summaryrefslogtreecommitdiffstats
path: root/src/corelib/tools/qtimezoneprivate_icu.cpp
blob: 254900eb9656a973e7a9d8c1c8eb1e9e5f7054b0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
/****************************************************************************
**
** Copyright (C) 2013 John Layt <jlayt@kde.org>
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qtimezone.h"
#include "qtimezoneprivate_p.h"

#include <unicode/ucal.h>

#include <qdebug.h>

QT_BEGIN_NAMESPACE

/*
    Private

    ICU implementation
*/

// ICU utilities

// Convert TimeType and NameType into ICU UCalendarDisplayNameType
static UCalendarDisplayNameType ucalDisplayNameType(QTimeZone::TimeType timeType, QTimeZone::NameType nameType)
{
    // TODO ICU C UCalendarDisplayNameType does not support full set of C++ TimeZone::EDisplayType
    switch (nameType) {
    case QTimeZone::ShortName :
    case QTimeZone::OffsetName :
        if (timeType == QTimeZone::DaylightTime)
            return UCAL_SHORT_DST;
        // Includes GenericTime
        return UCAL_SHORT_STANDARD;
    case QTimeZone::DefaultName :
    case QTimeZone::LongName :
        if (timeType == QTimeZone::DaylightTime)
            return UCAL_DST;
        // Includes GenericTime
        return UCAL_STANDARD;
    }
    return UCAL_STANDARD;
}

// Qt wrapper around ucal_getDefaultTimeZone()
static QByteArray ucalDefaultTimeZoneId()
{
    int32_t size = 30;
    QString result(size, Qt::Uninitialized);
    UErrorCode status = U_ZERO_ERROR;

    // size = ucal_getDefaultTimeZone(result, resultLength, status)
    size = ucal_getDefaultTimeZone(reinterpret_cast<UChar *>(result.data()), size, &status);

    // If overflow, then resize and retry
    if (status == U_BUFFER_OVERFLOW_ERROR) {
        result.resize(size);
        status = U_ZERO_ERROR;
        size = ucal_getDefaultTimeZone(reinterpret_cast<UChar *>(result.data()), size, &status);
    }

    // If successful on first or second go, resize and return
    if (U_SUCCESS(status)) {
        result.resize(size);
        return result.toUtf8();
    }

    return QByteArray();
}

// Qt wrapper around ucal_getTimeZoneDisplayName()
static QString ucalTimeZoneDisplayName(UCalendar *ucal, QTimeZone::TimeType timeType,
                                       QTimeZone::NameType nameType,
                                       const QString &localeCode)
{
    int32_t size = 50;
    QString result(size, Qt::Uninitialized);
    UErrorCode status = U_ZERO_ERROR;

    // size = ucal_getTimeZoneDisplayName(cal, type, locale, result, resultLength, status)
    size = ucal_getTimeZoneDisplayName(ucal,
                                       ucalDisplayNameType(timeType, nameType),
                                       localeCode.toUtf8(),
                                       reinterpret_cast<UChar *>(result.data()),
                                       size,
                                       &status);

    // If overflow, then resize and retry
    if (status == U_BUFFER_OVERFLOW_ERROR) {
        result.resize(size);
        status = U_ZERO_ERROR;
        size = ucal_getTimeZoneDisplayName(ucal,
                                           ucalDisplayNameType(timeType, nameType),
                                           localeCode.toUtf8(),
                                           reinterpret_cast<UChar *>(result.data()),
                                           size,
                                           &status);
    }

    // If successful on first or second go, resize and return
    if (U_SUCCESS(status)) {
        result.resize(size);
        return result;
    }

    return QString();
}

// Qt wrapper around ucal_get() for offsets
static bool ucalOffsetsAtTime(UCalendar *m_ucal, qint64 atMSecsSinceEpoch,
                              int *utcOffset, int *dstOffset)
{
    *utcOffset = 0;
    *dstOffset = 0;

    // Clone the ucal so we don't change the shared object
    UErrorCode status = U_ZERO_ERROR;
    UCalendar *ucal = ucal_clone(m_ucal, &status);
    if (!U_SUCCESS(status))
        return false;

    // Set the date to find the offset for
    status = U_ZERO_ERROR;
    ucal_setMillis(ucal, atMSecsSinceEpoch, &status);

    int32_t utc = 0;
    if (U_SUCCESS(status)) {
        status = U_ZERO_ERROR;
        // Returns msecs
        utc = ucal_get(ucal, UCAL_ZONE_OFFSET, &status) / 1000;
    }

    int32_t dst = 0;
    if (U_SUCCESS(status)) {
        status = U_ZERO_ERROR;
        // Returns msecs
        dst = ucal_get(ucal, UCAL_DST_OFFSET, &status) / 1000;
    }

    ucal_close(ucal);
    if (U_SUCCESS(status)) {
        *utcOffset = utc;
        *dstOffset = dst;
        return true;
    }
    return false;
}

// ICU Draft api in v50, should be stable in ICU v51. Available in C++ api from ICU v3.8
#if U_ICU_VERSION_MAJOR_NUM == 50
// Qt wrapper around qt_ucal_getTimeZoneTransitionDate & ucal_get
static QTimeZonePrivate::Data ucalTimeZoneTransition(UCalendar *m_ucal,
                                                     UTimeZoneTransitionType type,
                                                     qint64 atMSecsSinceEpoch)
{
    QTimeZonePrivate::Data tran = QTimeZonePrivate::invalidData();

    // Clone the ucal so we don't change the shared object
    UErrorCode status = U_ZERO_ERROR;
    UCalendar *ucal = ucal_clone(m_ucal, &status);
    if (!U_SUCCESS(status))
        return tran;

    // Set the date to find the transition for
    status = U_ZERO_ERROR;
    ucal_setMillis(ucal, atMSecsSinceEpoch, &status);

    // Find the transition time
    UDate tranMSecs = 0;
    status = U_ZERO_ERROR;
    bool ok = ucal_getTimeZoneTransitionDate(ucal, type, &tranMSecs, &status);

    // Set the transition time to find the offsets for
    if (U_SUCCESS(status) && ok) {
        status = U_ZERO_ERROR;
        ucal_setMillis(ucal, tranMSecs, &status);
    }

    int32_t utc = 0;
    if (U_SUCCESS(status) && ok) {
        status = U_ZERO_ERROR;
        utc = ucal_get(ucal, UCAL_ZONE_OFFSET, &status) / 1000;
    }

    int32_t dst = 0;
    if (U_SUCCESS(status) && ok) {
        status = U_ZERO_ERROR;
        dst = ucal_get(ucal, UCAL_DST_OFFSET, &status) / 1000;
    }

    ucal_close(ucal);
    if (!U_SUCCESS(status) || !ok)
        return tran;
    tran.atMSecsSinceEpoch = tranMSecs;
    tran.offsetFromUtc = utc + dst;
    tran.standardTimeOffset = utc;
    tran.daylightTimeOffset = dst;
    // TODO No ICU API, use short name instead
    if (dst == 0)
        tran.abbreviation = ucalTimeZoneDisplayName(m_ucal, QTimeZone::StandardTime,
                                                    QTimeZone::ShortName, QLocale().name());
    else
        tran.abbreviation = ucalTimeZoneDisplayName(m_ucal, QTimeZone::DaylightTime,
                                                    QTimeZone::ShortName, QLocale().name());
    return tran;
}
#endif // U_ICU_VERSION_SHORT

// Convert a uenum to a QList<QByteArray>
static QSet<QByteArray> uenumToIdSet(UEnumeration *uenum)
{
    QSet<QByteArray> set;
    int32_t size = 0;
    UErrorCode status = U_ZERO_ERROR;
    // TODO Perhaps use uenum_unext instead?
    QByteArray result = uenum_next(uenum, &size, &status);
    while (U_SUCCESS(status) && !result.isEmpty()) {
        set << result;
        status = U_ZERO_ERROR;
        result = uenum_next(uenum, &size, &status);
    }
    return set;
}

// Qt wrapper around ucal_getDSTSavings()
static int ucalDaylightOffset(const QByteArray &id)
{
    UErrorCode status = U_ZERO_ERROR;
    const int32_t dstMSecs = ucal_getDSTSavings(reinterpret_cast<const UChar *>(id.data()), &status);
    if (U_SUCCESS(status))
        return (dstMSecs / 1000);
    else
        return 0;
}

// Create the system default time zone
QIcuTimeZonePrivate::QIcuTimeZonePrivate()
    : m_ucal(0)
{
    // TODO No ICU C API to obtain sysem tz, assume default hasn't been changed
    init(ucalDefaultTimeZoneId());
}

// Create a named time zone
QIcuTimeZonePrivate::QIcuTimeZonePrivate(const QByteArray &ianaId)
    : m_ucal(0)
{
    // Need to check validity here as ICu will create a GMT tz if name is invalid
    if (availableTimeZoneIds().contains(ianaId))
        init(ianaId);
}

QIcuTimeZonePrivate::QIcuTimeZonePrivate(const QIcuTimeZonePrivate &other)
    : QTimeZonePrivate(other), m_ucal(0)
{
    // Clone the ucal so we don't close the shared object
    UErrorCode status = U_ZERO_ERROR;
    m_ucal = ucal_clone(other.m_ucal, &status);
    if (!U_SUCCESS(status)) {
        m_id.clear();
        m_ucal = 0;
    }
}

QIcuTimeZonePrivate::~QIcuTimeZonePrivate()
{
    ucal_close(m_ucal);
}

QTimeZonePrivate *QIcuTimeZonePrivate::clone()
{
    return new QIcuTimeZonePrivate(*this);
}

void QIcuTimeZonePrivate::init(const QByteArray &ianaId)
{
    m_id = ianaId;

    const QString id = QString::fromUtf8(m_id);
    UErrorCode status = U_ZERO_ERROR;
    //TODO Use UCAL_GREGORIAN for now to match QLocale, change to UCAL_DEFAULT once full ICU support
    m_ucal = ucal_open(reinterpret_cast<const UChar *>(id.data()), id.size(),
                       QLocale().name().toUtf8(), UCAL_GREGORIAN, &status);

    if (!U_SUCCESS(status)) {
        m_id.clear();
        m_ucal = 0;
    }
}

QString QIcuTimeZonePrivate::displayName(QTimeZone::TimeType timeType,
                                         QTimeZone::NameType nameType,
                                         const QLocale &locale) const
{
    // Return standard offset format name as ICU C api doesn't support it yet
    if (nameType == QTimeZone::OffsetName) {
        const Data nowData = data(QDateTime::currentDateTimeUtc().toMSecsSinceEpoch());
        // We can't use transitions reliably to find out right dst offset
        // Instead use dst offset api to try get it if needed
        if (timeType == QTimeZone::DaylightTime)
            return isoOffsetFormat(nowData.standardTimeOffset + ucalDaylightOffset(m_id));
        else
            return isoOffsetFormat(nowData.standardTimeOffset);
    }
    return ucalTimeZoneDisplayName(m_ucal, timeType, nameType, locale.name());
}

QString QIcuTimeZonePrivate::abbreviation(qint64 atMSecsSinceEpoch) const
{
    // TODO No ICU API, use short name instead
    if (isDaylightTime(atMSecsSinceEpoch))
        return displayName(QTimeZone::DaylightTime, QTimeZone::ShortName, QString());
    else
        return displayName(QTimeZone::StandardTime, QTimeZone::ShortName, QString());
}

int QIcuTimeZonePrivate::offsetFromUtc(qint64 atMSecsSinceEpoch) const
{
    int stdOffset = 0;
    int dstOffset = 0;
    ucalOffsetsAtTime(m_ucal, atMSecsSinceEpoch, &stdOffset, & dstOffset);
    return stdOffset + dstOffset;
}

int QIcuTimeZonePrivate::standardTimeOffset(qint64 atMSecsSinceEpoch) const
{
    int stdOffset = 0;
    int dstOffset = 0;
    ucalOffsetsAtTime(m_ucal, atMSecsSinceEpoch, &stdOffset, & dstOffset);
    return stdOffset;
}

int QIcuTimeZonePrivate::daylightTimeOffset(qint64 atMSecsSinceEpoch) const
{
    int stdOffset = 0;
    int dstOffset = 0;
    ucalOffsetsAtTime(m_ucal, atMSecsSinceEpoch, &stdOffset, & dstOffset);
    return dstOffset;
}

bool QIcuTimeZonePrivate::hasDaylightTime() const
{
    // TODO No direct ICU C api, work-around below not reliable?  Find a better way?
    return (ucalDaylightOffset(m_id) != 0);
}

bool QIcuTimeZonePrivate::isDaylightTime(qint64 atMSecsSinceEpoch) const
{
    // Clone the ucal so we don't change the shared object
    UErrorCode status = U_ZERO_ERROR;
    UCalendar *ucal = ucal_clone(m_ucal, &status);
    if (!U_SUCCESS(status))
        return false;

    // Set the date to find the offset for
    status = U_ZERO_ERROR;
    ucal_setMillis(ucal, atMSecsSinceEpoch, &status);

    bool result = false;
    if (U_SUCCESS(status)) {
        status = U_ZERO_ERROR;
        result = ucal_inDaylightTime(ucal, &status);
    }

    ucal_close(ucal);
    return result;
}

QTimeZonePrivate::Data QIcuTimeZonePrivate::data(qint64 forMSecsSinceEpoch) const
{
    // Available in ICU C++ api, and draft C api in v50
    // TODO When v51 released see if api is stable
    QTimeZonePrivate::Data data = invalidData();
#if U_ICU_VERSION_MAJOR_NUM == 50
    data = ucalTimeZoneTransition(m_ucal, UCAL_TZ_TRANSITION_PREVIOUS_INCLUSIVE,
                                  forMSecsSinceEpoch);
#else
    ucalOffsetsAtTime(m_ucal, forMSecsSinceEpoch, &data.standardTimeOffset,
                      &data.daylightTimeOffset);
    data.offsetFromUtc = data.standardTimeOffset + data.daylightTimeOffset;
    data.abbreviation = abbreviation(forMSecsSinceEpoch);
#endif // U_ICU_VERSION_MAJOR_NUM == 50
    data.atMSecsSinceEpoch = forMSecsSinceEpoch;
    return data;
}

bool QIcuTimeZonePrivate::hasTransitions() const
{
    // Available in ICU C++ api, and draft C api in v50
    // TODO When v51 released see if api is stable
#if U_ICU_VERSION_MAJOR_NUM == 50
    return true;
#else
    return false;
#endif // U_ICU_VERSION_MAJOR_NUM == 50
}

QTimeZonePrivate::Data QIcuTimeZonePrivate::nextTransition(qint64 afterMSecsSinceEpoch) const
{
    // Available in ICU C++ api, and draft C api in v50
    // TODO When v51 released see if api is stable
#if U_ICU_VERSION_MAJOR_NUM == 50
    return ucalTimeZoneTransition(m_ucal, UCAL_TZ_TRANSITION_NEXT, afterMSecsSinceEpoch);
#else
    Q_UNUSED(afterMSecsSinceEpoch)
    return invalidData();
#endif // U_ICU_VERSION_MAJOR_NUM == 50
}

QTimeZonePrivate::Data QIcuTimeZonePrivate::previousTransition(qint64 beforeMSecsSinceEpoch) const
{
    // Available in ICU C++ api, and draft C api in v50
    // TODO When v51 released see if api is stable
#if U_ICU_VERSION_MAJOR_NUM == 50
    return ucalTimeZoneTransition(m_ucal, UCAL_TZ_TRANSITION_PREVIOUS, beforeMSecsSinceEpoch);
#else
    Q_UNUSED(beforeMSecsSinceEpoch)
    return invalidData();
#endif // U_ICU_VERSION_MAJOR_NUM == 50
}

QByteArray QIcuTimeZonePrivate::systemTimeZoneId() const
{
    // No ICU C API to obtain sysem tz
    // TODO Assume default hasn't been changed and is the latests system
    return ucalDefaultTimeZoneId();
}

QSet<QByteArray> QIcuTimeZonePrivate::availableTimeZoneIds() const
{
    UErrorCode status = U_ZERO_ERROR;
    UEnumeration *uenum = ucal_openTimeZones(&status);
    QSet<QByteArray> set;
    if (U_SUCCESS(status))
        set = uenumToIdSet(uenum);
    uenum_close(uenum);
    return set;
}

QSet<QByteArray> QIcuTimeZonePrivate::availableTimeZoneIds(QLocale::Country country) const
{
    QByteArray regionCode = QLocalePrivate::countryToCode(country).toUtf8();
    UErrorCode status = U_ZERO_ERROR;
    UEnumeration *uenum = ucal_openCountryTimeZones(regionCode, &status);
    QSet<QByteArray> set;
    if (U_SUCCESS(status))
        set = uenumToIdSet(uenum);
    uenum_close(uenum);
    return set;
}

QSet<QByteArray> QIcuTimeZonePrivate::availableTimeZoneIds(int offsetFromUtc) const
{
// TODO Available directly in C++ api but not C api, from 4.8 onwards new filter method works
#if U_ICU_VERSION_MAJOR_NUM >= 49 || (U_ICU_VERSION_MAJOR_NUM == 4 && U_ICU_VERSION_MINOR_NUM == 8)
    UErrorCode status = U_ZERO_ERROR;
    UEnumeration *uenum = ucal_openTimeZoneIDEnumeration(UCAL_ZONE_TYPE_ANY, 0,
                                                         &offsetFromUtc, &status);
    QSet<QByteArray> set;
    if (U_SUCCESS(status))
        set = uenumToIdSet(uenum);
    uenum_close(uenum);
    return set;
#else
    return QTimeZonePrivate::availableTimeZoneIds(offsetFromUtc);
#endif
}

QT_END_NAMESPACE