1 | // |
2 | // buffered_write_stream.hpp |
3 | // ~~~~~~~~~~~~~~~~~~~~~~~~~ |
4 | // |
5 | // Copyright (c) 2003-2015 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 | |
11 | #ifndef BOOST_ASIO_BUFFERED_WRITE_STREAM_HPP |
12 | #define BOOST_ASIO_BUFFERED_WRITE_STREAM_HPP |
13 | |
14 | #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
15 | # pragma once |
16 | #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
17 | |
18 | #include <boost/asio/detail/config.hpp> |
19 | #include <cstddef> |
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/io_service.hpp> |
29 | #include <boost/asio/write.hpp> |
30 | |
31 | #include <boost/asio/detail/push_options.hpp> |
32 | |
33 | namespace boost { |
34 | namespace asio { |
35 | |
36 | /// Adds buffering to the write-related operations of a stream. |
37 | /** |
38 | * The buffered_write_stream class template can be used to add buffering to the |
39 | * synchronous and asynchronous write operations of a stream. |
40 | * |
41 | * @par Thread Safety |
42 | * @e Distinct @e objects: Safe.@n |
43 | * @e Shared @e objects: Unsafe. |
44 | * |
45 | * @par Concepts: |
46 | * AsyncReadStream, AsyncWriteStream, Stream, SyncReadStream, SyncWriteStream. |
47 | */ |
48 | template <typename Stream> |
49 | class buffered_write_stream |
50 | : private noncopyable |
51 | { |
52 | public: |
53 | /// The type of the next layer. |
54 | typedef typename remove_reference<Stream>::type next_layer_type; |
55 | |
56 | /// The type of the lowest layer. |
57 | typedef typename next_layer_type::lowest_layer_type lowest_layer_type; |
58 | |
59 | #if defined(GENERATING_DOCUMENTATION) |
60 | /// The default buffer size. |
61 | static const std::size_t default_buffer_size = implementation_defined; |
62 | #else |
63 | BOOST_ASIO_STATIC_CONSTANT(std::size_t, default_buffer_size = 1024); |
64 | #endif |
65 | |
66 | /// Construct, passing the specified argument to initialise the next layer. |
67 | template <typename Arg> |
68 | explicit buffered_write_stream(Arg& a) |
69 | : next_layer_(a), |
70 | storage_(default_buffer_size) |
71 | { |
72 | } |
73 | |
74 | /// Construct, passing the specified argument to initialise the next layer. |
75 | template <typename Arg> |
76 | buffered_write_stream(Arg& a, std::size_t buffer_size) |
77 | : next_layer_(a), |
78 | storage_(buffer_size) |
79 | { |
80 | } |
81 | |
82 | /// Get a reference to the next layer. |
83 | next_layer_type& next_layer() |
84 | { |
85 | return next_layer_; |
86 | } |
87 | |
88 | /// Get a reference to the lowest layer. |
89 | lowest_layer_type& lowest_layer() |
90 | { |
91 | return next_layer_.lowest_layer(); |
92 | } |
93 | |
94 | /// Get a const reference to the lowest layer. |
95 | const lowest_layer_type& lowest_layer() const |
96 | { |
97 | return next_layer_.lowest_layer(); |
98 | } |
99 | |
100 | /// Get the io_service associated with the object. |
101 | boost::asio::io_service& get_io_service() |
102 | { |
103 | return next_layer_.get_io_service(); |
104 | } |
105 | |
106 | /// Close the stream. |
107 | void close() |
108 | { |
109 | next_layer_.close(); |
110 | } |
111 | |
112 | /// Close the stream. |
113 | boost::system::error_code close(boost::system::error_code& ec) |
114 | { |
115 | return next_layer_.close(ec); |
116 | } |
117 | |
118 | /// Flush all data from the buffer to the next layer. Returns the number of |
119 | /// bytes written to the next layer on the last write operation. Throws an |
120 | /// exception on failure. |
121 | std::size_t flush(); |
122 | |
123 | /// Flush all data from the buffer to the next layer. Returns the number of |
124 | /// bytes written to the next layer on the last write operation, or 0 if an |
125 | /// error occurred. |
126 | std::size_t flush(boost::system::error_code& ec); |
127 | |
128 | /// Start an asynchronous flush. |
129 | template <typename WriteHandler> |
130 | BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler, |
131 | void (boost::system::error_code, std::size_t)) |
132 | async_flush(BOOST_ASIO_MOVE_ARG(WriteHandler) handler); |
133 | |
134 | /// Write the given data to the stream. Returns the number of bytes written. |
135 | /// Throws an exception on failure. |
136 | template <typename ConstBufferSequence> |
137 | std::size_t write_some(const ConstBufferSequence& buffers); |
138 | |
139 | /// Write the given data to the stream. Returns the number of bytes written, |
140 | /// or 0 if an error occurred and the error handler did not throw. |
141 | template <typename ConstBufferSequence> |
142 | std::size_t write_some(const ConstBufferSequence& buffers, |
143 | boost::system::error_code& ec); |
144 | |
145 | /// Start an asynchronous write. The data being written must be valid for the |
146 | /// lifetime of the asynchronous operation. |
147 | template <typename ConstBufferSequence, typename WriteHandler> |
148 | BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler, |
149 | void (boost::system::error_code, std::size_t)) |
150 | async_write_some(const ConstBufferSequence& buffers, |
151 | BOOST_ASIO_MOVE_ARG(WriteHandler) handler); |
152 | |
153 | /// Read some data from the stream. Returns the number of bytes read. Throws |
154 | /// an exception on failure. |
155 | template <typename MutableBufferSequence> |
156 | std::size_t read_some(const MutableBufferSequence& buffers) |
157 | { |
158 | return next_layer_.read_some(buffers); |
159 | } |
160 | |
161 | /// Read some data from the stream. Returns the number of bytes read or 0 if |
162 | /// an error occurred. |
163 | template <typename MutableBufferSequence> |
164 | std::size_t read_some(const MutableBufferSequence& buffers, |
165 | boost::system::error_code& ec) |
166 | { |
167 | return next_layer_.read_some(buffers, ec); |
168 | } |
169 | |
170 | /// Start an asynchronous read. The buffer into which the data will be read |
171 | /// must be valid for the lifetime of the asynchronous operation. |
172 | template <typename MutableBufferSequence, typename ReadHandler> |
173 | BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler, |
174 | void (boost::system::error_code, std::size_t)) |
175 | async_read_some(const MutableBufferSequence& buffers, |
176 | BOOST_ASIO_MOVE_ARG(ReadHandler) handler) |
177 | { |
178 | detail::async_result_init< |
179 | ReadHandler, void (boost::system::error_code, std::size_t)> init( |
180 | BOOST_ASIO_MOVE_CAST(ReadHandler)(handler)); |
181 | |
182 | next_layer_.async_read_some(buffers, |
183 | BOOST_ASIO_MOVE_CAST(BOOST_ASIO_HANDLER_TYPE(ReadHandler, |
184 | void (boost::system::error_code, std::size_t)))(init.handler)); |
185 | |
186 | return init.result.get(); |
187 | } |
188 | |
189 | /// Peek at the incoming data on the stream. Returns the number of bytes read. |
190 | /// Throws an exception on failure. |
191 | template <typename MutableBufferSequence> |
192 | std::size_t peek(const MutableBufferSequence& buffers) |
193 | { |
194 | return next_layer_.peek(buffers); |
195 | } |
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 next_layer_.peek(buffers, ec); |
204 | } |
205 | |
206 | /// Determine the amount of data that may be read without blocking. |
207 | std::size_t in_avail() |
208 | { |
209 | return next_layer_.in_avail(); |
210 | } |
211 | |
212 | /// Determine the amount of data that may be read without blocking. |
213 | std::size_t in_avail(boost::system::error_code& ec) |
214 | { |
215 | return next_layer_.in_avail(ec); |
216 | } |
217 | |
218 | private: |
219 | /// Copy data into the internal buffer from the specified source buffer. |
220 | /// Returns the number of bytes copied. |
221 | template <typename ConstBufferSequence> |
222 | std::size_t copy(const ConstBufferSequence& buffers); |
223 | |
224 | /// The next layer. |
225 | Stream next_layer_; |
226 | |
227 | // The data in the buffer. |
228 | detail::buffered_stream_storage storage_; |
229 | }; |
230 | |
231 | } // namespace asio |
232 | } // namespace boost |
233 | |
234 | #include <boost/asio/detail/pop_options.hpp> |
235 | |
236 | #include <boost/asio/impl/buffered_write_stream.hpp> |
237 | |
238 | #endif // BOOST_ASIO_BUFFERED_WRITE_STREAM_HPP |
239 | |