iostreams/detail/counted_array.hpp

0001 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
0002 // (C) Copyright 2005-2007 Jonathan Turkanis
0003 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0004 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
0005
0006 // See http://www.boost.org/libs/iostreams for documentation.
0007
0008 #ifndef BOOST_IOSTREAMS_DETAIL_COUNTED_ARRAY_HPP_INCLUDED
0009 #define BOOST_IOSTREAMS_DETAIL_COUNTED_ARRAY_HPP_INCLUDED
0010
0011 #include <algorithm>                               // min.
0012 #include <cstddef>                                 // size_t
0013 #include <string>                                  // char_traits
0014 #include <boost/iostreams/categories.hpp>
0015 #include <boost/iostreams/detail/char_traits.hpp>
0016 #include <boost/iostreams/detail/ios.hpp>          // streamsize.
0017
0018 namespace boost { namespace iostreams { namespace detail {
0019
0020 template<typename Ch>
0021 class counted_array_source {
0022 public:
0023     typedef Ch          char_type;
0024     typedef source_tag  category;
0025     counted_array_source(const Ch* buf, std::streamsize size)
0026         : buf_(buf), ptr_(0), end_(size)
0027         { }
0028     std::streamsize read(Ch* s, std::streamsize n)
0029     {
0030         using namespace std;
0031         streamsize result = (std::min)(n, end_ - ptr_);
0032         char_traits<char_type>::copy(
0033             s,
0034             buf_ + ptr_,
0035             static_cast<size_t>(result)
0036         );
0037         ptr_ += result;
0038         return result;
0039     }
0040     std::streamsize count() const { return ptr_; }
0041 private:
0042     const Ch*        buf_;
0043     std::streamsize  ptr_, end_;
0044 };
0045
0046 template<typename Ch>
0047 struct counted_array_sink {
0048 public:
0049     typedef Ch        char_type;
0050     typedef sink_tag  category;
0051     counted_array_sink(Ch* buf, std::streamsize size)
0052         : buf_(buf), ptr_(0), end_(size)
0053         { }
0054         std::streamsize write(const Ch* s, std::streamsize n)
0055     {
0056         using namespace std;
0057         std::streamsize result = (std::min)(n, end_ - ptr_);
0058         char_traits<char_type>::copy(
0059             buf_ + ptr_,
0060             s,
0061             static_cast<size_t>(result)
0062         );
0063         ptr_ += result;
0064         return result;
0065     }
0066     std::streamsize count() const { return ptr_; }
0067 private:
0068     Ch*              buf_;
0069     std::streamsize  ptr_, end_;
0070 };
0071
0072 } } } // End namespaces iostreams, boost.
0073
0074 #endif // #ifndef BOOST_IOSTREAMS_DETAIL_COUNTED_ARRAY_HPP_INCLUDED