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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 "double-conversion-string-to-double.h"
#include "measunit_impl.h"
#include "uassert.h"
#include "unicode/errorcode.h"
#include "unicode/localpointer.h"
#include "unicode/stringpiece.h"
#include "units_converter.h"
#include <algorithm>
#include <cmath>
#include <stdlib.h>
#include <utility>
U_NAMESPACE_BEGIN
namespace units {
void U_I18N_API Factor::multiplyBy(const Factor &rhs) {
factorNum *= rhs.factorNum;
factorDen *= rhs.factorDen;
for (int i = 0; i < CONSTANTS_COUNT; i++) {
constantExponents[i] += rhs.constantExponents[i];
}
// NOTE
// We need the offset when the source and the target are simple units. e.g. the source is
// celsius and the target is Fahrenheit. Therefore, we just keep the value using `std::max`.
offset = std::max(rhs.offset, offset);
}
void U_I18N_API Factor::divideBy(const Factor &rhs) {
factorNum *= rhs.factorDen;
factorDen *= rhs.factorNum;
for (int i = 0; i < CONSTANTS_COUNT; i++) {
constantExponents[i] -= rhs.constantExponents[i];
}
// NOTE
// We need the offset when the source and the target are simple units. e.g. the source is
// celsius and the target is Fahrenheit. Therefore, we just keep the value using `std::max`.
offset = std::max(rhs.offset, offset);
}
void U_I18N_API Factor::power(int32_t power) {
// multiply all the constant by the power.
for (int i = 0; i < CONSTANTS_COUNT; i++) {
constantExponents[i] *= power;
}
bool shouldFlip = power < 0; // This means that after applying the absolute power, we should flip
// the Numerator and Denominator.
factorNum = std::pow(factorNum, std::abs(power));
factorDen = std::pow(factorDen, std::abs(power));
if (shouldFlip) {
// Flip Numerator and Denominator.
std::swap(factorNum, factorDen);
}
}
void U_I18N_API Factor::applyPrefix(UMeasurePrefix unitPrefix) {
if (unitPrefix == UMeasurePrefix::UMEASURE_PREFIX_ONE) {
// No need to do anything
return;
}
int32_t prefixPower = umeas_getPrefixPower(unitPrefix);
double prefixFactor = std::pow((double)umeas_getPrefixBase(unitPrefix), (double)std::abs(prefixPower));
if (prefixPower >= 0) {
factorNum *= prefixFactor;
} else {
factorDen *= prefixFactor;
}
}
void U_I18N_API Factor::substituteConstants() {
for (int i = 0; i < CONSTANTS_COUNT; i++) {
if (this->constantExponents[i] == 0) {
continue;
}
auto absPower = std::abs(this->constantExponents[i]);
Signum powerSig = this->constantExponents[i] < 0 ? Signum::NEGATIVE : Signum::POSITIVE;
double absConstantValue = std::pow(constantsValues[i], absPower);
if (powerSig == Signum::NEGATIVE) {
this->factorDen *= absConstantValue;
} else {
this->factorNum *= absConstantValue;
}
this->constantExponents[i] = 0;
}
}
namespace {
/* Helpers */
using icu::double_conversion::StringToDoubleConverter;
// TODO: Make this a shared-utility function.
// Returns `double` from a scientific number(i.e. "1", "2.01" or "3.09E+4")
double strToDouble(StringPiece strNum, UErrorCode &status) {
// We are processing well-formed input, so we don't need any special options to
// StringToDoubleConverter.
StringToDoubleConverter converter(0, 0, 0, "", "");
int32_t count;
double result = converter.StringToDouble(strNum.data(), strNum.length(), &count);
if (count != strNum.length()) {
status = U_INVALID_FORMAT_ERROR;
}
return result;
}
// Returns `double` from a scientific number that could has a division sign (i.e. "1", "2.01", "3.09E+4"
// or "2E+2/3")
double strHasDivideSignToDouble(StringPiece strWithDivide, UErrorCode &status) {
int divisionSignInd = -1;
for (int i = 0, n = strWithDivide.length(); i < n; ++i) {
if (strWithDivide.data()[i] == '/') {
divisionSignInd = i;
break;
}
}
if (divisionSignInd >= 0) {
return strToDouble(strWithDivide.substr(0, divisionSignInd), status) /
strToDouble(strWithDivide.substr(divisionSignInd + 1), status);
}
return strToDouble(strWithDivide, status);
}
/*
Adds single factor to a `Factor` object. Single factor means "23^2", "23.3333", "ft2m^3" ...etc.
However, complex factor are not included, such as "ft2m^3*200/3"
*/
void addFactorElement(Factor &factor, StringPiece elementStr, Signum signum, UErrorCode &status) {
StringPiece baseStr;
StringPiece powerStr;
int32_t power =
1; // In case the power is not written, then, the power is equal 1 ==> `ft2m^1` == `ft2m`
// Search for the power part
int32_t powerInd = -1;
for (int32_t i = 0, n = elementStr.length(); i < n; ++i) {
if (elementStr.data()[i] == '^') {
powerInd = i;
break;
}
}
if (powerInd > -1) {
// There is power
baseStr = elementStr.substr(0, powerInd);
powerStr = elementStr.substr(powerInd + 1);
power = static_cast<int32_t>(strToDouble(powerStr, status));
} else {
baseStr = elementStr;
}
addSingleFactorConstant(baseStr, power, signum, factor, status);
}
/*
* Extracts `Factor` from a complete string factor. e.g. "ft2m^3*1007/cup2m3*3"
*/
Factor extractFactorConversions(StringPiece stringFactor, UErrorCode &status) {
Factor result;
Signum signum = Signum::POSITIVE;
auto factorData = stringFactor.data();
for (int32_t i = 0, start = 0, n = stringFactor.length(); i < n; i++) {
if (factorData[i] == '*' || factorData[i] == '/') {
StringPiece factorElement = stringFactor.substr(start, i - start);
addFactorElement(result, factorElement, signum, status);
start = i + 1; // Set `start` to point to the start of the new element.
} else if (i == n - 1) {
// Last element
addFactorElement(result, stringFactor.substr(start, i + 1), signum, status);
}
if (factorData[i] == '/') {
signum = Signum::NEGATIVE; // Change the signum because we reached the Denominator.
}
}
return result;
}
// Load factor for a single source
Factor loadSingleFactor(StringPiece source, const ConversionRates &ratesInfo, UErrorCode &status) {
const auto conversionUnit = ratesInfo.extractConversionInfo(source, status);
if (U_FAILURE(status)) return Factor();
if (conversionUnit == nullptr) {
status = U_INTERNAL_PROGRAM_ERROR;
return Factor();
}
Factor result = extractFactorConversions(conversionUnit->factor.toStringPiece(), status);
result.offset = strHasDivideSignToDouble(conversionUnit->offset.toStringPiece(), status);
return result;
}
// Load Factor of a compound source unit.
// In ICU4J, this is a pair of ConversionRates.getFactorToBase() functions.
Factor loadCompoundFactor(const MeasureUnitImpl &source, const ConversionRates &ratesInfo,
UErrorCode &status) {
Factor result;
for (int32_t i = 0, n = source.singleUnits.length(); i < n; i++) {
SingleUnitImpl singleUnit = *source.singleUnits[i];
Factor singleFactor = loadSingleFactor(singleUnit.getSimpleUnitID(), ratesInfo, status);
if (U_FAILURE(status)) return result;
// Prefix before power, because:
// - square-kilometer to square-meter: (1000)^2
// - square-kilometer to square-foot (approximate): (3.28*1000)^2
singleFactor.applyPrefix(singleUnit.unitPrefix);
// Apply the power of the `dimensionality`
singleFactor.power(singleUnit.dimensionality);
result.multiplyBy(singleFactor);
}
return result;
}
/**
* Checks if the source unit and the target unit are simple. For example celsius or fahrenheit. But not
* square-celsius or square-fahrenheit.
*
* NOTE:
* Empty unit means simple unit.
*
* In ICU4J, this is ConversionRates.checkSimpleUnit().
*/
UBool checkSimpleUnit(const MeasureUnitImpl &unit, UErrorCode &status) {
if (U_FAILURE(status)) return false;
if (unit.complexity != UMEASURE_UNIT_SINGLE) {
return false;
}
if (unit.singleUnits.length() == 0) {
// Empty units means simple unit.
return true;
}
auto singleUnit = *(unit.singleUnits[0]);
if (singleUnit.dimensionality != 1 || singleUnit.unitPrefix != UMEASURE_PREFIX_ONE) {
return false;
}
return true;
}
/**
* Extract conversion rate from `source` to `target`
*/
// In ICU4J, this function is partially inlined in the UnitsConverter constructor.
void loadConversionRate(ConversionRate &conversionRate, const MeasureUnitImpl &source,
const MeasureUnitImpl &target, Convertibility unitsState,
const ConversionRates &ratesInfo, UErrorCode &status) {
// Represents the conversion factor from the source to the target.
Factor finalFactor;
// Represents the conversion factor from the source to the base unit that specified in the conversion
// data which is considered as the root of the source and the target.
Factor sourceToBase = loadCompoundFactor(source, ratesInfo, status);
Factor targetToBase = loadCompoundFactor(target, ratesInfo, status);
// Merger Factors
finalFactor.multiplyBy(sourceToBase);
if (unitsState == Convertibility::CONVERTIBLE) {
finalFactor.divideBy(targetToBase);
} else if (unitsState == Convertibility::RECIPROCAL) {
finalFactor.multiplyBy(targetToBase);
} else {
status = UErrorCode::U_ARGUMENT_TYPE_MISMATCH;
return;
}
finalFactor.substituteConstants();
conversionRate.factorNum = finalFactor.factorNum;
conversionRate.factorDen = finalFactor.factorDen;
// This code corresponds to ICU4J's ConversionRates.getOffset().
// In case of simple units (such as: celsius or fahrenheit), offsets are considered.
if (checkSimpleUnit(source, status) && checkSimpleUnit(target, status)) {
conversionRate.sourceOffset =
sourceToBase.offset * sourceToBase.factorDen / sourceToBase.factorNum;
conversionRate.targetOffset =
targetToBase.offset * targetToBase.factorDen / targetToBase.factorNum;
}
// TODO(icu-units#127): should we consider failure if there's an offset for
// a not-simple-unit? What about kilokelvin / kilocelsius?
conversionRate.reciprocal = unitsState == Convertibility::RECIPROCAL;
}
struct UnitIndexAndDimension : UMemory {
int32_t index = 0;
int32_t dimensionality = 0;
UnitIndexAndDimension(const SingleUnitImpl &singleUnit, int32_t multiplier) {
index = singleUnit.index;
dimensionality = singleUnit.dimensionality * multiplier;
}
};
void mergeSingleUnitWithDimension(MaybeStackVector<UnitIndexAndDimension> &unitIndicesWithDimension,
const SingleUnitImpl &shouldBeMerged, int32_t multiplier) {
for (int32_t i = 0; i < unitIndicesWithDimension.length(); i++) {
auto &unitWithIndex = *unitIndicesWithDimension[i];
if (unitWithIndex.index == shouldBeMerged.index) {
unitWithIndex.dimensionality += shouldBeMerged.dimensionality * multiplier;
return;
}
}
unitIndicesWithDimension.emplaceBack(shouldBeMerged, multiplier);
}
void mergeUnitsAndDimensions(MaybeStackVector<UnitIndexAndDimension> &unitIndicesWithDimension,
const MeasureUnitImpl &shouldBeMerged, int32_t multiplier) {
for (int32_t unit_i = 0; unit_i < shouldBeMerged.singleUnits.length(); unit_i++) {
auto singleUnit = *shouldBeMerged.singleUnits[unit_i];
mergeSingleUnitWithDimension(unitIndicesWithDimension, singleUnit, multiplier);
}
}
UBool checkAllDimensionsAreZeros(const MaybeStackVector<UnitIndexAndDimension> &dimensionVector) {
for (int32_t i = 0; i < dimensionVector.length(); i++) {
if (dimensionVector[i]->dimensionality != 0) {
return false;
}
}
return true;
}
} // namespace
// Conceptually, this modifies factor: factor *= baseStr^(signum*power).
//
// baseStr must be a known constant or a value that strToDouble() is able to
// parse.
void U_I18N_API addSingleFactorConstant(StringPiece baseStr, int32_t power, Signum signum,
Factor &factor, UErrorCode &status) {
if (baseStr == "ft_to_m") {
factor.constantExponents[CONSTANT_FT2M] += power * signum;
} else if (baseStr == "ft2_to_m2") {
factor.constantExponents[CONSTANT_FT2M] += 2 * power * signum;
} else if (baseStr == "ft3_to_m3") {
factor.constantExponents[CONSTANT_FT2M] += 3 * power * signum;
} else if (baseStr == "in3_to_m3") {
factor.constantExponents[CONSTANT_FT2M] += 3 * power * signum;
factor.factorDen *= 12 * 12 * 12;
} else if (baseStr == "gal_to_m3") {
factor.factorNum *= 231;
factor.constantExponents[CONSTANT_FT2M] += 3 * power * signum;
factor.factorDen *= 12 * 12 * 12;
} else if (baseStr == "gal_imp_to_m3") {
factor.constantExponents[CONSTANT_GAL_IMP2M3] += power * signum;
} else if (baseStr == "G") {
factor.constantExponents[CONSTANT_G] += power * signum;
} else if (baseStr == "gravity") {
factor.constantExponents[CONSTANT_GRAVITY] += power * signum;
} else if (baseStr == "lb_to_kg") {
factor.constantExponents[CONSTANT_LB2KG] += power * signum;
} else if (baseStr == "glucose_molar_mass") {
factor.constantExponents[CONSTANT_GLUCOSE_MOLAR_MASS] += power * signum;
} else if (baseStr == "item_per_mole") {
factor.constantExponents[CONSTANT_ITEM_PER_MOLE] += power * signum;
} else if (baseStr == "PI") {
factor.constantExponents[CONSTANT_PI] += power * signum;
} else {
if (signum == Signum::NEGATIVE) {
factor.factorDen *= std::pow(strToDouble(baseStr, status), power);
} else {
factor.factorNum *= std::pow(strToDouble(baseStr, status), power);
}
}
}
/**
* Extracts the compound base unit of a compound unit (`source`). For example, if the source unit is
* `square-mile-per-hour`, the compound base unit will be `square-meter-per-second`
*/
MeasureUnitImpl U_I18N_API extractCompoundBaseUnit(const MeasureUnitImpl &source,
const ConversionRates &conversionRates,
UErrorCode &status) {
MeasureUnitImpl result;
if (U_FAILURE(status)) return result;
const auto &singleUnits = source.singleUnits;
for (int i = 0, count = singleUnits.length(); i < count; ++i) {
const auto &singleUnit = *singleUnits[i];
// Extract `ConversionRateInfo` using the absolute unit. For example: in case of `square-meter`,
// we will use `meter`
const auto rateInfo =
conversionRates.extractConversionInfo(singleUnit.getSimpleUnitID(), status);
if (U_FAILURE(status)) {
return result;
}
if (rateInfo == nullptr) {
status = U_INTERNAL_PROGRAM_ERROR;
return result;
}
// Multiply the power of the singleUnit by the power of the baseUnit. For example, square-hectare
// must be pow4-meter. (NOTE: hectare --> square-meter)
auto baseUnits =
MeasureUnitImpl::forIdentifier(rateInfo->baseUnit.toStringPiece(), status).singleUnits;
for (int32_t i = 0, baseUnitsCount = baseUnits.length(); i < baseUnitsCount; i++) {
baseUnits[i]->dimensionality *= singleUnit.dimensionality;
// TODO: Deal with SI-prefix
result.appendSingleUnit(*baseUnits[i], status);
if (U_FAILURE(status)) {
return result;
}
}
}
return result;
}
/**
* Determine the convertibility between `source` and `target`.
* For example:
* `meter` and `foot` are `CONVERTIBLE`.
* `meter-per-second` and `second-per-meter` are `RECIPROCAL`.
* `meter` and `pound` are `UNCONVERTIBLE`.
*
* NOTE:
* Only works with SINGLE and COMPOUND units. If one of the units is a
* MIXED unit, an error will occur. For more information, see UMeasureUnitComplexity.
*/
Convertibility U_I18N_API extractConvertibility(const MeasureUnitImpl &source,
const MeasureUnitImpl &target,
const ConversionRates &conversionRates,
UErrorCode &status) {
if (source.complexity == UMeasureUnitComplexity::UMEASURE_UNIT_MIXED ||
target.complexity == UMeasureUnitComplexity::UMEASURE_UNIT_MIXED) {
status = U_INTERNAL_PROGRAM_ERROR;
return UNCONVERTIBLE;
}
MeasureUnitImpl sourceBaseUnit = extractCompoundBaseUnit(source, conversionRates, status);
MeasureUnitImpl targetBaseUnit = extractCompoundBaseUnit(target, conversionRates, status);
if (U_FAILURE(status)) return UNCONVERTIBLE;
MaybeStackVector<UnitIndexAndDimension> convertible;
MaybeStackVector<UnitIndexAndDimension> reciprocal;
mergeUnitsAndDimensions(convertible, sourceBaseUnit, 1);
mergeUnitsAndDimensions(reciprocal, sourceBaseUnit, 1);
mergeUnitsAndDimensions(convertible, targetBaseUnit, -1);
mergeUnitsAndDimensions(reciprocal, targetBaseUnit, 1);
if (checkAllDimensionsAreZeros(convertible)) {
return CONVERTIBLE;
}
if (checkAllDimensionsAreZeros(reciprocal)) {
return RECIPROCAL;
}
return UNCONVERTIBLE;
}
UnitsConverter::UnitsConverter(const MeasureUnitImpl &source, const MeasureUnitImpl &target,
const ConversionRates &ratesInfo, UErrorCode &status)
: conversionRate_(source.copy(status), target.copy(status)) {
this->init(ratesInfo, status);
}
UnitsConverter::UnitsConverter(StringPiece sourceIdentifier, StringPiece targetIdentifier,
UErrorCode &status)
: conversionRate_(MeasureUnitImpl::forIdentifier(sourceIdentifier, status),
MeasureUnitImpl::forIdentifier(targetIdentifier, status)) {
if (U_FAILURE(status)) {
return;
}
ConversionRates ratesInfo(status);
this->init(ratesInfo, status);
}
void UnitsConverter::init(const ConversionRates &ratesInfo, UErrorCode &status) {
if (U_FAILURE(status)) {
return;
}
if (this->conversionRate_.source.complexity == UMeasureUnitComplexity::UMEASURE_UNIT_MIXED ||
this->conversionRate_.target.complexity == UMeasureUnitComplexity::UMEASURE_UNIT_MIXED) {
status = U_INTERNAL_PROGRAM_ERROR;
return;
}
Convertibility unitsState = extractConvertibility(this->conversionRate_.source,
this->conversionRate_.target, ratesInfo, status);
if (U_FAILURE(status)) return;
if (unitsState == Convertibility::UNCONVERTIBLE) {
status = U_INTERNAL_PROGRAM_ERROR;
return;
}
loadConversionRate(conversionRate_, conversionRate_.source, conversionRate_.target, unitsState,
ratesInfo, status);
}
int32_t UnitsConverter::compareTwoUnits(const MeasureUnitImpl &firstUnit,
const MeasureUnitImpl &secondUnit,
const ConversionRates &ratesInfo, UErrorCode &status) {
if (U_FAILURE(status)) {
return 0;
}
if (firstUnit.complexity == UMeasureUnitComplexity::UMEASURE_UNIT_MIXED ||
secondUnit.complexity == UMeasureUnitComplexity::UMEASURE_UNIT_MIXED) {
status = U_INTERNAL_PROGRAM_ERROR;
return 0;
}
Convertibility unitsState = extractConvertibility(firstUnit, secondUnit, ratesInfo, status);
if (U_FAILURE(status)) {
return 0;
}
if (unitsState == Convertibility::UNCONVERTIBLE || unitsState == Convertibility::RECIPROCAL) {
status = U_INTERNAL_PROGRAM_ERROR;
return 0;
}
// Represents the conversion factor from the firstUnit to the base
// unit that specified in the conversion data which is considered as
// the root of the firstUnit and the secondUnit.
Factor firstUnitToBase = loadCompoundFactor(firstUnit, ratesInfo, status);
Factor secondUnitToBase = loadCompoundFactor(secondUnit, ratesInfo, status);
firstUnitToBase.substituteConstants();
secondUnitToBase.substituteConstants();
double firstUnitToBaseConversionRate = firstUnitToBase.factorNum / firstUnitToBase.factorDen;
double secondUnitToBaseConversionRate = secondUnitToBase.factorNum / secondUnitToBase.factorDen;
double diff = firstUnitToBaseConversionRate - secondUnitToBaseConversionRate;
if (diff > 0) {
return 1;
}
if (diff < 0) {
return -1;
}
return 0;
}
double UnitsConverter::convert(double inputValue) const {
double result =
inputValue + conversionRate_.sourceOffset; // Reset the input to the target zero index.
// Convert the quantity to from the source scale to the target scale.
result *= conversionRate_.factorNum / conversionRate_.factorDen;
result -= conversionRate_.targetOffset; // Set the result to its index.
if (conversionRate_.reciprocal) {
if (result == 0) {
// TODO: demonstrate the resulting behaviour in tests... and figure
// out desired behaviour. (Theoretical result should be infinity,
// not 0.)
return 0.0;
}
result = 1.0 / result;
}
return result;
}
double UnitsConverter::convertInverse(double inputValue) const {
double result = inputValue;
if (conversionRate_.reciprocal) {
if (result == 0) {
// TODO: demonstrate the resulting behaviour in tests... and figure
// out desired behaviour. (Theoretical result should be infinity,
// not 0.)
return 0.0;
}
result = 1.0 / result;
}
result += conversionRate_.targetOffset;
result *= conversionRate_.factorDen / conversionRate_.factorNum;
result -= conversionRate_.sourceOffset;
return result;
}
ConversionInfo UnitsConverter::getConversionInfo() const {
ConversionInfo result;
result.conversionRate = conversionRate_.factorNum / conversionRate_.factorDen;
result.offset =
(conversionRate_.sourceOffset * (conversionRate_.factorNum / conversionRate_.factorDen)) -
conversionRate_.targetOffset;
result.reciprocal = conversionRate_.reciprocal;
return result;
}
} // namespace units
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_FORMATTING */