1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/intl/icu/source/i18n/tmunit.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,117 @@
1.4 +/*
1.5 + *******************************************************************************
1.6 + * Copyright (C) 2008-2012, Google, International Business Machines Corporation and
1.7 + * others. All Rights Reserved.
1.8 + *******************************************************************************
1.9 + */
1.10 +
1.11 +#include "utypeinfo.h" // for 'typeid' to work
1.12 +
1.13 +#include "unicode/tmunit.h"
1.14 +
1.15 +#if !UCONFIG_NO_FORMATTING
1.16 +
1.17 +U_NAMESPACE_BEGIN
1.18 +
1.19 +UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TimeUnit)
1.20 +
1.21 +
1.22 +/*
1.23 + * There are only 7 time units.
1.24 + * So, TimeUnit could be made as singleton
1.25 + * (similar to uniset_props.cpp, or unorm.cpp,
1.26 + * in which a static TimeUnit* array is created, and
1.27 + * the creatInstance() returns a const TimeUnit*).
1.28 + * But the constraint is TimeUnit is a data member of Measure.
1.29 + * But Measure (which is an existing API) does not expect it's "unit" member
1.30 + * as singleton. Meaure takes ownership of the "unit" member.
1.31 + * In its constructor, it does not take a const "unit" pointer.
1.32 + * Also, Measure can clone and destruct the "unit" pointer.
1.33 + * In order to preserve the old behavior and let Measure handle singleton "unit",
1.34 + * 1. a flag need to be added in Measure;
1.35 + * 2. a new constructor which takes const "unit" as parameter need to be added,
1.36 + * and this new constructor will set the flag on.
1.37 + * 3. clone and destructor need to check upon this flag to distinguish on how
1.38 + * to handle the "unit".
1.39 + *
1.40 + * Since TimeUnit is such a light weight object, comparing with the heavy weight
1.41 + * format operation, we decided to avoid the above complication.
1.42 + *
1.43 + * So, both TimeUnit and CurrencyUnit (the 2 subclasses of MeasureUnit) are
1.44 + * immutable and non-singleton.
1.45 + *
1.46 + * Currently, TimeUnitAmount and CurrencyAmount are immutable.
1.47 + * If an application needs to create a long list of TimeUnitAmount on the same
1.48 + * time unit but different number, for example,
1.49 + * 1 hour, 2 hour, 3 hour, ................. 10,000 hour,
1.50 + * there might be performance hit because 10,000 TimeUnit object,
1.51 + * although all are the same time unit, will be created in heap and deleted.
1.52 + *
1.53 + * To address this performance issue, if there is any in the future,
1.54 + * we should and need to change TimeUnitAmount and CurrencyAmount to be
1.55 + * immutable by allowing a setter on the number.
1.56 + * Or we need to add 2 parallel mutable classes in order to
1.57 + * preserve the existing API.
1.58 + * Or we can use freezable.
1.59 + */
1.60 +TimeUnit* U_EXPORT2
1.61 +TimeUnit::createInstance(TimeUnit::UTimeUnitFields timeUnitField,
1.62 + UErrorCode& status) {
1.63 + if (U_FAILURE(status)) {
1.64 + return NULL;
1.65 + }
1.66 + if (timeUnitField < 0 || timeUnitField >= UTIMEUNIT_FIELD_COUNT) {
1.67 + status = U_ILLEGAL_ARGUMENT_ERROR;
1.68 + return NULL;
1.69 + }
1.70 + return new TimeUnit(timeUnitField);
1.71 +}
1.72 +
1.73 +
1.74 +TimeUnit::TimeUnit(TimeUnit::UTimeUnitFields timeUnitField) {
1.75 + fTimeUnitField = timeUnitField;
1.76 +}
1.77 +
1.78 +
1.79 +TimeUnit::TimeUnit(const TimeUnit& other)
1.80 +: MeasureUnit(other) {
1.81 + *this = other;
1.82 +}
1.83 +
1.84 +
1.85 +UObject*
1.86 +TimeUnit::clone() const {
1.87 + return new TimeUnit(*this);
1.88 +}
1.89 +
1.90 +
1.91 +TimeUnit&
1.92 +TimeUnit::operator=(const TimeUnit& other) {
1.93 + if (this == &other) {
1.94 + return *this;
1.95 + }
1.96 + fTimeUnitField = other.fTimeUnitField;
1.97 + return *this;
1.98 +}
1.99 +
1.100 +
1.101 +UBool
1.102 +TimeUnit::operator==(const UObject& other) const {
1.103 + return (typeid(*this) == typeid(other)
1.104 + && fTimeUnitField == ((TimeUnit*)&other)->fTimeUnitField);
1.105 +}
1.106 +
1.107 +
1.108 +TimeUnit::UTimeUnitFields
1.109 +TimeUnit::getTimeUnitField() const {
1.110 + return fTimeUnitField;
1.111 +}
1.112 +
1.113 +
1.114 +TimeUnit::~TimeUnit() {
1.115 +}
1.116 +
1.117 +
1.118 +U_NAMESPACE_END
1.119 +
1.120 +#endif
