File indexing completed on 2023-09-24 04:04:57

 /*
    This file is part of the KDE libraries
    Copyright (c) 2005-2008 David Jarvie <djarvie@kde.org>
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.
 
    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 */
 
 #include "ktzfiletimezone.h"
 
 #include <config-date.h>
 
 #if HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
 #if HAVE_TIME_H
 #include <time.h>
 #endif
 
 #include <QDebug>
 #include <QFile>
 #include <QDataStream>
 #include <QVector>
 
 // Use this replacement for QDateTime::setTime_t(uint) since our time
 // values are signed.
 static QDateTime fromTime_t(qint32 seconds)
 {
     static const QDate epochDate(1970, 1, 1);
     static const QTime epochTime(0, 0, 0);
     int days = seconds / 86400;
     seconds -= days * 86400;
     if (seconds < 0) {
         --days;
         seconds += 86400;
     }
     return QDateTime(epochDate.addDays(days), epochTime.addSecs(seconds), Qt::UTC);
 }
 
 /******************************************************************************/
 
 KTzfileTimeZoneBackend::KTzfileTimeZoneBackend(KTzfileTimeZoneSource *source, const QString &name,
         const QString &countryCode, float latitude, float longitude, const QString &comment)
     : KTimeZoneBackend(source, name, countryCode, latitude, longitude, comment)
 {}
 
 KTzfileTimeZoneBackend::~KTzfileTimeZoneBackend()
 {}
 
 KTimeZoneBackend *KTzfileTimeZoneBackend::clone() const
 {
     return new KTzfileTimeZoneBackend(*this);
 }
 
 QByteArray KTzfileTimeZoneBackend::type() const
 {
     return "KTzfileTimeZone";
 }
 
 bool KTzfileTimeZoneBackend::hasTransitions(const KTimeZone *caller) const
 {
     Q_UNUSED(caller)
     return true;
 }
 
 /******************************************************************************/
 
 KTzfileTimeZone::KTzfileTimeZone(KTzfileTimeZoneSource *source, const QString &name,
                                  const QString &countryCode, float latitude, float longitude,
                                  const QString &comment)
     : KTimeZone(new KTzfileTimeZoneBackend(source, name, countryCode, latitude, longitude, comment))
 {}
 
 KTzfileTimeZone::~KTzfileTimeZone()
 {}
 
 /******************************************************************************/
 
 class KTzfileTimeZoneDataPrivate
 {
 public:
 };
 
 KTzfileTimeZoneData::KTzfileTimeZoneData()
 //  : d(new KTzfileTimeZoneDataPrivate)
 { }
 
 KTzfileTimeZoneData::KTzfileTimeZoneData(const KTzfileTimeZoneData &rhs)
     : KTimeZoneData(rhs)
 //    d(new KTzfileTimeZoneDataPrivate)
 {
 }
 
 KTzfileTimeZoneData::~KTzfileTimeZoneData()
 {
 //    delete d;
 }
 
 KTzfileTimeZoneData &KTzfileTimeZoneData::operator=(const KTzfileTimeZoneData &rhs)
 {
     KTimeZoneData::operator=(rhs);
     return *this;
 }
 
 KTimeZoneData *KTzfileTimeZoneData::clone() const
 {
     return new KTzfileTimeZoneData(*this);
 }
 
 bool KTzfileTimeZoneData::hasTransitions() const
 {
     return true;
 }
 
 /******************************************************************************/
 
 class KTzfileTimeZoneSourcePrivate
 {
 public:
     KTzfileTimeZoneSourcePrivate(const QString &loc)
         : location(loc) {}
     ~KTzfileTimeZoneSourcePrivate() {}
 
     QString location;
 };
 
 KTzfileTimeZoneSource::KTzfileTimeZoneSource(const QString &location)
     : d(new KTzfileTimeZoneSourcePrivate(location))
 {
     if (location.length() > 1  &&  location.endsWith(QLatin1Char('/'))) {
         d->location.chop(1);
     }
 }
 
 KTzfileTimeZoneSource::~KTzfileTimeZoneSource()
 {
     delete d;
 }
 
 QString KTzfileTimeZoneSource::location() const
 {
     return d->location;
 }
 
 KTimeZoneData *KTzfileTimeZoneSource::parse(const KTimeZone &zone) const
 {
     quint32 abbrCharCount;     // the number of characters of time zone abbreviation strings
     quint32 ttisgmtcnt;
     quint8  is;
     quint8  T_, Z_, i_, f_;    // tzfile identifier prefix
 
     QString path = zone.name();
     if (!path.startsWith(QLatin1Char('/'))) {
         if (d->location == QLatin1String("/")) {
             path.prepend(d->location);
         } else {
             path = d->location + QLatin1Char('/') + path;
         }
     }
     QFile f(path);
     if (!f.open(QIODevice::ReadOnly)) {
         qCritical() << "Cannot open " << f.fileName() << endl;
         return nullptr;
     }
     QDataStream str(&f);
 
     // Read the file type identifier
     str >> T_ >> Z_ >> i_ >> f_;
     if (T_ != 'T' || Z_ != 'Z' || i_ != 'i' || f_ != 'f') {
         qCritical() << "Not a TZFILE: " << f.fileName() << endl;
         return nullptr;
     }
     // Discard 16 bytes reserved for future use
     unsigned i;
     for (i = 0; i < 4; ++i) {
         str >> ttisgmtcnt;
     }
 
     KTzfileTimeZoneData *data = new KTzfileTimeZoneData;
 
     // Read the sizes of arrays held in the file
     quint32 nTransitionTimes;
     quint32 nLocalTimeTypes;
     quint32 nLeapSecondAdjusts;
     quint32 nIsStandard;
     quint32 nIsUtc;
     str >> nIsUtc
         >> nIsStandard
         >> nLeapSecondAdjusts
         >> nTransitionTimes
         >> nLocalTimeTypes
         >> abbrCharCount;
     // qDebug() << "header: " << nIsUtc << ", " << nIsStandard << ", " << nLeapSecondAdjusts << ", " <<
     //    nTransitionTimes << ", " << nLocalTimeTypes << ", " << abbrCharCount << endl;
 
     // Read the transition times, at which the rules for computing local time change
     struct TransitionTime {
         qint32 time;            // time (as returned by time(2)) at which the rules for computing local time change
         quint8 localTimeIndex;  // index into the LocalTimeType array
     };
 //qDebug()<<"Reading zone "<<zone.name();
     TransitionTime *transitionTimes = new TransitionTime[nTransitionTimes];
     for (i = 0;  i < nTransitionTimes;  ++i) {
         str >> transitionTimes[i].time;
     }
     for (i = 0;  i < nTransitionTimes;  ++i) {
         str >> transitionTimes[i].localTimeIndex;
 //qDebug() << "Transition time "<<i<<": "<<transitionTimes[i].time<<"   lt index="<<(int)transitionTimes[i].localTimeIndex;
     }
 
     // Read the local time types
     struct LocalTimeType {
         qint32 gmtoff;     // number of seconds to be added to UTC
         bool   isdst;      // whether tm_isdst should be set by localtime(3)
         quint8 abbrIndex;  // index into the list of time zone abbreviations
         bool   isutc;      // transition times are in UTC. If UTC, isstd is ignored.
         bool   isstd;      // if true, transition times are in standard time;
         // if false, transition times are in wall clock time,
         // i.e. standard time or daylight savings time
         // whichever is current before the transition
     };
     LocalTimeType *localTimeTypes = new LocalTimeType[nLocalTimeTypes];
     LocalTimeType *ltt = localTimeTypes;
     for (i = 0;  i < nLocalTimeTypes;  ++ltt, ++i) {
         str >> ltt->gmtoff;
         str >> is;
         ltt->isdst = (is != 0);
         str >> ltt->abbrIndex;
         // qDebug() << "local type: " << ltt->gmtoff << ", " << is << ", " << ltt->abbrIndex;
         ltt->isstd = false;   // default if no data
         ltt->isutc = false;   // default if no data
     }
 
     // Read the timezone abbreviations. They are stored as null terminated strings in
     // a character array.
     // Make sure we don't fall foul of maliciously coded time zone abbreviations.
     if (abbrCharCount > 64) {
         qCritical() << "excessive length for timezone abbreviations: " << abbrCharCount << endl;
         delete data;
         delete[] transitionTimes;
         delete[] localTimeTypes;
         return nullptr;
     }
     QByteArray array(abbrCharCount, 0);
     str.readRawData(array.data(), array.size());
     const char *abbrs = array.constData();
     if (abbrs[abbrCharCount - 1] != 0) {
         // These abbreviations are corrupt!
         qCritical() << "timezone abbreviations not null terminated: " << abbrs[abbrCharCount - 1] << endl;
         delete data;
         delete[] transitionTimes;
         delete[] localTimeTypes;
         return nullptr;
     }
     quint8 n = 0;
     QList<QByteArray> abbreviations;
     for (i = 0;  i < abbrCharCount;  ++n, i += strlen(abbrs + i) + 1) {
         abbreviations += QByteArray(abbrs + i);
         // Convert the LocalTimeTypes pointer to a sequential index
         ltt = localTimeTypes;
         for (unsigned j = 0;  j < nLocalTimeTypes;  ++ltt, ++j) {
             if (ltt->abbrIndex == i) {
                 ltt->abbrIndex = n;
             }
         }
     }
 
     // Read the leap second adjustments
     qint32  t;
     quint32 s;
     QList<KTimeZone::LeapSeconds> leapChanges;
     for (i = 0;  i < nLeapSecondAdjusts;  ++i) {
         str >> t >> s;
         // qDebug() << "leap entry: " << t << ", " << s;
         // Don't use QDateTime::setTime_t() because it takes an unsigned argument
         leapChanges += KTimeZone::LeapSeconds(fromTime_t(t), static_cast<int>(s));
     }
     data->setLeapSecondChanges(leapChanges);
 
     // Read the standard/wall time indicators.
     // These are true if the transition times associated with local time types
     // are specified as standard time, false if wall clock time.
     for (i = 0;  i < nIsStandard;  ++i) {
         str >> is;
         localTimeTypes[i].isstd = (is != 0);
         // qDebug() << "standard: " << is;
     }
 
     // Read the UTC/local time indicators.
     // These are true if the transition times associated with local time types
     // are specified as UTC, false if local time.
     for (i = 0;  i < nIsUtc;  ++i) {
         str >> is;
         localTimeTypes[i].isutc = (is != 0);
         // qDebug() << "UTC: " << is;
     }
 
     // Find the starting offset from UTC to use before the first transition time.
     // This is first non-daylight savings local time type, or if there is none,
     // the first local time type.
     LocalTimeType *firstLtt = nullptr;
     ltt = localTimeTypes;
     for (i = 0;  i < nLocalTimeTypes;  ++ltt, ++i) {
         if (!ltt->isdst) {
             firstLtt = ltt;
             break;
         }
     }
 
     // Compile the time type data into a list of KTimeZone::Phase instances.
     // Also check for local time types which are identical (this does happen)
     // and use the same Phase instance for each.
     QByteArray abbrev;
     QList<KTimeZone::Phase> phases;
     QList<QByteArray> phaseAbbrevs;
     QVector<int> lttLookup(nLocalTimeTypes);
     ltt = localTimeTypes;
     for (i = 0;  i < nLocalTimeTypes;  ++ltt, ++i) {
         if (ltt->abbrIndex >= abbreviations.count()) {
             qCritical() << "KTzfileTimeZoneSource::parse(): abbreviation index out of range" << endl;
             abbrev = "???";
         } else {
             abbrev = abbreviations[ltt->abbrIndex];
         }
         // Check for an identical Phase
         int phindex = 0;
         for (int j = 0, jend = phases.count();  j < jend;  ++j, ++phindex) {
             if (ltt->gmtoff == phases[j].utcOffset()
                     && (bool)ltt->isdst == phases[j].isDst()
                     &&  abbrev == phaseAbbrevs[j]) {
                 break;
             }
         }
         lttLookup[i] = phindex;
         if (phindex == phases.count()) {
             phases += KTimeZone::Phase(ltt->gmtoff, abbrev, ltt->isdst);
             phaseAbbrevs += abbrev;
         }
     }
     KTimeZone::Phase prePhase(firstLtt->gmtoff,
                               (firstLtt->abbrIndex < abbreviations.count() ? abbreviations[firstLtt->abbrIndex] : ""),
                               false);
     data->setPhases(phases, prePhase);
 
     // Compile the transition list
     QList<KTimeZone::Transition> transitions;
     TransitionTime *tt = transitionTimes;
     for (i = 0;  i < nTransitionTimes;  ++tt, ++i) {
         if (tt->localTimeIndex >= nLocalTimeTypes) {
             qCritical() << "KTzfileTimeZoneSource::parse(): transition ignored: local time type out of range: " << (int)tt->localTimeIndex << " > " << nLocalTimeTypes << endl;
             continue;
         }
 
         // Convert local transition times to UTC
         ltt = &localTimeTypes[tt->localTimeIndex];
         const KTimeZone::Phase phase = phases[lttLookup[tt->localTimeIndex]];
 //qDebug(161) << "Transition time "<<i<<": "<<fromTime_t(tt->time)<<", offset="<<phase.utcOffset()/60;
         transitions += KTimeZone::Transition(fromTime_t(tt->time), phase);
     }
     data->setTransitions(transitions);
 //for(int xxx=1;xxx<data->transitions().count();xxx++)
 //qDebug(161) << "Transition time "<<xxx<<": "<<data->transitions()[xxx].time()<<", offset="<<data->transitions()[xxx].phase().utcOffset()/60;
     delete[] localTimeTypes;
     delete[] transitionTimes;
 
     return data;
 }