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-rw-r--r--src/corelib/tools/qtimezoneprivate_tz.cpp139
1 files changed, 91 insertions, 48 deletions
diff --git a/src/corelib/tools/qtimezoneprivate_tz.cpp b/src/corelib/tools/qtimezoneprivate_tz.cpp
index 10b61c3a40..1714c9802f 100644
--- a/src/corelib/tools/qtimezoneprivate_tz.cpp
+++ b/src/corelib/tools/qtimezoneprivate_tz.cpp
@@ -199,7 +199,7 @@ static QVector<QTzTransition> parseTzTransitions(QDataStream &ds, int tzh_timecn
}
} else {
// Parse tzh_timecnt x 4-byte transition times
- int val;
+ qint32 val;
for (int i = 0; i < tzh_timecnt && ds.status() == QDataStream::Ok; ++i) {
ds >> val;
transitions[i].tz_time = val;
@@ -452,13 +452,31 @@ static inline bool asciiIsLetter(char ch)
return ch >= 'a' && ch <= 'z';
}
+namespace {
+
+struct PosixZone
+{
+ enum {
+ InvalidOffset = INT_MIN,
+ };
+
+ QString name;
+ int offset;
+
+ static PosixZone invalid() { return {QString(), InvalidOffset}; }
+ static PosixZone parse(const char *&pos, const char *end);
+
+ bool hasValidOffset() const Q_DECL_NOTHROW { return offset != InvalidOffset; }
+};
+
+} // unnamed namespace
+
// Returns the zone name, the offset (in seconds) and advances \a begin to
// where the parsing ended. Returns a zone of INT_MIN in case an offset
// couldn't be read.
-static QPair<QString, int> parsePosixZoneNameAndOffset(const char *&pos, const char *end)
+PosixZone PosixZone::parse(const char *&pos, const char *end)
{
static const char offsetChars[] = "0123456789:";
- QPair<QString, int> result = qMakePair(QString(), INT_MIN);
const char *nameBegin = pos;
const char *nameEnd;
@@ -480,7 +498,7 @@ static QPair<QString, int> parsePosixZoneNameAndOffset(const char *&pos, const c
pos = nameEnd;
}
if (nameEnd - nameBegin < 3)
- return result; // name must be at least 3 characters long
+ return invalid(); // name must be at least 3 characters long
// zone offset, form [+-]hh:mm:ss
const char *zoneBegin = pos;
@@ -493,11 +511,10 @@ static QPair<QString, int> parsePosixZoneNameAndOffset(const char *&pos, const c
++zoneEnd;
}
- result.first = QString::fromUtf8(nameBegin, nameEnd - nameBegin);
- if (zoneEnd > zoneBegin)
- result.second = parsePosixOffset(zoneBegin, zoneEnd);
+ QString name = QString::fromUtf8(nameBegin, nameEnd - nameBegin);
+ const int offset = zoneEnd > zoneBegin ? parsePosixOffset(zoneBegin, zoneEnd) : InvalidOffset;
pos = zoneEnd;
- return result;
+ return {std::move(name), offset};
}
static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArray &posixRule,
@@ -517,19 +534,19 @@ static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArra
// See the section about TZ at http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html
QList<QByteArray> parts = posixRule.split(',');
- QPair<QString, int> stdZone, dstZone;
+ PosixZone stdZone, dstZone;
{
const QByteArray &zoneinfo = parts.at(0);
const char *begin = zoneinfo.constBegin();
- stdZone = parsePosixZoneNameAndOffset(begin, zoneinfo.constEnd());
- if (stdZone.second == INT_MIN) {
- stdZone.second = 0; // reset to UTC if we failed to parse
+ stdZone = PosixZone::parse(begin, zoneinfo.constEnd());
+ if (!stdZone.hasValidOffset()) {
+ stdZone.offset = 0; // reset to UTC if we failed to parse
} else if (begin < zoneinfo.constEnd()) {
- dstZone = parsePosixZoneNameAndOffset(begin, zoneinfo.constEnd());
- if (dstZone.second == INT_MIN) {
+ dstZone = PosixZone::parse(begin, zoneinfo.constEnd());
+ if (!dstZone.hasValidOffset()) {
// if the dst offset isn't provided, it is 1 hour ahead of the standard offset
- dstZone.second = stdZone.second + (60 * 60);
+ dstZone.offset = stdZone.offset + (60 * 60);
}
}
}
@@ -538,10 +555,10 @@ static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArra
if (parts.count() == 1) {
QTimeZonePrivate::Data data;
data.atMSecsSinceEpoch = lastTranMSecs;
- data.offsetFromUtc = stdZone.second;
- data.standardTimeOffset = stdZone.second;
+ data.offsetFromUtc = stdZone.offset;
+ data.standardTimeOffset = stdZone.offset;
data.daylightTimeOffset = 0;
- data.abbreviation = stdZone.first;
+ data.abbreviation = stdZone.name;
result << data;
return result;
}
@@ -568,18 +585,18 @@ static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArra
for (int year = startYear; year <= endYear; ++year) {
QTimeZonePrivate::Data dstData;
QDateTime dst(calculatePosixDate(dstDateRule, year), dstTime, Qt::UTC);
- dstData.atMSecsSinceEpoch = dst.toMSecsSinceEpoch() - (stdZone.second * 1000);
- dstData.offsetFromUtc = dstZone.second;
- dstData.standardTimeOffset = stdZone.second;
- dstData.daylightTimeOffset = dstZone.second - stdZone.second;
- dstData.abbreviation = dstZone.first;
+ dstData.atMSecsSinceEpoch = dst.toMSecsSinceEpoch() - (stdZone.offset * 1000);
+ dstData.offsetFromUtc = dstZone.offset;
+ dstData.standardTimeOffset = stdZone.offset;
+ dstData.daylightTimeOffset = dstZone.offset - stdZone.offset;
+ dstData.abbreviation = dstZone.name;
QTimeZonePrivate::Data stdData;
QDateTime std(calculatePosixDate(stdDateRule, year), stdTime, Qt::UTC);
- stdData.atMSecsSinceEpoch = std.toMSecsSinceEpoch() - (dstZone.second * 1000);
- stdData.offsetFromUtc = stdZone.second;
- stdData.standardTimeOffset = stdZone.second;
+ stdData.atMSecsSinceEpoch = std.toMSecsSinceEpoch() - (dstZone.offset * 1000);
+ stdData.offsetFromUtc = stdZone.offset;
+ stdData.standardTimeOffset = stdZone.offset;
stdData.daylightTimeOffset = 0;
- stdData.abbreviation = stdZone.first;
+ stdData.abbreviation = stdZone.name;
// Part of the high year will overflow
if (year == 292278994 && (dstData.atMSecsSinceEpoch < 0 || stdData.atMSecsSinceEpoch < 0)) {
if (dstData.atMSecsSinceEpoch > 0) {
@@ -598,37 +615,21 @@ static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArra
// Create the system default time zone
QTzTimeZonePrivate::QTzTimeZonePrivate()
-#if QT_CONFIG(icu)
- : m_icu(0)
-#endif
{
init(systemTimeZoneId());
}
// Create a named time zone
QTzTimeZonePrivate::QTzTimeZonePrivate(const QByteArray &ianaId)
-#if QT_CONFIG(icu)
- : m_icu(0)
-#endif
{
init(ianaId);
}
-QTzTimeZonePrivate::QTzTimeZonePrivate(const QTzTimeZonePrivate &other)
- : QTimeZonePrivate(other), m_tranTimes(other.m_tranTimes),
- m_tranRules(other.m_tranRules), m_abbreviations(other.m_abbreviations),
-#if QT_CONFIG(icu)
- m_icu(other.m_icu),
-#endif
- m_posixRule(other.m_posixRule)
-{
-}
-
QTzTimeZonePrivate::~QTzTimeZonePrivate()
{
}
-QTimeZonePrivate *QTzTimeZonePrivate::clone()
+QTzTimeZonePrivate *QTzTimeZonePrivate::clone() const
{
return new QTzTimeZonePrivate(*this);
}
@@ -725,19 +726,61 @@ void QTzTimeZonePrivate::init(const QByteArray &ianaId)
}
}
- // Now for each transition time calculate our rule and save them
- m_tranTimes.reserve(tranList.count());
- for (const QTzTransition &tz_tran : qAsConst(tranList)) {
+ // Now for each transition time calculate and store our rule:
+ const int tranCount = tranList.count();;
+ m_tranTimes.reserve(tranCount);
+ // The DST offset when in effect: usually stable, usually an hour:
+ int lastDstOff = 3600;
+ for (int i = 0; i < tranCount; i++) {
+ const QTzTransition &tz_tran = tranList.at(i);
QTzTransitionTime tran;
QTzTransitionRule rule;
const QTzType tz_type = typeList.at(tz_tran.tz_typeind);
// Calculate the associated Rule
- if (!tz_type.tz_isdst)
+ if (!tz_type.tz_isdst) {
utcOffset = tz_type.tz_gmtoff;
+ } else if (Q_UNLIKELY(tz_type.tz_gmtoff != utcOffset + lastDstOff)) {
+ /*
+ This might be a genuine change in DST offset, but could also be
+ DST starting at the same time as the standard offset changed. See
+ if DST's end gives a more plausible utcOffset (i.e. one closer to
+ the last we saw, or a simple whole hour):
+ */
+ // Standard offset inferred from net offset and expected DST offset:
+ const int inferStd = tz_type.tz_gmtoff - lastDstOff; // != utcOffset
+ for (int j = i + 1; j < tranCount; j++) {
+ const QTzType new_type = typeList.at(tranList.at(j).tz_typeind);
+ if (!new_type.tz_isdst) {
+ const int newUtc = new_type.tz_gmtoff;
+ if (newUtc == utcOffset) {
+ // DST-end can't help us, avoid lots of messy checks.
+ // else: See if the end matches the familiar DST offset:
+ } else if (newUtc == inferStd) {
+ utcOffset = newUtc;
+ // else: let either end shift us to one hour as DST offset:
+ } else if (tz_type.tz_gmtoff - 3600 == utcOffset) {
+ // Start does it
+ } else if (tz_type.tz_gmtoff - 3600 == newUtc) {
+ utcOffset = newUtc; // End does it
+ // else: prefer whichever end gives DST offset closer to
+ // last, but consider any offset > 0 "closer" than any <= 0:
+ } else if (newUtc < tz_type.tz_gmtoff
+ ? (utcOffset >= tz_type.tz_gmtoff
+ || qAbs(newUtc - inferStd) < qAbs(utcOffset - inferStd))
+ : (utcOffset >= tz_type.tz_gmtoff
+ && qAbs(newUtc - inferStd) < qAbs(utcOffset - inferStd))) {
+ utcOffset = newUtc;
+ }
+ break;
+ }
+ }
+ lastDstOff = tz_type.tz_gmtoff - utcOffset;
+ }
rule.stdOffset = utcOffset;
rule.dstOffset = tz_type.tz_gmtoff - utcOffset;
rule.abbreviationIndex = tz_type.tz_abbrind;
+
// If the rule already exist then use that, otherwise add it
int ruleIndex = m_tranRules.indexOf(rule);
if (ruleIndex == -1) {
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-05 14:04:10 +0000