1/*
2 *******************************************************************************
3 * Copyright (C) 2008-2014, Google, International Business Machines Corporation and
4 * others. All Rights Reserved.
5 *******************************************************************************
6 */
7
8#include "unicode/tmunit.h"
9#include "uassert.h"
10
11#if !UCONFIG_NO_FORMATTING
12
13U_NAMESPACE_BEGIN
14
15UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TimeUnit)
16
17
18/*
19 * There are only 7 time units.
20 * So, TimeUnit could be made as singleton
21 * (similar to uniset_props.cpp, or unorm.cpp,
22 * in which a static TimeUnit* array is created, and
23 * the creatInstance() returns a const TimeUnit*).
24 * But the constraint is TimeUnit is a data member of Measure.
25 * But Measure (which is an existing API) does not expect it's "unit" member
26 * as singleton. Meaure takes ownership of the "unit" member.
27 * In its constructor, it does not take a const "unit" pointer.
28 * Also, Measure can clone and destruct the "unit" pointer.
29 * In order to preserve the old behavior and let Measure handle singleton "unit",
30 * 1. a flag need to be added in Measure;
31 * 2. a new constructor which takes const "unit" as parameter need to be added,
32 *    and this new constructor will set the flag on.
33 * 3. clone and destructor need to check upon this flag to distinguish on how
34 *    to handle the "unit".
35 *
36 * Since TimeUnit is such a light weight object, comparing with the heavy weight
37 * format operation, we decided to avoid the above complication.
38 *
39 * So, both TimeUnit and CurrencyUnit (the 2 subclasses of MeasureUnit) are
40 * immutable and non-singleton.
41 *
42 * Currently, TimeUnitAmount and CurrencyAmount are immutable.
43 * If an application needs to create a long list of TimeUnitAmount on the same
44 * time unit but different number, for example,
45 * 1 hour, 2 hour, 3 hour, ................. 10,000 hour,
46 * there might be performance hit because 10,000 TimeUnit object,
47 * although all are the same time unit, will be created in heap and deleted.
48 *
49 * To address this performance issue, if there is any in the future,
50 * we should and need to change TimeUnitAmount and CurrencyAmount to be
51 * immutable by allowing a setter on the number.
52 * Or we need to add 2 parallel mutable classes in order to
53 * preserve the existing API.
54 * Or we can use freezable.
55 */
56TimeUnit* U_EXPORT2
57TimeUnit::createInstance(TimeUnit::UTimeUnitFields timeUnitField,
58                         UErrorCode& status) {
59    if (U_FAILURE(status)) {
60        return NULL;
61    }
62    if (timeUnitField < 0 || timeUnitField >= UTIMEUNIT_FIELD_COUNT) {
63        status = U_ILLEGAL_ARGUMENT_ERROR;
64        return NULL;
65    }
66    return new TimeUnit(timeUnitField);
67}
68
69
70TimeUnit::TimeUnit(TimeUnit::UTimeUnitFields timeUnitField) {
71    fTimeUnitField = timeUnitField;
72    switch (fTimeUnitField) {
73    case UTIMEUNIT_YEAR:
74        initTime("year");
75        break;
76    case UTIMEUNIT_MONTH:
77        initTime("month");
78        break;
79    case UTIMEUNIT_DAY:
80        initTime("day");
81        break;
82    case UTIMEUNIT_WEEK:
83        initTime("week");
84        break;
85    case UTIMEUNIT_HOUR:
86        initTime("hour");
87        break;
88    case UTIMEUNIT_MINUTE:
89        initTime("minute");
90        break;
91    case UTIMEUNIT_SECOND:
92        initTime("second");
93        break;
94    default:
95        U_ASSERT(false);
96        break;
97    }
98}
99
100TimeUnit::TimeUnit(const TimeUnit& other)
101:   MeasureUnit(other), fTimeUnitField(other.fTimeUnitField) {
102}
103
104UObject*
105TimeUnit::clone() const {
106    return new TimeUnit(*this);
107}
108
109TimeUnit&
110TimeUnit::operator=(const TimeUnit& other) {
111    if (this == &other) {
112        return *this;
113    }
114    MeasureUnit::operator=(other);
115    fTimeUnitField = other.fTimeUnitField;
116    return *this;
117}
118
119TimeUnit::UTimeUnitFields
120TimeUnit::getTimeUnitField() const {
121    return fTimeUnitField;
122}
123
124TimeUnit::~TimeUnit() {
125}
126
127
128U_NAMESPACE_END
129
130#endif
131