ceph/src/boost/libs/iostreams/include/boost/iostreams/filter/grep.hpp

   1 /*
   2  * Distributed under the Boost Software License, Version 1.0.(See accompanying
   3  * file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
   4  *
   5  * See http://www.boost.org/libs/iostreams for documentation.
   6
   7  * File:        boost/iostreams/filter/grep.hpp
   8  * Date:        Mon May 26 17:48:45 MDT 2008
   9  * Copyright:   2008 CodeRage, LLC
  10  * Author:      Jonathan Turkanis
  11  * Contact:     turkanis at coderage dot com
  12  *
  13  * Defines the class template basic_grep_filter and its specializations
  14  * grep_filter and wgrep_filter.
  15  */
  16
  17 #ifndef BOOST_IOSTREAMS_GREP_FILTER_HPP_INCLUDED
  18 #define BOOST_IOSTREAMS_GREP_FILTER_HPP_INCLUDED
  19
  20 #if defined(_MSC_VER)
  21 # pragma once
  22 #endif
  23
  24 #include <iostream>
  25
  26 #include <memory>  // allocator.
  27 #include <boost/iostreams/char_traits.hpp>
  28 #include <boost/iostreams/filter/line.hpp>
  29 #include <boost/iostreams/pipeline.hpp>
  30 #include <boost/regex.hpp>
  31
  32 namespace boost { namespace iostreams {
  33
  34 namespace grep {
  35
  36 const int invert      = 1;
  37 const int whole_line  = invert << 1;
  38
  39 } // End namespace grep.
  40
  41 template< typename Ch,
  42           typename Tr = regex_traits<Ch>,
  43           typename Alloc = std::allocator<Ch> >
  44 class basic_grep_filter : public basic_line_filter<Ch, Alloc> {
  45 private:
  46     typedef basic_line_filter<Ch, Alloc>               base_type;
  47 public:
  48     typedef typename base_type::char_type              char_type;
  49     typedef typename base_type::category               category;
  50     typedef char_traits<char_type>                     traits_type;
  51     typedef typename base_type::string_type            string_type;
  52     typedef basic_regex<Ch, Tr>                        regex_type;
  53     typedef regex_constants::match_flag_type           match_flag_type;
  54     basic_grep_filter( const regex_type& re,
  55                        match_flag_type match_flags =
  56                            regex_constants::match_default,
  57                        int options = 0 );
  58     int count() const { return count_; }
  59
  60     template<typename Sink>
  61     void close(Sink& snk, BOOST_IOS::openmode which)
  62     {
  63         base_type::close(snk, which);
  64         options_ &= ~f_initialized;
  65     }
  66 private:
  67     virtual string_type do_filter(const string_type& line)
  68     {
  69         if ((options_ & f_initialized) == 0) {
  70             options_ |= f_initialized;
  71             count_ = 0;
  72         }
  73         bool matches = (options_ & grep::whole_line) ?
  74             regex_match(line, re_, match_flags_) :
  75             regex_search(line, re_, match_flags_);
  76         if (options_ & grep::invert)
  77             matches = !matches;
  78         if (matches)
  79             ++count_;
  80         return matches ? line + traits_type::newline() : string_type();
  81     }
  82
  83     // Private flags bitwise OR'd with constants from namespace grep
  84     enum flags_ {
  85         f_initialized = 65536
  86     };
  87
  88     regex_type       re_;
  89     match_flag_type  match_flags_;
  90     int              options_;
  91     int              count_;
  92 };
  93 BOOST_IOSTREAMS_PIPABLE(basic_grep_filter, 3)
  94
  95 typedef basic_grep_filter<char>     grep_filter;
  96 typedef basic_grep_filter<wchar_t>  wgrep_filter;
  97
  98 //------------------Implementation of basic_grep_filter-----------------------//
  99
 100 template<typename Ch, typename Tr, typename Alloc>
 101 basic_grep_filter<Ch, Tr, Alloc>::basic_grep_filter
 102     (const regex_type& re, match_flag_type match_flags, int options)
 103     : base_type(true), re_(re), match_flags_(match_flags),
 104       options_(options), count_(0)
 105     { }
 106
 107 } } // End namespaces iostreams, boost.
 108
 109 #endif      // #ifndef BOOST_IOSTREAMS_REGEX_FILTER_HPP_INCLUDED