1// Copyright (C) 2022 The Qt Company Ltd.
2// Copyright (C) 2016 Intel Corporation.
3// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
4
5#ifndef QDATETIME_P_H
6#define QDATETIME_P_H
7
8//
9// W A R N I N G
10// -------------
11//
12// This file is not part of the Qt API. It exists purely as an
13// implementation detail. This header file may change from version to
14// version without notice, or even be removed.
15//
16// We mean it.
17//
18
19#include <QtCore/private/qglobal_p.h>
20#include "qplatformdefs.h"
21#include "QtCore/qatomic.h"
22#include "QtCore/qdatetime.h"
23#include "QtCore/qshareddata.h"
24#include "QtCore/qtimezone.h"
25
26#if QT_CONFIG(timezone)
27#include "qtimezone.h"
28#endif
29
30#include <chrono>
31
32QT_BEGIN_NAMESPACE
33
34class QDateTimePrivate : public QSharedData
35{
36public:
37 // forward the declarations from QDateTime (this makes them public)
38 typedef QDateTime::ShortData QDateTimeShortData;
39 typedef QDateTime::Data QDateTimeData;
40
41 // Never change or delete this enum, it is required for backwards compatible
42 // serialization of QDateTime before 5.2, so is essentially public API
43 enum Spec {
44 LocalUnknown = -1,
45 LocalStandard = 0,
46 LocalDST = 1,
47 UTC = 2,
48 OffsetFromUTC = 3,
49 TimeZone = 4
50 };
51
52 // Daylight Time Status
53 enum DaylightStatus {
54 UnknownDaylightTime = -1,
55 StandardTime = 0,
56 DaylightTime = 1
57 };
58
59 // Status of date/time
60 enum StatusFlag {
61 ShortData = 0x01,
62
63 ValidDate = 0x02,
64 ValidTime = 0x04,
65 ValidDateTime = 0x08,
66
67 TimeSpecMask = 0x30,
68
69 SetToStandardTime = 0x40,
70 SetToDaylightTime = 0x80,
71 ValidityMask = ValidDate | ValidTime | ValidDateTime,
72 DaylightMask = SetToStandardTime | SetToDaylightTime,
73 };
74 Q_DECLARE_FLAGS(StatusFlags, StatusFlag)
75
76
77 enum TransitionOption {
78 // Handling of a spring-forward (or other gap):
79 GapUseBefore = 2,
80 GapUseAfter = 4,
81 // Handling of a fall-back (or other repeated period):
82 FoldUseBefore = 0x20,
83 FoldUseAfter = 0x40,
84 // Quirk for negative DST:
85 FlipForReverseDst = 0x400,
86
87 GapMask = GapUseBefore | GapUseAfter,
88 FoldMask = FoldUseBefore | FoldUseAfter,
89 };
90 Q_DECLARE_FLAGS(TransitionOptions, TransitionOption)
91
92 enum {
93 TimeSpecShift = 4,
94 };
95
96 struct ZoneState {
97 qint64 when; // ms after zone/local 1970 start; may be revised from the input time.
98 int offset = 0; // seconds
99 DaylightStatus dst = UnknownDaylightTime;
100 // Other fields are set, if possible, even when valid is false due to spring-forward.
101 bool valid = false;
102
103 ZoneState(qint64 local) : when(local) {}
104 ZoneState(qint64 w, int o, DaylightStatus d, bool v = true)
105 : when(w), offset(o), dst(d), valid(v) {}
106 };
107
108 static QDateTime::Data create(QDate toDate, QTime toTime, const QTimeZone &timeZone,
109 QDateTime::TransitionResolution resolve);
110#if QT_CONFIG(timezone)
111 static ZoneState zoneStateAtMillis(const QTimeZone &zone, qint64 millis,
112 TransitionOptions resolve);
113#endif // timezone
114
115 static ZoneState expressUtcAsLocal(qint64 utcMSecs);
116
117 static ZoneState localStateAtMillis(qint64 millis, TransitionOptions resolve);
118 static QString localNameAtMillis(qint64 millis, DaylightStatus dst); // empty if unknown
119
120 StatusFlags m_status = StatusFlag(Qt::LocalTime << TimeSpecShift);
121 qint64 m_msecs = 0;
122 int m_offsetFromUtc = 0;
123 QTimeZone m_timeZone;
124};
125
126Q_DECLARE_OPERATORS_FOR_FLAGS(QDateTimePrivate::StatusFlags)
127Q_DECLARE_OPERATORS_FOR_FLAGS(QDateTimePrivate::TransitionOptions)
128
129namespace QtPrivate {
130namespace DateTimeConstants {
131using namespace std::chrono;
132inline
133constexpr qint64 SECS_PER_MIN = minutes::period::num;
134inline
135constexpr qint64 SECS_PER_HOUR = hours::period::num;
136inline
137constexpr qint64 SECS_PER_DAY = SECS_PER_HOUR * 24; // std::chrono::days is C++20
138
139inline
140constexpr qint64 MINS_PER_HOUR = std::ratio_divide<hours::period, minutes::period>::num;
141
142inline
143constexpr qint64 MSECS_PER_SEC = milliseconds::period::den;
144inline
145constexpr qint64 MSECS_PER_MIN = SECS_PER_MIN * MSECS_PER_SEC;
146inline
147constexpr qint64 MSECS_PER_HOUR = SECS_PER_HOUR * MSECS_PER_SEC;
148inline
149constexpr qint64 MSECS_PER_DAY = SECS_PER_DAY * MSECS_PER_SEC;
150
151inline
152constexpr qint64 JULIAN_DAY_FOR_EPOCH = 2440588; // result of QDate(1970, 1, 1).toJulianDay()
153
154inline
155constexpr qint64 JulianDayMax = Q_INT64_C( 784354017364);
156inline
157constexpr qint64 JulianDayMin = Q_INT64_C(-784350574879);
158}
159}
160
161QT_END_NAMESPACE
162
163#endif // QDATETIME_P_H
164

source code of qtbase/src/corelib/time/qdatetime_p.h