sl@0: // (C) Copyright Jonathan Turkanis 2005.
sl@0: // Distributed under the Boost Software License, Version 1.0. (See accompanying
sl@0: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
sl@0: 
sl@0: // See http://www.boost.org/libs/iostreams for documentation.
sl@0: 
sl@0: #ifndef BOOST_IOSTREAMS_RESTRICT_HPP_INCLUDED
sl@0: #define BOOST_IOSTREAMS_RESTRICT_HPP_INCLUDED
sl@0: 
sl@0: #if defined(_MSC_VER) && (_MSC_VER >= 1020)
sl@0: # pragma once
sl@0: #endif
sl@0: 
sl@0: #include <algorithm>          // min.
sl@0: #include <utility>            // pair.
sl@0: #include <boost/cstdint.hpp>  // intmax_t.
sl@0: #include <boost/config.hpp>   // DEDUCED_TYPENAME.
sl@0: #include <boost/iostreams/categories.hpp>
sl@0: #include <boost/iostreams/char_traits.hpp>
sl@0: #include <boost/iostreams/detail/adapter/basic_adapter.hpp>
sl@0: #include <boost/iostreams/detail/call_traits.hpp>
sl@0: #include <boost/iostreams/detail/enable_if_stream.hpp>
sl@0: #include <boost/iostreams/detail/error.hpp>
sl@0: #include <boost/iostreams/detail/ios.hpp>     // failure.
sl@0: #include <boost/iostreams/detail/select.hpp>
sl@0: #include <boost/iostreams/operations.hpp>
sl@0: #include <boost/iostreams/skip.hpp>
sl@0: #include <boost/iostreams/traits.hpp>         // mode_of, is_direct.
sl@0: #include <boost/mpl/bool.hpp>
sl@0: #include <boost/static_assert.hpp>
sl@0: #include <boost/type_traits/is_convertible.hpp>
sl@0: 
sl@0: #include <boost/iostreams/detail/config/disable_warnings.hpp> // VC7.1 C4244.
sl@0: 
sl@0: namespace boost { namespace iostreams {
sl@0: 
sl@0: namespace detail {
sl@0: 
sl@0: //
sl@0: // Template name: restricted_indirect_device.
sl@0: // Description: Provides an restricted view of an indirect Device.
sl@0: // Template paramters:
sl@0: //      Device - An indirect model of Device that models either Source or
sl@0: //          SeekableDevice.
sl@0: //
sl@0: template<typename Device>
sl@0: class restricted_indirect_device : public basic_adapter<Device> {
sl@0: private:
sl@0:     typedef typename detail::param_type<Device>::type  param_type;
sl@0: public:
sl@0:     typedef typename char_type_of<Device>::type        char_type;
sl@0:     struct category
sl@0:         : mode_of<Device>::type,
sl@0:           device_tag,
sl@0:           closable_tag,
sl@0:           flushable_tag,
sl@0:           localizable_tag,
sl@0:           optimally_buffered_tag
sl@0:         { };
sl@0:     restricted_indirect_device( param_type dev, stream_offset off,
sl@0:                                 stream_offset len = -1 );
sl@0:     std::streamsize read(char_type* s, std::streamsize n);
sl@0:     std::streamsize write(const char_type* s, std::streamsize n);
sl@0:     stream_offset seek(stream_offset off, BOOST_IOS::seekdir way);
sl@0: private:
sl@0:     stream_offset beg_, pos_, end_;
sl@0: };
sl@0: 
sl@0: //
sl@0: // Template name: restricted_direct_device.
sl@0: // Description: Provides an restricted view of a Direct Device.
sl@0: // Template paramters:
sl@0: //      Device - A model of Direct and Device.
sl@0: //
sl@0: template<typename Device>
sl@0: class restricted_direct_device : public basic_adapter<Device> {
sl@0: public:
sl@0:     typedef typename char_type_of<Device>::type  char_type;
sl@0:     typedef std::pair<char_type*, char_type*>    pair_type;
sl@0:     struct category
sl@0:         : mode_of<Device>::type,
sl@0:           device_tag,
sl@0:           direct_tag,
sl@0:           closable_tag,
sl@0:           localizable_tag
sl@0:         { };
sl@0:     restricted_direct_device( const Device& dev, stream_offset off,
sl@0:                               stream_offset len = -1 );
sl@0:     pair_type input_sequence();
sl@0:     pair_type output_sequence();
sl@0: private:
sl@0:     pair_type sequence(mpl::true_);
sl@0:     pair_type sequence(mpl::false_);
sl@0:     char_type *beg_, *end_;
sl@0: };
sl@0: 
sl@0: //
sl@0: // Template name: restricted_filter.
sl@0: // Description: Provides an restricted view of a Filter.
sl@0: // Template paramters:
sl@0: //      Filter - An indirect model of Filter.
sl@0: //
sl@0: template<typename Filter>
sl@0: class restricted_filter : public basic_adapter<Filter> {
sl@0: public:
sl@0:     typedef typename char_type_of<Filter>::type char_type;
sl@0:     struct category
sl@0:         : mode_of<Filter>::type,
sl@0:           filter_tag,
sl@0:           multichar_tag,
sl@0:           closable_tag,
sl@0:           localizable_tag,
sl@0:           optimally_buffered_tag
sl@0:         { };
sl@0:     restricted_filter( const Filter& flt, stream_offset off, 
sl@0:                        stream_offset len = -1 );
sl@0: 
sl@0:     template<typename Source>
sl@0:     std::streamsize read(Source& src, char_type* s, std::streamsize n)
sl@0:     {
sl@0:         using namespace std;
sl@0:         if (!open_)
sl@0:             open(src);
sl@0:         streamsize amt =
sl@0:             end_ != -1 ?
sl@0:                 (std::min) (n, static_cast<streamsize>(end_ - pos_)) :
sl@0:                 n;
sl@0:         streamsize result = iostreams::read(this->component(), src, s, amt);
sl@0:         if (result != -1)
sl@0:             pos_ += result;
sl@0:         return result;
sl@0:     }
sl@0: 
sl@0:     template<typename Sink>
sl@0:     std::streamsize write(Sink& snk, const char_type* s, std::streamsize n)
sl@0:     {
sl@0:         if (!open_)
sl@0:             open(snk);
sl@0:         if (end_ != -1 && pos_ + n >= end_)
sl@0:             bad_write();
sl@0:         std::streamsize result = 
sl@0:             iostreams::write(this->component(), snk, s, n);
sl@0:         pos_ += result;
sl@0:         return result;
sl@0:     }
sl@0: 
sl@0:     template<typename Device>
sl@0:     stream_offset seek(Device& dev, stream_offset off, BOOST_IOS::seekdir way)
sl@0:     {
sl@0:         stream_offset next;
sl@0:         if (way == BOOST_IOS::beg) {
sl@0:             next = beg_ + off;
sl@0:         } else if (way == BOOST_IOS::cur) {
sl@0:             next = pos_ + off;
sl@0:         } else if (end_ != -1) {
sl@0:             next = end_ + off;
sl@0:         } else {
sl@0:             // Restriction is half-open; seek relative to the actual end.
sl@0:             pos_ = this->component().seek(dev, off, BOOST_IOS::end);
sl@0:             if (pos_ < beg_)
sl@0:                 bad_seek();
sl@0:             return pos_ - beg_;
sl@0:         }
sl@0:         if (next < beg_ || end_ != -1 && next >= end_)
sl@0:             bad_seek();
sl@0:         pos_ = this->component().seek(dev, next, BOOST_IOS::cur);
sl@0:         return pos_ - beg_;
sl@0:     }
sl@0: private:
sl@0:     template<typename Device>
sl@0:     void open(Device& dev)
sl@0:     {
sl@0:         open_ = true;
sl@0:         iostreams::skip(this->component(), dev, beg_);
sl@0:     }
sl@0:     stream_offset  beg_, pos_, end_;
sl@0:     bool           open_;
sl@0: };
sl@0: 
sl@0: template<typename T>
sl@0: struct restriction_traits
sl@0:     : iostreams::select<  // Disambiguation for Tru64.
sl@0:           is_filter<T>,  restricted_filter<T>,
sl@0:           is_direct<T>,  restricted_direct_device<T>,
sl@0:           else_,         restricted_indirect_device<T>
sl@0:       >
sl@0:     { };
sl@0: 
sl@0: } // End namespace detail.
sl@0: 
sl@0: template<typename T>
sl@0: struct restriction : public detail::restriction_traits<T>::type {
sl@0:     typedef typename detail::param_type<T>::type          param_type;
sl@0:     typedef typename detail::restriction_traits<T>::type  base_type;
sl@0:     restriction(param_type t, stream_offset off, stream_offset len = -1)
sl@0:         : base_type(t, off, len)
sl@0:         { }
sl@0: };
sl@0: 
sl@0: //--------------Implementation of restrict------------------------------------//
sl@0: 
sl@0: // Note: The following workarounds are patterned after resolve.hpp. It has not
sl@0: // yet been confirmed that they are necessary.
sl@0: 
sl@0: #ifndef BOOST_IOSTREAMS_BROKEN_OVERLOAD_RESOLUTION //-------------------------//
sl@0: # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //-------------------------------//
sl@0: 
sl@0: template<typename T>
sl@0: restriction<T> restrict( const T& t, stream_offset off, stream_offset len = -1
sl@0:                          BOOST_IOSTREAMS_DISABLE_IF_STREAM(T) )
sl@0: { return restriction<T>(t, off, len); }
sl@0: 
sl@0: template<typename Ch, typename Tr>
sl@0: restriction< std::basic_streambuf<Ch, Tr> >
sl@0: restrict(std::basic_streambuf<Ch, Tr>& sb, stream_offset off, stream_offset len = -1)
sl@0: { return restriction< std::basic_streambuf<Ch, Tr> >(sb, off, len); }
sl@0: 
sl@0: template<typename Ch, typename Tr>
sl@0: restriction< std::basic_istream<Ch, Tr> >
sl@0: restrict(std::basic_istream<Ch, Tr>& is, stream_offset off, stream_offset len = -1)
sl@0: { return restriction< std::basic_istream<Ch, Tr> >(is, off, len); }
sl@0: 
sl@0: template<typename Ch, typename Tr>
sl@0: restriction< std::basic_ostream<Ch, Tr> >
sl@0: restrict(std::basic_ostream<Ch, Tr>& os, stream_offset off, stream_offset len = -1)
sl@0: { return restriction< std::basic_ostream<Ch, Tr> >(os, off, len); }
sl@0: 
sl@0: template<typename Ch, typename Tr>
sl@0: restriction< std::basic_iostream<Ch, Tr> >
sl@0: restrict(std::basic_iostream<Ch, Tr>& io, stream_offset off, stream_offset len = -1)
sl@0: { return restriction< std::basic_iostream<Ch, Tr> >(io, off, len); }
sl@0: 
sl@0: # else // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //---------------------//
sl@0: 
sl@0: template<typename T>
sl@0: restriction<T> restrict( const T& t, stream_offset off, stream_offset len = -1
sl@0:                          BOOST_IOSTREAMS_DISABLE_IF_STREAM(T) )
sl@0: { return restriction<T>(t, off, len); }
sl@0: 
sl@0: restriction<std::streambuf> 
sl@0: restrict(std::streambuf& sb, stream_offset off, stream_offset len = -1)
sl@0: { return restriction<std::streambuf>(sb, off, len); }
sl@0: 
sl@0: restriction<std::istream> 
sl@0: restrict(std::istream<Ch, Tr>& is, stream_offset off, stream_offset len = -1)
sl@0: { return restriction<std::istream>(is, off, len); }
sl@0: 
sl@0: restriction<std::ostream> 
sl@0: restrict(std::ostream<Ch, Tr>& os, stream_offset off, stream_offset len = -1)
sl@0: { return restriction<std::ostream>(os, off, len); }
sl@0: 
sl@0: restriction<std::iostream> 
sl@0: restrict(std::iostream<Ch, Tr>& io, stream_offset off, stream_offset len = -1)
sl@0: { return restriction<std::iostream>(io, off, len); }
sl@0: 
sl@0: # endif // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //--------------------//
sl@0: #else // #ifndef BOOST_IOSTREAMS_BROKEN_OVERLOAD_RESOLUTION //----------------//
sl@0: 
sl@0: template<typename T>
sl@0: restriction<T> 
sl@0: restrict(const T& t, stream_offset off, stream_offset len, mpl::true_)
sl@0: {   // Bad overload resolution.
sl@0:     return restriction<T>(const_cast<T&>(t, off, len));
sl@0: }
sl@0: 
sl@0: template<typename T>
sl@0: restriction<T> 
sl@0: restrict(const T& t, stream_offset off, stream_offset len, mpl::false_)
sl@0: { return restriction<T>(t, off, len); }
sl@0: 
sl@0: template<typename T>
sl@0: restriction<T> 
sl@0: restrict( const T& t, stream_offset off, stream_offset len = -1
sl@0:           BOOST_IOSTREAMS_DISABLE_IF_STREAM(T) )
sl@0: { return restrict(t, off, len, is_std_io<T>()); }
sl@0: 
sl@0: # if !BOOST_WORKAROUND(__BORLANDC__, < 0x600) && \
sl@0:      !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) && \
sl@0:      !defined(__GNUC__) // ---------------------------------------------------//
sl@0: 
sl@0: template<typename T>
sl@0: restriction<T>
sl@0: restrict(T& t, stream_offset off, stream_offset len = -1)
sl@0: { return restriction<T>(t, off, len); }
sl@0: 
sl@0: # endif // Borland 5.x, VC6-7.0 or GCC 2.9x //--------------------------------//
sl@0: #endif // #ifndef BOOST_IOSTREAMS_BROKEN_OVERLOAD_RESOLUTION //---------------//
sl@0: //----------------------------------------------------------------------------//
sl@0: 
sl@0: namespace detail {
sl@0: 
sl@0: //--------------Implementation of restricted_indirect_device------------------//
sl@0: 
sl@0: template<typename Device>
sl@0: restricted_indirect_device<Device>::restricted_indirect_device
sl@0:     (param_type dev, stream_offset off, stream_offset len)
sl@0:     : basic_adapter<Device>(dev), beg_(off), pos_(off), 
sl@0:       end_(len != -1 ? off + len : -1)
sl@0: {
sl@0:     if (len < -1 || off < 0)
sl@0:         throw BOOST_IOSTREAMS_FAILURE("bad offset");
sl@0:     iostreams::skip(this->component(), off);
sl@0: }
sl@0: 
sl@0: template<typename Device>
sl@0: inline std::streamsize restricted_indirect_device<Device>::read
sl@0:     (char_type* s, std::streamsize n)
sl@0: {
sl@0:     using namespace std;
sl@0:     streamsize amt =
sl@0:         end_ != -1 ?
sl@0:             (std::min) (n, static_cast<streamsize>(end_ - pos_)) :
sl@0:             n;
sl@0:     streamsize result = iostreams::read(this->component(), s, amt);
sl@0:     if (result != -1)
sl@0:         pos_ += result;
sl@0:     return result;
sl@0: }
sl@0: 
sl@0: template<typename Device>
sl@0: inline std::streamsize restricted_indirect_device<Device>::write
sl@0:     (const char_type* s, std::streamsize n)
sl@0: {
sl@0:     if (end_ != -1 && pos_ + n >= end_)
sl@0:         bad_write();
sl@0:     std::streamsize result = iostreams::write(this->component(), s, n);
sl@0:     pos_ += result;
sl@0:     return result;
sl@0: }
sl@0: 
sl@0: template<typename Device>
sl@0: stream_offset restricted_indirect_device<Device>::seek
sl@0:     (stream_offset off, BOOST_IOS::seekdir way)
sl@0: {
sl@0:     stream_offset next;
sl@0:     if (way == BOOST_IOS::beg) {
sl@0:         next = beg_ + off;
sl@0:     } else if (way == BOOST_IOS::cur) {
sl@0:         next = pos_ + off;
sl@0:     } else if (end_ != -1) {
sl@0:         next = end_ + off;
sl@0:     } else {
sl@0:         // Restriction is half-open; seek relative to the actual end.
sl@0:         pos_ = iostreams::seek(this->component(), off, BOOST_IOS::end);
sl@0:         if (pos_ < beg_)
sl@0:             bad_seek();
sl@0:         return pos_ - beg_;
sl@0:     }
sl@0:     if (next < beg_ || end_ != -1 && next >= end_)
sl@0:         bad_seek();
sl@0:     pos_ = iostreams::seek(this->component(), next - pos_, BOOST_IOS::cur);
sl@0:     return pos_ - beg_;
sl@0: }
sl@0: 
sl@0: //--------------Implementation of restricted_direct_device--------------------//
sl@0: 
sl@0: template<typename Device>
sl@0: restricted_direct_device<Device>::restricted_direct_device
sl@0:     (const Device& dev, stream_offset off, stream_offset len)
sl@0:     : basic_adapter<Device>(dev), beg_(0), end_(0)
sl@0: {
sl@0:     std::pair<char_type*, char_type*> seq =
sl@0:         sequence(is_convertible<category, input>());
sl@0:     if ( off < 0 || len < -1 || 
sl@0:          len != -1 && off + len > seq.second - seq.first )
sl@0:     {
sl@0:         throw BOOST_IOSTREAMS_FAILURE("bad offset");
sl@0:     }
sl@0:     beg_ = seq.first + off;
sl@0:     end_ = len != -1 ? 
sl@0:         seq.first + off + len :
sl@0:         seq.second;
sl@0: }
sl@0: 
sl@0: template<typename Device>
sl@0: typename restricted_direct_device<Device>::pair_type
sl@0: restricted_direct_device<Device>::input_sequence()
sl@0: {
sl@0:     BOOST_STATIC_ASSERT((is_convertible<category, input>::value));
sl@0:     return std::make_pair(beg_, end_);
sl@0: }
sl@0: 
sl@0: template<typename Device>
sl@0: typename restricted_direct_device<Device>::pair_type
sl@0: restricted_direct_device<Device>::output_sequence()
sl@0: {
sl@0:     BOOST_STATIC_ASSERT((is_convertible<category, output>::value));
sl@0:     return std::make_pair(beg_, end_);
sl@0: }
sl@0: 
sl@0: template<typename Device>
sl@0: typename restricted_direct_device<Device>::pair_type
sl@0: restricted_direct_device<Device>::sequence(mpl::true_)
sl@0: { return iostreams::input_sequence(this->component()); }
sl@0: 
sl@0: template<typename Device>
sl@0: typename restricted_direct_device<Device>::pair_type
sl@0: restricted_direct_device<Device>::sequence(mpl::false_)
sl@0: { return iostreams::output_sequence(this->component()); }
sl@0: 
sl@0: //--------------Implementation of restricted_filter---------------------------//
sl@0: 
sl@0: template<typename Filter>
sl@0: restricted_filter<Filter>::restricted_filter
sl@0:     (const Filter& flt, stream_offset off, stream_offset len)
sl@0:     : basic_adapter<Filter>(flt), beg_(off),
sl@0:       pos_(off), end_(len != -1 ? off + len : -1), open_(false)
sl@0: {
sl@0:     if (len < -1 || off < 0)
sl@0:         throw BOOST_IOSTREAMS_FAILURE("bad offset");
sl@0: }
sl@0: 
sl@0: } // End namespace detail.
sl@0: 
sl@0: } } // End namespaces iostreams, boost.
sl@0: 
sl@0: 
sl@0: #endif // #ifndef BOOST_IOSTREAMS_RESTRICT_HPP_INCLUDED