/*
* Copyright (C) 2012 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* Imported from:
* https://chromium.googlesource.com/chromium/src.git/+/master/third_party/WebKit/Source/platform/Decimal.h
* Check UPSTREAM-GIT-SHA for the commit ID of the last update from Blink core.
*/
#ifndef Decimal_h
#define Decimal_h
#include "mozilla/Assertions.h"
#include <stdint.h>
#include "mozilla/Types.h"
#include <string>
#ifndef ASSERT
#define DEFINED_ASSERT_FOR_DECIMAL_H 1
#define ASSERT MOZ_ASSERT
#endif
#define PLATFORM_EXPORT
// To use USING_FAST_MALLOC we'd need:
// https://chromium.googlesource.com/chromium/src.git/+/master/third_party/WebKit/Source/wtf/Allocator.h
// Since we don't allocate Decimal objects, no need.
#define USING_FAST_MALLOC(type) \
void ignore_this_dummy_method() =
delete
#define DISALLOW_NEW() \
private: \
void*
operator new(size_t) =
delete; \
void*
operator new(size_t,
void*) =
delete; \
public:
namespace blink {
namespace DecimalPrivate {
constexpr
int ExponentMax = 1023;
constexpr
int ExponentMin = -1023;
constexpr
int Precision = 18;
static const uint64_t MaxCoefficient = UINT64_C(0xDE0B6B3A763FFFF);
// 999999999999999999 == 18 9's
class SpecialValueHandler;
}
struct DecimalLiteral {
int32_t value;
friend constexpr DecimalLiteral
operator*(int32_t lhs, DecimalLiteral rhs) {
return {lhs * rhs.value};
}
constexpr DecimalLiteral operator-() {
return {-value};
}
};
constexpr DecimalLiteral
operator""_d(
unsigned long long value) {
return {
static_cast<int32_t>(value)};
}
// This class represents decimal base floating point number.
//
// FIXME: Once all C++ compiler support decimal type, we should replace this
// class to compiler supported one. See below URI for current status of decimal
// type for C++: // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1977.html
class PLATFORM_EXPORT Decimal {
USING_FAST_MALLOC(Decimal);
public:
enum Sign {
Positive,
Negative,
};
// You should not use EncodedData other than unit testing.
class EncodedData {
DISALLOW_NEW();
// For accessing FormatClass.
friend class Decimal;
friend class DecimalPrivate::SpecialValueHandler;
public:
constexpr EncodedData(Sign sign,
int exponent, uint64_t coefficient)
: m_coefficient(0),
m_exponent(0),
m_formatClass(coefficient ? ClassNormal : ClassZero),
m_sign(sign) {
if (exponent >= DecimalPrivate::ExponentMin &&
exponent <= DecimalPrivate::ExponentMax) {
while (coefficient > DecimalPrivate::MaxCoefficient) {
coefficient /= 10;
++exponent;
}
}
if (exponent > DecimalPrivate::ExponentMax) {
m_formatClass = ClassInfinity;
return;
}
if (exponent < DecimalPrivate::ExponentMin) {
m_formatClass = ClassZero;
return;
}
m_coefficient = coefficient;
m_exponent =
static_cast<int16_t>(exponent);
}
bool operator==(
const EncodedData&)
const;
bool operator!=(
const EncodedData& another)
const {
return !
operator==(another); }
uint64_t coefficient()
const {
return m_coefficient; }
int countDigits()
const;
int exponent()
const {
return m_exponent; }
bool isFinite()
const {
return !isSpecial(); }
bool isInfinity()
const {
return m_formatClass == ClassInfinity; }
bool isNaN()
const {
return m_formatClass == ClassNaN; }
bool isSpecial()
const {
return m_formatClass == ClassInfinity || m_formatClass == ClassNaN
; }
bool isZero() const { return m_formatClass == ClassZero; }
Sign sign() const { return m_sign; }
void setSign(Sign sign) { m_sign = sign; }
private:
enum FormatClass {
ClassInfinity,
ClassNormal,
ClassNaN,
ClassZero,
};
constexpr EncodedData(Sign sign, FormatClass formatClass)
: m_coefficient(0),
m_exponent(0),
m_formatClass(formatClass),
m_sign(sign) {}
FormatClass formatClass() const { return m_formatClass; }
uint64_t m_coefficient;
int16_t m_exponent;
FormatClass m_formatClass;
Sign m_sign;
};
constexpr explicit Decimal(DecimalLiteral i32)
: m_data(i32.value < 0 ? Negative : Positive, 0,
i32.value < 0 ? static_cast<uint64_t>(-static_cast<int64_t>(i32.value))
: static_cast<uint64_t>(i32.value)) {}
MFBT_API explicit Decimal(int32_t i32 = 0);
MFBT_API Decimal(Sign sign, int exponent, uint64_t coefficient);
MFBT_API Decimal(const Decimal&);
MFBT_API Decimal& operator=(const Decimal&);
MFBT_API Decimal& operator+=(const Decimal&);
MFBT_API Decimal& operator-=(const Decimal&);
MFBT_API Decimal& operator*=(const Decimal&);
MFBT_API Decimal& operator/=(const Decimal&);
MFBT_API Decimal operator-() const;
MFBT_API bool operator==(const Decimal&) const;
MFBT_API bool operator!=(const Decimal&) const;
MFBT_API bool operator<(const Decimal&) const;
MFBT_API bool operator<=(const Decimal&) const;
MFBT_API bool operator>(const Decimal&) const;
MFBT_API bool operator>=(const Decimal&) const;
MFBT_API Decimal operator+(const Decimal&) const;
MFBT_API Decimal operator-(const Decimal&) const;
MFBT_API Decimal operator*(const Decimal&) const;
MFBT_API Decimal operator/(const Decimal&) const;
int exponent() const
{
ASSERT(isFinite());
return m_data.exponent();
}
bool isFinite() const { return m_data.isFinite(); }
bool isInfinity() const { return m_data.isInfinity(); }
bool isNaN() const { return m_data.isNaN(); }
bool isNegative() const { return sign() == Negative; }
bool isPositive() const { return sign() == Positive; }
bool isSpecial() const { return m_data.isSpecial(); }
bool isZero() const { return m_data.isZero(); }
MFBT_API Decimal abs() const;
MFBT_API Decimal ceil() const;
MFBT_API Decimal floor() const;
MFBT_API Decimal remainder(const Decimal&) const;
MFBT_API Decimal round() const;
MFBT_API double toDouble() const;
// Note: toString method supports infinity and nan but fromString not.
MFBT_API std::string toString() const;
static MFBT_API Decimal fromDouble(double);
// fromString supports following syntax EBNF:
// number ::= sign? digit+ ('.' digit*) (exponent-marker sign? digit+)?
// | sign? '.' digit+ (exponent-marker sign? digit+)?
// sign ::= '+' | '-'
// exponent-marker ::= 'e' | 'E'
// digit ::= '0' | '1' | ... | '9'
// Note: fromString doesn't support "infinity" and "nan".
static MFBT_API Decimal fromString(const std::string& aValue);
static MFBT_API Decimal infinity(Sign);
static constexpr Decimal nan() {
return Decimal(EncodedData(Positive, EncodedData::ClassNaN));
}
static MFBT_API Decimal zero(Sign);
// You should not use below methods. We expose them for unit testing.
constexpr explicit Decimal(const EncodedData& data) : m_data(data) {}
const EncodedData& value() const { return m_data; }
private:
struct AlignedOperands {
uint64_t lhsCoefficient;
uint64_t rhsCoefficient;
int exponent;
};
MFBT_API explicit Decimal(double);
MFBT_API Decimal compareTo(const Decimal&) const;
static MFBT_API AlignedOperands alignOperands(const Decimal& lhs, const Decimal& ;rhs);
static inline Sign invertSign(Sign sign) { return sign == Negative ? Positive : Negative; }
Sign sign() const { return m_data.sign(); }
EncodedData m_data;
};
} // namespace blink
namespace mozilla {
typedef blink::Decimal Decimal;
using blink::operator""_d;
} // namespace mozilla
#undef USING_FAST_MALLOC
#ifdef DEFINED_ASSERT_FOR_DECIMAL_H
#undef DEFINED_ASSERT_FOR_DECIMAL_H
#undef ASSERT
#endif
#endif // Decimal_h
