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: The function template copy, which reads data from a Source 
Chris@16: // and writes it to a Sink until the end of the sequence is reached, returning 
Chris@16: // the number of characters transfered.
Chris@16: 
Chris@16: // The implementation is complicated by the need to handle smart adapters
Chris@16: // and direct devices.
Chris@16: 
Chris@16: #ifndef BOOST_IOSTREAMS_COPY_HPP_INCLUDED
Chris@16: #define BOOST_IOSTREAMS_COPY_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>                 // Make sure ptrdiff_t is in std.
Chris@16: #include <algorithm>                        // copy, min.
Chris@16: #include <cstddef>                          // ptrdiff_t.
Chris@16: #include <utility>                          // pair.
Chris@16: #include <boost/bind.hpp>
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: #include <boost/iostreams/chain.hpp>
Chris@16: #include <boost/iostreams/constants.hpp>
Chris@16: #include <boost/iostreams/detail/adapter/non_blocking_adapter.hpp>        
Chris@16: #include <boost/iostreams/detail/buffer.hpp>
Chris@16: #include <boost/iostreams/detail/enable_if_stream.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>   // failure, streamsize.                   
Chris@16: #include <boost/iostreams/detail/resolve.hpp>                   
Chris@16: #include <boost/iostreams/detail/wrap_unwrap.hpp>
Chris@16: #include <boost/iostreams/operations.hpp>  // read, write, close.
Chris@16: #include <boost/iostreams/pipeline.hpp>
Chris@16: #include <boost/static_assert.hpp>  
Chris@16: #include <boost/type_traits/is_same.hpp> 
Chris@16: 
Chris@16: namespace boost { namespace iostreams {
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16:     // The following four overloads of copy_impl() optimize 
Chris@16:     // copying in the case that one or both of the two devices
Chris@16:     // models Direct (see 
Chris@16:     // http://www.boost.org/libs/iostreams/doc/index.html?path=4.1.1.4)
Chris@16: 
Chris@16: // Copy from a direct source to a direct sink
Chris@16: template<typename Source, typename Sink>
Chris@16: std::streamsize copy_impl( Source& src, Sink& snk, 
Chris@16:                            std::streamsize /* buffer_size */,
Chris@16:                            mpl::true_, mpl::true_ )
Chris@16: {   
Chris@16:     using namespace std;
Chris@16:     typedef typename char_type_of<Source>::type  char_type;
Chris@16:     typedef std::pair<char_type*, char_type*>    pair_type;
Chris@16:     pair_type p1 = iostreams::input_sequence(src);
Chris@16:     pair_type p2 = iostreams::output_sequence(snk);
Chris@16:     std::streamsize total = 
Chris@16:         static_cast<std::streamsize>(
Chris@16:             (std::min)(p1.second - p1.first, p2.second - p2.first)
Chris@16:         );
Chris@16:     std::copy(p1.first, p1.first + total, p2.first);
Chris@16:     return total;
Chris@16: }
Chris@16: 
Chris@16: // Copy from a direct source to an indirect sink
Chris@16: template<typename Source, typename Sink>
Chris@16: std::streamsize copy_impl( Source& src, Sink& snk, 
Chris@16:                            std::streamsize /* buffer_size */,
Chris@16:                            mpl::true_, mpl::false_ )
Chris@16: {
Chris@16:     using namespace std;
Chris@16:     typedef typename char_type_of<Source>::type  char_type;
Chris@16:     typedef std::pair<char_type*, char_type*>    pair_type;
Chris@16:     pair_type p = iostreams::input_sequence(src);
Chris@16:     std::streamsize size, total;
Chris@16:     for ( total = 0, size = static_cast<std::streamsize>(p.second - p.first);
Chris@16:           total < size; )
Chris@16:     {
Chris@16:         std::streamsize amt = 
Chris@16:             iostreams::write(snk, p.first + total, size - total); 
Chris@16:         total += amt;
Chris@16:     }
Chris@16:     return total;
Chris@16: }
Chris@16: 
Chris@16: // Copy from an indirect source to a direct sink
Chris@16: template<typename Source, typename Sink>
Chris@16: std::streamsize copy_impl( Source& src, Sink& snk, 
Chris@16:                            std::streamsize buffer_size,
Chris@16:                            mpl::false_, mpl::true_ )
Chris@16: {
Chris@16:     typedef typename char_type_of<Source>::type  char_type;
Chris@16:     typedef std::pair<char_type*, char_type*>    pair_type;
Chris@16:     detail::basic_buffer<char_type>  buf(buffer_size);
Chris@16:     pair_type                        p = snk.output_sequence();
Chris@16:     std::streamsize                  total = 0;
Chris@16:     std::ptrdiff_t                   capacity = p.second - p.first;
Chris@16:     while (true) {
Chris@16:         std::streamsize amt = 
Chris@16:             iostreams::read(
Chris@16:                 src, 
Chris@16:                 buf.data(),
Chris@16:                 buffer_size < capacity - total ?
Chris@16:                     buffer_size :
Chris@16:                     static_cast<std::streamsize>(capacity - total)
Chris@16:             );
Chris@16:         if (amt == -1)
Chris@16:             break;
Chris@16:         std::copy(buf.data(), buf.data() + amt, p.first + total);
Chris@16:         total += amt;
Chris@16:     }
Chris@16:     return total;
Chris@16: }
Chris@16: 
Chris@16: // Copy from an indirect source to an indirect sink
Chris@16: template<typename Source, typename Sink>
Chris@16: std::streamsize copy_impl( Source& src, Sink& snk, 
Chris@16:                            std::streamsize buffer_size,
Chris@16:                            mpl::false_, mpl::false_ )
Chris@16: { 
Chris@16:     typedef typename char_type_of<Source>::type char_type;
Chris@16:     detail::basic_buffer<char_type>  buf(buffer_size);
Chris@16:     non_blocking_adapter<Sink>       nb(snk);
Chris@16:     std::streamsize                  total = 0;
Chris@16:     bool                             done = false;
Chris@16:     while (!done) {
Chris@16:         std::streamsize amt;
Chris@16:         done = (amt = iostreams::read(src, buf.data(), buffer_size)) == -1;
Chris@16:         if (amt != -1) {
Chris@16:             iostreams::write(nb, buf.data(), amt);
Chris@16:             total += amt;
Chris@16:         }
Chris@16:     }
Chris@16:     return total;
Chris@16: }
Chris@16: 
Chris@16:     // The following function object is used with 
Chris@16:     // boost::iostreams::detail::execute() in the primary 
Chris@16:     // overload of copy_impl(), below
Chris@16: 
Chris@16: // Function object that delegates to one of the above four 
Chris@16: // overloads of compl_impl()
Chris@16: template<typename Source, typename Sink>
Chris@16: class copy_operation {
Chris@16: public:
Chris@16:     typedef std::streamsize result_type;
Chris@16:     copy_operation(Source& src, Sink& snk, std::streamsize buffer_size)
Chris@16:         : src_(src), snk_(snk), buffer_size_(buffer_size)
Chris@16:         { }
Chris@16:     std::streamsize operator()() 
Chris@16:     {
Chris@16:         return copy_impl( src_, snk_, buffer_size_, 
Chris@16:                           is_direct<Source>(), is_direct<Sink>() );
Chris@16:     }
Chris@16: private:
Chris@16:     copy_operation& operator=(const copy_operation&);
Chris@16:     Source&          src_;
Chris@16:     Sink&            snk_;
Chris@16:     std::streamsize  buffer_size_;
Chris@16: };
Chris@16: 
Chris@16: // Primary overload of copy_impl. Delegates to one of the above four 
Chris@16: // overloads of compl_impl(), depending on which of the two given 
Chris@16: // devices, if any, models Direct (see 
Chris@16: // http://www.boost.org/libs/iostreams/doc/index.html?path=4.1.1.4)
Chris@16: template<typename Source, typename Sink>
Chris@16: std::streamsize copy_impl(Source src, Sink snk, std::streamsize buffer_size)
Chris@16: {
Chris@16:     using namespace std;
Chris@16:     typedef typename char_type_of<Source>::type  src_char;
Chris@16:     typedef typename char_type_of<Sink>::type    snk_char;
Chris@16:     BOOST_STATIC_ASSERT((is_same<src_char, snk_char>::value));
Chris@16:     return detail::execute_all(
Chris@16:                copy_operation<Source, Sink>(src, snk, buffer_size),
Chris@16:                detail::call_close_all(src),
Chris@16:                detail::call_close_all(snk)
Chris@16:            );
Chris@16: }
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16:                     
Chris@16: //------------------Definition of copy----------------------------------------//
Chris@16: 
Chris@16: // Overload of copy() for the case where neither the source nor the sink is
Chris@16: // a standard stream or stream buffer
Chris@16: template<typename Source, typename Sink>
Chris@16: std::streamsize
Chris@16: copy( const Source& src, const Sink& snk,
Chris@16:       std::streamsize buffer_size = default_device_buffer_size
Chris@16:       BOOST_IOSTREAMS_DISABLE_IF_STREAM(Source)
Chris@16:       BOOST_IOSTREAMS_DISABLE_IF_STREAM(Sink) )
Chris@16: { 
Chris@16:     typedef typename char_type_of<Source>::type char_type;
Chris@16:     return detail::copy_impl( detail::resolve<input, char_type>(src), 
Chris@16:                               detail::resolve<output, char_type>(snk), 
Chris@16:                               buffer_size ); 
Chris@16: }
Chris@16: 
Chris@16: #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) //---------------------------------//
Chris@16: 
Chris@16: // Overload of copy() for the case where the source, but not the sink, is
Chris@16: // a standard stream or stream buffer
Chris@16: template<typename Source, typename Sink>
Chris@16: std::streamsize
Chris@16: copy( Source& src, const Sink& snk,
Chris@16:       std::streamsize buffer_size = default_device_buffer_size
Chris@16:       BOOST_IOSTREAMS_ENABLE_IF_STREAM(Source)
Chris@16:       BOOST_IOSTREAMS_DISABLE_IF_STREAM(Sink) ) 
Chris@16: { 
Chris@16:     typedef typename char_type_of<Source>::type char_type;
Chris@16:     return detail::copy_impl( detail::wrap(src), 
Chris@16:                               detail::resolve<output, char_type>(snk), 
Chris@16:                               buffer_size );
Chris@16: }
Chris@16: 
Chris@16: // Overload of copy() for the case where the sink, but not the source, is
Chris@16: // a standard stream or stream buffer
Chris@16: template<typename Source, typename Sink>
Chris@16: std::streamsize
Chris@16: copy( const Source& src, Sink& snk,
Chris@16:       std::streamsize buffer_size = default_device_buffer_size
Chris@16:       BOOST_IOSTREAMS_DISABLE_IF_STREAM(Source)
Chris@16:       BOOST_IOSTREAMS_ENABLE_IF_STREAM(Sink) ) 
Chris@16: { 
Chris@16:     typedef typename char_type_of<Source>::type char_type;
Chris@16:     return detail::copy_impl( detail::resolve<input, char_type>(src), 
Chris@16:                               detail::wrap(snk), buffer_size );
Chris@16: }
Chris@16: 
Chris@16: // Overload of copy() for the case where neither the source nor the sink is
Chris@16: // a standard stream or stream buffer
Chris@16: template<typename Source, typename Sink>
Chris@16: std::streamsize
Chris@16: copy( Source& src, Sink& snk,
Chris@16:       std::streamsize buffer_size = default_device_buffer_size
Chris@16:       BOOST_IOSTREAMS_ENABLE_IF_STREAM(Source)
Chris@16:       BOOST_IOSTREAMS_ENABLE_IF_STREAM(Sink) ) 
Chris@16: { 
Chris@16:     return detail::copy_impl(detail::wrap(src), detail::wrap(snk), buffer_size);
Chris@16: }
Chris@16: 
Chris@16: #endif // #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) //-----------------------//
Chris@16: 
Chris@16: } } // End namespaces iostreams, boost.
Chris@16: 
Chris@16: #endif // #ifndef BOOST_IOSTREAMS_COPY_HPP_INCLUDED