if (*r1 != *r2) {
+            return false;
+        }
+    }
+    return true;
+}
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(RuleBasedTimeZone)
+
+RuleBasedTimeZone::RuleBasedTimeZone(const UnicodeString& id, InitialTimeZoneRule* initialRule)
+: BasicTimeZone(id), fInitialRule(initialRule), fHistoricRules(nullptr), fFinalRules(nullptr),
+  fHistoricTransitions(nullptr), fUpToDate(false) {
+}
+
+RuleBasedTimeZone::RuleBasedTimeZone(const RuleBasedTimeZone& source)
+: BasicTimeZone(source), fInitialRule(source.fInitialRule->clone()),
+  fHistoricTransitions(nullptr), fUpToDate(false) {
+    fHistoricRules = copyRules(source.fHistoricRules);
+    fFinalRules = copyRules(source.fFinalRules);
+    if (source.fUpToDate) {
+        UErrorCode status = U_ZERO_ERROR;
+        complete(status);
+    }
+}
+
+RuleBasedTimeZone::~RuleBasedTimeZone() {
+    deleteTransitions();
+    deleteRules();
+}
+
+RuleBasedTimeZone&
+RuleBasedTimeZone::operator=(const RuleBasedTimeZone& right) {
+    if (*this != right) {
+        BasicTimeZone::operator=(right);
+        deleteRules();
+        fInitialRule = right.fInitialRule->clone();
+        fHistoricRules = copyRules(right.fHistoricRules);
+        fFinalRules = copyRules(right.fFinalRules);
+        deleteTransitions();
+        fUpToDate = false;
+    }
+    return *this;
+}
+
+bool
+RuleBasedTimeZone::operator==(const TimeZone& that) const {
+    if (this == &that) {
+        return true;
+    }
+    if (typeid(*this) != typeid(that) || !BasicTimeZone::operator==(that)) {
+        return false;
+    }
+    RuleBasedTimeZone *rbtz = (RuleBasedTimeZone*)&that;
+    if (*fInitialRule != *(rbtz->fInitialRule)) {
+        return false;
+    }
+    if (compareRules(fHistoricRules, rbtz->fHistoricRules)
+        && compareRules(fFinalRules, rbtz->fFinalRules)) {
+        return true;
+    }
+    return false;
+}
+
+bool
+RuleBasedTimeZone::operator!=(const TimeZone& that) const {
+    return !operator==(that);
+}
+
+void
+RuleBasedTimeZone::addTransitionRule(TimeZoneRule* rule, UErrorCode& status) {
+    LocalPointer<TimeZoneRule>lpRule(rule);
+    if (U_FAILURE(status)) {
+        return;
+    }
+    AnnualTimeZoneRule* atzrule = dynamic_cast<AnnualTimeZoneRule*>(rule);
+    if (atzrule != nullptr && atzrule->getEndYear() == AnnualTimeZoneRule::MAX_YEAR) {
+        // A final rule
+        if (fFinalRules == nullptr) {
+            LocalPointer<UVector> lpFinalRules(new UVector(uprv_deleteUObject, nullptr, status), status);
+            if (U_FAILURE(status)) {
+                return;
+            }
+            fFinalRules = lpFinalRules.orphan();
+        } else if (fFinalRules->size() >= 2) {
+            // Cannot handle more than two final rules
+            status = U_INVALID_STATE_ERROR;
+            return;
+        }
+        fFinalRules->adoptElement(lpRule.orphan(), status);
+    } else {
+        // Non-final rule
+        if (fHistoricRules == nullptr) {
+            LocalPointer<UVector> lpHistoricRules(new UVector(uprv_deleteUObject, nullptr, status), status);
+            if (U_FAILURE(status)) {
+                return;
+            }
+            fHistoricRules = lpHistoricRules.orphan();
+        }
+        fHistoricRules->adoptElement(lpRule.orphan(), status);
+    }
+    // Mark dirty, so transitions are recalculated at next complete() call
+    fUpToDate = false;
+}
+
+
+void
+RuleBasedTimeZone::completeConst(UErrorCode& status) const {
+    static UMutex gLock;
+    if (U_FAILURE(status)) {
+        return;
+    }
+    umtx_lock(&gLock);
+    if (!fUpToDate) {
+        RuleBasedTimeZone *ncThis = const_cast<RuleBasedTimeZone*>(this);
+        ncThis->complete(status);
+    }
+    umtx_unlock(&gLock);
+}
+
+void
+RuleBasedTimeZone::complete(UErrorCode& status) {
+    if (U_FAILURE(status)) {
+        return;
+    }
+    if (fUpToDate) {
+        return;
+    }
+    // Make sure either no final rules or a pair of AnnualTimeZoneRules
+    // are available.
+    if (fFinalRules != nullptr && fFinalRules->size() != 2) {
+        status = U_INVALID_STATE_ERROR;
+        return;
+    }
+
+    // Create a TimezoneTransition and add to the list
+    if (fHistoricRules != nullptr || fFinalRules != nullptr) {
+        TimeZoneRule *curRule = fInitialRule;
+        UDate lastTransitionTime = MIN_MILLIS;
+
+        // Build the transition array which represents historical time zone
+        // transitions.
+        if (fHistoricRules != nullptr && fHistoricRules->size() > 0) {
+            int32_t i;
+            int32_t historicCount = fHistoricRules->size();
+            LocalMemory<bool> done((bool *)uprv_malloc(sizeof(bool) * historicCount));
+            if (done == nullptr) {
+                status = U_MEMORY_ALLOCATION_ERROR;
+                goto cleanup;
+            }
+            for (i = 0; i < historicCount; i++) {
+                done[i] = false;
+            }
+            while (true) {
+                int32_t curStdOffset = curRule->getRawOffset();
+                int32_t curDstSavings = curRule->getDSTSavings();
+                UDate nextTransitionTime = MAX_MILLIS;
+                TimeZoneRule *nextRule = nullptr;
+                TimeZoneRule *r = nullptr;
+                UBool avail;
+                UDate tt;
+                UnicodeString curName, name;
+                curRule->getName(curName);
+
+                for (i = 0; i < historicCount; i++) {
+                    if (done[i]) {
+                        continue;
+                    }
+                    r = (TimeZoneRule*)fHistoricRules->elementAt(i);
+                    avail = r->getNextStart(lastTransitionTime, curStdOffset, curDstSavings, false, tt);
+                    if (!avail) {
+                        // No more transitions from this rule - skip this rule next time
+                        done[i] = true;
+                    } else {
+                        r->getName(name);
+                        if (*r == *curRule ||
+                            (name == curName && r->getRawOffset() == curRule->getRawOffset()
+                            && r->getDSTSavings() == curRule->getDSTSavings())) {
+                            continue;
+                        }
+                        if (tt < nextTransitionTime) {
+                            nextTransitionTime = tt;
+                            nextRule = r;
+                        }
+                    }
+                }
+
+                if (nextRule ==  nullptr) {
+                    // Check if all historic rules are done
+                    UBool bDoneAll = true;
+                    for (int32_t j = 0; j < historicCount; j++) {
+                        if (!done[j]) {
+                            bDoneAll = false;
+                            break;
+                        }
+                    }
+                    if (bDoneAll) {
+                        break;
+                    }
+                }
+
+                if (fFinalRules != nullptr) {
+                    // Check if one of final rules has earlier transition date
+                    for (i = 0; i < 2 /* fFinalRules->size() */; i++) {
+                        TimeZoneRule *fr = (TimeZoneRule*)fFinalRules->elementAt(i);
+                        if (*fr == *curRule) {
+                            continue;
+                        }
+                        r = (TimeZoneRule*)fFinalRules->elementAt(i);
+                        avail = r->getNextStart(lastTransitionTime, curStdOffset, curDstSavings, false, tt);
+                        if (avail) {
+                            if (tt < nextTransitionTime) {
+                                nextTransitionTime = tt;
+                                nextRule = r;
+                            }
+                        }
+                    }
+                }
+
+                if (nextRule == nullptr) {
+                    // Nothing more
+                    break;
+                }
+
+                if (fHistoricTransitions == nullptr) {
+                    LocalPointer<UVector> lpHistoricTransitions(
+                        new UVector(deleteTransition, nullptr, status), status);
+                    if (U_FAILURE(status)) {
+                        goto cleanup;
+                    }
+                    fHistoricTransitions = lpHistoricTransitions.orphan();
+                }
+                LocalPointer<Transition> trst(new Transition, status);
+                if (U_FAILURE(status)) {
+                    goto cleanup;
+                }
+                trst->time = nextTransitionTime;
+                trst->from = curRule;
+                trst->to = nextRule;
+                fHistoricTransitions->adoptElement(trst.orphan(), status);
+                if (U_FAILURE(status)) {
+                    goto cleanup;
+                }
+                lastTransitionTime = nextTransitionTime;
+                curRule = nextRule;
+            }
+        }
+        if (fFinalRules != nullptr) {
+            if (fHistoricTransitions == nullptr) {
+                LocalPointer<UVector> lpHistoricTransitions(
+                    new UVector(deleteTransition, nullptr, status), status);
+                if (U_FAILURE(status)) {
+                    goto cleanup;
+                }
+                fHistoricTransitions = lpHistoricTransitions.orphan();
+            }
+            // Append the first transition for each
+            TimeZoneRule *rule0 = (TimeZoneRule*)fFinalRules->elementAt(0);
+            TimeZoneRule *rule1 = (TimeZoneRule*)fFinalRules->elementAt(1);
+            UDate tt0, tt1;
+            UBool avail0 = rule0->getNextStart(lastTransitionTime, curRule->getRawOffset(), curRule->getDSTSavings(), false, tt0);
+            UBool avail1 = rule1->getNextStart(lastTransitionTime, curRule->getRawOffset(), curRule->getDSTSavings(), false, tt1);
+            if (!avail0 || !avail1) {
+                // Should not happen, because both rules are permanent
+                status = U_INVALID_STATE_ERROR;
+                goto cleanup;
+            }
+            LocalPointer<Transition> final0(new Transition, status);
+            LocalPointer<Transition> final1(new Transition, status);
+            if (U_FAILURE(status)) {
+               goto cleanup;
+            }
+            if (tt0 < tt1) {
+                final0->time = tt0;
+                final0->from = curRule;
+                final0->to = rule0;
+                rule1->getNextStart(tt0, rule0->getRawOffset(), rule0->getDSTSavings(), false, final1->time);
+                final1->from = rule0;
+                final1->to = rule1;
+            } else {
+                final0->time = tt1;
+                final0->from = curRule;
+                final0->to = rule1;
+                rule0->getNextStart(tt1, rule1->getRawOffset(), rule1->getDSTSavings(), false, final1->time);
+                final1->from = rule1;
+                final1->to = rule0;
+            }
+            fHistoricTransitions->adoptElement(final0.orphan(), status);
+            fHistoricTransitions->adoptElement(final1.orphan(), status);
+            if (U_FAILURE(status)) {
+                goto cleanup;
+            }
+        }
+    }
+    fUpToDate = true;
+    return;
+
+cleanup:
+    deleteTransitions();
+    fUpToDate = false;
+}
+
+RuleBasedTimeZone*
+RuleBasedTimeZone::clone() const {
+    return new RuleBasedTimeZone(*this);
+}
+
+int32_t
+RuleBasedTimeZone::getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
+                             uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const {
+    if (U_FAILURE(status)) {
+        return 0;
+    }
+    if (month < UCAL_JANUARY || month > UCAL_DECEMBER) {
+        status = U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    } else {
+        return getOffset(era, year, month, day, dayOfWeek, millis,
+                         Grego::monthLength(year, month), status);
+    }
+}
+
+int32_t
+RuleBasedTimeZone::getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
+                             uint8_t /*dayOfWeek*/, int32_t millis,
+                             int32_t /*monthLength*/, UErrorCode& status) const {
+    // dayOfWeek and monthLength are unused
+    if (U_FAILURE(status)) {
+        return 0;
+    }
+    if (era == GregorianCalendar::BC) {
+        // Convert to extended year
+        year = 1 - year;
+    }
+    int32_t rawOffset, dstOffset;
+    UDate time = (UDate)Grego::fieldsToDay(year, month, day) * U_MILLIS_PER_DAY + millis;
+    getOffsetInternal(time, true, kDaylight, kStandard, rawOffset, dstOffset, status);
+    if (U_FAILURE(status)) {
+        return 0;
+    }
+    return (rawOffset + dstOffset);
+}
+
+void
+RuleBasedTimeZone::getOffset(UDate date, UBool local, int32_t& rawOffset,
+                             int32_t& dstOffset, UErrorCode& status) const {
+    getOffsetInternal(date, local, kFormer, kLatter, rawOffset, dstOffset, status);
+}
+
+void RuleBasedTimeZone::getOffsetFromLocal(UDate date, UTimeZoneLocalOption nonExistingTimeOpt,
+                                           UTimeZoneLocalOption duplicatedTimeOpt,
+                                           int32_t& rawOffset, int32_t& dstOffset, UErrorCode& status) const {
+    getOffsetInternal(date, true, nonExistingTimeOpt, duplicatedTimeOpt, rawOffset, dstOffset, status);
+}
+
+
+/*
+ * The internal getOffset implementation
+ */
+void
+RuleBasedTimeZone::getOffsetInternal(UDate date, UBool local,
+                                     int32_t NonExistingTimeOpt, int32_t DuplicatedTimeOpt,
+                                     int32_t& rawOffset, int32_t& dstOffset,
+                                     UErrorCode& status) const {
+    rawOffset = 0;
+    dstOffset = 0;
+
+    if (U_FAILURE(status)) {
+        return;
+    }
+    if (!fUpToDate) {
+        // Transitions are not yet resolved.  We cannot do it here
+        // because this method is const.  Thus, do nothing and return
+        // error status.
+        status = U_INVALID_STATE_ERROR;
+        return;
+    }
+    const TimeZoneRule *rule = nullptr;
+    if (fHistoricTransitions == nullptr) {
+        rule = fInitialRule;
+    } else {
+        UDate tstart = getTransitionTime((Transition*)fHistoricTransitions->elementAt(0),
+            local, NonExistingTimeOpt, DuplicatedTimeOpt);
+        if (date < tstart) {
+            rule = fInitialRule;
+        } else {
+            int32_t idx = fHistoricTransitions->size() - 1;
+            UDate tend = getTransitionTime((Transition*)fHistoricTransitions->elementAt(idx),
+                local, NonExistingTimeOpt, DuplicatedTimeOpt);
+            if (date > tend) {
+                if (fFinalRules != nullptr) {
+                    rule = findRuleInFinal(date, local, NonExistingTimeOpt, DuplicatedTimeOpt);
+                }
+                if (rule == nullptr) {
+                    // no final rules or the given time is before the first transition
+                    // specified by the final rules -> use the last rule 
+                    rule = ((Transition*)fHistoricTransitions->elementAt(idx))->to;
+                }
+            } else {
+                // Find a historical transition
+                while (idx >= 0) {
+                    if (date >= getTransitionTime((Transition*)fHistoricTransitions->elementAt(idx),
+                        local, NonExistingTimeOpt, DuplicatedTimeOpt)) {
+                        break;
+                    }
+                    idx--;
+                }
+                rule = ((Transition*)fHistoricTransitions->elementAt(idx))->to;
+            }
+        }
+    }
+    if (rule != nullptr) {
+        rawOffset = rule->getRawOffset();
+        dstOffset = rule->getDSTSavings();
+    }
+}
+
+void
+RuleBasedTimeZone::setRawOffset(int32_t /*offsetMillis*/) {
+    // We don't support this operation at this moment.
+    // Nothing to do!
+}
+
+int32_t
+RuleBasedTimeZone::getRawOffset() const {
+    // Note: This implementation returns standard GMT offset
+    // as of current time.
+    UErrorCode status = U_ZERO_ERROR;
+    int32_t raw, dst;
+    getOffset(uprv_getUTCtime(), false, raw, dst, status);
+    return raw;
+}
+
+UBool
+RuleBasedTimeZone::useDaylightTime() const {
+    // Note: This implementation returns true when
+    // daylight saving time is used as of now or
+    // after the next transition.
+    UErrorCode status = U_ZERO_ERROR;
+    UDate now = uprv_getUTCtime();
+    int32_t raw, dst;
+    getOffset(now, false, raw, dst, status);
+    if (dst != 0) {
+        return true;
+    }
+    // If DST is not used now, check if DST is used after the next transition
+    UDate time;
+    TimeZoneRule *from, *to;
+    UBool avail = findNext(now, false, time, from, to);
+    if (avail && to->getDSTSavings() != 0) {
+        return true;
+    }
+    return false;
+}
+
+UBool
+RuleBasedTimeZone::inDaylightTime(UDate date, UErrorCode& status) const {
+    if (U_FAILURE(status)) {
+        return false;
+    }
+    int32_t raw, dst;
+    getOffset(date, false, raw, dst, status);
+    if (dst != 0) {
+        return true;
+    }
+    return false;
+}
+
+UBool
+RuleBasedTimeZone::hasSameRules(const TimeZone& other) const {
+    if (this == &other) {
+        return true;
+    }
+    if (typeid(*this) != typeid(other)) {
+        return false;
+    }
+    const RuleBasedTimeZone& that = static_cast<const RuleBasedTimeZone&>(other);
+    if (*fInitialRule != *(that.fInitialRule)) {
+        return false;
+    }
+    if (compareRules(fHistoricRules, that.fHistoricRules)
+        && compareRules(fFinalRules, that.fFinalRules)) {
+        return true;
+    }
+    return false;
+}
+
+UBool
+RuleBasedTimeZone::getNextTransition(UDate base, UBool inclusive, TimeZoneTransition& result) const {
+    UErrorCode status = U_ZERO_ERROR;
+    completeConst(status);
+    if (U_FAILURE(status)) {
+        return false;
+    }
+    UDate transitionTime;
+    TimeZoneRule *fromRule, *toRule;
+    UBool found = findNext(base, inclusive, transitionTime, fromRule, toRule);
+    if (found) {
+        result.setTime(transitionTime);
+        result.setFrom(*fromRule);
+        result.setTo(*toRule);
+        return true;
+    }
+    return false;
+}
+
+UBool
+RuleBasedTimeZone::getPreviousTransition(UDate base, UBool inclusive, TimeZoneTransition& result) const {
+    UErrorCode status = U_ZERO_ERROR;
+    completeConst(status);
+    if (U_FAILURE(status)) {
+        return false;
+    }
+    UDate transitionTime;
+    TimeZoneRule *fromRule, *toRule;
+    UBool found = findPrev(base, inclusive, transitionTime, fromRule, toRule);
+    if (found) {
+        result.setTime(transitionTime);
+        result.setFrom(*fromRule);
+        result.setTo(*toRule);
+        return true;
+    }
+    return false;
+}
+
+int32_t
+RuleBasedTimeZone::countTransitionRules(UErrorCode& /*status*/) const {
+    int32_t count = 0;
+    if (fHistoricRules != nullptr) {
+        count += fHistoricRules->size();
+    }
+    if (fFinalRules != nullptr) {
+        count += fFinalRules->size();
+    }
+    return count;
+}
+
+void
+RuleBasedTimeZone::getTimeZoneRules(const InitialTimeZoneRule*& initial,
+                                    const TimeZoneRule* trsrules[],
+                                    int32_t& trscount,
+                                    UErrorCode& status) const {
+    if (U_FAILURE(status)) {
+        return;
+    }
+    // Initial rule
+    initial = fInitialRule;
+
+    // Transition rules
+    int32_t cnt = 0;
+    int32_t idx;
+    if (fHistoricRules != nullptr && cnt < trscount) {
+        int32_t historicCount = fHistoricRules->size();
+        idx = 0;
+        while (cnt < trscount && idx < historicCount) {
+            trsrules[cnt++] = (const TimeZoneRule*)fHistoricRules->elementAt(idx++);
+        }
+    }
+    if (fFinalRules != nullptr && cnt < trscount) {
+        int32_t finalCount = fFinalRules->size();
+        idx = 0;
+        while (cnt < trscount && idx < finalCount) {
+            trsrules[cnt++] = (const TimeZoneRule*)fFinalRules->elementAt(idx++);
+        }
+    }
+    // Set the result length
+    trscount = cnt;
+}
+
+void
+RuleBasedTimeZone::deleteRules() {
+    delete fInitialRule;
+    fInitialRule = nullptr;
+    if (fHistoricRules != nullptr) {
+        delete fHistoricRules;
+        fHistoricRules = nullptr;
+    }
+    if (fFinalRules != nullptr) {
+        delete fFinalRules;
+        fFinalRules = nullptr;
+    }
+}
+
+void
+RuleBasedTimeZone::deleteTransitions() {
+    if (fHistoricTransitions != nullptr) {
+        delete fHistoricTransitions;
+    }
+    fHistoricTransitions = nullptr;
+}
+
+UVector*
+RuleBasedTimeZone::copyRules(UVector* source) {
+    if (source == nullptr) {
+        return nullptr;
+    }
+    UErrorCode ec = U_ZERO_ERROR;
+    int32_t size = source->size();
+    LocalPointer<UVector> rules(new UVector(uprv_deleteUObject, nullptr, size, ec), ec);
+    if (U_FAILURE(ec)) {
+        return nullptr;
+    }
+    int32_t i;
+    for (i = 0; i < size; i++) {
+        LocalPointer<TimeZoneRule> rule(((TimeZoneRule*)source->elementAt(i))->clone(), ec);
+        rules->adoptElement(rule.orphan(), ec);
+        if (U_FAILURE(ec)) {
+            return nullptr;
+        }
+    }
+    return rules.orphan();
+}
+
+TimeZoneRule*
+RuleBasedTimeZone::findRuleInFinal(UDate date, UBool local,
+                                   int32_t NonExistingTimeOpt, int32_t DuplicatedTimeOpt) const {
+    if (fFinalRules == nullptr) {
+        return nullptr;
+    }
+
+    AnnualTimeZoneRule* fr0 = (AnnualTimeZoneRule*)fFinalRules->elementAt(0);
+    AnnualTimeZoneRule* fr1 = (AnnualTimeZoneRule*)fFinalRules->elementAt(1);
+    if (fr0 == nullptr || fr1 == nullptr) {
+        return nullptr;
+    }
+
+    UDate start0, start1;
+    UDate base;
+    int32_t localDelta;
+
+    base = date;
+    if (local) {
+        localDelta = getLocalDelta(fr1->getRawOffset(), fr1->getDSTSavings(),
+                                   fr0->getRawOffset(), fr0->getDSTSavings(),
+                                   NonExistingTimeOpt, DuplicatedTimeOpt);
+        base -= localDelta;
+    }
+    UBool avail0 = fr0->getPreviousStart(base, fr1->getRawOffset(), fr1->getDSTSavings(), true, start0);
+
+    base = date;
+    if (local) {
+        localDelta = getLocalDelta(fr0->getRawOffset(), fr0->getDSTSavings(),
+                                   fr1->getRawOffset(), fr1->getDSTSavings(),
+                                   NonExistingTimeOpt, DuplicatedTimeOpt);
+        base -= localDelta;
+    }
+    UBool avail1 = fr1->getPreviousStart(base, fr0->getRawOffset(), fr0->getDSTSavings(), true, start1);
+
+    if (!avail0 || !avail1) {
+        if (avail0) {
+            return fr0;
+        } else if (avail1) {
+            return fr1;
+        }
+        // Both rules take effect after the given time
+        return nullptr;
+    }
+
+    return (start0 > start1) ? fr0 : fr1;
+}
+
+UBool
+RuleBasedTimeZone::findNext(UDate base, UBool inclusive, UDate& transitionTime,
+                            TimeZoneRule*& fromRule, TimeZoneRule*& toRule) const {
+    if (fHistoricTransitions == nullptr) {
+        return false;
+    }
+    UBool isFinal = false;
+    UBool found = false;
+    Transition result;
+    Transition *tzt = (Transition*)fHistoricTransitions->elementAt(0);
+    UDate tt = tzt->time;
+    if (tt > base || (inclusive && tt == base)) {
+        result = *tzt;
+        found = true;
+    } else {
+        int32_t idx = fHistoricTransitions->size() - 1;        
+        tzt = (Transition*)fHistoricTransitions->elementAt(idx);
+        tt = tzt->time;
+        if (inclusive && tt == base) {
+            result = *tzt;
+            found = true;
+        } else if (tt <= base) {
+            if (fFinalRules != nullptr) {
+                // Find a transion time with finalRules
+                TimeZoneRule *r0 = (TimeZoneRule*)fFinalRules->elementAt(0);
+                TimeZoneRule *r1 = (TimeZoneRule*)fFinalRules->elementAt(1);
+                UDate start0, start1;
+                UBool avail0 = r0->getNextStart(base, r1->getRawOffset(), r1->getDSTSavings(), inclusive, start0);
+                UBool avail1 = r1->getNextStart(base, r0->getRawOffset(), r0->getDSTSavings(), inclusive, start1);
+                //  avail0/avail1 should be always true
+                if (!avail0 && !avail1) {
+                    return false;
+                }
+                if (!avail1 || start0 < start1) {
+                    result.time = start0;
+                    result.from = r1;
+                    result.to = r0;
+                } else {
+                    result.time = start1;
+                    result.from = r0;
+                    result.to = r1;
+                }
+                isFinal = true;
+                found = true;
+            }
+        } else {
+            // Find a transition within the historic transitions
+            idx--;
+            Transition *prev = tzt;
+            while (idx > 0) {
+                tzt = (Transition*)fHistoricTransitions->elementAt(idx);
+                tt = tzt->time;
+                if (tt < base || (!inclusive && tt == base)) {
+                    break;
+                }
+                idx--;
+                prev = tzt;
+            }
+            result.time = prev->time;
+            result.from = prev->from;
+            result.to = prev->to;
+            found = true;
+        }
+    }
+    if (found) {
+        // For now, this implementation ignore transitions with only zone name changes.
+        if (result.from->getRawOffset() == result.to->getRawOffset()
+            && result.from->getDSTSavings() == result.to->getDSTSavings()) {
+            if (isFinal) {
+                return false;
+            } else {
+                // No offset changes.  Try next one if not final
+                return findNext(result.time, false /* always exclusive */,
+                    transitionTime, fromRule, toRule);
+            }
+        }
+        transitionTime = result.time;
+        fromRule = result.from;
+        toRule = result.to;
+        return true;
+    }
+    return false;
+}
+
+UBool
+RuleBasedTimeZone::findPrev(UDate base, UBool inclusive, UDate& transitionTime,
+                            TimeZoneRule*& fromRule, TimeZoneRule*& toRule) const {
+    if (fHistoricTransitions == nullptr) {
+        return false;
+    }
+    UBool found = false;
+    Transition result;
+    Transition *tzt = (Transition*)fHistoricTransitions->elementAt(0);
+    UDate tt = tzt->time;
+    if (inclusive && tt == base) {
+        result = *tzt;
+        found = true;
+    } else if (tt < base) {
+        int32_t idx = fHistoricTransitions->size() - 1;        
+        tzt = (Transition*)fHistoricTransitions->elementAt(idx);
+        tt = tzt->time;
+        if (inclusive && tt == base) {
+            result = *tzt;
+            found = true;
+        } else if (tt < base) {
+            if (fFinalRules != nullptr) {
+                // Find a transion time with finalRules
+                TimeZoneRule *r0 = (TimeZoneRule*)fFinalRules->elementAt(0);
+                TimeZoneRule *r1 = (TimeZoneRule*)fFinalRules->elementAt(1);
+                UDate start0, start1;
+                UBool avail0 = r0->getPreviousStart(base, r1->getRawOffset(), r1->getDSTSavings(), inclusive, start0);
+                UBool avail1 = r1->getPreviousStart(base, r0->getRawOffset(), r0->getDSTSavings(), inclusive, start1);
+                //  avail0/avail1 should be always true
+                if (!avail0 && !avail1) {
+                    return false;
+                }
+                if (!avail1 || start0 > start1) {
+                    result.time = start0;
+                    result.from = r1;
+                    result.to = r0;
+                } else {
+                    result.time = start1;
+                    result.from = r0;
+                    result.to = r1;
+                }
+            } else {
+                result = *tzt;
+            }
+            found = true;
+        } else {
+            // Find a transition within the historic transitions
+            idx--;
+            while (idx >= 0) {
+                tzt = (Transition*)fHistoricTransitions->elementAt(idx);
+                tt = tzt->time;
+                if (tt < base || (inclusive && tt == base)) {
+                    break;
+                }
+                idx--;
+            }
+            result = *tzt;
+            found = true;
+        }
+    }
+    if (found) {
+        // For now, this implementation ignore transitions with only zone name changes.
+        if (result.from->getRawOffset() == result.to->getRawOffset()
+            && result.from->getDSTSavings() == result.to->getDSTSavings()) {
+            // No offset changes.  Try next one if not final
+            return findPrev(result.time, false /* always exclusive */,
+                transitionTime, fromRule, toRule);
+        }
+        transitionTime = result.time;
+        fromRule = result.from;
+        toRule = result.to;
+        return true;
+    }
+    return false;
+}
+
+UDate
+RuleBasedTimeZone::getTransitionTime(Transition* transition, UBool local,
+                                     int32_t NonExistingTimeOpt, int32_t DuplicatedTimeOpt) const {
+    UDate time = transition->time;
+    if (local) {
+        time += getLocalDelta(transition->from->getRawOffset(), transition->from->getDSTSavings(),
+                              transition->to->getRawOffset(), transition->to->getDSTSavings(),
+                              NonExistingTimeOpt, DuplicatedTimeOpt);
+    }
+    return time;
+}
+
+int32_t
+RuleBasedTimeZone::getLocalDelta(int32_t rawBefore, int32_t dstBefore, int32_t rawAfter, int32_t dstAfter,
+                             int32_t NonExistingTimeOpt, int32_t DuplicatedTimeOpt) const {
+    int32_t delta = 0;
+
+    int32_t offsetBefore = rawBefore + dstBefore;
+    int32_t offsetAfter = rawAfter + dstAfter;
+
+    UBool dstToStd = (dstBefore != 0) && (dstAfter == 0);
+    UBool stdToDst = (dstBefore == 0) && (dstAfter != 0);
+
+    if (offsetAfter - offsetBefore >= 0) {
+        // Positive transition, which makes a non-existing local time range
+        if (((NonExistingTimeOpt & kStdDstMask) == kStandard && dstToStd)
+                || ((NonExistingTimeOpt & kStdDstMask) == kDaylight && stdToDst)) {
+            delta = offsetBefore;
+        } else if (((NonExistingTimeOpt & kStdDstMask) == kStandard && stdToDst)
+                || ((NonExistingTimeOpt & kStdDstMask) == kDaylight && dstToStd)) {
+            delta = offsetAfter;
+        } else if ((NonExistingTimeOpt & kFormerLatterMask) == kLatter) {
+            delta = offsetBefore;
+        } else {
+            // Interprets the time with rule before the transition,
+            // default for non-existing time range
+            delta = offsetAfter;
+        }
+    } else {
+        // Negative transition, which makes a duplicated local time range
+        if (((DuplicatedTimeOpt & kStdDstMask) == kStandard && dstToStd)
+                || ((DuplicatedTimeOpt & kStdDstMask) == kDaylight && stdToDst)) {
+            delta = offsetAfter;
+        } else if (((DuplicatedTimeOpt & kStdDstMask) == kStandard && stdToDst)
+                || ((DuplicatedTimeOpt & kStdDstMask) == kDaylight && dstToStd)) {
+            delta = offsetBefore;
+        } else if ((DuplicatedTimeOpt & kFormerLatterMask) == kFormer) {
+            delta = offsetBefore;
+        } else {
+            // Interprets the time with rule after the transition,
+            // default for duplicated local time range
+            delta = offsetAfter;
+        }
+    }
+    return delta;
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_FORMATTING */
+
+//eof
+