summaryrefslogtreecommitdiffstats
blob: 91493e3577ed920929f9c65dd9e5bb594a5bdad3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
//
// buffered_read_stream.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2014 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef BOOST_ASIO_BUFFERED_READ_STREAM_HPP
#define BOOST_ASIO_BUFFERED_READ_STREAM_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include <boost/asio/detail/config.hpp>
#include <cstddef>
#include <boost/asio/async_result.hpp>
#include <boost/asio/buffered_read_stream_fwd.hpp>
#include <boost/asio/buffer.hpp>
#include <boost/asio/detail/bind_handler.hpp>
#include <boost/asio/detail/buffer_resize_guard.hpp>
#include <boost/asio/detail/buffered_stream_storage.hpp>
#include <boost/asio/detail/noncopyable.hpp>
#include <boost/asio/detail/type_traits.hpp>
#include <boost/asio/error.hpp>
#include <boost/asio/io_service.hpp>

#include <boost/asio/detail/push_options.hpp>

namespace boost {
namespace asio {

/// Adds buffering to the read-related operations of a stream.
/**
 * The buffered_read_stream class template can be used to add buffering to the
 * synchronous and asynchronous read operations of a stream.
 *
 * @par Thread Safety
 * @e Distinct @e objects: Safe.@n
 * @e Shared @e objects: Unsafe.
 *
 * @par Concepts:
 * AsyncReadStream, AsyncWriteStream, Stream, SyncReadStream, SyncWriteStream.
 */
template <typename Stream>
class buffered_read_stream
  : private noncopyable
{
public:
  /// The type of the next layer.
  typedef typename remove_reference<Stream>::type next_layer_type;

  /// The type of the lowest layer.
  typedef typename next_layer_type::lowest_layer_type lowest_layer_type;

#if defined(GENERATING_DOCUMENTATION)
  /// The default buffer size.
  static const std::size_t default_buffer_size = implementation_defined;
#else
  BOOST_ASIO_STATIC_CONSTANT(std::size_t, default_buffer_size = 1024);
#endif

  /// Construct, passing the specified argument to initialise the next layer.
  template <typename Arg>
  explicit buffered_read_stream(Arg& a)
    : next_layer_(a),
      storage_(default_buffer_size)
  {
  }

  /// Construct, passing the specified argument to initialise the next layer.
  template <typename Arg>
  buffered_read_stream(Arg& a, std::size_t buffer_size)
    : next_layer_(a),
      storage_(buffer_size)
  {
  }

  /// Get a reference to the next layer.
  next_layer_type& next_layer()
  {
    return next_layer_;
  }

  /// Get a reference to the lowest layer.
  lowest_layer_type& lowest_layer()
  {
    return next_layer_.lowest_layer();
  }

  /// Get a const reference to the lowest layer.
  const lowest_layer_type& lowest_layer() const
  {
    return next_layer_.lowest_layer();
  }

  /// Get the io_service associated with the object.
  boost::asio::io_service& get_io_service()
  {
    return next_layer_.get_io_service();
  }

  /// Close the stream.
  void close()
  {
    next_layer_.close();
  }

  /// Close the stream.
  boost::system::error_code close(boost::system::error_code& ec)
  {
    return next_layer_.close(ec);
  }

  /// Write the given data to the stream. Returns the number of bytes written.
  /// Throws an exception on failure.
  template <typename ConstBufferSequence>
  std::size_t write_some(const ConstBufferSequence& buffers)
  {
    return next_layer_.write_some(buffers);
  }

  /// Write the given data to the stream. Returns the number of bytes written,
  /// or 0 if an error occurred.
  template <typename ConstBufferSequence>
  std::size_t write_some(const ConstBufferSequence& buffers,
      boost::system::error_code& ec)
  {
    return next_layer_.write_some(buffers, ec);
  }

  /// Start an asynchronous write. The data being written must be valid for the
  /// lifetime of the asynchronous operation.
  template <typename ConstBufferSequence, typename WriteHandler>
  BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
      void (boost::system::error_code, std::size_t))
  async_write_some(const ConstBufferSequence& buffers,
      BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
  {
    detail::async_result_init<
      WriteHandler, void (boost::system::error_code, std::size_t)> init(
        BOOST_ASIO_MOVE_CAST(WriteHandler)(handler));

    next_layer_.async_write_some(buffers,
        BOOST_ASIO_MOVE_CAST(BOOST_ASIO_HANDLER_TYPE(WriteHandler,
            void (boost::system::error_code, std::size_t)))(init.handler));

    return init.result.get();
  }

  /// Fill the buffer with some data. Returns the number of bytes placed in the
  /// buffer as a result of the operation. Throws an exception on failure.
  std::size_t fill();

  /// Fill the buffer with some data. Returns the number of bytes placed in the
  /// buffer as a result of the operation, or 0 if an error occurred.
  std::size_t fill(boost::system::error_code& ec);

  /// Start an asynchronous fill.
  template <typename ReadHandler>
  BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
      void (boost::system::error_code, std::size_t))
  async_fill(BOOST_ASIO_MOVE_ARG(ReadHandler) handler);

  /// Read some data from the stream. Returns the number of bytes read. Throws
  /// an exception on failure.
  template <typename MutableBufferSequence>
  std::size_t read_some(const MutableBufferSequence& buffers);

  /// Read some data from the stream. Returns the number of bytes read or 0 if
  /// an error occurred.
  template <typename MutableBufferSequence>
  std::size_t read_some(const MutableBufferSequence& buffers,
      boost::system::error_code& ec);

  /// Start an asynchronous read. The buffer into which the data will be read
  /// must be valid for the lifetime of the asynchronous operation.
  template <typename MutableBufferSequence, typename ReadHandler>
  BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
      void (boost::system::error_code, std::size_t))
  async_read_some(const MutableBufferSequence& buffers,
      BOOST_ASIO_MOVE_ARG(ReadHandler) handler);

  /// Peek at the incoming data on the stream. Returns the number of bytes read.
  /// Throws an exception on failure.
  template <typename MutableBufferSequence>
  std::size_t peek(const MutableBufferSequence& buffers);

  /// Peek at the incoming data on the stream. Returns the number of bytes read,
  /// or 0 if an error occurred.
  template <typename MutableBufferSequence>
  std::size_t peek(const MutableBufferSequence& buffers,
      boost::system::error_code& ec);

  /// Determine the amount of data that may be read without blocking.
  std::size_t in_avail()
  {
    return storage_.size();
  }

  /// Determine the amount of data that may be read without blocking.
  std::size_t in_avail(boost::system::error_code& ec)
  {
    ec = boost::system::error_code();
    return storage_.size();
  }

private:
  /// Copy data out of the internal buffer to the specified target buffer.
  /// Returns the number of bytes copied.
  template <typename MutableBufferSequence>
  std::size_t copy(const MutableBufferSequence& buffers)
  {
    std::size_t bytes_copied = boost::asio::buffer_copy(
        buffers, storage_.data(), storage_.size());
    storage_.consume(bytes_copied);
    return bytes_copied;
  }

  /// Copy data from the internal buffer to the specified target buffer, without
  /// removing the data from the internal buffer. Returns the number of bytes
  /// copied.
  template <typename MutableBufferSequence>
  std::size_t peek_copy(const MutableBufferSequence& buffers)
  {
    return boost::asio::buffer_copy(buffers, storage_.data(), storage_.size());
  }

  /// The next layer.
  Stream next_layer_;

  // The data in the buffer.
  detail::buffered_stream_storage storage_;
};

} // namespace asio
} // namespace boost

#include <boost/asio/detail/pop_options.hpp>

#include <boost/asio/impl/buffered_read_stream.hpp>

#endif // BOOST_ASIO_BUFFERED_READ_STREAM_HPP