iostreams/filter/counter.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_COUNTER_HPP_INCLUDED
0009 #define BOOST_IOSTREAMS_COUNTER_HPP_INCLUDED
0010
0011 #if defined(_MSC_VER)
0012 # pragma once
0013 #endif
0014
0015 #include <algorithm>  // count.
0016 #include <boost/iostreams/categories.hpp>
0017 #include <boost/iostreams/char_traits.hpp>
0018 #include <boost/iostreams/operations.hpp>
0019 #include <boost/iostreams/pipeline.hpp>
0020
0021 // Must come last.
0022 #include <boost/iostreams/detail/config/disable_warnings.hpp> // VC7.1 C4244.
0023
0024 namespace boost { namespace iostreams {
0025
0026 //
0027 // Template name: basic_counter.
0028 // Template parameters:
0029 //      Ch - The character type.
0030 // Description: Filter which counts lines and characters.
0031 //
0032 template<typename Ch>
0033 class basic_counter  {
0034 public:
0035     typedef Ch char_type;
0036     struct category
0037         : dual_use,
0038           filter_tag,
0039           multichar_tag,
0040           optimally_buffered_tag
0041         { };
0042     explicit basic_counter(int first_line = 0, int first_char = 0)
0043         : lines_(first_line), chars_(first_char)
0044         { }
0045     int lines() const { return lines_; }
0046     int characters() const { return chars_; }
0047     std::streamsize optimal_buffer_size() const { return 0; }
0048
0049     template<typename Source>
0050     std::streamsize read(Source& src, char_type* s, std::streamsize n)
0051     {
0052         std::streamsize result = iostreams::read(src, s, n);
0053         if (result == -1)
0054             return -1;
0055         lines_ += std::count(s, s + result, char_traits<Ch>::newline());
0056         chars_ += result;
0057         return result;
0058     }
0059
0060     template<typename Sink>
0061     std::streamsize write(Sink& snk, const char_type* s, std::streamsize n)
0062     {
0063         std::streamsize result = iostreams::write(snk, s, n);
0064         lines_ += std::count(s, s + result, char_traits<Ch>::newline());
0065         chars_ += result;
0066         return result;
0067     }
0068 private:
0069     int lines_;
0070     int chars_;
0071 };
0072 BOOST_IOSTREAMS_PIPABLE(basic_counter, 1)
0073
0074
0075 typedef basic_counter<char>     counter;
0076 typedef basic_counter<wchar_t>  wcounter;
0077
0078 } } // End namespaces iostreams, boost.
0079
0080 #include <boost/iostreams/detail/config/enable_warnings.hpp>
0081
0082 #endif // #ifndef BOOST_IOSTREAMS_COUNTER_HPP_INCLUDED