ValueConverters.h

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// Copyright Onix Solutions Limited [OnixS]. All rights reserved.
//
// This software owned by Onix Solutions Limited [OnixS] and is
// protected by copyright law and international copyright treaties.
//
// Access to and use of the software is governed by the terms of the applicable
// OnixS Software Services Agreement (the Agreement) and Customer end user license
// agreements granting a non-assignable, non-transferable and non-exclusive license
// to use the software for it's own data processing purposes under the terms defined
// in the Agreement.
//
// Except as otherwise granted within the terms of the Agreement, copying or
// reproduction of any part of this source code or associated reference material
// to any other location for further reproduction or redistribution, and any
// amendments to this copyright notice, are expressly prohibited.
//
// Any reproduction or redistribution for sale or hiring of the Software not in
// accordance with the terms of the Agreement is a violation of copyright law.
//
 
#pragma once
 
#include <OnixS/CME/MDH/messaging/String.h>
#include <OnixS/CME/MDH/messaging/Time.h>
 
#include <OnixS/CME/MDH/messaging/Decimal.h>
#include <OnixS/CME/MDH/messaging/Decimal.Operations.h>
#include <OnixS/CME/MDH/messaging/Integral.h>
#include <OnixS/CME/MDH/messaging/Serialization.h>
 
#include <OnixS/CME/MDH/messaging/TagBased/ValueContainer.h>
#include <OnixS/CME/MDH/messaging/ExceptionHelpers.h>
 
ONIXS_CMEMDH_MESSAGING_TAGBASED_NAMESPACE_BEGIN

struct ONIXS_CMEMDH_EXPORTED ValueConverter
{
    virtual const Char* typeName() const noexcept = 0;

    virtual void toStr(std::string&, const ValueContainer&) const {}

    virtual StrRef toStr(Char*, size_t, const ValueContainer&) const
    {
        throwBadConversion(typeName());
    }

    virtual bool convert(StrRef&, const ValueContainer&) const noexcept
    {
        return false;
    }
 
    template <class StringRef>
    bool convert(StringRef& ref, const ValueContainer& container) const
    {
        StrRef converted;
 
        if (convert(converted, container))
        {
            ref = StringRef(converted);
 
            return true;
        }
 
        return false;
    }

    virtual bool convert(Char&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(Int8&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(UInt8&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(Int16&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(UInt16&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(Int32&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(UInt32&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(Int64&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(UInt64&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(Decimal&, const ValueContainer&) const noexcept
    {
        return false;
    }

    virtual bool convert(Timestamp&, const ValueContainer&) const
    {
        return false;
    }

    virtual bool convert(MaturityMonthYear&, const ValueContainer&) const noexcept
    {
        return false;
    }
 
    ~ValueConverter();
};
 
struct ONIXS_CMEMDH_EXPORTED NullConverter : ValueConverter
{
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "Null";
    }
 
    ONIXS_CMEMDH_NODISCARD static const ValueConverter& self() noexcept;
 
    ~NullConverter() = default;
};

struct ONIXS_CMEMDH_EXPORTED StrRefConverter : ValueConverter
{
    using ValueConverter::convert;
 
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "String";
    }
 
    void toStr(std::string& str, const ValueContainer& container) const override
    {
        const StrRef& ref = container.get<StrRef>();
 
        str.assign(ref.data(), ref.size());
    }
 
    StrRef toStr(Char*, size_t, const ValueContainer& container) const noexcept override
    {
        return container.get<StrRef>();
    }
 
    bool convert(StrRef& ref, const ValueContainer& container) const noexcept override
    {
        ref = container.get<StrRef>();
 
        return true;
    }
 
    bool convert(Char& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        if (1 == str.size())
        {
            value = str[0];
 
            return true;
        }
        else if (str.empty())
        {
            value = 0;
 
            return true;
        }
 
        return false;
    }
 
    bool convert(Int8& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    bool convert(UInt8& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    bool convert(Int16& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    bool convert(UInt16& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    bool convert(Int32& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    bool convert(UInt32& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    bool convert(Int64& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    bool convert(UInt64& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    bool convert(Decimal& value, const ValueContainer& container) const noexcept override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    bool convert(Timestamp& value, const ValueContainer& container) const override
    {
        const StrRef& str = container.get<StrRef>();
 
        return fromStr(value, str.data(), str.size());
    }
 
    static const ValueConverter& self() noexcept;
 
    ~StrRefConverter() = default;
};
 
//

struct ONIXS_CMEMDH_EXPORTED CharConverter : ValueConverter
{
    using ValueConverter::convert;
 
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "Char";
    }
 
    void toStr(std::string& str, const ValueContainer& container) const override
    {
        str.append(1, container.get<Char>());
    }
 
    StrRef toStr(Char*, size_t, const ValueContainer& container) const noexcept override
    {
        return StrRef(&container.get<Char>(), 1);
    }
 
    bool convert(StrRef& ref, const ValueContainer& container) const noexcept override
    {
        ref = StrRef(&container.get<Char>(), 1);
 
        return true;
    }
 
    bool convert(Char& value, const ValueContainer& container) const noexcept override
    {
        value = container.get<Char>();
 
        return true;
    }
 
    bool convert(Int8& value, const ValueContainer& container) const noexcept override
    {
        return charToDigit(value, container.get<Char>());
    }
 
    bool convert(UInt8& value, const ValueContainer& container) const noexcept override
    {
        return charToDigit(value, container.get<Char>());
    }
 
    bool convert(Int16& value, const ValueContainer& container) const noexcept override
    {
        return charToDigit(value, container.get<Char>());
    }
 
    bool convert(UInt16& value, const ValueContainer& container) const noexcept override
    {
        return charToDigit(value, container.get<Char>());
    }
 
    bool convert(Int32& value, const ValueContainer& container) const noexcept override
    {
        return charToDigit(value, container.get<Char>());
    }
 
    bool convert(UInt32& value, const ValueContainer& container) const noexcept override
    {
        return charToDigit(value, container.get<Char>());
    }
 
    bool convert(Int64& value, const ValueContainer& container) const noexcept override
    {
        return charToDigit(value, container.get<Char>());
    }
 
    bool convert(UInt64& value, const ValueContainer& container) const noexcept override
    {
        return charToDigit(value, container.get<Char>());
    }
 
    bool convert(Decimal& value, const ValueContainer& container) const noexcept override
    {
        Decimal::Mantissa mantissa;
 
        if (charToDigit(mantissa, container.get<Char>()))
        {
            value = Decimal(mantissa, 0);
 
            return true;
        }
 
        return false;
    }
 
    static const ValueConverter& self() noexcept;
 
    ~CharConverter() = default;
 
private:
    template <class Integer>
    static bool charToDigit(Integer& converted, Char original) noexcept
    {
        if ('0' <= original && '9' >= original)
        {
            converted = static_cast<Integer>(original - '0');
 
            return true;
        }
 
        return false;
    }
};

template <class Integer, class Descendant = void>
class IntegerConverter : public ValueConverter
{
    template <class Integral, bool IsSigned>
    struct FitsToChar
    {
        bool operator()(Integral value) const noexcept
        {
            return (0 <= value && value < 10);
        }
    };
 
    template <class Integral>
    struct FitsToChar<Integral, false>
    {
        bool operator()(Integral value) const noexcept
        {
            return (value < 10);
        }
    };
 
    typedef FitsToChar<Integer, !(static_cast<Integer>(-1) > static_cast<Integer>(0))> CanFitToChar;
 
public:
    using ValueConverter::convert;
 
    void toStr(std::string& str, const ValueContainer& container) const override
    {
        ONIXS_CMEMDH_MESSAGING_NAMESPACE::toStr(str, container.get<Integer>());
    }
 
    StrRef toStr(Char* buf, size_t size, const ValueContainer& container) const override
    {
        assert(buf);
 
        const size_t converted = ONIXS_CMEMDH_MESSAGING_NAMESPACE::toStr(container.get<Integer>(), buf, size);
 
        assert(converted < size);
        assert(converted != 0);
 
        return StrRef(buf, converted);
    }
 
    bool convert(Char& value, const ValueContainer& container) const noexcept override
    {
        const Integer actual = container.get<Integer>();
 
        if (CanFitToChar()(actual))
        {
            value = static_cast<Char>('0' + actual);
 
            return true;
        }
 
        return false;
    }
 
    bool convert(Int8& value, const ValueContainer& container) const noexcept override
    {
        value = numericCast<Int8>(container.get<Integer>());
 
        return true;
    }
 
    bool convert(UInt8& value, const ValueContainer& container) const noexcept override
    {
        value = numericCast<UInt8>(container.get<Integer>());
 
        return true;
    }
 
    bool convert(Int16& value, const ValueContainer& container) const noexcept override
    {
        value = numericCast<Int16>(container.get<Integer>());
 
        return true;
    }
 
    bool convert(UInt16& value, const ValueContainer& container) const noexcept override
    {
        value = numericCast<UInt16>(container.get<Integer>());
 
        return true;
    }
 
    bool convert(Int32& value, const ValueContainer& container) const noexcept override
    {
        value = numericCast<Int32>(container.get<Integer>());
 
        return true;
    }
 
    bool convert(UInt32& value, const ValueContainer& container) const noexcept override
    {
        value = numericCast<UInt32>(container.get<Integer>());
 
        return true;
    }
 
    bool convert(Int64& value, const ValueContainer& container) const noexcept override
    {
        value = numericCast<Int64>(container.get<Integer>());
 
        return true;
    }
 
    bool convert(UInt64& value, const ValueContainer& container) const noexcept override
    {
        value = numericCast<UInt64>(container.get<Integer>());
 
        return true;
    }
 
    bool convert(Decimal& value, const ValueContainer& container) const noexcept override
    {
        value = Decimal(numericCast<Decimal::Mantissa>(container.get<Integer>()), 0);
 
        return true;
    }
 
    bool convert(Timestamp& value, const ValueContainer& container) const noexcept override
    {
        value = makeTimestamp(numericCast<UInt64>(container.get<Integer>()));
 
        return true;
    }
 
    ~IntegerConverter() = default;
};

struct ONIXS_CMEMDH_EXPORTED Int8Converter : IntegerConverter<Int8>
{
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "Int8";
    }
 
    static const ValueConverter& self() noexcept;
 
    ~Int8Converter() = default;
};

struct ONIXS_CMEMDH_EXPORTED UInt8Converter : IntegerConverter<UInt8>
{
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "UInt8";
    }
 
    static const ValueConverter& self() noexcept;
 
    ~UInt8Converter() = default;
};

struct ONIXS_CMEMDH_EXPORTED Int16Converter : IntegerConverter<Int16>
{
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "Int16";
    }
 
    static const ValueConverter& self() noexcept;
 
    ~Int16Converter() = default;
};

struct ONIXS_CMEMDH_EXPORTED UInt16Converter : IntegerConverter<UInt16>
{
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "UInt16";
    }
 
    static const ValueConverter& self() noexcept;
 
    ~UInt16Converter() = default;
};

struct ONIXS_CMEMDH_EXPORTED Int32Converter : IntegerConverter<Int32>
{
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "Int32";
    }
 
    static const ValueConverter& self() noexcept;
 
    ~Int32Converter() = default;
};

struct ONIXS_CMEMDH_EXPORTED UInt32Converter : IntegerConverter<UInt32>
{
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "UInt32";
    }
 
    static const ValueConverter& self() noexcept;
 
    ~UInt32Converter() = default;
};

struct ONIXS_CMEMDH_EXPORTED Int64Converter : IntegerConverter<Int64>
{
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "Int64";
    }
 
    static const ValueConverter& self() noexcept;
 
    ~Int64Converter() = default;
};

struct ONIXS_CMEMDH_EXPORTED UInt64Converter : IntegerConverter<UInt64>
{
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "UInt64";
    }
 
    static const ValueConverter& self() noexcept;
 
    ~UInt64Converter() = default;
};

struct ONIXS_CMEMDH_EXPORTED DecimalConverter : ValueConverter
{
    using ValueConverter::convert;
 
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "Decimal";
    }
 
    void toStr(std::string& str, const ValueContainer& container) const override
    {
        ONIXS_CMEMDH_MESSAGING_NAMESPACE::toStr(str, container.get<Decimal>());
    }
 
    StrRef toStr(Char* buf, size_t size, const ValueContainer& container) const override
    {
        assert(buf);
 
        const size_t converted = ONIXS_CMEMDH_MESSAGING_NAMESPACE::toStr(container.get<Decimal>(), buf, size);
 
        assert(converted != 0);
        assert(converted < size);
 
        return StrRef(buf, converted);
    }
 
    bool convert(Decimal& value, const ValueContainer& container) const noexcept override
    {
        value = container.get<Decimal>();
 
        return true;
    }
 
    static const ValueConverter& self() noexcept;
 
    ~DecimalConverter() = default;
};
 
//

struct ONIXS_CMEMDH_EXPORTED TimestampConverter : ValueConverter
{
    using ValueConverter::convert;
 
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "Timestamp";
    }
 
    void toStr(std::string& str, const ValueContainer& container) const override
    {
        ONIXS_CMEMDH_MESSAGING_NAMESPACE::toStr(str, container.get<Timestamp>());
    }
 
    StrRef toStr(Char* buf, size_t size, const ValueContainer& container) const override
    {
        assert(buf);
 
        const size_t converted = ONIXS_CMEMDH_MESSAGING_NAMESPACE::toStr(container.get<Timestamp>(), buf, size);
 
        assert(converted < size);
        assert(converted != 0);
 
        return StrRef(buf, converted);
    }
 
    bool convert(Int64& value, const ValueContainer& container) const noexcept override
    {
        value = numericCast<Int64>(container.get<Timestamp>().sinceEpoch());
 
        return true;
    }
 
    bool convert(UInt64& value, const ValueContainer& container) const noexcept override
    {
        value = container.get<Timestamp>().sinceEpoch();
 
        return true;
    }
 
    bool convert(Timestamp& value, const ValueContainer& container) const noexcept override
    {
        value = container.get<Timestamp>();
 
        return true;
    }
 
    static const ValueConverter& self() noexcept;
 
    ~TimestampConverter() = default;
};

struct ONIXS_CMEMDH_EXPORTED MaturityMonthYearConverter : ValueConverter
{
    using ValueConverter::convert;
    using ValueConverter::toStr;
 
    ONIXS_CMEMDH_NODISCARD const Char* typeName() const noexcept override
    {
        return "MaturityMonthYear";
    }
 
    void toStr(std::string& str, const ValueContainer& container) const override
    {
        ONIXS_CMEMDH_MESSAGING_NAMESPACE::toStr(str, container.get<MaturityMonthYear>());
    }
 
    bool convert(MaturityMonthYear& value, const ValueContainer& container) const noexcept override
    {
        value = container.get<MaturityMonthYear>();
 
        return true;
    }
 
    static const ValueConverter& self() noexcept;
 
    ~MaturityMonthYearConverter() = default;
};

struct ValueKinds
{
    enum Enum
    {
        Ordinary,
        Enumeration,
        Bits
    };
};

template <class Value>
class ValueKind
{
    typedef char Ordinary[1];
 
    typedef char Enumeration[2];
 
    typedef char Bits[3];
 
    template <class Other>
    static Bits& kind(typename Other::Bits*);
 
    template <class Other>
    static Enumeration& kind(typename Other::Enum*);
 
    template <class Other>
    static Ordinary& kind(...);
 
public:
    enum
    {
        Kind =
            (sizeof(Bits) == sizeof(kind<Value>(nullptr))
                 ? ValueKinds::Bits
                 : (sizeof(Enumeration) == sizeof(kind<Value>(nullptr)) ? ValueKinds::Enumeration : ValueKinds::Ordinary
                   ))
    };
};

template <class Value, int>
struct ValueConversionTraits
{
    typedef Value Result;

    static Result convert(const ValueConverter& converter, const ValueContainer& container)
    {
        Result result;
 
        if (!converter.convert(result, container))
        {
            throwBadConversion(converter.typeName());
        }
 
        return result;
    }

    static bool convert(Result& result, const ValueConverter& converter, const ValueContainer& container)
    {
        return converter.convert(result, container);
    }
};

template <class Enumeration>
struct ValueConversionTraits<Enumeration, ValueKinds::Enumeration>
{
    typedef typename Enumeration::Enum Result;

    static Result convert(const ValueConverter& converter, const ValueContainer& container)
    {
        typename Enumeration::Base result;
 
        if (!converter.convert(result, container))
        {
            throwBadConversion(converter.typeName());
        }
 
        return static_cast<Result>(result);
    }

    static bool convert(Result& result, const ValueConverter& converter, const ValueContainer& container)
    {
        typename Enumeration::Base base;
 
        if (converter.convert(base, container))
        {
            result = static_cast<Result>(base);
 
            return true;
        }
 
        return false;
    }
};

template <class BitSet>
struct ValueConversionTraits<BitSet, ValueKinds::Bits>
{
    typedef BitSet Result;

    static BitSet convert(const ValueConverter& converter, const ValueContainer& container)
    {
        typename BitSet::Bits bits;
 
        if (!converter.convert(bits, container))
        {
            throwBadConversion(converter.typeName());
        }
 
        return BitSet(bits);
    }

    static bool convert(BitSet& result, const ValueConverter& converter, const ValueContainer& container)
    {
        typename BitSet::Bits bits;
 
        if (converter.convert(bits, container))
        {
            result = BitSet(bits);
 
            return true;
        }
 
        return false;
    }
};

template <class Value>
struct ValueConversion
{
    typedef ValueConversionTraits<Value, ValueKind<Value>::Kind> Traits;

    typedef typename Traits::Result Result;

    typename Traits::Result operator()(const ValueConverter& converter, const ValueContainer& container) const
    {
        return Traits::convert(converter, container);
    }

    bool
    operator()(typename Traits::Result& result, const ValueConverter& converter, const ValueContainer& container) const
    {
        return Traits::convert(result, converter, container);
    }
};
 
ONIXS_CMEMDH_MESSAGING_TAGBASED_NAMESPACE_END