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_STREAMBUF_HPP_INCLUDED
Chris@16: #define BOOST_IOSTREAMS_DETAIL_DIRECT_STREAMBUF_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/assert.hpp>
Chris@16: #include <cstddef>
Chris@16: #include <typeinfo>
Chris@16: #include <utility>                                 // pair.
Chris@16: #include <boost/config.hpp>                        // BOOST_DEDUCED_TYPENAME, 
Chris@16: #include <boost/iostreams/detail/char_traits.hpp>  // member template friends.
Chris@16: #include <boost/iostreams/detail/config/wide_streams.hpp>
Chris@16: #include <boost/iostreams/detail/error.hpp>
Chris@16: #include <boost/iostreams/detail/execute.hpp>
Chris@16: #include <boost/iostreams/detail/functional.hpp>
Chris@16: #include <boost/iostreams/detail/ios.hpp>
Chris@16: #include <boost/iostreams/detail/optional.hpp>
Chris@16: #include <boost/iostreams/detail/streambuf.hpp>
Chris@16: #include <boost/iostreams/detail/streambuf/linked_streambuf.hpp>
Chris@16: #include <boost/iostreams/operations.hpp>
Chris@16: #include <boost/iostreams/positioning.hpp>
Chris@16: #include <boost/iostreams/traits.hpp>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: 
Chris@16: // Must come last.
Chris@16: #include <boost/iostreams/detail/config/disable_warnings.hpp> // MSVC.
Chris@16: 
Chris@16: namespace boost { namespace iostreams { 
Chris@16:     
Chris@16: namespace detail {
Chris@16: 
Chris@16: template< typename T,
Chris@16:           typename Tr = 
Chris@16:               BOOST_IOSTREAMS_CHAR_TRAITS(
Chris@16:                  BOOST_DEDUCED_TYPENAME char_type_of<T>::type 
Chris@16:               ) >
Chris@16: class direct_streambuf 
Chris@16:     : public linked_streambuf<BOOST_DEDUCED_TYPENAME char_type_of<T>::type, Tr>
Chris@16: {
Chris@16: public:
Chris@16:     typedef typename char_type_of<T>::type                char_type;
Chris@16:     BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS(Tr)
Chris@16: private:
Chris@16:     typedef linked_streambuf<char_type, traits_type>      base_type;
Chris@16:     typedef typename category_of<T>::type                 category;
Chris@16:     typedef BOOST_IOSTREAMS_BASIC_STREAMBUF(
Chris@16:                 char_type, traits_type
Chris@16:             )                                             streambuf_type;
Chris@16: public: // stream needs access.
Chris@16:     void open(const T& t, std::streamsize buffer_size, 
Chris@16:               std::streamsize pback_size);
Chris@16:     bool is_open() const;
Chris@16:     void close();
Chris@16:     bool auto_close() const { return auto_close_; }
Chris@16:     void set_auto_close(bool close) { auto_close_ = close; }
Chris@16:     bool strict_sync() { return true; }
Chris@16: 
Chris@16:     // Declared in linked_streambuf.
Chris@16:     T* component() { return storage_.get(); }
Chris@16: protected:
Chris@16: #if !BOOST_WORKAROUND(__GNUC__, == 2)
Chris@16:     BOOST_IOSTREAMS_USING_PROTECTED_STREAMBUF_MEMBERS(base_type)
Chris@16: #endif
Chris@16:     direct_streambuf();
Chris@16: 
Chris@16:     //--------------Virtual functions-----------------------------------------//
Chris@16: 
Chris@16:     // Declared in linked_streambuf.
Chris@16:     void close_impl(BOOST_IOS::openmode m);
Chris@16:     const std::type_info& component_type() const { return typeid(T); }
Chris@16:     void* component_impl() { return component(); } 
Chris@16: #ifdef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES
Chris@16:     public:
Chris@16: #endif
Chris@16: 
Chris@16:     // Declared in basic_streambuf.
Chris@16:     int_type underflow();
Chris@16:     int_type pbackfail(int_type c);
Chris@16:     int_type overflow(int_type c);
Chris@16:     pos_type seekoff( off_type off, BOOST_IOS::seekdir way,
Chris@16:                       BOOST_IOS::openmode which );
Chris@16:     pos_type seekpos(pos_type sp, BOOST_IOS::openmode which);
Chris@16: private:
Chris@16:     pos_type seek_impl( stream_offset off, BOOST_IOS::seekdir way,
Chris@16:                         BOOST_IOS::openmode which );
Chris@16:     void init_input(any_tag) { }
Chris@16:     void init_input(input);
Chris@16:     void init_output(any_tag) { }
Chris@16:     void init_output(output);
Chris@16:     void init_get_area();
Chris@16:     void init_put_area();
Chris@16:     bool one_head() const;
Chris@16:     bool two_head() const;
Chris@16:     optional<T>  storage_;
Chris@16:     char_type   *ibeg_, *iend_, *obeg_, *oend_;
Chris@16:     bool         auto_close_;
Chris@16: };
Chris@16:                     
Chris@16: //------------------Implementation of direct_streambuf------------------------//
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: direct_streambuf<T, Tr>::direct_streambuf() 
Chris@16:     : ibeg_(0), iend_(0), obeg_(0), oend_(0), auto_close_(true) 
Chris@16: { this->set_true_eof(true); }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: void direct_streambuf<T, Tr>::open
Chris@16:     (const T& t, std::streamsize, std::streamsize)
Chris@16: {
Chris@16:     storage_.reset(t);
Chris@16:     init_input(category());
Chris@16:     init_output(category());
Chris@16:     setg(0, 0, 0);
Chris@16:     setp(0, 0);
Chris@16:     this->set_needs_close();
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: bool direct_streambuf<T, Tr>::is_open() const 
Chris@16: { return ibeg_ != 0 || obeg_ != 0; }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: void direct_streambuf<T, Tr>::close() 
Chris@16: { 
Chris@16:     base_type* self = this;
Chris@16:     detail::execute_all( detail::call_member_close(*self, BOOST_IOS::in),
Chris@16:                          detail::call_member_close(*self, BOOST_IOS::out),
Chris@16:                          detail::call_reset(storage_) );
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: typename direct_streambuf<T, Tr>::int_type 
Chris@16: direct_streambuf<T, Tr>::underflow()
Chris@16: {
Chris@16:     if (!ibeg_) 
Chris@16:         boost::throw_exception(cant_read());
Chris@16:     if (!gptr()) 
Chris@16:         init_get_area();
Chris@16:     return gptr() != iend_ ? 
Chris@16:         traits_type::to_int_type(*gptr()) : 
Chris@16:         traits_type::eof();
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: typename direct_streambuf<T, Tr>::int_type 
Chris@16: direct_streambuf<T, Tr>::pbackfail(int_type c)
Chris@16: {
Chris@16:     using namespace std;
Chris@16:     if (!ibeg_) 
Chris@16:         boost::throw_exception(cant_read());
Chris@16:     if (gptr() != 0 && gptr() != ibeg_) {
Chris@16:         gbump(-1);
Chris@16:         if (!traits_type::eq_int_type(c, traits_type::eof()))
Chris@16:             *gptr() = traits_type::to_char_type(c);
Chris@16:         return traits_type::not_eof(c);
Chris@16:     }
Chris@16:     boost::throw_exception(bad_putback());
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: typename direct_streambuf<T, Tr>::int_type 
Chris@16: direct_streambuf<T, Tr>::overflow(int_type c)
Chris@16: {
Chris@16:     using namespace std;
Chris@16:     if (!obeg_)
Chris@16:         boost::throw_exception(BOOST_IOSTREAMS_FAILURE("no write access"));
Chris@16:     if (!pptr()) init_put_area();
Chris@16:     if (!traits_type::eq_int_type(c, traits_type::eof())) {
Chris@16:         if (pptr() == oend_)
Chris@16:             boost::throw_exception(
Chris@16:                 BOOST_IOSTREAMS_FAILURE("write area exhausted")
Chris@16:             );
Chris@16:         *pptr() = traits_type::to_char_type(c);
Chris@16:         pbump(1);
Chris@16:         return c;
Chris@16:     }
Chris@16:     return traits_type::not_eof(c);
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: inline typename direct_streambuf<T, Tr>::pos_type
Chris@16: direct_streambuf<T, Tr>::seekoff
Chris@16:     (off_type off, BOOST_IOS::seekdir way, BOOST_IOS::openmode which)
Chris@16: { return seek_impl(off, way, which); }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: inline typename direct_streambuf<T, Tr>::pos_type
Chris@16: direct_streambuf<T, Tr>::seekpos
Chris@16:     (pos_type sp, BOOST_IOS::openmode which)
Chris@16: { 
Chris@16:     return seek_impl(position_to_offset(sp), BOOST_IOS::beg, which);
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: void direct_streambuf<T, Tr>::close_impl(BOOST_IOS::openmode which)
Chris@16: {
Chris@16:     if (which == BOOST_IOS::in && ibeg_ != 0) {
Chris@16:         setg(0, 0, 0);
Chris@16:         ibeg_ = iend_ = 0;
Chris@16:     }
Chris@16:     if (which == BOOST_IOS::out && obeg_ != 0) {
Chris@16:         sync();
Chris@16:         setp(0, 0);
Chris@16:         obeg_ = oend_ = 0;
Chris@16:     }
Chris@16:     boost::iostreams::close(*storage_, which);
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: typename direct_streambuf<T, Tr>::pos_type direct_streambuf<T, Tr>::seek_impl
Chris@16:     (stream_offset off, BOOST_IOS::seekdir way, BOOST_IOS::openmode which)
Chris@16: {
Chris@16:     using namespace std;
Chris@16:     BOOST_IOS::openmode both = BOOST_IOS::in | BOOST_IOS::out;
Chris@16:     if (two_head() && (which & both) == both)
Chris@16:         boost::throw_exception(bad_seek());
Chris@16:     stream_offset result = -1;
Chris@16:     bool one = one_head();
Chris@16:     if (one && (pptr() != 0 || gptr()== 0))
Chris@16:         init_get_area(); // Switch to input mode, for code reuse.
Chris@16:     if (one || ((which & BOOST_IOS::in) != 0 && ibeg_ != 0)) {
Chris@16:         if (!gptr()) setg(ibeg_, ibeg_, iend_);
Chris@16:         ptrdiff_t next = 0;
Chris@16:         switch (way) {
Chris@16:         case BOOST_IOS::beg: next = off; break;
Chris@16:         case BOOST_IOS::cur: next = (gptr() - ibeg_) + off; break;
Chris@16:         case BOOST_IOS::end: next = (iend_ - ibeg_) + off; break;
Chris@16:         default: BOOST_ASSERT(0);
Chris@16:         }
Chris@16:         if (next < 0 || next > (iend_ - ibeg_))
Chris@16:             boost::throw_exception(bad_seek());
Chris@16:         setg(ibeg_, ibeg_ + next, iend_);
Chris@16:         result = next;
Chris@16:     }
Chris@16:     if (!one && (which & BOOST_IOS::out) != 0 && obeg_ != 0) {
Chris@16:         if (!pptr()) setp(obeg_, oend_);
Chris@16:         ptrdiff_t next = 0;
Chris@16:         switch (way) {
Chris@16:         case BOOST_IOS::beg: next = off; break;
Chris@16:         case BOOST_IOS::cur: next = (pptr() - obeg_) + off; break;
Chris@16:         case BOOST_IOS::end: next = (oend_ - obeg_) + off; break;
Chris@16:         default: BOOST_ASSERT(0);
Chris@16:         }
Chris@16:         if (next < 0 || next > (oend_ - obeg_))
Chris@16:             boost::throw_exception(bad_seek());
Chris@16:         pbump(static_cast<int>(next - (pptr() - obeg_)));
Chris@16:         result = next;
Chris@16:     }
Chris@16:     return offset_to_position(result);
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: void direct_streambuf<T, Tr>::init_input(input)
Chris@16: {
Chris@16:     std::pair<char_type*, char_type*> p = input_sequence(*storage_);
Chris@16:     ibeg_ = p.first;
Chris@16:     iend_ = p.second;
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: void direct_streambuf<T, Tr>::init_output(output)
Chris@16: {
Chris@16:     std::pair<char_type*, char_type*> p = output_sequence(*storage_);
Chris@16:     obeg_ = p.first;
Chris@16:     oend_ = p.second;
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: void direct_streambuf<T, Tr>::init_get_area()
Chris@16: {
Chris@16:     setg(ibeg_, ibeg_, iend_);
Chris@16:     if (one_head() && pptr()) {
Chris@16:         gbump(static_cast<int>(pptr() - obeg_));
Chris@16:         setp(0, 0);
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: void direct_streambuf<T, Tr>::init_put_area()
Chris@16: {
Chris@16:     setp(obeg_, oend_);
Chris@16:     if (one_head() && gptr()) {
Chris@16:         pbump(static_cast<int>(gptr() - ibeg_));
Chris@16:         setg(0, 0, 0);
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: inline bool direct_streambuf<T, Tr>::one_head() const
Chris@16: { return ibeg_ && obeg_ && ibeg_ == obeg_; }
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: inline bool direct_streambuf<T, Tr>::two_head() const
Chris@16: { return ibeg_ && obeg_ && ibeg_ != obeg_; }
Chris@16: 
Chris@16: //----------------------------------------------------------------------------//
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: } } // End namespaces iostreams, boost.
Chris@16: 
Chris@16: #include <boost/iostreams/detail/config/enable_warnings.hpp> // MSVC
Chris@16: 
Chris@16: #endif // #ifndef BOOST_IOSTREAMS_DETAIL_DIRECT_STREAMBUF_HPP_INCLUDED