1 | // |
2 | // buffered_read_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_READ_STREAM_HPP |
12 | #define BOOST_ASIO_BUFFERED_READ_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/async_result.hpp> |
21 | #include <boost/asio/buffered_read_stream_fwd.hpp> |
22 | #include <boost/asio/buffer.hpp> |
23 | #include <boost/asio/detail/bind_handler.hpp> |
24 | #include <boost/asio/detail/buffer_resize_guard.hpp> |
25 | #include <boost/asio/detail/buffered_stream_storage.hpp> |
26 | #include <boost/asio/detail/noncopyable.hpp> |
27 | #include <boost/asio/detail/type_traits.hpp> |
28 | #include <boost/asio/error.hpp> |
29 | #include <boost/asio/io_service.hpp> |
30 | |
31 | #include <boost/asio/detail/push_options.hpp> |
32 | |
33 | namespace boost { |
34 | namespace asio { |
35 | |
36 | /// Adds buffering to the read-related operations of a stream. |
37 | /** |
38 | * The buffered_read_stream class template can be used to add buffering to the |
39 | * synchronous and asynchronous read 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_read_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_read_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_read_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 | /// 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 next_layer_.write_some(buffers); |
124 | } |
125 | |
126 | /// Write the given data to the stream. Returns the number of bytes written, |
127 | /// or 0 if an error occurred. |
128 | template <typename ConstBufferSequence> |
129 | std::size_t write_some(const ConstBufferSequence& buffers, |
130 | boost::system::error_code& ec) |
131 | { |
132 | return next_layer_.write_some(buffers, ec); |
133 | } |
134 | |
135 | /// Start an asynchronous write. The data being written must be valid for the |
136 | /// lifetime of the asynchronous operation. |
137 | template <typename ConstBufferSequence, typename WriteHandler> |
138 | BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler, |
139 | void (boost::system::error_code, std::size_t)) |
140 | async_write_some(const ConstBufferSequence& buffers, |
141 | BOOST_ASIO_MOVE_ARG(WriteHandler) handler) |
142 | { |
143 | detail::async_result_init< |
144 | WriteHandler, void (boost::system::error_code, std::size_t)> init( |
145 | BOOST_ASIO_MOVE_CAST(WriteHandler)(handler)); |
146 | |
147 | next_layer_.async_write_some(buffers, |
148 | BOOST_ASIO_MOVE_CAST(BOOST_ASIO_HANDLER_TYPE(WriteHandler, |
149 | void (boost::system::error_code, std::size_t)))(init.handler)); |
150 | |
151 | return init.result.get(); |
152 | } |
153 | |
154 | /// Fill the buffer with some data. Returns the number of bytes placed in the |
155 | /// buffer as a result of the operation. Throws an exception on failure. |
156 | std::size_t fill(); |
157 | |
158 | /// Fill the buffer with some data. Returns the number of bytes placed in the |
159 | /// buffer as a result of the operation, or 0 if an error occurred. |
160 | std::size_t fill(boost::system::error_code& ec); |
161 | |
162 | /// Start an asynchronous fill. |
163 | template <typename ReadHandler> |
164 | BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler, |
165 | void (boost::system::error_code, std::size_t)) |
166 | async_fill(BOOST_ASIO_MOVE_ARG(ReadHandler) handler); |
167 | |
168 | /// Read some data from the stream. Returns the number of bytes read. Throws |
169 | /// an exception on failure. |
170 | template <typename MutableBufferSequence> |
171 | std::size_t read_some(const MutableBufferSequence& buffers); |
172 | |
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); |
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 | /// Peek at the incoming data on the stream. Returns the number of bytes read. |
188 | /// Throws an exception on failure. |
189 | template <typename MutableBufferSequence> |
190 | std::size_t peek(const MutableBufferSequence& buffers); |
191 | |
192 | /// Peek at the incoming data on the stream. Returns the number of bytes read, |
193 | /// or 0 if an error occurred. |
194 | template <typename MutableBufferSequence> |
195 | std::size_t peek(const MutableBufferSequence& buffers, |
196 | boost::system::error_code& ec); |
197 | |
198 | /// Determine the amount of data that may be read without blocking. |
199 | std::size_t in_avail() |
200 | { |
201 | return storage_.size(); |
202 | } |
203 | |
204 | /// Determine the amount of data that may be read without blocking. |
205 | std::size_t in_avail(boost::system::error_code& ec) |
206 | { |
207 | ec = boost::system::error_code(); |
208 | return storage_.size(); |
209 | } |
210 | |
211 | private: |
212 | /// Copy data out of the internal buffer to the specified target buffer. |
213 | /// Returns the number of bytes copied. |
214 | template <typename MutableBufferSequence> |
215 | std::size_t copy(const MutableBufferSequence& buffers) |
216 | { |
217 | std::size_t bytes_copied = boost::asio::buffer_copy( |
218 | buffers, storage_.data(), storage_.size()); |
219 | storage_.consume(count: bytes_copied); |
220 | return bytes_copied; |
221 | } |
222 | |
223 | /// Copy data from the internal buffer to the specified target buffer, without |
224 | /// removing the data from the internal buffer. Returns the number of bytes |
225 | /// copied. |
226 | template <typename MutableBufferSequence> |
227 | std::size_t peek_copy(const MutableBufferSequence& buffers) |
228 | { |
229 | return boost::asio::buffer_copy(buffers, storage_.data(), storage_.size()); |
230 | } |
231 | |
232 | /// The next layer. |
233 | Stream next_layer_; |
234 | |
235 | // The data in the buffer. |
236 | detail::buffered_stream_storage storage_; |
237 | }; |
238 | |
239 | } // namespace asio |
240 | } // namespace boost |
241 | |
242 | #include <boost/asio/detail/pop_options.hpp> |
243 | |
244 | #include <boost/asio/impl/buffered_read_stream.hpp> |
245 | |
246 | #endif // BOOST_ASIO_BUFFERED_READ_STREAM_HPP |
247 | |