wchar_support.cpp

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2011 the Initial Developer.
 *  All Rights Reserved.
 *  
 *  Contributor(s):
 *
 *  Alternatively, the contents of this file may be used under the terms of the 
 *  GNU General Public License Version 2 or later (the GPL), in which case the 
 *  provisions of GPL are applicable instead of those above.  If you wish to allow use
 *  of your version of this file only under the terms of the GPL and not to allow 
 *  others to use your version of this file under the CPAL, indicate your decision by 
 *  deleting the provisions above and replace them with the notice and other 
 *  provisions required by the GPL License. If you do not delete the provisions above,
 *  a recipient may use your version of this file under either the CPAL or the GPL.
 *  
 *  *** END LICENSE INFORMATION ***
 */
 
#include "lass_common.h"
#include "wchar_support.h"
#include <cstring>
 
#if LASS_HAVE_MULTIBYTETOWIDECHAR
#   define WIN32_LEAN_AND_MEAN
#   define NOMINMAX
#   include <windows.h>
#   include "../num/num_cast.h"
#endif
 
#if LASS_HAVE_ICONV
#   include <iconv.h>
#   include <errno.h>
#   include "thread.h"
#endif
 
namespace lass
{
namespace util
{
 
#if LASS_HAVE_WCHAR_SUPPORT
 
std::wstring utf8ToWchar(const std::string& utf8) 
{ 
    std::wstring wide;
    utf8ToWchar(utf8.data(), utf8.length(), wide); 
    return wide;
}
 
std::wstring utf8ToWchar(const char* utf8) 
{ 
    std::wstring wide;
    utf8ToWchar(utf8, ::strlen(utf8), wide); 
    return wide;
}
 
std::wstring utf8ToWchar(const char* utf8, size_t length)
{
    std::wstring wide;
    utf8ToWchar(utf8, length, wide); 
    return wide;
}
 
std::string wcharToUtf8(const std::wstring& wide)
{
    std::string utf8;
    wcharToUtf8(wide.data(), wide.length(), utf8);
    return utf8;
}
 
std::string wcharToUtf8(const wchar_t* wide)
{
    std::string utf8;
    wcharToUtf8(wide, ::wcslen(wide), utf8);
    return utf8;
}
 
std::string wcharToUtf8(const wchar_t* wide, size_t length)
{
    std::string utf8;
    wcharToUtf8(wide, length, utf8);
    return utf8;
}
 
 
 
#   if LASS_HAVE_MULTIBYTETOWIDECHAR
 
LASS_META_ASSERT( sizeof(wchar_t) == sizeof(WCHAR), wchar_t_should_be_of_same_size_as_WCHAR ); 
 
void utf8ToWchar(const char* utf8, size_t length, std::wstring &wide)
{
    if (!length)
    {
        wide.clear();
        return;
    }
    const int utf8Length = num::numCast<int>(length);
    const int wideLength = LASS_ENFORCE_WINAPI(MultiByteToWideChar(CP_UTF8, 0, utf8, utf8Length, 0, 0));
    wide.resize(num::numCast<size_t>(wideLength));
    LASS_ENFORCE_WINAPI(MultiByteToWideChar(CP_UTF8, 0, utf8, utf8Length, &wide[0], wideLength));
}
 
void wcharToUtf8(const wchar_t* wide, size_t length, std::string &utf8)
{
    if (!length)
    {
        utf8.clear();
        return;
    }
    const int wideLength = num::numCast<int>(length);
    const int utf8Length = LASS_ENFORCE_WINAPI(WideCharToMultiByte(CP_UTF8, 0, wide, wideLength, 0, 0, NULL, NULL));
    utf8.resize(num::numCast<size_t>(utf8Length));
    LASS_ENFORCE_WINAPI(WideCharToMultiByte(CP_UTF8, 0, wide, wideLength, &utf8[0], utf8Length, NULL, NULL));
}
 
#   elif LASS_HAVE_ICONV
 
namespace
{
    LASS_META_ASSERT(sizeof(wchar_t) == 2 || sizeof(wchar_t) == 4, expects_wchar_t_to_be_16_or_32_bit);
 
    class Converter
    {
    public:
        Converter(const char* tocode, const char* fromcode)
        {
            handle_ = LASS_ENFORCE_CLIB_EX( iconv_open(tocode, fromcode), (iconv_t)-1 );
        }
        ~Converter()
        {
            iconv_close(handle_);
        }
        template <typename string_type>
        void convert(const char* in, size_t inBytes, string_type &result)
        {
            typedef typename string_type::value_type char_type;
            iconv(handle_, 0, 0, 0, 0); // reset
            result.clear();
            
#       if LASS_HAVE_ICONV_CONST_CHAR
            const char* pIn = in;
#       else
            char* pIn = const_cast<char*>(in);
#       endif
 
            while (inBytes)
            {
                char* pOut = buffer_;
                size_t outLeft = bufsize_;
 
                if (iconv(handle_, &pIn, &inBytes, &pOut, &outLeft) == (size_t)-1)
                {
                    if (errno == E2BIG)
                    {
                        const size_t bytes = bufsize_ - outLeft;
                        LASS_ASSERT(bytes % sizeof(char_type) == 0);
                        result.append( reinterpret_cast<char_type*>( buffer_ ), bytes / sizeof(char_type) );
                    }
                    else
                    {
                        LASS_THROW("BLABLA");
                    }
                }
                else
                {
                    const size_t bytes = bufsize_ - outLeft;
                    LASS_ASSERT(bytes % sizeof(char_type) == 0 && (bytes / sizeof(char_type)) > 0);
                    result.append( reinterpret_cast<char_type*>( buffer_ ), bytes / sizeof(char_type) - 1 );
                }
            }
        }
    private:
        enum { bufsize_ = 1024 };
        iconv_t handle_;
        char buffer_[bufsize_];
    };
 
    typedef ThreadLocalPtr<Converter> TConverterPtr;
 
    const char* wchar_encoding =
#       if LASS_HAVE_WCHAR_T == 2
#           if LASS_HAVE_BIG_ENDIAN
                "UTF-16BE";
#           else
                "UTF-16LE";
#           endif
#       elif LASS_HAVE_WCHAR_T == 4
#           if LASS_HAVE_BIG_ENDIAN
                "UTF-32BE";
#           else
                "UTF-32LE";
#           endif
#       else
#           error "[LASS BUILD MSG] unsupported wchar_t size"
#       endif
}
 
void utf8ToWchar(const char* utf8, size_t length, std::wstring &wide)
{
    static TConverterPtr converter;
    if ( !converter )
    {
        std::unique_ptr<Converter> p(new Converter(wchar_encoding, "UTF-8"));
        converter.reset(std::move(p));
    }
    converter->convert( utf8, length + 1, wide );
}
 
void wcharToUtf8(const wchar_t* wide, size_t length, std::string &utf8)
{
    static TConverterPtr converter;
    if ( !converter )
    {
        std::unique_ptr<Converter> p(new Converter("UTF-8", wchar_encoding));
        converter.reset(std::move(p));
    }
    converter->convert( reinterpret_cast<const char*>(wide), sizeof(wchar_t) * (length + 1), utf8 );
}
 
#   else
 
#       pragma LASS_NOTE("no wchar_t support implemented, it will be unavailable.")
 
#   endif
 
#endif
 
}
}
 
// EOF