Chris@16: // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
Chris@16: // (C) Copyright 2003-2007 Jonathan Turkanis
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
Chris@16: 
Chris@16: // See http://www.boost.org/libs/iostreams for documentation.
Chris@16: 
Chris@16: // Contains machinery for performing code conversion.
Chris@16: 
Chris@16: #ifndef BOOST_IOSTREAMS_CODE_CONVERTER_HPP_INCLUDED
Chris@16: #define BOOST_IOSTREAMS_CODE_CONVERTER_HPP_INCLUDED
Chris@16: 
Chris@16: #if defined(_MSC_VER) && (_MSC_VER >= 1020)
Chris@16: # pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/iostreams/detail/config/wide_streams.hpp>
Chris@16: #if defined(BOOST_IOSTREAMS_NO_WIDE_STREAMS) || \
Chris@16:     defined(BOOST_IOSTREAMS_NO_LOCALE) \
Chris@16:     /**/
Chris@16: # error code conversion not supported on this platform
Chris@16: #endif
Chris@16: 
Chris@16: #include <algorithm>                       // max.
Chris@16: #include <cstring>                         // memcpy.
Chris@16: #include <exception>
Chris@16: #include <boost/config.hpp>                // DEDUCED_TYPENAME, 
Chris@16: #include <boost/iostreams/char_traits.hpp>
Chris@16: #include <boost/iostreams/constants.hpp>   // default_filter_buffer_size.
Chris@16: #include <boost/iostreams/detail/adapter/concept_adapter.hpp>
Chris@16: #include <boost/iostreams/detail/adapter/direct_adapter.hpp>
Chris@16: #include <boost/iostreams/detail/buffer.hpp>
Chris@16: #include <boost/iostreams/detail/call_traits.hpp>
Chris@16: #include <boost/iostreams/detail/codecvt_holder.hpp>
Chris@16: #include <boost/iostreams/detail/codecvt_helper.hpp>
Chris@16: #include <boost/iostreams/detail/double_object.hpp>
Chris@16: #include <boost/iostreams/detail/execute.hpp>
Chris@16: #include <boost/iostreams/detail/forward.hpp>
Chris@16: #include <boost/iostreams/detail/functional.hpp>
Chris@16: #include <boost/iostreams/detail/ios.hpp> // failure, openmode, int types.
Chris@16: #include <boost/iostreams/detail/optional.hpp>
Chris@16: #include <boost/iostreams/detail/select.hpp>
Chris@16: #include <boost/iostreams/traits.hpp>
Chris@16: #include <boost/iostreams/operations.hpp>
Chris@16: #include <boost/shared_ptr.hpp>
Chris@16: #include <boost/static_assert.hpp>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: #include <boost/type_traits/is_convertible.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: 
Chris@16: // Must come last.
Chris@16: #include <boost/iostreams/detail/config/disable_warnings.hpp> // Borland 5.x
Chris@16: 
Chris@16: namespace boost { namespace iostreams {
Chris@16: 
Chris@16: struct code_conversion_error : BOOST_IOSTREAMS_FAILURE {
Chris@16:     code_conversion_error() 
Chris@16:         : BOOST_IOSTREAMS_FAILURE("code conversion error")
Chris@16:         { }
Chris@16: };
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: //--------------Definition of strncpy_if_same---------------------------------//
Chris@16: 
Chris@16: // Helper template for strncpy_if_same, below.
Chris@16: template<bool B>
Chris@16: struct strncpy_if_same_impl;
Chris@16: 
Chris@16: template<>
Chris@16: struct strncpy_if_same_impl<true> {
Chris@16:     template<typename Ch>
Chris@16:     static Ch* copy(Ch* tgt, const Ch* src, std::streamsize n)
Chris@16:     { return BOOST_IOSTREAMS_CHAR_TRAITS(Ch)::copy(tgt, src, n); }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct strncpy_if_same_impl<false> {
Chris@16:     template<typename Src, typename Tgt>
Chris@16:     static Tgt* copy(Tgt* tgt, const Src*, std::streamsize) { return tgt; }
Chris@16: };
Chris@16: 
Chris@16: template<typename Src, typename Tgt>
Chris@16: Tgt* strncpy_if_same(Tgt* tgt, const Src* src, std::streamsize n)
Chris@16: {
Chris@16:     typedef strncpy_if_same_impl<is_same<Src, Tgt>::value> impl;
Chris@16:     return impl::copy(tgt, src, n);
Chris@16: }
Chris@16: 
Chris@16: //--------------Definition of conversion_buffer-------------------------------//
Chris@16: 
Chris@16: // Buffer and conversion state for reading.
Chris@16: template<typename Codecvt, typename Alloc>
Chris@16: class conversion_buffer 
Chris@16:     : public buffer<
Chris@16:                  BOOST_DEDUCED_TYPENAME detail::codecvt_extern<Codecvt>::type,
Chris@16:                  Alloc
Chris@16:              > 
Chris@16: {
Chris@16: public:
Chris@16:     typedef typename Codecvt::state_type state_type;
Chris@16:     conversion_buffer() 
Chris@16:         : buffer<
Chris@16:               BOOST_DEDUCED_TYPENAME detail::codecvt_extern<Codecvt>::type,
Chris@16:               Alloc
Chris@16:           >(0) 
Chris@16:     { 
Chris@16:         reset(); 
Chris@16:     }
Chris@16:     state_type& state() { return state_; }
Chris@16:     void reset() 
Chris@16:     { 
Chris@16:         if (this->size()) 
Chris@16:             this->set(0, 0);
Chris@16:         state_ = state_type(); 
Chris@16:     }
Chris@16: private:
Chris@16:     state_type state_;
Chris@16: };
Chris@16: 
Chris@16: //--------------Definition of converter_impl----------------------------------//
Chris@16: 
Chris@16: // Contains member data, open/is_open/close and buffer management functions.
Chris@16: template<typename Device, typename Codecvt, typename Alloc>
Chris@16: struct code_converter_impl {
Chris@16:     typedef typename codecvt_extern<Codecvt>::type          extern_type;
Chris@16:     typedef typename category_of<Device>::type              device_category;
Chris@16:     typedef is_convertible<device_category, input>          can_read;
Chris@16:     typedef is_convertible<device_category, output>         can_write;
Chris@16:     typedef is_convertible<device_category, bidirectional>  is_bidir;
Chris@16:     typedef typename 
Chris@16:             iostreams::select<  // Disambiguation for Tru64.
Chris@16:                 is_bidir, bidirectional,
Chris@16:                 can_read, input,
Chris@16:                 can_write, output
Chris@16:             >::type                                         mode;      
Chris@16:     typedef typename
Chris@16:             mpl::if_<
Chris@16:                 is_direct<Device>,
Chris@16:                 direct_adapter<Device>,
Chris@16:                 Device
Chris@16:             >::type                                         device_type;
Chris@16:     typedef optional< concept_adapter<device_type> >        storage_type;
Chris@16:     typedef is_convertible<device_category, two_sequence>   is_double;
Chris@16:     typedef conversion_buffer<Codecvt, Alloc>               buffer_type;
Chris@16: 
Chris@16:     code_converter_impl() : cvt_(), flags_(0) { }
Chris@16: 
Chris@16:     ~code_converter_impl()
Chris@16:     { 
Chris@16:         try { 
Chris@16:             if (flags_ & f_open) close(); 
Chris@16:         } catch (...) { /* */ } 
Chris@16:     }
Chris@16: 
Chris@16:     template <class T>
Chris@16:     void open(const T& dev, int buffer_size)
Chris@16:     {
Chris@16:         if (flags_ & f_open)
Chris@16:             boost::throw_exception(BOOST_IOSTREAMS_FAILURE("already open"));
Chris@16:         if (buffer_size == -1)
Chris@16:             buffer_size = default_filter_buffer_size;
Chris@16:         int max_length = cvt_.get().max_length();
Chris@16:         buffer_size = (std::max)(buffer_size, 2 * max_length);
Chris@16:         if (can_read::value) {
Chris@16:             buf_.first().resize(buffer_size);
Chris@16:             buf_.first().set(0, 0);
Chris@16:         }
Chris@16:         if (can_write::value && !is_double::value) {
Chris@16:             buf_.second().resize(buffer_size);
Chris@16:             buf_.second().set(0, 0);
Chris@16:         }
Chris@16:         dev_.reset(concept_adapter<device_type>(dev));
Chris@16:         flags_ = f_open;
Chris@16:     }
Chris@16: 
Chris@16:     void close()
Chris@16:     {
Chris@16:         detail::execute_all(
Chris@16:             detail::call_member_close(*this, BOOST_IOS::in),
Chris@16:             detail::call_member_close(*this, BOOST_IOS::out)
Chris@16:         );
Chris@16:     }
Chris@16: 
Chris@16:     void close(BOOST_IOS::openmode which)
Chris@16:     {
Chris@16:         if (which == BOOST_IOS::in && (flags_ & f_input_closed) == 0) {
Chris@16:             flags_ |= f_input_closed;
Chris@16:             iostreams::close(dev(), BOOST_IOS::in);
Chris@16:         }
Chris@16:         if (which == BOOST_IOS::out && (flags_ & f_output_closed) == 0) {
Chris@16:             flags_ |= f_output_closed;
Chris@16:             detail::execute_all(
Chris@16:                 detail::flush_buffer(buf_.second(), dev(), can_write::value),
Chris@16:                 detail::call_close(dev(), BOOST_IOS::out),
Chris@16:                 detail::call_reset(dev_),
Chris@16:                 detail::call_reset(buf_.first()),
Chris@16:                 detail::call_reset(buf_.second())
Chris@16:             );
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     bool is_open() const { return (flags_ & f_open) != 0;}
Chris@16: 
Chris@16:     device_type& dev() { return **dev_; }
Chris@16: 
Chris@16:     enum flag_type {
Chris@16:         f_open             = 1,
Chris@16:         f_input_closed     = f_open << 1,
Chris@16:         f_output_closed    = f_input_closed << 1
Chris@16:     };
Chris@16: 
Chris@16:     codecvt_holder<Codecvt>  cvt_;
Chris@16:     storage_type             dev_;
Chris@16:     double_object<
Chris@16:         buffer_type, 
Chris@16:         is_double
Chris@16:     >                        buf_;
Chris@16:     int                      flags_;
Chris@16: };
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: //--------------Definition of converter---------------------------------------//
Chris@16: 
Chris@16: #define BOOST_IOSTREAMS_CONVERTER_PARAMS() , int buffer_size = -1
Chris@16: #define BOOST_IOSTREAMS_CONVERTER_ARGS() , buffer_size
Chris@16: 
Chris@16: template<typename Device, typename Codecvt, typename Alloc>
Chris@16: struct code_converter_base {
Chris@16:     typedef detail::code_converter_impl<
Chris@16:                 Device, Codecvt, Alloc
Chris@16:             > impl_type;
Chris@16:     code_converter_base() : pimpl_(new impl_type) { }
Chris@16:     shared_ptr<impl_type> pimpl_;
Chris@16: };
Chris@16: 
Chris@16: template< typename Device, 
Chris@16:           typename Codecvt = detail::default_codecvt, 
Chris@16:           typename Alloc = std::allocator<char> >
Chris@16: class code_converter 
Chris@16:     : protected code_converter_base<Device, Codecvt, Alloc>
Chris@16: {
Chris@16: private:
Chris@16:     typedef detail::code_converter_impl<
Chris@16:                 Device, Codecvt, Alloc
Chris@16:             >                                                       impl_type;
Chris@16:     typedef typename impl_type::device_type                         device_type;
Chris@16:     typedef typename impl_type::buffer_type                         buffer_type;
Chris@16:     typedef typename detail::codecvt_holder<Codecvt>::codecvt_type  codecvt_type;
Chris@16:     typedef typename detail::codecvt_intern<Codecvt>::type          intern_type;
Chris@16:     typedef typename detail::codecvt_extern<Codecvt>::type          extern_type;
Chris@16:     typedef typename detail::codecvt_state<Codecvt>::type           state_type;
Chris@16: public:
Chris@16:     typedef intern_type                                             char_type;    
Chris@16:     struct category 
Chris@16:         : impl_type::mode, device_tag, closable_tag, localizable_tag
Chris@16:         { };
Chris@16:     BOOST_STATIC_ASSERT((
Chris@16:         is_same<
Chris@16:             extern_type, 
Chris@16:             BOOST_DEDUCED_TYPENAME char_type_of<Device>::type
Chris@16:         >::value
Chris@16:     ));
Chris@16: public:
Chris@16:     code_converter() { }
Chris@16: #if BOOST_WORKAROUND(__GNUC__, < 3)
Chris@16:     code_converter(code_converter& rhs) 
Chris@16:         : code_converter_base<Device, Codecvt, Alloc>(rhs)
Chris@16:         { }
Chris@16:     code_converter(const code_converter& rhs) 
Chris@16:         : code_converter_base<Device, Codecvt, Alloc>(rhs)
Chris@16:         { }
Chris@16: #endif
Chris@16:     BOOST_IOSTREAMS_FORWARD( code_converter, open_impl, Device,
Chris@16:                              BOOST_IOSTREAMS_CONVERTER_PARAMS, 
Chris@16:                              BOOST_IOSTREAMS_CONVERTER_ARGS )
Chris@16: 
Chris@16:         // fstream-like interface.
Chris@16: 
Chris@16:     bool is_open() const { return this->pimpl_->is_open(); }
Chris@16:     void close(BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
Chris@16:     { impl().close(which); }
Chris@16: 
Chris@16:         // Device interface.
Chris@16: 
Chris@16:     std::streamsize read(char_type*, std::streamsize);
Chris@16:     std::streamsize write(const char_type*, std::streamsize);
Chris@16:     void imbue(const std::locale& loc) { impl().cvt_.imbue(loc); }
Chris@16: 
Chris@16:         // Direct device access.
Chris@16: 
Chris@16:     Device& operator*() { return detail::unwrap_direct(dev()); }
Chris@16:     Device* operator->() { return &detail::unwrap_direct(dev()); }
Chris@16: private:
Chris@16:     template<typename T> // Used for forwarding.
Chris@16:     void open_impl(const T& t BOOST_IOSTREAMS_CONVERTER_PARAMS()) 
Chris@16:     { 
Chris@16:         impl().open(t BOOST_IOSTREAMS_CONVERTER_ARGS()); 
Chris@16:     }
Chris@16: 
Chris@16:     const codecvt_type& cvt() { return impl().cvt_.get(); }
Chris@16:     device_type& dev() { return impl().dev(); }
Chris@16:     buffer_type& in() { return impl().buf_.first(); }
Chris@16:     buffer_type& out() { return impl().buf_.second(); }
Chris@16:     impl_type& impl() { return *this->pimpl_; }
Chris@16: };
Chris@16: 
Chris@16: //--------------Implementation of converter-----------------------------------//
Chris@16: 
Chris@16: // Implementation note: if end of stream contains a partial character,
Chris@16: // it is ignored.
Chris@16: template<typename Device, typename Codevt, typename Alloc>
Chris@16: std::streamsize code_converter<Device, Codevt, Alloc>::read
Chris@16:     (char_type* s, std::streamsize n)
Chris@16: {
Chris@16:     const extern_type*   next;        // Next external char.
Chris@16:     intern_type*         nint;        // Next internal char.
Chris@16:     std::streamsize      total = 0;   // Characters read.
Chris@16:     int                  status = iostreams::char_traits<char>::good();
Chris@16:     bool                 partial = false;
Chris@16:     buffer_type&         buf = in();
Chris@16: 
Chris@16:     do {
Chris@16: 
Chris@16:         // Fill buffer.
Chris@16:         if (buf.ptr() == buf.eptr() || partial) {
Chris@16:             status = buf.fill(dev());
Chris@16:             if (buf.ptr() == buf.eptr())
Chris@16:                 break;
Chris@16:             partial = false;
Chris@16:         }
Chris@16: 
Chris@16:         // Convert.
Chris@16:         std::codecvt_base::result result =
Chris@16:             cvt().in( buf.state(),
Chris@16:                       buf.ptr(), buf.eptr(), next,
Chris@16:                       s + total, s + n, nint );
Chris@16:         buf.ptr() += next - buf.ptr();
Chris@16:         total = static_cast<std::streamsize>(nint - s);
Chris@16: 
Chris@16:         switch (result) {
Chris@16:         case std::codecvt_base::partial:
Chris@16:             partial = true;
Chris@16:             break;
Chris@16:         case std::codecvt_base::ok:
Chris@16:             break;
Chris@16:         case std::codecvt_base::noconv:
Chris@16:             {
Chris@16:                 std::streamsize amt = 
Chris@16:                     std::min<std::streamsize>(next - buf.ptr(), n - total);
Chris@16:                 detail::strncpy_if_same(s + total, buf.ptr(), amt);
Chris@16:                 total += amt;
Chris@16:             }
Chris@16:             break;
Chris@16:         case std::codecvt_base::error:
Chris@16:         default:
Chris@16:             buf.state() = state_type();
Chris@16:             boost::throw_exception(code_conversion_error());
Chris@16:         }
Chris@16: 
Chris@16:     } while (total < n && status != EOF && status != WOULD_BLOCK);
Chris@16: 
Chris@16:     return total == 0 && status == EOF ? -1 : total;
Chris@16: }
Chris@16: 
Chris@16: template<typename Device, typename Codevt, typename Alloc>
Chris@16: std::streamsize code_converter<Device, Codevt, Alloc>::write
Chris@16:     (const char_type* s, std::streamsize n)
Chris@16: {
Chris@16:     buffer_type&        buf = out();
Chris@16:     extern_type*        next;              // Next external char.
Chris@16:     const intern_type*  nint;              // Next internal char.
Chris@16:     std::streamsize     total = 0;         // Characters written.
Chris@16:     bool                partial = false;
Chris@16: 
Chris@16:     while (total < n) {
Chris@16: 
Chris@16:         // Empty buffer.
Chris@16:         if (buf.eptr() == buf.end() || partial) {
Chris@16:             if (!buf.flush(dev()))
Chris@16:                 break;
Chris@16:             partial = false;
Chris@16:         }
Chris@16:        
Chris@16:         // Convert.
Chris@16:         std::codecvt_base::result result =
Chris@16:             cvt().out( buf.state(),
Chris@16:                        s + total, s + n, nint,
Chris@16:                        buf.eptr(), buf.end(), next );
Chris@16:         int progress = (int) (next - buf.eptr());
Chris@16:         buf.eptr() += progress;
Chris@16: 
Chris@16:         switch (result) {
Chris@16:         case std::codecvt_base::partial:
Chris@16:             partial = true;
Chris@16:             BOOST_FALLTHROUGH;
Chris@16:         case std::codecvt_base::ok:
Chris@16:             total = static_cast<std::streamsize>(nint - s);
Chris@16:             break;
Chris@16:         case std::codecvt_base::noconv:
Chris@16:             {
Chris@16:                 std::streamsize amt = 
Chris@16:                     std::min<std::streamsize>( nint - total - s, 
Chris@16:                                                buf.end() - buf.eptr() );
Chris@16:                 detail::strncpy_if_same(buf.eptr(), s + total, amt);
Chris@16:                 total += amt;
Chris@16:             }
Chris@16:             break;
Chris@16:         case std::codecvt_base::error:
Chris@16:         default:
Chris@16:             buf.state() = state_type();
Chris@16:             boost::throw_exception(code_conversion_error());
Chris@16:         }
Chris@16:     }
Chris@16:     return total;
Chris@16: }
Chris@16: 
Chris@16: //----------------------------------------------------------------------------//
Chris@16: 
Chris@16: } } // End namespaces iostreams, boost.
Chris@16: 
Chris@16: #include <boost/iostreams/detail/config/enable_warnings.hpp> // Borland 5.x
Chris@16: 
Chris@16: #endif // #ifndef BOOST_IOSTREAMS_CODE_CONVERTER_HPP_INCLUDED