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Diffstat (limited to 'src/boost/nowide/utf8_codecvt.hpp')
| -rw-r--r-- | src/boost/nowide/utf8_codecvt.hpp | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/src/boost/nowide/utf8_codecvt.hpp b/src/boost/nowide/utf8_codecvt.hpp new file mode 100644 index 000000000..cc5046fc8 --- /dev/null +++ b/src/boost/nowide/utf8_codecvt.hpp @@ -0,0 +1,499 @@ +// +// Copyright (c) 2015 Artyom Beilis (Tonkikh) +// +// Distributed under the Boost Software License, Version 1.0. (See +// accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt) +// +#ifndef BOOST_NOWIDE_UTF8_CODECVT_HPP +#define BOOST_NOWIDE_UTF8_CODECVT_HPP + +#include <boost/locale/utf.hpp> +#include <boost/cstdint.hpp> +#include <boost/static_assert.hpp> +#include <locale> + +namespace boost { +namespace nowide { + +// +// Make sure that mbstate can keep 16 bit of UTF-16 sequence +// +BOOST_STATIC_ASSERT(sizeof(std::mbstate_t)>=2); + +#ifdef _MSC_VER +// MSVC do_length is non-standard it counts wide characters instead of narrow and does not change mbstate +#define BOOST_NOWIDE_DO_LENGTH_MBSTATE_CONST +#endif + +template<typename CharType,int CharSize=sizeof(CharType)> +class utf8_codecvt; + +template<typename CharType> +class utf8_codecvt<CharType,2> : public std::codecvt<CharType,char,std::mbstate_t> +{ +public: + utf8_codecvt(size_t refs = 0) : std::codecvt<CharType,char,std::mbstate_t>(refs) + { + } +protected: + + typedef CharType uchar; + + virtual std::codecvt_base::result do_unshift(std::mbstate_t &s,char *from,char * /*to*/,char *&next) const + { + boost::uint16_t &state = *reinterpret_cast<boost::uint16_t *>(&s); +#ifdef DEBUG_CODECVT + std::cout << "Entering unshift " << std::hex << state << std::dec << std::endl; +#endif + if(state != 0) + return std::codecvt_base::error; + next=from; + return std::codecvt_base::ok; + } + virtual int do_encoding() const throw() + { + return 0; + } + virtual int do_max_length() const throw() + { + return 4; + } + virtual bool do_always_noconv() const throw() + { + return false; + } + + virtual int + do_length( std::mbstate_t + #ifdef BOOST_NOWIDE_DO_LENGTH_MBSTATE_CONST + const + #endif + &std_state, + char const *from, + char const *from_end, + size_t max) const + { + #ifndef BOOST_NOWIDE_DO_LENGTH_MBSTATE_CONST + char const *save_from = from; + boost::uint16_t &state = *reinterpret_cast<boost::uint16_t *>(&std_state); + #else + size_t save_max = max; + boost::uint16_t state = *reinterpret_cast<boost::uint16_t const *>(&std_state); + #endif + while(max > 0 && from < from_end){ + char const *prev_from = from; + boost::uint32_t ch=boost::locale::utf::utf_traits<char>::decode(from,from_end); + if(ch==boost::locale::utf::incomplete || ch==boost::locale::utf::illegal) { + from = prev_from; + break; + } + max --; + if(ch > 0xFFFF) { + if(state == 0) { + from = prev_from; + state = 1; + } + else { + state = 0; + } + } + } + #ifndef BOOST_NOWIDE_DO_LENGTH_MBSTATE_CONST + return from - save_from; + #else + return save_max - max; + #endif + } + + + virtual std::codecvt_base::result + do_in( std::mbstate_t &std_state, + char const *from, + char const *from_end, + char const *&from_next, + uchar *to, + uchar *to_end, + uchar *&to_next) const + { + std::codecvt_base::result r=std::codecvt_base::ok; + + // mbstate_t is POD type and should be initialized to 0 (i.a. state = stateT()) + // according to standard. We use it to keep a flag 0/1 for surrogate pair writing + // + // if 0 no code above >0xFFFF observed, of 1 a code above 0xFFFF observerd + // and first pair is written, but no input consumed + boost::uint16_t &state = *reinterpret_cast<boost::uint16_t *>(&std_state); + while(to < to_end && from < from_end) + { +#ifdef DEBUG_CODECVT + std::cout << "Entering IN--------------" << std::endl; + std::cout << "State " << std::hex << state <<std::endl; + std::cout << "Left in " << std::dec << from_end - from << " out " << to_end -to << std::endl; +#endif + char const *from_saved = from; + + uint32_t ch=boost::locale::utf::utf_traits<char>::decode(from,from_end); + + if(ch==boost::locale::utf::illegal) { + from = from_saved; + r=std::codecvt_base::error; + break; + } + if(ch==boost::locale::utf::incomplete) { + from = from_saved; + r=std::codecvt_base::partial; + break; + } + // Normal codepoints go direcly to stream + if(ch <= 0xFFFF) { + *to++=ch; + } + else { + // for other codepoints we do following + // + // 1. We can't consume our input as we may find ourselfs + // in state where all input consumed but not all output written,i.e. only + // 1st pair is written + // 2. We only write first pair and mark this in the state, we also revert back + // the from pointer in order to make sure this codepoint would be read + // once again and then we would consume our input together with writing + // second surrogate pair + ch-=0x10000; + boost::uint16_t vh = ch >> 10; + boost::uint16_t vl = ch & 0x3FF; + boost::uint16_t w1 = vh + 0xD800; + boost::uint16_t w2 = vl + 0xDC00; + if(state == 0) { + from = from_saved; + *to++ = w1; + state = 1; + } + else { + *to++ = w2; + state = 0; + } + } + } + from_next=from; + to_next=to; + if(r == std::codecvt_base::ok && (from!=from_end || state!=0)) + r = std::codecvt_base::partial; +#ifdef DEBUG_CODECVT + std::cout << "Returning "; + switch(r) { + case std::codecvt_base::ok: + std::cout << "ok" << std::endl; + break; + case std::codecvt_base::partial: + std::cout << "partial" << std::endl; + break; + case std::codecvt_base::error: + std::cout << "error" << std::endl; + break; + default: + std::cout << "other" << std::endl; + break; + } + std::cout << "State " << std::hex << state <<std::endl; + std::cout << "Left in " << std::dec << from_end - from << " out " << to_end -to << std::endl; +#endif + return r; + } + + virtual std::codecvt_base::result + do_out( std::mbstate_t &std_state, + uchar const *from, + uchar const *from_end, + uchar const *&from_next, + char *to, + char *to_end, + char *&to_next) const + { + std::codecvt_base::result r=std::codecvt_base::ok; + // mbstate_t is POD type and should be initialized to 0 (i.a. state = stateT()) + // according to standard. We assume that sizeof(mbstate_t) >=2 in order + // to be able to store first observerd surrogate pair + // + // State: state!=0 - a first surrogate pair was observerd (state = first pair), + // we expect the second one to come and then zero the state + /// + boost::uint16_t &state = *reinterpret_cast<boost::uint16_t *>(&std_state); + while(to < to_end && from < from_end) + { +#ifdef DEBUG_CODECVT + std::cout << "Entering OUT --------------" << std::endl; + std::cout << "State " << std::hex << state <<std::endl; + std::cout << "Left in " << std::dec << from_end - from << " out " << to_end -to << std::endl; +#endif + boost::uint32_t ch=0; + if(state != 0) { + // if the state idecates that 1st surrogate pair was written + // we should make sure that the second one that comes is actually + // second surrogate + boost::uint16_t w1 = state; + boost::uint16_t w2 = *from; + // we don't forward from as writing may fail to incomplete or + // partial conversion + if(0xDC00 <= w2 && w2<=0xDFFF) { + boost::uint16_t vh = w1 - 0xD800; + boost::uint16_t vl = w2 - 0xDC00; + ch=((uint32_t(vh) << 10) | vl) + 0x10000; + } + else { + // Invalid surrogate + r=std::codecvt_base::error; + break; + } + } + else { + ch = *from; + if(0xD800 <= ch && ch<=0xDBFF) { + // if this is a first surrogate pair we put + // it into the state and consume it, note we don't + // go forward as it should be illegal so we increase + // the from pointer manually + state = ch; + from++; + continue; + } + else if(0xDC00 <= ch && ch<=0xDFFF) { + // if we observe second surrogate pair and + // first only may be expected we should break from the loop with error + // as it is illegal input + r=std::codecvt_base::error; + break; + } + } + if(!boost::locale::utf::is_valid_codepoint(ch)) { + r=std::codecvt_base::error; + break; + } + int len = boost::locale::utf::utf_traits<char>::width(ch); + if(to_end - to < len) { + r=std::codecvt_base::partial; + break; + } + to = boost::locale::utf::utf_traits<char>::encode(ch,to); + state = 0; + from++; + } + from_next=from; + to_next=to; + if(r==std::codecvt_base::ok && from!=from_end) + r = std::codecvt_base::partial; +#ifdef DEBUG_CODECVT + std::cout << "Returning "; + switch(r) { + case std::codecvt_base::ok: + std::cout << "ok" << std::endl; + break; + case std::codecvt_base::partial: + std::cout << "partial" << std::endl; + break; + case std::codecvt_base::error: + std::cout << "error" << std::endl; + break; + default: + std::cout << "other" << std::endl; + break; + } + std::cout << "State " << std::hex << state <<std::endl; + std::cout << "Left in " << std::dec << from_end - from << " out " << to_end -to << std::endl; +#endif + return r; + } + +}; + +template<typename CharType> +class utf8_codecvt<CharType,4> : public std::codecvt<CharType,char,std::mbstate_t> +{ +public: + utf8_codecvt(size_t refs = 0) : std::codecvt<CharType,char,std::mbstate_t>(refs) + { + } +protected: + + typedef CharType uchar; + + virtual std::codecvt_base::result do_unshift(std::mbstate_t &/*s*/,char *from,char * /*to*/,char *&next) const + { + next=from; + return std::codecvt_base::ok; + } + virtual int do_encoding() const throw() + { + return 0; + } + virtual int do_max_length() const throw() + { + return 4; + } + virtual bool do_always_noconv() const throw() + { + return false; + } + + virtual int + do_length( std::mbstate_t + #ifdef BOOST_NOWIDE_DO_LENGTH_MBSTATE_CONST + const + #endif + &/*state*/, + char const *from, + char const *from_end, + size_t max) const + { + #ifndef BOOST_NOWIDE_DO_LENGTH_MBSTATE_CONST + char const *start_from = from; + #else + size_t save_max = max; + #endif + + while(max > 0 && from < from_end){ + char const *save_from = from; + boost::uint32_t ch=boost::locale::utf::utf_traits<char>::decode(from,from_end); + if(ch==boost::locale::utf::incomplete || ch==boost::locale::utf::illegal) { + from = save_from; + break; + } + max--; + } + #ifndef BOOST_NOWIDE_DO_LENGTH_MBSTATE_CONST + return from - start_from; + #else + return save_max - max; + #endif + } + + + virtual std::codecvt_base::result + do_in( std::mbstate_t &/*state*/, + char const *from, + char const *from_end, + char const *&from_next, + uchar *to, + uchar *to_end, + uchar *&to_next) const + { + std::codecvt_base::result r=std::codecvt_base::ok; + + // mbstate_t is POD type and should be initialized to 0 (i.a. state = stateT()) + // according to standard. We use it to keep a flag 0/1 for surrogate pair writing + // + // if 0 no code above >0xFFFF observed, of 1 a code above 0xFFFF observerd + // and first pair is written, but no input consumed + while(to < to_end && from < from_end) + { +#ifdef DEBUG_CODECVT + std::cout << "Entering IN--------------" << std::endl; + std::cout << "State " << std::hex << state <<std::endl; + std::cout << "Left in " << std::dec << from_end - from << " out " << to_end -to << std::endl; +#endif + char const *from_saved = from; + + uint32_t ch=boost::locale::utf::utf_traits<char>::decode(from,from_end); + + if(ch==boost::locale::utf::illegal) { + r=std::codecvt_base::error; + from = from_saved; + break; + } + if(ch==boost::locale::utf::incomplete) { + r=std::codecvt_base::partial; + from=from_saved; + break; + } + *to++=ch; + } + from_next=from; + to_next=to; + if(r == std::codecvt_base::ok && from!=from_end) + r = std::codecvt_base::partial; +#ifdef DEBUG_CODECVT + std::cout << "Returning "; + switch(r) { + case std::codecvt_base::ok: + std::cout << "ok" << std::endl; + break; + case std::codecvt_base::partial: + std::cout << "partial" << std::endl; + break; + case std::codecvt_base::error: + std::cout << "error" << std::endl; + break; + default: + std::cout << "other" << std::endl; + break; + } + std::cout << "State " << std::hex << state <<std::endl; + std::cout << "Left in " << std::dec << from_end - from << " out " << to_end -to << std::endl; +#endif + return r; + } + + virtual std::codecvt_base::result + do_out( std::mbstate_t &std_state, + uchar const *from, + uchar const *from_end, + uchar const *&from_next, + char *to, + char *to_end, + char *&to_next) const + { + std::codecvt_base::result r=std::codecvt_base::ok; + while(to < to_end && from < from_end) + { +#ifdef DEBUG_CODECVT + std::cout << "Entering OUT --------------" << std::endl; + std::cout << "State " << std::hex << state <<std::endl; + std::cout << "Left in " << std::dec << from_end - from << " out " << to_end -to << std::endl; +#endif + boost::uint32_t ch=0; + ch = *from; + if(!boost::locale::utf::is_valid_codepoint(ch)) { + r=std::codecvt_base::error; + break; + } + int len = boost::locale::utf::utf_traits<char>::width(ch); + if(to_end - to < len) { + r=std::codecvt_base::partial; + break; + } + to = boost::locale::utf::utf_traits<char>::encode(ch,to); + from++; + } + from_next=from; + to_next=to; + if(r==std::codecvt_base::ok && from!=from_end) + r = std::codecvt_base::partial; +#ifdef DEBUG_CODECVT + std::cout << "Returning "; + switch(r) { + case std::codecvt_base::ok: + std::cout << "ok" << std::endl; + break; + case std::codecvt_base::partial: + std::cout << "partial" << std::endl; + break; + case std::codecvt_base::error: + std::cout << "error" << std::endl; + break; + default: + std::cout << "other" << std::endl; + break; + } + std::cout << "State " << std::hex << state <<std::endl; + std::cout << "Left in " << std::dec << from_end - from << " out " << to_end -to << std::endl; +#endif + return r; + } +}; + +} // nowide +} // namespace boost + +#endif +/// +// vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4 |