FlaxEngine/Source/Engine/Utilities/StringConverter.h

// Copyright (c) Wojciech Figat. All rights reserved.

#pragma once

#include "Engine/Platform/StringUtils.h"
#include "Engine/Core/Memory/Memory.h"

template<typename CharType, int InlinedSize = 128>
class StringAsBase
{
protected:
    const CharType* _static = nullptr;
    CharType* _dynamic = nullptr;
    CharType _inlined[InlinedSize];

public:
    ~StringAsBase()
    {
        Allocator::Free(_dynamic);
    }

public:
    const CharType* Get() const
    {
        return _static ? _static : (_dynamic ? _dynamic : _inlined);
    }

    int32 Length() const
    {
        return StringUtils::Length(Get());
    }
};

template<int InlinedSize = 128>
class StringAsANSI : public StringAsBase<char, InlinedSize>
{
public:
    typedef char CharType;
    typedef StringAsBase<CharType, InlinedSize> Base;

public:
    StringAsANSI(const char* text)
    {
        this->_static = text;
    }

    StringAsANSI(const Char* text)
        : StringAsANSI(text, StringUtils::Length(text))
    {
    }

    StringAsANSI(const Char* text, int32 length)
    {
        if (length + 1 < InlinedSize)
        {
            StringUtils::ConvertUTF162ANSI(text, this->_inlined, length);
            this->_inlined[length] = 0;
        }
        else
        {
            this->_dynamic = (CharType*)Allocator::Allocate((length + 1) * sizeof(CharType));
            StringUtils::ConvertUTF162ANSI(text, this->_dynamic, length);
            this->_dynamic[length] = 0;
        }
    }
};

template<int InlinedSize = 128>
class StringAsUTF8 : public StringAsBase<char, InlinedSize>
{
public:
    typedef char CharType;
    typedef StringAsBase<CharType, InlinedSize> Base;

public:
    StringAsUTF8(const char* text)
    {
        this->_static = text;
    }

    StringAsUTF8(const Char* text)
        : StringAsUTF8(text, StringUtils::Length(text))
    {
    }

    StringAsUTF8(const Char* text, int32 length)
    {
        int32 lengthUtf8;
        if (length + 1 < InlinedSize)
        {
            StringUtils::ConvertUTF162UTF8(text, this->_inlined, length, lengthUtf8);
            this->_inlined[lengthUtf8] = 0;
        }
        else
        {
            this->_dynamic = StringUtils::ConvertUTF162UTF8(text, length, lengthUtf8);
            this->_dynamic[lengthUtf8] = 0;
        }
    }
};

template<int InlinedSize = 128>
class StringAsUTF16 : public StringAsBase<Char, InlinedSize>
{
public:
    typedef Char CharType;
    typedef StringAsBase<CharType, InlinedSize> Base;

public:
    StringAsUTF16(const char* text)
        : StringAsUTF16(text, StringUtils::Length(text))
    {
    }

    StringAsUTF16(const char* text, int32 length)
    {
        if (length + 1 < InlinedSize)
        {
            StringUtils::ConvertANSI2UTF16(text, this->_inlined, length, length);
            this->_inlined[length] = 0;
        }
        else
        {
            this->_dynamic = (CharType*)Allocator::Allocate((length + 1) * sizeof(CharType));
            StringUtils::ConvertANSI2UTF16(text, this->_dynamic, length, length);
            this->_dynamic[length] = 0;
        }
    }

    StringAsUTF16(const Char* text)
    {
        this->_static = text;
    }
};

template<typename CharType = Char>
class StringAsTerminated
{
protected:
    const CharType* _static = nullptr;
    CharType* _dynamic = nullptr;

public:
    StringAsTerminated(const CharType* str, int32 length)
    {
        if (length != 0 && str[length] == 0) // Unsafe to access out of bounds...
        {
            _static = str;
        }
        else
        {
            _dynamic = (CharType*)Allocator::Allocate((length + 1) * sizeof(CharType));
            Platform::MemoryCopy(_dynamic, str, length * sizeof(CharType));
            _dynamic[length] = 0;
        }
    }

    ~StringAsTerminated()
    {
        Allocator::Free(_dynamic);
    }

    operator const CharType*() const
    {
        return _static ? _static : _dynamic;
    }
};