url/impl/decode_view.hpp

0001 //
0002 // Copyright (c) 2022 Alan de Freitas (alandefreitas@gmail.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_IMPL_PCT_ENCODED_VIEW_HPP
0011 #define BOOST_URL_IMPL_PCT_ENCODED_VIEW_HPP
0012
0013 #include <boost/url/grammar/type_traits.hpp>
0014 #include <boost/static_assert.hpp>
0015
0016 namespace boost {
0017 namespace urls {
0018
0019 class decode_view::iterator
0020 {
0021     char const* begin_ = nullptr;
0022     char const* pos_ = nullptr;
0023     bool space_as_plus_ = true;
0024
0025     friend decode_view;
0026
0027     iterator(
0028         char const* str,
0029         bool space_as_plus) noexcept
0030         : begin_(str)
0031         , pos_(str)
0032         , space_as_plus_(
0033             space_as_plus)
0034     {
0035     }
0036
0037     // end ctor
0038     iterator(
0039         char const* str,
0040         size_type n,
0041         bool space_as_plus) noexcept
0042         : begin_(str)
0043         , pos_(str + n)
0044         , space_as_plus_(space_as_plus)
0045     {
0046     }
0047
0048 public:
0049     using value_type = char;
0050     using reference = char;
0051     using pointer = void const*;
0052     using const_reference = char;
0053     using size_type = std::size_t;
0054     using difference_type = std::ptrdiff_t;
0055     using iterator_category =
0056         std::bidirectional_iterator_tag;
0057
0058     iterator() = default;
0059
0060     iterator(iterator const&) = default;
0061
0062     iterator&
0063     operator=(iterator const&) = default;
0064
0065     BOOST_URL_DECL
0066     reference
0067     operator*() const noexcept;
0068
0069     iterator&
0070     operator++() noexcept
0071     {
0072         BOOST_ASSERT(pos_ != nullptr);
0073         if (*pos_ != '%')
0074             ++pos_;
0075         else
0076             pos_ += 3;
0077         return *this;
0078     }
0079
0080     iterator&
0081     operator--() noexcept
0082     {
0083         BOOST_ASSERT(pos_ != begin_);
0084         if (pos_ - begin_ < 3 ||
0085                 pos_[-3] != '%')
0086             --pos_;
0087         else
0088             pos_ -= 3;
0089         return *this;
0090     }
0091
0092     iterator
0093     operator++(int) noexcept
0094     {
0095         auto tmp = *this;
0096         ++*this;
0097         return tmp;
0098     }
0099
0100     iterator
0101     operator--(int) noexcept
0102     {
0103         auto tmp = *this;
0104         --*this;
0105         return tmp;
0106     }
0107
0108     char const*
0109     base()
0110     {
0111         return pos_;
0112     }
0113
0114     bool
0115     operator==(
0116         iterator const& other) const noexcept
0117     {
0118         return pos_ == other.pos_;
0119     }
0120
0121     bool
0122     operator!=(
0123         iterator const& other) const noexcept
0124     {
0125         return !(*this == other);
0126     }
0127 };
0128
0129 //------------------------------------------------
0130
0131 inline
0132 auto
0133 decode_view::
0134 begin() const noexcept ->
0135     const_iterator
0136 {
0137     return {p_, space_as_plus_};
0138 }
0139
0140 inline
0141 auto
0142 decode_view::
0143 end() const noexcept ->
0144     const_iterator
0145 {
0146     return {p_, n_, space_as_plus_};
0147 }
0148
0149 inline
0150 auto
0151 decode_view::
0152 front() const noexcept ->
0153     const_reference
0154 {
0155     BOOST_ASSERT( !empty() );
0156     return *begin();
0157 }
0158
0159 inline
0160 auto
0161 decode_view::
0162 back() const noexcept ->
0163     const_reference
0164 {
0165     BOOST_ASSERT( !empty() );
0166     return *--end();
0167 }
0168
0169 namespace detail {
0170
0171 template <class T>
0172 BOOST_CXX14_CONSTEXPR
0173 int
0174 decoded_strcmp(decode_view s0, T s1)
0175 {
0176     auto const n0 = s0.size();
0177     auto const n1 = s1.size();
0178     auto n = (std::min)(n0, n1);
0179     auto it0 = s0.begin();
0180     auto it1 = s1.begin();
0181     while (n--)
0182     {
0183         const char c0 = *it0++;
0184         const char c1 = *it1++;
0185         if (c0 == c1)
0186             continue;
0187         return 1 - 2 * (static_cast<unsigned char>(c0)
0188                       < static_cast<unsigned char>(c1));
0189     }
0190     return 1 - (n0 == n1) - 2 * (n0 < n1);
0191 }
0192
0193 } // detail
0194
0195
0196 #if defined(BOOST_NO_CXX14_CONSTEXPR)
0197 inline
0198 #else
0199 BOOST_CXX14_CONSTEXPR
0200 #endif
0201 int
0202 decode_view::
0203 compare(core::string_view other) const noexcept
0204 {
0205     return detail::decoded_strcmp(*this, other);
0206 }
0207
0208 #if defined(BOOST_NO_CXX14_CONSTEXPR)
0209 inline
0210 #else
0211 BOOST_CXX14_CONSTEXPR
0212 #endif
0213 int
0214 decode_view::
0215 compare(decode_view other) const noexcept
0216 {
0217     return detail::decoded_strcmp(*this, other);
0218 }
0219
0220 } // urls
0221 } // boost
0222
0223 #endif