2 // buffered_write_stream.hpp
3 // ~~~~~~~~~~~~~~~~~~~~~~~~~
5 // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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)
11 #ifndef BOOST_ASIO_BUFFERED_WRITE_STREAM_HPP
12 #define BOOST_ASIO_BUFFERED_WRITE_STREAM_HPP
14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
18 #include <boost/asio/detail/config.hpp>
20 #include <boost/asio/buffered_write_stream_fwd.hpp>
21 #include <boost/asio/buffer.hpp>
22 #include <boost/asio/completion_condition.hpp>
23 #include <boost/asio/detail/bind_handler.hpp>
24 #include <boost/asio/detail/buffered_stream_storage.hpp>
25 #include <boost/asio/detail/noncopyable.hpp>
26 #include <boost/asio/detail/type_traits.hpp>
27 #include <boost/asio/error.hpp>
28 #include <boost/asio/write.hpp>
30 #include <boost/asio/detail/push_options.hpp>
35 /// Adds buffering to the write-related operations of a stream.
37 * The buffered_write_stream class template can be used to add buffering to the
38 * synchronous and asynchronous write operations of a stream.
41 * @e Distinct @e objects: Safe.@n
42 * @e Shared @e objects: Unsafe.
45 * AsyncReadStream, AsyncWriteStream, Stream, SyncReadStream, SyncWriteStream.
47 template <typename Stream>
48 class buffered_write_stream
52 /// The type of the next layer.
53 typedef typename remove_reference<Stream>::type next_layer_type;
55 /// The type of the lowest layer.
56 typedef typename next_layer_type::lowest_layer_type lowest_layer_type;
58 /// The type of the executor associated with the object.
59 typedef typename lowest_layer_type::executor_type executor_type;
61 #if defined(GENERATING_DOCUMENTATION)
62 /// The default buffer size.
63 static const std::size_t default_buffer_size = implementation_defined;
65 BOOST_ASIO_STATIC_CONSTANT(std::size_t, default_buffer_size = 1024);
68 /// Construct, passing the specified argument to initialise the next layer.
69 template <typename Arg>
70 explicit buffered_write_stream(Arg& a)
72 storage_(default_buffer_size)
76 /// Construct, passing the specified argument to initialise the next layer.
77 template <typename Arg>
78 buffered_write_stream(Arg& a, std::size_t buffer_size)
84 /// Get a reference to the next layer.
85 next_layer_type& next_layer()
90 /// Get a reference to the lowest layer.
91 lowest_layer_type& lowest_layer()
93 return next_layer_.lowest_layer();
96 /// Get a const reference to the lowest layer.
97 const lowest_layer_type& lowest_layer() const
99 return next_layer_.lowest_layer();
102 /// Get the executor associated with the object.
103 executor_type get_executor() BOOST_ASIO_NOEXCEPT
105 return next_layer_.lowest_layer().get_executor();
108 /// Close the stream.
114 /// Close the stream.
115 BOOST_ASIO_SYNC_OP_VOID close(boost::system::error_code& ec)
117 next_layer_.close(ec);
118 BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
121 /// Flush all data from the buffer to the next layer. Returns the number of
122 /// bytes written to the next layer on the last write operation. Throws an
123 /// exception on failure.
126 /// Flush all data from the buffer to the next layer. Returns the number of
127 /// bytes written to the next layer on the last write operation, or 0 if an
129 std::size_t flush(boost::system::error_code& ec);
131 /// Start an asynchronous flush.
133 BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
134 std::size_t)) WriteHandler
135 BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
136 BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(WriteHandler,
137 void (boost::system::error_code, std::size_t))
139 BOOST_ASIO_MOVE_ARG(WriteHandler) handler
140 BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(executor_type));
142 /// Write the given data to the stream. Returns the number of bytes written.
143 /// Throws an exception on failure.
144 template <typename ConstBufferSequence>
145 std::size_t write_some(const ConstBufferSequence& buffers);
147 /// Write the given data to the stream. Returns the number of bytes written,
148 /// or 0 if an error occurred and the error handler did not throw.
149 template <typename ConstBufferSequence>
150 std::size_t write_some(const ConstBufferSequence& buffers,
151 boost::system::error_code& ec);
153 /// Start an asynchronous write. The data being written must be valid for the
154 /// lifetime of the asynchronous operation.
155 template <typename ConstBufferSequence,
156 BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
157 std::size_t)) WriteHandler
158 BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
159 BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(WriteHandler,
160 void (boost::system::error_code, std::size_t))
161 async_write_some(const ConstBufferSequence& buffers,
162 BOOST_ASIO_MOVE_ARG(WriteHandler) handler
163 BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(executor_type));
165 /// Read some data from the stream. Returns the number of bytes read. Throws
166 /// an exception on failure.
167 template <typename MutableBufferSequence>
168 std::size_t read_some(const MutableBufferSequence& buffers)
170 return next_layer_.read_some(buffers);
173 /// Read some data from the stream. Returns the number of bytes read or 0 if
174 /// an error occurred.
175 template <typename MutableBufferSequence>
176 std::size_t read_some(const MutableBufferSequence& buffers,
177 boost::system::error_code& ec)
179 return next_layer_.read_some(buffers, ec);
182 /// Start an asynchronous read. The buffer into which the data will be read
183 /// must be valid for the lifetime of the asynchronous operation.
184 template <typename MutableBufferSequence,
185 BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
186 std::size_t)) ReadHandler
187 BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
188 BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
189 void (boost::system::error_code, std::size_t))
190 async_read_some(const MutableBufferSequence& buffers,
191 BOOST_ASIO_MOVE_ARG(ReadHandler) handler
192 BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
194 return next_layer_.async_read_some(buffers,
195 BOOST_ASIO_MOVE_CAST(ReadHandler)(handler));
198 /// Peek at the incoming data on the stream. Returns the number of bytes read.
199 /// Throws an exception on failure.
200 template <typename MutableBufferSequence>
201 std::size_t peek(const MutableBufferSequence& buffers)
203 return next_layer_.peek(buffers);
206 /// Peek at the incoming data on the stream. Returns the number of bytes read,
207 /// or 0 if an error occurred.
208 template <typename MutableBufferSequence>
209 std::size_t peek(const MutableBufferSequence& buffers,
210 boost::system::error_code& ec)
212 return next_layer_.peek(buffers, ec);
215 /// Determine the amount of data that may be read without blocking.
216 std::size_t in_avail()
218 return next_layer_.in_avail();
221 /// Determine the amount of data that may be read without blocking.
222 std::size_t in_avail(boost::system::error_code& ec)
224 return next_layer_.in_avail(ec);
228 /// Copy data into the internal buffer from the specified source buffer.
229 /// Returns the number of bytes copied.
230 template <typename ConstBufferSequence>
231 std::size_t copy(const ConstBufferSequence& buffers);
236 // The data in the buffer.
237 detail::buffered_stream_storage storage_;
243 #include <boost/asio/detail/pop_options.hpp>
245 #include <boost/asio/impl/buffered_write_stream.hpp>
247 #endif // BOOST_ASIO_BUFFERED_WRITE_STREAM_HPP