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: #ifndef BOOST_IOSTREAMS_DETAIL_DIRECT_ADAPTER_HPP_INCLUDED
Chris@16: #define BOOST_IOSTREAMS_DETAIL_DIRECT_ADAPTER_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/config.hpp>       // SFINAE, MSVC, put ptrdiff_t in std.
Chris@16: #include <algorithm>              // copy, min.
Chris@16: #include <cstddef>                // ptrdiff_t.
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: #include <boost/iostreams/categories.hpp>
Chris@16: #include <boost/iostreams/detail/config/limits.hpp>        // forwarding.
Chris@16: #include <boost/iostreams/detail/config/wide_streams.hpp>  // locale.
Chris@16: #include <boost/iostreams/detail/double_object.hpp>
Chris@16: #include <boost/iostreams/detail/error.hpp>
Chris@16: #include <boost/iostreams/detail/ios.hpp>  // openmode, seekdir, int types.
Chris@16: #include <boost/iostreams/traits.hpp>      // mode_of, is_direct.
Chris@16: #include <boost/iostreams/operations.hpp>
Chris@16: #include <boost/mpl/bool.hpp> 
Chris@16: #include <boost/mpl/or.hpp> 
Chris@16: #include <boost/preprocessor/iteration/local.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_binary_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_params.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: 
Chris@16: // Must come last.
Chris@16: #include <boost/iostreams/detail/config/disable_warnings.hpp> // VC7.1
Chris@16: 
Chris@16: namespace boost { namespace iostreams { namespace detail {
Chris@16:                     
Chris@16: //------------------Definition of direct_adapter_base-------------------------//
Chris@16: 
Chris@16: // Put all initialization in base class to faciliate forwarding.
Chris@16: template<typename Direct>
Chris@16: class direct_adapter_base {
Chris@16: public:
Chris@16:     typedef typename char_type_of<Direct>::type  char_type;
Chris@16:     typedef typename mode_of<Direct>::type       mode_type;
Chris@16:     struct category 
Chris@16:         : mode_type,
Chris@16:           device_tag,
Chris@16:           closable_tag
Chris@16:           #ifndef BOOST_IOSTREAMS_NO_LOCALE
Chris@16:           , localizable_tag
Chris@16:           #endif
Chris@16:         { };
Chris@16: protected:
Chris@16:     explicit direct_adapter_base(const Direct& d);
Chris@16:     typedef is_convertible<category, two_sequence> is_double;
Chris@16:     struct pointers {
Chris@16:         char_type *beg, *ptr, *end;
Chris@16:     };
Chris@16:     void init_input(mpl::true_);
Chris@16:     void init_input(mpl::false_) { }
Chris@16:     void init_output(mpl::true_);
Chris@16:     void init_output(mpl::false_) { }
Chris@16:     double_object<pointers, is_double>  ptrs_;
Chris@16:     Direct                              d_;
Chris@16: };
Chris@16: 
Chris@16: template<typename Direct>
Chris@16: class direct_adapter : private direct_adapter_base<Direct> {
Chris@16: private:
Chris@16:     typedef direct_adapter_base<Direct>      base_type;
Chris@16:     typedef typename base_type::pointers     pointers;
Chris@16:     typedef typename base_type::is_double    is_double;
Chris@16:     using base_type::ptrs_;
Chris@16:     using base_type::d_;
Chris@16: public:
Chris@16:     typedef typename base_type::char_type    char_type;
Chris@16:     typedef typename base_type::category     category;
Chris@16: 
Chris@16:         // Constructors
Chris@16: 
Chris@16: #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1310)
Chris@16:     direct_adapter(const Direct& d) : base_type(d) { }   
Chris@16:     direct_adapter(const direct_adapter& d) : base_type(d) { }
Chris@16: # define BOOST_PP_LOCAL_LIMITS (1, BOOST_IOSTREAMS_MAX_FORWARDING_ARITY)
Chris@16: #else
Chris@16:     template<typename U>
Chris@16:     struct is_direct
Chris@16:         : mpl::or_< 
Chris@16:               is_same<U, direct_adapter<Direct> >, 
Chris@16:               is_same<U, Direct> 
Chris@16:           >
Chris@16:         { };
Chris@16:     template<typename U>
Chris@16:     direct_adapter(const U& u) 
Chris@16:         : base_type(forward(u, is_direct<U>()))
Chris@16:         { }
Chris@16: # define BOOST_PP_LOCAL_LIMITS (2, BOOST_IOSTREAMS_MAX_FORWARDING_ARITY)
Chris@16: #endif
Chris@16: 
Chris@16: #define BOOST_PP_LOCAL_MACRO(n) \
Chris@16:     template<BOOST_PP_ENUM_PARAMS(n, typename P)> \
Chris@16:     direct_adapter(BOOST_PP_ENUM_BINARY_PARAMS(n, const P, &p)) \
Chris@16:         : base_type(Direct(BOOST_PP_ENUM_PARAMS(n, p))) \
Chris@16:         { } \
Chris@16:     /**/
Chris@16: #include BOOST_PP_LOCAL_ITERATE()
Chris@16: #undef BOOST_PP_LOCAL_MACRO
Chris@16: 
Chris@16:         // Device interface.
Chris@16: 
Chris@16:     std::streamsize read(char_type* s, std::streamsize n);
Chris@16:     std::streamsize write(const char_type* s, std::streamsize n);
Chris@16:     std::streampos seek( stream_offset, BOOST_IOS::seekdir,
Chris@16:                          BOOST_IOS::openmode = BOOST_IOS::in | BOOST_IOS::out );
Chris@16:     void close();
Chris@16:     void close(BOOST_IOS::openmode which);
Chris@16: #ifndef BOOST_IOSTREAMS_NO_LOCALE
Chris@16:     void imbue(const std::locale&);
Chris@16: #endif
Chris@16: 
Chris@16:         // Direct device access.
Chris@16: 
Chris@16:     Direct& operator*() { return d_; }
Chris@16:     Direct* operator->() { return &d_; }
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, <= 1310)
Chris@16: private:
Chris@16:     template<typename U>
Chris@16:     static Direct forward(const U& u, mpl::true_) { return u; }
Chris@16:     template<typename U>
Chris@16:     static Direct forward(const U& u, mpl::false_) { return Direct(u); }
Chris@16: #endif
Chris@16: };
Chris@16: 
Chris@16: //--------------Definition of wrap_direct and unwrap_direct-------------------//
Chris@16: 
Chris@16: template<typename Device>
Chris@16: struct wrap_direct_traits 
Chris@16:     : mpl::if_<
Chris@16:           is_direct<Device>,
Chris@16:           direct_adapter<Device>,
Chris@16:           Device
Chris@16:       >
Chris@16:     { };
Chris@16: 
Chris@16: template<typename Device>
Chris@16: typename wrap_direct_traits<Device>::type
Chris@16: inline wrap_direct(Device dev) 
Chris@16: { 
Chris@16:     typedef typename wrap_direct_traits<Device>::type type;
Chris@16:     return type(dev); 
Chris@16: }
Chris@16: 
Chris@16: template<typename Device>
Chris@16: inline Device& unwrap_direct(Device& d) { return d; }  
Chris@16: 
Chris@16: template<typename Device>
Chris@16: inline Device& unwrap_direct(direct_adapter<Device>& d) { return *d; }  
Chris@16: 
Chris@16: //--------------Implementation of direct_adapter_base-------------------------//
Chris@16: 
Chris@16: template<typename Direct>
Chris@16: direct_adapter_base<Direct>::direct_adapter_base(const Direct& d) : d_(d)
Chris@16: {
Chris@16:     init_input(is_convertible<category, input>());
Chris@16:     init_output(is_convertible<category, output>());
Chris@16: }
Chris@16: 
Chris@16: template<typename Direct>
Chris@16: void direct_adapter_base<Direct>::init_input(mpl::true_) 
Chris@16: {
Chris@16:     std::pair<char_type*, char_type*> seq = iostreams::input_sequence(d_);
Chris@16:     ptrs_.first().beg = seq.first;
Chris@16:     ptrs_.first().ptr = seq.first;
Chris@16:     ptrs_.first().end = seq.second;
Chris@16: }
Chris@16: 
Chris@16: template<typename Direct>
Chris@16: void direct_adapter_base<Direct>::init_output(mpl::true_) 
Chris@16: {
Chris@16:     std::pair<char_type*, char_type*> seq = iostreams::output_sequence(d_);
Chris@16:     ptrs_.second().beg = seq.first;
Chris@16:     ptrs_.second().ptr = seq.first;
Chris@16:     ptrs_.second().end = seq.second;
Chris@16: }
Chris@16: 
Chris@16: //--------------Implementation of direct_adapter------------------------------//
Chris@16: 
Chris@16: template<typename Direct>
Chris@16: inline std::streamsize direct_adapter<Direct>::read
Chris@16:     (char_type* s, std::streamsize n)
Chris@16: {
Chris@16:     using namespace std;
Chris@16:     pointers& get = ptrs_.first();
Chris@16:     std::streamsize avail = 
Chris@16:         static_cast<std::streamsize>(get.end - get.ptr);
Chris@16:     std::streamsize result = (std::min)(n, avail);
Chris@16:     std::copy(get.ptr, get.ptr + result, s);
Chris@16:     get.ptr += result;
Chris@16:     return result != 0 ? result : -1;
Chris@16: }
Chris@16: 
Chris@16: template<typename Direct>
Chris@16: inline std::streamsize direct_adapter<Direct>::write
Chris@16:     (const char_type* s, std::streamsize n)
Chris@16: {
Chris@16:     using namespace std;
Chris@16:     pointers& put = ptrs_.second();
Chris@16:     if (n > static_cast<std::streamsize>(put.end - put.ptr))
Chris@16:         boost::throw_exception(write_area_exhausted());
Chris@16:     std::copy(s, s + n, put.ptr);
Chris@16:     put.ptr += n;
Chris@16:     return n;
Chris@16: }
Chris@16: 
Chris@16: template<typename Direct>
Chris@16: inline std::streampos direct_adapter<Direct>::seek
Chris@16:     ( stream_offset off, BOOST_IOS::seekdir way, 
Chris@16:       BOOST_IOS::openmode which )
Chris@16: {
Chris@16:     using namespace std;
Chris@16:     pointers& get = ptrs_.first();
Chris@16:     pointers& put = ptrs_.second();
Chris@16:     if (way == BOOST_IOS::cur && get.ptr != put.ptr)
Chris@16:        boost::throw_exception(bad_seek());
Chris@16:     ptrdiff_t next = 0;
Chris@16:     if ((which & BOOST_IOS::in) || !is_double::value) {
Chris@16:         if (way == BOOST_IOS::beg)
Chris@16:             next = off; 
Chris@16:         else if (way == BOOST_IOS::cur)
Chris@16:             next = get.ptr - get.beg + off; 
Chris@16:         else
Chris@16:             next = get.end - get.beg + off; 
Chris@16:         if (next >= 0 && next <= get.end - get.beg)
Chris@16:             get.ptr = get.beg + next;
Chris@16:         else
Chris@16:             boost::throw_exception(bad_seek());
Chris@16:     }
Chris@16:     if ((which & BOOST_IOS::out) && is_double::value) {
Chris@16:         if (way == BOOST_IOS::beg)
Chris@16:             next = off; 
Chris@16:         else if (way == BOOST_IOS::cur)
Chris@16:             next = put.ptr - put.beg + off; 
Chris@16:         else
Chris@16:             next = put.end - put.beg + off; 
Chris@16:         if (next >= 0 && next <= put.end - put.beg)
Chris@16:             put.ptr = put.beg + next;
Chris@16:         else
Chris@16:             boost::throw_exception(bad_seek());
Chris@16:     }
Chris@16:     return offset_to_position(next);
Chris@16: }
Chris@16: 
Chris@16: template<typename Direct>
Chris@16: void direct_adapter<Direct>::close() 
Chris@16: { 
Chris@16:     BOOST_STATIC_ASSERT((!is_convertible<category, two_sequence>::value));
Chris@16:     detail::close_all(d_);
Chris@16: }
Chris@16: 
Chris@16: template<typename Direct>
Chris@16: void direct_adapter<Direct>::close(BOOST_IOS::openmode which) 
Chris@16: { 
Chris@16:     BOOST_STATIC_ASSERT((is_convertible<category, two_sequence>::value));
Chris@16:     boost::iostreams::close(d_, which);
Chris@16: }
Chris@16: 
Chris@16: #ifndef BOOST_IOSTREAMS_NO_LOCALE
Chris@16:     template<typename Direct>
Chris@16:     void direct_adapter<Direct>::imbue(const std::locale& loc) 
Chris@16:     { boost::iostreams::imbue(d_, loc); }
Chris@16: #endif
Chris@16: 
Chris@16: } } } // End namespaces detail, iostreams, boost.
Chris@16: 
Chris@16: #include <boost/iostreams/detail/config/enable_warnings.hpp>
Chris@16: 
Chris@16: #endif // #ifndef BOOST_IOSTREAMS_DETAIL_DIRECT_ADAPTER_HPP_INCLUDED