buffered_read_stream.hpp 14 KB

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  1. //
  2. // impl/buffered_read_stream.hpp
  3. // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2019 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 BOOST_ASIO_IMPL_BUFFERED_READ_STREAM_HPP
  11. #define BOOST_ASIO_IMPL_BUFFERED_READ_STREAM_HPP
  12. #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  13. # pragma once
  14. #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  15. #include <boost/asio/associated_allocator.hpp>
  16. #include <boost/asio/associated_executor.hpp>
  17. #include <boost/asio/detail/handler_alloc_helpers.hpp>
  18. #include <boost/asio/detail/handler_cont_helpers.hpp>
  19. #include <boost/asio/detail/handler_invoke_helpers.hpp>
  20. #include <boost/asio/detail/handler_type_requirements.hpp>
  21. #include <boost/asio/detail/non_const_lvalue.hpp>
  22. #include <boost/asio/detail/push_options.hpp>
  23. namespace boost {
  24. namespace asio {
  25. template <typename Stream>
  26. std::size_t buffered_read_stream<Stream>::fill()
  27. {
  28. detail::buffer_resize_guard<detail::buffered_stream_storage>
  29. resize_guard(storage_);
  30. std::size_t previous_size = storage_.size();
  31. storage_.resize(storage_.capacity());
  32. storage_.resize(previous_size + next_layer_.read_some(buffer(
  33. storage_.data() + previous_size,
  34. storage_.size() - previous_size)));
  35. resize_guard.commit();
  36. return storage_.size() - previous_size;
  37. }
  38. template <typename Stream>
  39. std::size_t buffered_read_stream<Stream>::fill(boost::system::error_code& ec)
  40. {
  41. detail::buffer_resize_guard<detail::buffered_stream_storage>
  42. resize_guard(storage_);
  43. std::size_t previous_size = storage_.size();
  44. storage_.resize(storage_.capacity());
  45. storage_.resize(previous_size + next_layer_.read_some(buffer(
  46. storage_.data() + previous_size,
  47. storage_.size() - previous_size),
  48. ec));
  49. resize_guard.commit();
  50. return storage_.size() - previous_size;
  51. }
  52. namespace detail
  53. {
  54. template <typename ReadHandler>
  55. class buffered_fill_handler
  56. {
  57. public:
  58. buffered_fill_handler(detail::buffered_stream_storage& storage,
  59. std::size_t previous_size, ReadHandler& handler)
  60. : storage_(storage),
  61. previous_size_(previous_size),
  62. handler_(BOOST_ASIO_MOVE_CAST(ReadHandler)(handler))
  63. {
  64. }
  65. #if defined(BOOST_ASIO_HAS_MOVE)
  66. buffered_fill_handler(const buffered_fill_handler& other)
  67. : storage_(other.storage_),
  68. previous_size_(other.previous_size_),
  69. handler_(other.handler_)
  70. {
  71. }
  72. buffered_fill_handler(buffered_fill_handler&& other)
  73. : storage_(other.storage_),
  74. previous_size_(other.previous_size_),
  75. handler_(BOOST_ASIO_MOVE_CAST(ReadHandler)(other.handler_))
  76. {
  77. }
  78. #endif // defined(BOOST_ASIO_HAS_MOVE)
  79. void operator()(const boost::system::error_code& ec,
  80. const std::size_t bytes_transferred)
  81. {
  82. storage_.resize(previous_size_ + bytes_transferred);
  83. handler_(ec, bytes_transferred);
  84. }
  85. //private:
  86. detail::buffered_stream_storage& storage_;
  87. std::size_t previous_size_;
  88. ReadHandler handler_;
  89. };
  90. template <typename ReadHandler>
  91. inline void* asio_handler_allocate(std::size_t size,
  92. buffered_fill_handler<ReadHandler>* this_handler)
  93. {
  94. return boost_asio_handler_alloc_helpers::allocate(
  95. size, this_handler->handler_);
  96. }
  97. template <typename ReadHandler>
  98. inline void asio_handler_deallocate(void* pointer, std::size_t size,
  99. buffered_fill_handler<ReadHandler>* this_handler)
  100. {
  101. boost_asio_handler_alloc_helpers::deallocate(
  102. pointer, size, this_handler->handler_);
  103. }
  104. template <typename ReadHandler>
  105. inline bool asio_handler_is_continuation(
  106. buffered_fill_handler<ReadHandler>* this_handler)
  107. {
  108. return boost_asio_handler_cont_helpers::is_continuation(
  109. this_handler->handler_);
  110. }
  111. template <typename Function, typename ReadHandler>
  112. inline void asio_handler_invoke(Function& function,
  113. buffered_fill_handler<ReadHandler>* this_handler)
  114. {
  115. boost_asio_handler_invoke_helpers::invoke(
  116. function, this_handler->handler_);
  117. }
  118. template <typename Function, typename ReadHandler>
  119. inline void asio_handler_invoke(const Function& function,
  120. buffered_fill_handler<ReadHandler>* this_handler)
  121. {
  122. boost_asio_handler_invoke_helpers::invoke(
  123. function, this_handler->handler_);
  124. }
  125. struct initiate_async_buffered_fill
  126. {
  127. template <typename ReadHandler, typename Stream>
  128. void operator()(BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
  129. buffered_stream_storage* storage, Stream* next_layer) const
  130. {
  131. // If you get an error on the following line it means that your handler
  132. // does not meet the documented type requirements for a ReadHandler.
  133. BOOST_ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check;
  134. non_const_lvalue<ReadHandler> handler2(handler);
  135. std::size_t previous_size = storage->size();
  136. storage->resize(storage->capacity());
  137. next_layer->async_read_some(
  138. buffer(
  139. storage->data() + previous_size,
  140. storage->size() - previous_size),
  141. buffered_fill_handler<typename decay<ReadHandler>::type>(
  142. *storage, previous_size, handler2.value));
  143. }
  144. };
  145. } // namespace detail
  146. #if !defined(GENERATING_DOCUMENTATION)
  147. template <typename ReadHandler, typename Allocator>
  148. struct associated_allocator<
  149. detail::buffered_fill_handler<ReadHandler>, Allocator>
  150. {
  151. typedef typename associated_allocator<ReadHandler, Allocator>::type type;
  152. static type get(const detail::buffered_fill_handler<ReadHandler>& h,
  153. const Allocator& a = Allocator()) BOOST_ASIO_NOEXCEPT
  154. {
  155. return associated_allocator<ReadHandler, Allocator>::get(h.handler_, a);
  156. }
  157. };
  158. template <typename ReadHandler, typename Executor>
  159. struct associated_executor<
  160. detail::buffered_fill_handler<ReadHandler>, Executor>
  161. {
  162. typedef typename associated_executor<ReadHandler, Executor>::type type;
  163. static type get(const detail::buffered_fill_handler<ReadHandler>& h,
  164. const Executor& ex = Executor()) BOOST_ASIO_NOEXCEPT
  165. {
  166. return associated_executor<ReadHandler, Executor>::get(h.handler_, ex);
  167. }
  168. };
  169. #endif // !defined(GENERATING_DOCUMENTATION)
  170. template <typename Stream>
  171. template <typename ReadHandler>
  172. BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
  173. void (boost::system::error_code, std::size_t))
  174. buffered_read_stream<Stream>::async_fill(
  175. BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
  176. {
  177. return async_initiate<ReadHandler,
  178. void (boost::system::error_code, std::size_t)>(
  179. detail::initiate_async_buffered_fill(), handler, &storage_, &next_layer_);
  180. }
  181. template <typename Stream>
  182. template <typename MutableBufferSequence>
  183. std::size_t buffered_read_stream<Stream>::read_some(
  184. const MutableBufferSequence& buffers)
  185. {
  186. using boost::asio::buffer_size;
  187. if (buffer_size(buffers) == 0)
  188. return 0;
  189. if (storage_.empty())
  190. this->fill();
  191. return this->copy(buffers);
  192. }
  193. template <typename Stream>
  194. template <typename MutableBufferSequence>
  195. std::size_t buffered_read_stream<Stream>::read_some(
  196. const MutableBufferSequence& buffers, boost::system::error_code& ec)
  197. {
  198. ec = boost::system::error_code();
  199. using boost::asio::buffer_size;
  200. if (buffer_size(buffers) == 0)
  201. return 0;
  202. if (storage_.empty() && !this->fill(ec))
  203. return 0;
  204. return this->copy(buffers);
  205. }
  206. namespace detail
  207. {
  208. template <typename MutableBufferSequence, typename ReadHandler>
  209. class buffered_read_some_handler
  210. {
  211. public:
  212. buffered_read_some_handler(detail::buffered_stream_storage& storage,
  213. const MutableBufferSequence& buffers, ReadHandler& handler)
  214. : storage_(storage),
  215. buffers_(buffers),
  216. handler_(BOOST_ASIO_MOVE_CAST(ReadHandler)(handler))
  217. {
  218. }
  219. #if defined(BOOST_ASIO_HAS_MOVE)
  220. buffered_read_some_handler(const buffered_read_some_handler& other)
  221. : storage_(other.storage_),
  222. buffers_(other.buffers_),
  223. handler_(other.handler_)
  224. {
  225. }
  226. buffered_read_some_handler(buffered_read_some_handler&& other)
  227. : storage_(other.storage_),
  228. buffers_(other.buffers_),
  229. handler_(BOOST_ASIO_MOVE_CAST(ReadHandler)(other.handler_))
  230. {
  231. }
  232. #endif // defined(BOOST_ASIO_HAS_MOVE)
  233. void operator()(const boost::system::error_code& ec, std::size_t)
  234. {
  235. if (ec || storage_.empty())
  236. {
  237. const std::size_t length = 0;
  238. handler_(ec, length);
  239. }
  240. else
  241. {
  242. const std::size_t bytes_copied = boost::asio::buffer_copy(
  243. buffers_, storage_.data(), storage_.size());
  244. storage_.consume(bytes_copied);
  245. handler_(ec, bytes_copied);
  246. }
  247. }
  248. //private:
  249. detail::buffered_stream_storage& storage_;
  250. MutableBufferSequence buffers_;
  251. ReadHandler handler_;
  252. };
  253. template <typename MutableBufferSequence, typename ReadHandler>
  254. inline void* asio_handler_allocate(std::size_t size,
  255. buffered_read_some_handler<
  256. MutableBufferSequence, ReadHandler>* this_handler)
  257. {
  258. return boost_asio_handler_alloc_helpers::allocate(
  259. size, this_handler->handler_);
  260. }
  261. template <typename MutableBufferSequence, typename ReadHandler>
  262. inline void asio_handler_deallocate(void* pointer, std::size_t size,
  263. buffered_read_some_handler<
  264. MutableBufferSequence, ReadHandler>* this_handler)
  265. {
  266. boost_asio_handler_alloc_helpers::deallocate(
  267. pointer, size, this_handler->handler_);
  268. }
  269. template <typename MutableBufferSequence, typename ReadHandler>
  270. inline bool asio_handler_is_continuation(
  271. buffered_read_some_handler<
  272. MutableBufferSequence, ReadHandler>* this_handler)
  273. {
  274. return boost_asio_handler_cont_helpers::is_continuation(
  275. this_handler->handler_);
  276. }
  277. template <typename Function, typename MutableBufferSequence,
  278. typename ReadHandler>
  279. inline void asio_handler_invoke(Function& function,
  280. buffered_read_some_handler<
  281. MutableBufferSequence, ReadHandler>* this_handler)
  282. {
  283. boost_asio_handler_invoke_helpers::invoke(
  284. function, this_handler->handler_);
  285. }
  286. template <typename Function, typename MutableBufferSequence,
  287. typename ReadHandler>
  288. inline void asio_handler_invoke(const Function& function,
  289. buffered_read_some_handler<
  290. MutableBufferSequence, ReadHandler>* this_handler)
  291. {
  292. boost_asio_handler_invoke_helpers::invoke(
  293. function, this_handler->handler_);
  294. }
  295. struct initiate_async_buffered_read_some
  296. {
  297. template <typename ReadHandler, typename Stream,
  298. typename MutableBufferSequence>
  299. void operator()(BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
  300. buffered_stream_storage* storage, Stream* next_layer,
  301. const MutableBufferSequence& buffers) const
  302. {
  303. // If you get an error on the following line it means that your handler
  304. // does not meet the documented type requirements for a ReadHandler.
  305. BOOST_ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check;
  306. using boost::asio::buffer_size;
  307. non_const_lvalue<ReadHandler> handler2(handler);
  308. if (buffer_size(buffers) == 0 || !storage->empty())
  309. {
  310. next_layer->async_read_some(BOOST_ASIO_MUTABLE_BUFFER(0, 0),
  311. buffered_read_some_handler<MutableBufferSequence,
  312. typename decay<ReadHandler>::type>(
  313. *storage, buffers, handler2.value));
  314. }
  315. else
  316. {
  317. initiate_async_buffered_fill()(
  318. buffered_read_some_handler<MutableBufferSequence,
  319. typename decay<ReadHandler>::type>(
  320. *storage, buffers, handler2.value),
  321. storage, next_layer);
  322. }
  323. }
  324. };
  325. } // namespace detail
  326. #if !defined(GENERATING_DOCUMENTATION)
  327. template <typename MutableBufferSequence,
  328. typename ReadHandler, typename Allocator>
  329. struct associated_allocator<
  330. detail::buffered_read_some_handler<MutableBufferSequence, ReadHandler>,
  331. Allocator>
  332. {
  333. typedef typename associated_allocator<ReadHandler, Allocator>::type type;
  334. static type get(
  335. const detail::buffered_read_some_handler<
  336. MutableBufferSequence, ReadHandler>& h,
  337. const Allocator& a = Allocator()) BOOST_ASIO_NOEXCEPT
  338. {
  339. return associated_allocator<ReadHandler, Allocator>::get(h.handler_, a);
  340. }
  341. };
  342. template <typename MutableBufferSequence,
  343. typename ReadHandler, typename Executor>
  344. struct associated_executor<
  345. detail::buffered_read_some_handler<MutableBufferSequence, ReadHandler>,
  346. Executor>
  347. {
  348. typedef typename associated_executor<ReadHandler, Executor>::type type;
  349. static type get(
  350. const detail::buffered_read_some_handler<
  351. MutableBufferSequence, ReadHandler>& h,
  352. const Executor& ex = Executor()) BOOST_ASIO_NOEXCEPT
  353. {
  354. return associated_executor<ReadHandler, Executor>::get(h.handler_, ex);
  355. }
  356. };
  357. #endif // !defined(GENERATING_DOCUMENTATION)
  358. template <typename Stream>
  359. template <typename MutableBufferSequence, typename ReadHandler>
  360. BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
  361. void (boost::system::error_code, std::size_t))
  362. buffered_read_stream<Stream>::async_read_some(
  363. const MutableBufferSequence& buffers,
  364. BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
  365. {
  366. return async_initiate<ReadHandler,
  367. void (boost::system::error_code, std::size_t)>(
  368. detail::initiate_async_buffered_read_some(),
  369. handler, &storage_, &next_layer_, buffers);
  370. }
  371. template <typename Stream>
  372. template <typename MutableBufferSequence>
  373. std::size_t buffered_read_stream<Stream>::peek(
  374. const MutableBufferSequence& buffers)
  375. {
  376. if (storage_.empty())
  377. this->fill();
  378. return this->peek_copy(buffers);
  379. }
  380. template <typename Stream>
  381. template <typename MutableBufferSequence>
  382. std::size_t buffered_read_stream<Stream>::peek(
  383. const MutableBufferSequence& buffers, boost::system::error_code& ec)
  384. {
  385. ec = boost::system::error_code();
  386. if (storage_.empty() && !this->fill(ec))
  387. return 0;
  388. return this->peek_copy(buffers);
  389. }
  390. } // namespace asio
  391. } // namespace boost
  392. #include <boost/asio/detail/pop_options.hpp>
  393. #endif // BOOST_ASIO_IMPL_BUFFERED_READ_STREAM_HPP