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// © 2020 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
#include "unicode/utypes.h"
#if !UCONFIG_NO_FORMATTING
#include "charstr.h"
#include "cmemory.h"
#include "cstring.h"
#include "measunit_impl.h"
#include "number_decimalquantity.h"
#include "number_roundingutils.h"
#include "resource.h"
#include "unicode/measure.h"
#include "units_data.h"
#include "units_router.h"
#include <cmath>
U_NAMESPACE_BEGIN
namespace units {
using number::Precision;
using number::impl::parseIncrementOption;
Precision UnitsRouter::parseSkeletonToPrecision(icu::UnicodeString precisionSkeleton,
UErrorCode &status) {
if (U_FAILURE(status)) {
// As a member of UsagePrefsHandler, which is a friend of Precision, we
// get access to the default constructor.
return {};
}
constexpr int32_t kSkelPrefixLen = 20;
if (!precisionSkeleton.startsWith(UNICODE_STRING_SIMPLE("precision-increment/"))) {
status = U_INVALID_FORMAT_ERROR;
return {};
}
U_ASSERT(precisionSkeleton[kSkelPrefixLen - 1] == u'/');
StringSegment segment(precisionSkeleton, false);
segment.adjustOffset(kSkelPrefixLen);
Precision result;
parseIncrementOption(segment, result, status);
return result;
}
UnitsRouter::UnitsRouter(MeasureUnit inputUnit, StringPiece region, StringPiece usage,
UErrorCode &status) {
// TODO: do we want to pass in ConversionRates and UnitPreferences instead
// of loading in each UnitsRouter instance? (Or make global?)
ConversionRates conversionRates(status);
UnitPreferences prefs(status);
MeasureUnitImpl inputUnitImpl = MeasureUnitImpl::forMeasureUnitMaybeCopy(inputUnit, status);
MeasureUnit baseUnit =
(extractCompoundBaseUnit(inputUnitImpl, conversionRates, status)).build(status);
CharString category = getUnitCategory(baseUnit.getIdentifier(), status);
const UnitPreference *const *unitPreferences;
int32_t preferencesCount;
prefs.getPreferencesFor(category.data(), usage, region, unitPreferences, preferencesCount, status);
for (int i = 0; i < preferencesCount; ++i) {
const auto &preference = *unitPreferences[i];
MeasureUnitImpl complexTargetUnitImpl =
MeasureUnitImpl::forIdentifier(preference.unit.data(), status);
if (U_FAILURE(status)) {
return;
}
UnicodeString precision = preference.skeleton;
// For now, we only have "precision-increment" in Units Preferences skeleton.
// Therefore, we check if the skeleton starts with "precision-increment" and force the program to
// fail otherwise.
// NOTE:
// It is allowed to have an empty precision.
if (!precision.isEmpty() && !precision.startsWith(u"precision-increment", 19)) {
status = U_INTERNAL_PROGRAM_ERROR;
return;
}
outputUnits_.emplaceBackAndCheckErrorCode(status,
complexTargetUnitImpl.copy(status).build(status));
converterPreferences_.emplaceBackAndCheckErrorCode(status, inputUnitImpl, complexTargetUnitImpl,
preference.geq, std::move(precision),
conversionRates, status);
if (U_FAILURE(status)) {
return;
}
}
}
RouteResult UnitsRouter::route(double quantity, icu::number::impl::RoundingImpl *rounder, UErrorCode &status) const {
// Find the matching preference
const ConverterPreference *converterPreference = nullptr;
for (int32_t i = 0, n = converterPreferences_.length(); i < n; i++) {
converterPreference = converterPreferences_[i];
if (converterPreference->converter.greaterThanOrEqual(std::abs(quantity) * (1 + DBL_EPSILON),
converterPreference->limit)) {
break;
}
}
U_ASSERT(converterPreference != nullptr);
// Set up the rounder for this preference's precision
if (rounder != nullptr && rounder->fPrecision.isBogus()) {
if (converterPreference->precision.length() > 0) {
rounder->fPrecision = parseSkeletonToPrecision(converterPreference->precision, status);
} else {
// We use the same rounding mode as COMPACT notation: known to be a
// human-friendly rounding mode: integers, but add a decimal digit
// as needed to ensure we have at least 2 significant digits.
rounder->fPrecision = Precision::integer().withMinDigits(2);
}
}
return RouteResult(converterPreference->converter.convert(quantity, rounder, status),
converterPreference->targetUnit.copy(status));
}
const MaybeStackVector<MeasureUnit> *UnitsRouter::getOutputUnits() const {
// TODO: consider pulling this from converterPreferences_ and dropping
// outputUnits_?
return &outputUnits_;
}
} // namespace units
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_FORMATTING */