registered_buffer.hpp 8.4 KB

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  1. //
  2. // registered_buffer.hpp
  3. // ~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
  6. //
  7. // Distributed under the Boost Software License, Version 1.0. (See accompanying
  8. // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  9. //
  10. #ifndef ASIO_REGISTERED_BUFFER_HPP
  11. #define ASIO_REGISTERED_BUFFER_HPP
  12. #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  13. # pragma once
  14. #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  15. #include "asio/detail/config.hpp"
  16. #include "asio/buffer.hpp"
  17. #include "asio/detail/push_options.hpp"
  18. namespace asio {
  19. namespace detail {
  20. class buffer_registration_base;
  21. } // namespace detail
  22. class const_registered_buffer;
  23. /// Type used to identify a registered buffer.
  24. class registered_buffer_id
  25. {
  26. public:
  27. /// The native buffer identifier type.
  28. typedef int native_handle_type;
  29. /// Default constructor creates an invalid registered buffer identifier.
  30. registered_buffer_id() ASIO_NOEXCEPT
  31. : scope_(0),
  32. index_(-1)
  33. {
  34. }
  35. /// Get the native buffer identifier type.
  36. native_handle_type native_handle() const ASIO_NOEXCEPT
  37. {
  38. return index_;
  39. }
  40. /// Compare two IDs for equality.
  41. friend bool operator==(const registered_buffer_id& lhs,
  42. const registered_buffer_id& rhs) ASIO_NOEXCEPT
  43. {
  44. return lhs.scope_ == rhs.scope_ && lhs.index_ == rhs.index_;
  45. }
  46. /// Compare two IDs for equality.
  47. friend bool operator!=(const registered_buffer_id& lhs,
  48. const registered_buffer_id& rhs) ASIO_NOEXCEPT
  49. {
  50. return lhs.scope_ != rhs.scope_ || lhs.index_ != rhs.index_;
  51. }
  52. private:
  53. friend class detail::buffer_registration_base;
  54. // Hidden constructor used by buffer registration.
  55. registered_buffer_id(const void* scope, int index) ASIO_NOEXCEPT
  56. : scope_(scope),
  57. index_(index)
  58. {
  59. }
  60. const void* scope_;
  61. int index_;
  62. };
  63. /// Holds a registered buffer over modifiable data.
  64. /**
  65. * Satisfies the @c MutableBufferSequence type requirements.
  66. */
  67. class mutable_registered_buffer
  68. {
  69. public:
  70. #if !defined(ASIO_HAS_DECLTYPE) \
  71. && !defined(GENERATING_DOCUMENTATION)
  72. typedef mutable_buffer value_type;
  73. #endif // !defined(ASIO_HAS_DECLTYPE)
  74. // && !defined(GENERATING_DOCUMENTATION)
  75. /// Default constructor creates an invalid registered buffer.
  76. mutable_registered_buffer() ASIO_NOEXCEPT
  77. : buffer_(),
  78. id_()
  79. {
  80. }
  81. /// Get the underlying mutable buffer.
  82. const mutable_buffer& buffer() const ASIO_NOEXCEPT
  83. {
  84. return buffer_;
  85. }
  86. /// Get a pointer to the beginning of the memory range.
  87. /**
  88. * @returns <tt>buffer().data()</tt>.
  89. */
  90. void* data() const ASIO_NOEXCEPT
  91. {
  92. return buffer_.data();
  93. }
  94. /// Get the size of the memory range.
  95. /**
  96. * @returns <tt>buffer().size()</tt>.
  97. */
  98. std::size_t size() const ASIO_NOEXCEPT
  99. {
  100. return buffer_.size();
  101. }
  102. /// Get the registered buffer identifier.
  103. const registered_buffer_id& id() const ASIO_NOEXCEPT
  104. {
  105. return id_;
  106. }
  107. /// Move the start of the buffer by the specified number of bytes.
  108. mutable_registered_buffer& operator+=(std::size_t n) ASIO_NOEXCEPT
  109. {
  110. buffer_ += n;
  111. return *this;
  112. }
  113. private:
  114. friend class detail::buffer_registration_base;
  115. // Hidden constructor used by buffer registration and operators.
  116. mutable_registered_buffer(const mutable_buffer& b,
  117. const registered_buffer_id& i) ASIO_NOEXCEPT
  118. : buffer_(b),
  119. id_(i)
  120. {
  121. }
  122. #if !defined(GENERATING_DOCUMENTATION)
  123. friend mutable_registered_buffer buffer(
  124. const mutable_registered_buffer& b, std::size_t n) ASIO_NOEXCEPT;
  125. #endif // !defined(GENERATING_DOCUMENTATION)
  126. mutable_buffer buffer_;
  127. registered_buffer_id id_;
  128. };
  129. /// Holds a registered buffer over non-modifiable data.
  130. /**
  131. * Satisfies the @c ConstBufferSequence type requirements.
  132. */
  133. class const_registered_buffer
  134. {
  135. public:
  136. #if !defined(ASIO_HAS_DECLTYPE) \
  137. && !defined(GENERATING_DOCUMENTATION)
  138. typedef const_buffer value_type;
  139. #endif // !defined(ASIO_HAS_DECLTYPE)
  140. // && !defined(GENERATING_DOCUMENTATION)
  141. /// Default constructor creates an invalid registered buffer.
  142. const_registered_buffer() ASIO_NOEXCEPT
  143. : buffer_(),
  144. id_()
  145. {
  146. }
  147. /// Construct a non-modifiable buffer from a modifiable one.
  148. const_registered_buffer(
  149. const mutable_registered_buffer& b) ASIO_NOEXCEPT
  150. : buffer_(b.buffer()),
  151. id_(b.id())
  152. {
  153. }
  154. /// Get the underlying constant buffer.
  155. const const_buffer& buffer() const ASIO_NOEXCEPT
  156. {
  157. return buffer_;
  158. }
  159. /// Get a pointer to the beginning of the memory range.
  160. /**
  161. * @returns <tt>buffer().data()</tt>.
  162. */
  163. const void* data() const ASIO_NOEXCEPT
  164. {
  165. return buffer_.data();
  166. }
  167. /// Get the size of the memory range.
  168. /**
  169. * @returns <tt>buffer().size()</tt>.
  170. */
  171. std::size_t size() const ASIO_NOEXCEPT
  172. {
  173. return buffer_.size();
  174. }
  175. /// Get the registered buffer identifier.
  176. const registered_buffer_id& id() const ASIO_NOEXCEPT
  177. {
  178. return id_;
  179. }
  180. /// Move the start of the buffer by the specified number of bytes.
  181. const_registered_buffer& operator+=(std::size_t n) ASIO_NOEXCEPT
  182. {
  183. buffer_ += n;
  184. return *this;
  185. }
  186. private:
  187. // Hidden constructor used by operators.
  188. const_registered_buffer(const const_buffer& b,
  189. const registered_buffer_id& i) ASIO_NOEXCEPT
  190. : buffer_(b),
  191. id_(i)
  192. {
  193. }
  194. #if !defined(GENERATING_DOCUMENTATION)
  195. friend const_registered_buffer buffer(
  196. const const_registered_buffer& b, std::size_t n) ASIO_NOEXCEPT;
  197. #endif // !defined(GENERATING_DOCUMENTATION)
  198. const_buffer buffer_;
  199. registered_buffer_id id_;
  200. };
  201. /** @addtogroup buffer_sequence_begin */
  202. /// Get an iterator to the first element in a buffer sequence.
  203. inline const mutable_buffer* buffer_sequence_begin(
  204. const mutable_registered_buffer& b) ASIO_NOEXCEPT
  205. {
  206. return &b.buffer();
  207. }
  208. /// Get an iterator to the first element in a buffer sequence.
  209. inline const const_buffer* buffer_sequence_begin(
  210. const const_registered_buffer& b) ASIO_NOEXCEPT
  211. {
  212. return &b.buffer();
  213. }
  214. /** @} */
  215. /** @addtogroup buffer_sequence_end */
  216. /// Get an iterator to one past the end element in a buffer sequence.
  217. inline const mutable_buffer* buffer_sequence_end(
  218. const mutable_registered_buffer& b) ASIO_NOEXCEPT
  219. {
  220. return &b.buffer() + 1;
  221. }
  222. /// Get an iterator to one past the end element in a buffer sequence.
  223. inline const const_buffer* buffer_sequence_end(
  224. const const_registered_buffer& b) ASIO_NOEXCEPT
  225. {
  226. return &b.buffer() + 1;
  227. }
  228. /** @} */
  229. /** @addtogroup buffer */
  230. /// Obtain a buffer representing the entire registered buffer.
  231. inline mutable_registered_buffer buffer(
  232. const mutable_registered_buffer& b) ASIO_NOEXCEPT
  233. {
  234. return b;
  235. }
  236. /// Obtain a buffer representing the entire registered buffer.
  237. inline const_registered_buffer buffer(
  238. const const_registered_buffer& b) ASIO_NOEXCEPT
  239. {
  240. return b;
  241. }
  242. /// Obtain a buffer representing part of a registered buffer.
  243. inline mutable_registered_buffer buffer(
  244. const mutable_registered_buffer& b, std::size_t n) ASIO_NOEXCEPT
  245. {
  246. return mutable_registered_buffer(buffer(b.buffer_, n), b.id_);
  247. }
  248. /// Obtain a buffer representing part of a registered buffer.
  249. inline const_registered_buffer buffer(
  250. const const_registered_buffer& b, std::size_t n) ASIO_NOEXCEPT
  251. {
  252. return const_registered_buffer(buffer(b.buffer_, n), b.id_);
  253. }
  254. /** @} */
  255. /// Create a new modifiable registered buffer that is offset from the start of
  256. /// another.
  257. /**
  258. * @relates mutable_registered_buffer
  259. */
  260. inline mutable_registered_buffer operator+(
  261. const mutable_registered_buffer& b, std::size_t n) ASIO_NOEXCEPT
  262. {
  263. mutable_registered_buffer tmp(b);
  264. tmp += n;
  265. return tmp;
  266. }
  267. /// Create a new modifiable buffer that is offset from the start of another.
  268. /**
  269. * @relates mutable_registered_buffer
  270. */
  271. inline mutable_registered_buffer operator+(std::size_t n,
  272. const mutable_registered_buffer& b) ASIO_NOEXCEPT
  273. {
  274. return b + n;
  275. }
  276. /// Create a new non-modifiable registered buffer that is offset from the start
  277. /// of another.
  278. /**
  279. * @relates const_registered_buffer
  280. */
  281. inline const_registered_buffer operator+(const const_registered_buffer& b,
  282. std::size_t n) ASIO_NOEXCEPT
  283. {
  284. const_registered_buffer tmp(b);
  285. tmp += n;
  286. return tmp;
  287. }
  288. /// Create a new non-modifiable buffer that is offset from the start of another.
  289. /**
  290. * @relates const_registered_buffer
  291. */
  292. inline const_registered_buffer operator+(std::size_t n,
  293. const const_registered_buffer& b) ASIO_NOEXCEPT
  294. {
  295. return b + n;
  296. }
  297. } // namespace asio
  298. #include "asio/detail/pop_options.hpp"
  299. #endif // ASIO_REGISTERED_BUFFER_HPP