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