| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | // | ||
| 2 | // Copyright (c) 2021 Vinnie Falco (vinnie dot falco at gmail dot com) | ||
| 3 | // | ||
| 4 | // Distributed under the Boost Software License, Version 1.0. (See accompanying | ||
| 5 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | ||
| 6 | // | ||
| 7 | // Official repository: https://github.com/boostorg/url | ||
| 8 | // | ||
| 9 | |||
| 10 | #ifndef BOOST_URL_GRAMMAR_STRING_TOKEN_HPP | ||
| 11 | #define BOOST_URL_GRAMMAR_STRING_TOKEN_HPP | ||
| 12 | |||
| 13 | #include <boost/url/detail/config.hpp> | ||
| 14 | #include <boost/core/detail/string_view.hpp> | ||
| 15 | #include <boost/url/detail/except.hpp> | ||
| 16 | #include <memory> | ||
| 17 | #include <string> | ||
| 18 | |||
| 19 | namespace boost { | ||
| 20 | namespace urls { | ||
| 21 | namespace string_token { | ||
| 22 | |||
| 23 | /** Base class for string tokens, and algorithm parameters | ||
| 24 | |||
| 25 | This abstract interface provides a means | ||
| 26 | for an algorithm to generically obtain a | ||
| 27 | modifiable, contiguous character buffer | ||
| 28 | of prescribed size. As the author of an | ||
| 29 | algorithm simply declare an rvalue | ||
| 30 | reference as a parameter type. | ||
| 31 | |||
| 32 | <br> | ||
| 33 | |||
| 34 | Instances of this type are intended only | ||
| 35 | to be used once and then destroyed. | ||
| 36 | |||
| 37 | @par Example | ||
| 38 | The declared function accepts any | ||
| 39 | temporary instance of `arg` to be | ||
| 40 | used for writing: | ||
| 41 | @code | ||
| 42 | void algorithm( string_token::arg&& dest ); | ||
| 43 | @endcode | ||
| 44 | |||
| 45 | To implement the interface for your type | ||
| 46 | or use-case, derive from the class and | ||
| 47 | implement the prepare function. | ||
| 48 | */ | ||
| 49 | struct arg | ||
| 50 | { | ||
| 51 | /** Return a modifiable character buffer | ||
| 52 | |||
| 53 | This function attempts to obtain a | ||
| 54 | character buffer with space for at | ||
| 55 | least `n` characters. Upon success, | ||
| 56 | a pointer to the beginning of the | ||
| 57 | buffer is returned. Ownership is not | ||
| 58 | transferred; the caller should not | ||
| 59 | attempt to free the storage. The | ||
| 60 | buffer shall remain valid until | ||
| 61 | `this` is destroyed. | ||
| 62 | |||
| 63 | @note | ||
| 64 | This function may only be called once. | ||
| 65 | After invoking the function, the only | ||
| 66 | valid operation is destruction. | ||
| 67 | */ | ||
| 68 | virtual char* prepare(std::size_t n) = 0; | ||
| 69 | |||
| 70 | // prevent misuse | ||
| 71 | 6744 | virtual ~arg() = default; | |
| 72 | 3372 | arg() = default; | |
| 73 | arg(arg&&) = default; | ||
| 74 | arg(arg const&) = delete; | ||
| 75 | arg& operator=(arg&&) = delete; | ||
| 76 | arg& operator=(arg const&) = delete; | ||
| 77 | }; | ||
| 78 | |||
| 79 | //------------------------------------------------ | ||
| 80 | |||
| 81 | /** Metafunction returning true if T is a StringToken | ||
| 82 | */ | ||
| 83 | #ifdef BOOST_URL_DOCS | ||
| 84 | template<class T> | ||
| 85 | using is_token = __see_below__; | ||
| 86 | #else | ||
| 87 | template<class T, class = void> | ||
| 88 | struct is_token : std::false_type {}; | ||
| 89 | |||
| 90 | template<class T> | ||
| 91 | struct is_token<T, void_t< | ||
| 92 | decltype(std::declval<T&>().prepare( | ||
| 93 | std::declval<std::size_t>())), | ||
| 94 | decltype(std::declval<T&>().result()) | ||
| 95 | > > : std::integral_constant<bool, | ||
| 96 | std::is_convertible<decltype( | ||
| 97 | std::declval<T&>().result()), | ||
| 98 | typename T::result_type>::value && | ||
| 99 | std::is_same<decltype( | ||
| 100 | std::declval<T&>().prepare(0)), | ||
| 101 | char*>::value && | ||
| 102 | std::is_base_of<arg, T>::value && | ||
| 103 | std::is_convertible<T const volatile*, | ||
| 104 | arg const volatile*>::value | ||
| 105 | > | ||
| 106 | { | ||
| 107 | }; | ||
| 108 | #endif | ||
| 109 | |||
| 110 | //------------------------------------------------ | ||
| 111 | |||
| 112 | /** A token for returning a plain string | ||
| 113 | */ | ||
| 114 | #ifdef BOOST_URL_DOCS | ||
| 115 | using return_string = __implementation_defined__; | ||
| 116 | #else | ||
| 117 | struct return_string | ||
| 118 | : arg | ||
| 119 | { | ||
| 120 | using result_type = std::string; | ||
| 121 | |||
| 122 | char* | ||
| 123 | 3028 | prepare(std::size_t n) override | |
| 124 | { | ||
| 125 | 3028 | s_.resize(n); | |
| 126 | 3028 | return &s_[0]; | |
| 127 | } | ||
| 128 | |||
| 129 | result_type | ||
| 130 | 3028 | result() noexcept | |
| 131 | { | ||
| 132 | 3028 | return std::move(s_); | |
| 133 | } | ||
| 134 | |||
| 135 | private: | ||
| 136 | result_type s_; | ||
| 137 | }; | ||
| 138 | #endif | ||
| 139 | |||
| 140 | //------------------------------------------------ | ||
| 141 | |||
| 142 | /** A token for appending to a plain string | ||
| 143 | */ | ||
| 144 | #ifdef BOOST_URL_DOCS | ||
| 145 | template< | ||
| 146 | class Allocator = | ||
| 147 | std::allocator<char>> | ||
| 148 | __implementation_defined__ | ||
| 149 | append_to( | ||
| 150 | std::basic_string< | ||
| 151 | char, | ||
| 152 | std::char_traits<char>, | ||
| 153 | Allocator>& s); | ||
| 154 | #else | ||
| 155 | template<class Alloc> | ||
| 156 | struct append_to_t | ||
| 157 | : arg | ||
| 158 | { | ||
| 159 | using string_type = std::basic_string< | ||
| 160 | char, std::char_traits<char>, | ||
| 161 | Alloc>; | ||
| 162 | |||
| 163 | using result_type = string_type&; | ||
| 164 | |||
| 165 | explicit | ||
| 166 | 3 | append_to_t( | |
| 167 | string_type& s) noexcept | ||
| 168 | 3 | : s_(s) | |
| 169 | { | ||
| 170 | 3 | } | |
| 171 | |||
| 172 | char* | ||
| 173 | 3 | prepare(std::size_t n) override | |
| 174 | { | ||
| 175 | 3 | std::size_t n0 = s_.size(); | |
| 176 |
1/2✗ Branch 1 not taken.
✓ Branch 2 taken 3 times.
|
3 | if(n > s_.max_size() - n0) |
| 177 | ✗ | urls::detail::throw_length_error(); | |
| 178 | 3 | s_.resize(n0 + n); | |
| 179 | 3 | return &s_[n0]; | |
| 180 | } | ||
| 181 | |||
| 182 | result_type | ||
| 183 | 3 | result() noexcept | |
| 184 | { | ||
| 185 | 3 | return s_; | |
| 186 | } | ||
| 187 | |||
| 188 | private: | ||
| 189 | string_type& s_; | ||
| 190 | }; | ||
| 191 | |||
| 192 | template< | ||
| 193 | class Alloc = | ||
| 194 | std::allocator<char>> | ||
| 195 | append_to_t<Alloc> | ||
| 196 | 3 | append_to( | |
| 197 | std::basic_string< | ||
| 198 | char, | ||
| 199 | std::char_traits<char>, | ||
| 200 | Alloc>& s) | ||
| 201 | { | ||
| 202 | 3 | return append_to_t<Alloc>(s); | |
| 203 | } | ||
| 204 | #endif | ||
| 205 | |||
| 206 | //------------------------------------------------ | ||
| 207 | |||
| 208 | /** A token for assigning to a plain string | ||
| 209 | */ | ||
| 210 | #ifdef BOOST_URL_DOCS | ||
| 211 | template< | ||
| 212 | class Allocator = | ||
| 213 | std::allocator<char>> | ||
| 214 | __implementation_defined__ | ||
| 215 | assign_to( | ||
| 216 | std::basic_string< | ||
| 217 | char, | ||
| 218 | std::char_traits<char>, | ||
| 219 | Allocator>& s); | ||
| 220 | #else | ||
| 221 | template<class Alloc> | ||
| 222 | struct assign_to_t | ||
| 223 | : arg | ||
| 224 | { | ||
| 225 | using string_type = std::basic_string< | ||
| 226 | char, std::char_traits<char>, | ||
| 227 | Alloc>; | ||
| 228 | |||
| 229 | using result_type = string_type&; | ||
| 230 | |||
| 231 | explicit | ||
| 232 | 337 | assign_to_t( | |
| 233 | string_type& s) noexcept | ||
| 234 | 337 | : s_(s) | |
| 235 | { | ||
| 236 | 337 | } | |
| 237 | |||
| 238 | char* | ||
| 239 | 337 | prepare(std::size_t n) override | |
| 240 | { | ||
| 241 | 337 | s_.resize(n); | |
| 242 | 337 | return &s_[0]; | |
| 243 | } | ||
| 244 | |||
| 245 | result_type | ||
| 246 | 337 | result() noexcept | |
| 247 | { | ||
| 248 | 337 | return s_; | |
| 249 | } | ||
| 250 | |||
| 251 | private: | ||
| 252 | string_type& s_; | ||
| 253 | }; | ||
| 254 | |||
| 255 | template< | ||
| 256 | class Alloc = | ||
| 257 | std::allocator<char>> | ||
| 258 | assign_to_t<Alloc> | ||
| 259 | 337 | assign_to( | |
| 260 | std::basic_string< | ||
| 261 | char, | ||
| 262 | std::char_traits<char>, | ||
| 263 | Alloc>& s) | ||
| 264 | { | ||
| 265 | 337 | return assign_to_t<Alloc>(s); | |
| 266 | } | ||
| 267 | #endif | ||
| 268 | |||
| 269 | //------------------------------------------------ | ||
| 270 | |||
| 271 | /** A token for producing a durable core::string_view from a temporary string | ||
| 272 | */ | ||
| 273 | #ifdef BOOST_URL_DOCS | ||
| 274 | template< | ||
| 275 | class Allocator = | ||
| 276 | std::allocator<char>> | ||
| 277 | __implementation_defined__ | ||
| 278 | preserve_size( | ||
| 279 | std::basic_string< | ||
| 280 | char, | ||
| 281 | std::char_traits<char>, | ||
| 282 | Allocator>& s); | ||
| 283 | #else | ||
| 284 | template<class Alloc> | ||
| 285 | struct preserve_size_t | ||
| 286 | : arg | ||
| 287 | { | ||
| 288 | using result_type = core::string_view; | ||
| 289 | |||
| 290 | using string_type = std::basic_string< | ||
| 291 | char, std::char_traits<char>, | ||
| 292 | Alloc>; | ||
| 293 | |||
| 294 | explicit | ||
| 295 | 4 | preserve_size_t( | |
| 296 | string_type& s) noexcept | ||
| 297 | 4 | : s_(s) | |
| 298 | { | ||
| 299 | 4 | } | |
| 300 | |||
| 301 | char* | ||
| 302 | 4 | prepare(std::size_t n) override | |
| 303 | { | ||
| 304 | 4 | n_ = n; | |
| 305 | // preserve size() to | ||
| 306 | // avoid value-init | ||
| 307 |
2/2✓ Branch 1 taken 2 times.
✓ Branch 2 taken 2 times.
|
4 | if(s_.size() < n) |
| 308 | 2 | s_.resize(n); | |
| 309 | 4 | return &s_[0]; | |
| 310 | } | ||
| 311 | |||
| 312 | result_type | ||
| 313 | 4 | result() noexcept | |
| 314 | { | ||
| 315 | 4 | return core::string_view( | |
| 316 | 8 | s_.data(), n_); | |
| 317 | } | ||
| 318 | |||
| 319 | private: | ||
| 320 | string_type& s_; | ||
| 321 | std::size_t n_ = 0; | ||
| 322 | }; | ||
| 323 | |||
| 324 | template< | ||
| 325 | class Alloc = | ||
| 326 | std::allocator<char>> | ||
| 327 | preserve_size_t<Alloc> | ||
| 328 | 4 | preserve_size( | |
| 329 | std::basic_string< | ||
| 330 | char, | ||
| 331 | std::char_traits<char>, | ||
| 332 | Alloc>& s) | ||
| 333 | { | ||
| 334 | 4 | return preserve_size_t<Alloc>(s); | |
| 335 | } | ||
| 336 | #endif | ||
| 337 | |||
| 338 | } // string_token | ||
| 339 | |||
| 340 | namespace grammar { | ||
| 341 | namespace string_token = ::boost::urls::string_token; | ||
| 342 | } // grammar | ||
| 343 | |||
| 344 | } // urls | ||
| 345 | } // boost | ||
| 346 | |||
| 347 | #endif | ||
| 348 |