buffered_stream.hpp 8.0 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264
  1. //
  2. // buffered_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_BUFFERED_STREAM_HPP
  11. #define BOOST_ASIO_BUFFERED_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/detail/config.hpp>
  16. #include <cstddef>
  17. #include <boost/asio/async_result.hpp>
  18. #include <boost/asio/buffered_read_stream.hpp>
  19. #include <boost/asio/buffered_write_stream.hpp>
  20. #include <boost/asio/buffered_stream_fwd.hpp>
  21. #include <boost/asio/detail/noncopyable.hpp>
  22. #include <boost/asio/error.hpp>
  23. #include <boost/asio/detail/push_options.hpp>
  24. namespace boost {
  25. namespace asio {
  26. /// Adds buffering to the read- and write-related operations of a stream.
  27. /**
  28. * The buffered_stream class template can be used to add buffering to the
  29. * synchronous and asynchronous read and write operations of a stream.
  30. *
  31. * @par Thread Safety
  32. * @e Distinct @e objects: Safe.@n
  33. * @e Shared @e objects: Unsafe.
  34. *
  35. * @par Concepts:
  36. * AsyncReadStream, AsyncWriteStream, Stream, SyncReadStream, SyncWriteStream.
  37. */
  38. template <typename Stream>
  39. class buffered_stream
  40. : private noncopyable
  41. {
  42. public:
  43. /// The type of the next layer.
  44. typedef typename remove_reference<Stream>::type next_layer_type;
  45. /// The type of the lowest layer.
  46. typedef typename next_layer_type::lowest_layer_type lowest_layer_type;
  47. /// The type of the executor associated with the object.
  48. typedef typename lowest_layer_type::executor_type executor_type;
  49. /// Construct, passing the specified argument to initialise the next layer.
  50. template <typename Arg>
  51. explicit buffered_stream(Arg& a)
  52. : inner_stream_impl_(a),
  53. stream_impl_(inner_stream_impl_)
  54. {
  55. }
  56. /// Construct, passing the specified argument to initialise the next layer.
  57. template <typename Arg>
  58. explicit buffered_stream(Arg& a, std::size_t read_buffer_size,
  59. std::size_t write_buffer_size)
  60. : inner_stream_impl_(a, write_buffer_size),
  61. stream_impl_(inner_stream_impl_, read_buffer_size)
  62. {
  63. }
  64. /// Get a reference to the next layer.
  65. next_layer_type& next_layer()
  66. {
  67. return stream_impl_.next_layer().next_layer();
  68. }
  69. /// Get a reference to the lowest layer.
  70. lowest_layer_type& lowest_layer()
  71. {
  72. return stream_impl_.lowest_layer();
  73. }
  74. /// Get a const reference to the lowest layer.
  75. const lowest_layer_type& lowest_layer() const
  76. {
  77. return stream_impl_.lowest_layer();
  78. }
  79. /// Get the executor associated with the object.
  80. executor_type get_executor() BOOST_ASIO_NOEXCEPT
  81. {
  82. return stream_impl_.lowest_layer().get_executor();
  83. }
  84. /// Close the stream.
  85. void close()
  86. {
  87. stream_impl_.close();
  88. }
  89. /// Close the stream.
  90. BOOST_ASIO_SYNC_OP_VOID close(boost::system::error_code& ec)
  91. {
  92. stream_impl_.close(ec);
  93. BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
  94. }
  95. /// Flush all data from the buffer to the next layer. Returns the number of
  96. /// bytes written to the next layer on the last write operation. Throws an
  97. /// exception on failure.
  98. std::size_t flush()
  99. {
  100. return stream_impl_.next_layer().flush();
  101. }
  102. /// Flush all data from the buffer to the next layer. Returns the number of
  103. /// bytes written to the next layer on the last write operation, or 0 if an
  104. /// error occurred.
  105. std::size_t flush(boost::system::error_code& ec)
  106. {
  107. return stream_impl_.next_layer().flush(ec);
  108. }
  109. /// Start an asynchronous flush.
  110. template <typename WriteHandler>
  111. BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
  112. void (boost::system::error_code, std::size_t))
  113. async_flush(BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
  114. {
  115. return stream_impl_.next_layer().async_flush(
  116. BOOST_ASIO_MOVE_CAST(WriteHandler)(handler));
  117. }
  118. /// Write the given data to the stream. Returns the number of bytes written.
  119. /// Throws an exception on failure.
  120. template <typename ConstBufferSequence>
  121. std::size_t write_some(const ConstBufferSequence& buffers)
  122. {
  123. return stream_impl_.write_some(buffers);
  124. }
  125. /// Write the given data to the stream. Returns the number of bytes written,
  126. /// or 0 if an error occurred.
  127. template <typename ConstBufferSequence>
  128. std::size_t write_some(const ConstBufferSequence& buffers,
  129. boost::system::error_code& ec)
  130. {
  131. return stream_impl_.write_some(buffers, ec);
  132. }
  133. /// Start an asynchronous write. The data being written must be valid for the
  134. /// lifetime of the asynchronous operation.
  135. template <typename ConstBufferSequence, typename WriteHandler>
  136. BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
  137. void (boost::system::error_code, std::size_t))
  138. async_write_some(const ConstBufferSequence& buffers,
  139. BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
  140. {
  141. return stream_impl_.async_write_some(buffers,
  142. BOOST_ASIO_MOVE_CAST(WriteHandler)(handler));
  143. }
  144. /// Fill the buffer with some data. Returns the number of bytes placed in the
  145. /// buffer as a result of the operation. Throws an exception on failure.
  146. std::size_t fill()
  147. {
  148. return stream_impl_.fill();
  149. }
  150. /// Fill the buffer with some data. Returns the number of bytes placed in the
  151. /// buffer as a result of the operation, or 0 if an error occurred.
  152. std::size_t fill(boost::system::error_code& ec)
  153. {
  154. return stream_impl_.fill(ec);
  155. }
  156. /// Start an asynchronous fill.
  157. template <typename ReadHandler>
  158. BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
  159. void (boost::system::error_code, std::size_t))
  160. async_fill(BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
  161. {
  162. return stream_impl_.async_fill(BOOST_ASIO_MOVE_CAST(ReadHandler)(handler));
  163. }
  164. /// Read some data from the stream. Returns the number of bytes read. Throws
  165. /// an exception on failure.
  166. template <typename MutableBufferSequence>
  167. std::size_t read_some(const MutableBufferSequence& buffers)
  168. {
  169. return stream_impl_.read_some(buffers);
  170. }
  171. /// Read some data from the stream. Returns the number of bytes read or 0 if
  172. /// an error occurred.
  173. template <typename MutableBufferSequence>
  174. std::size_t read_some(const MutableBufferSequence& buffers,
  175. boost::system::error_code& ec)
  176. {
  177. return stream_impl_.read_some(buffers, ec);
  178. }
  179. /// Start an asynchronous read. The buffer into which the data will be read
  180. /// must be valid for the lifetime of the asynchronous operation.
  181. template <typename MutableBufferSequence, typename ReadHandler>
  182. BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
  183. void (boost::system::error_code, std::size_t))
  184. async_read_some(const MutableBufferSequence& buffers,
  185. BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
  186. {
  187. return stream_impl_.async_read_some(buffers,
  188. BOOST_ASIO_MOVE_CAST(ReadHandler)(handler));
  189. }
  190. /// Peek at the incoming data on the stream. Returns the number of bytes read.
  191. /// Throws an exception on failure.
  192. template <typename MutableBufferSequence>
  193. std::size_t peek(const MutableBufferSequence& buffers)
  194. {
  195. return stream_impl_.peek(buffers);
  196. }
  197. /// Peek at the incoming data on the stream. Returns the number of bytes read,
  198. /// or 0 if an error occurred.
  199. template <typename MutableBufferSequence>
  200. std::size_t peek(const MutableBufferSequence& buffers,
  201. boost::system::error_code& ec)
  202. {
  203. return stream_impl_.peek(buffers, ec);
  204. }
  205. /// Determine the amount of data that may be read without blocking.
  206. std::size_t in_avail()
  207. {
  208. return stream_impl_.in_avail();
  209. }
  210. /// Determine the amount of data that may be read without blocking.
  211. std::size_t in_avail(boost::system::error_code& ec)
  212. {
  213. return stream_impl_.in_avail(ec);
  214. }
  215. private:
  216. // The buffered write stream.
  217. typedef buffered_write_stream<Stream> write_stream_type;
  218. write_stream_type inner_stream_impl_;
  219. // The buffered read stream.
  220. typedef buffered_read_stream<write_stream_type&> read_stream_type;
  221. read_stream_type stream_impl_;
  222. };
  223. } // namespace asio
  224. } // namespace boost
  225. #include <boost/asio/detail/pop_options.hpp>
  226. #endif // BOOST_ASIO_BUFFERED_STREAM_HPP