rfc/impl/pct_encoded_rule.hpp

0001 //
0002 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007 // Official repository: https://github.com/boostorg/url
0008 //
0009
0010 #ifndef BOOST_URL_RFC_IMPL_PCT_ENCODED_RULE_HPP
0011 #define BOOST_URL_RFC_IMPL_PCT_ENCODED_RULE_HPP
0012
0013 #include <boost/url/grammar/charset.hpp>
0014 #include <boost/url/grammar/error.hpp>
0015 #include <boost/url/grammar/hexdig_chars.hpp>
0016
0017 namespace boost {
0018 namespace urls {
0019
0020 namespace detail {
0021
0022 template<class CharSet>
0023 auto
0024 parse_encoded(
0025     char const*& it,
0026     char const* end,
0027     CharSet const& cs) noexcept ->
0028         system::result<pct_string_view>
0029 {
0030     auto const start = it;
0031     std::size_t n = 0;
0032     char const* it0;
0033 skip:
0034     it0 = it;
0035     it = grammar::find_if_not(
0036         it0, end, cs);
0037     n += it - it0;
0038     if(it == end)
0039         goto finish;
0040     if(*it != '%')
0041         goto finish;
0042     for(;;)
0043     {
0044         ++it;
0045         if(it == end)
0046         {
0047             // expected HEXDIG
0048             BOOST_URL_RETURN_EC(
0049                 grammar::error::invalid);
0050         }
0051         auto r = grammar::hexdig_value(*it);
0052         if(r < 0)
0053         {
0054             // expected HEXDIG
0055             BOOST_URL_RETURN_EC(
0056                 grammar::error::invalid);
0057         }
0058         ++it;
0059         if(it == end)
0060         {
0061             // expected HEXDIG
0062             BOOST_URL_RETURN_EC(
0063                 grammar::error::invalid);
0064         }
0065         r = grammar::hexdig_value(*it);
0066         if(r < 0)
0067         {
0068             // expected HEXDIG
0069             BOOST_URL_RETURN_EC(
0070                 grammar::error::invalid);
0071         }
0072         ++n;
0073         ++it;
0074         if(it == end)
0075             break;
0076         if(*it != '%')
0077             goto skip;
0078     }
0079 finish:
0080     return make_pct_string_view_unsafe(
0081         start, it - start, n);
0082 }
0083
0084 } // detail
0085
0086 //------------------------------------------------
0087
0088 template<class CharSet>
0089 auto
0090 pct_encoded_rule_t<CharSet>::
0091 parse(
0092     char const*& it,
0093     char const* end) const noexcept ->
0094         system::result<value_type>
0095 {
0096     return detail::parse_encoded(
0097         it, end, cs_);
0098 }
0099
0100 } // urls
0101 } // boost
0102
0103 #endif