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+/*
+ * 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;
+ MFBT_API bool toString(char* strBuf, size_t bufLength) 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 MFBT_API Decimal nan();
+ static MFBT_API Decimal zero(Sign);
+
+ // You should not use below methods. We expose them for unit testing.
+ MFBT_API explicit Decimal(const EncodedData&);
+ 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