ceph/src/boost/boost/asio/buffered_write_stream.hpp

   1 //
   2 // buffered_write_stream.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2018 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_context.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   /// The type of the executor associated with the object.
  60   typedef typename lowest_layer_type::executor_type executor_type;
  61
  62 #if defined(GENERATING_DOCUMENTATION)
  63   /// The default buffer size.
  64   static const std::size_t default_buffer_size = implementation_defined;
  65 #else
  66   BOOST_ASIO_STATIC_CONSTANT(std::size_t, default_buffer_size = 1024);
  67 #endif
  68
  69   /// Construct, passing the specified argument to initialise the next layer.
  70   template <typename Arg>
  71   explicit buffered_write_stream(Arg& a)
  72     : next_layer_(a),
  73       storage_(default_buffer_size)
  74   {
  75   }
  76
  77   /// Construct, passing the specified argument to initialise the next layer.
  78   template <typename Arg>
  79   buffered_write_stream(Arg& a, std::size_t buffer_size)
  80     : next_layer_(a),
  81       storage_(buffer_size)
  82   {
  83   }
  84
  85   /// Get a reference to the next layer.
  86   next_layer_type& next_layer()
  87   {
  88     return next_layer_;
  89   }
  90
  91   /// Get a reference to the lowest layer.
  92   lowest_layer_type& lowest_layer()
  93   {
  94     return next_layer_.lowest_layer();
  95   }
  96
  97   /// Get a const reference to the lowest layer.
  98   const lowest_layer_type& lowest_layer() const
  99   {
 100     return next_layer_.lowest_layer();
 101   }
 102
 103   /// Get the executor associated with the object.
 104   executor_type get_executor() BOOST_ASIO_NOEXCEPT
 105   {
 106     return next_layer_.lowest_layer().get_executor();
 107   }
 108
 109 #if !defined(BOOST_ASIO_NO_DEPRECATED)
 110   /// (Deprecated: Use get_executor().) Get the io_context associated with the
 111   /// object.
 112   boost::asio::io_context& get_io_context()
 113   {
 114     return next_layer_.get_io_context();
 115   }
 116
 117   /// (Deprecated: Use get_executor().) Get the io_context associated with the
 118   /// object.
 119   boost::asio::io_context& get_io_service()
 120   {
 121     return next_layer_.get_io_service();
 122   }
 123 #endif // !defined(BOOST_ASIO_NO_DEPRECATED)
 124
 125   /// Close the stream.
 126   void close()
 127   {
 128     next_layer_.close();
 129   }
 130
 131   /// Close the stream.
 132   BOOST_ASIO_SYNC_OP_VOID close(boost::system::error_code& ec)
 133   {
 134     next_layer_.close(ec);
 135     BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
 136   }
 137
 138   /// Flush all data from the buffer to the next layer. Returns the number of
 139   /// bytes written to the next layer on the last write operation. Throws an
 140   /// exception on failure.
 141   std::size_t flush();
 142
 143   /// Flush all data from the buffer to the next layer. Returns the number of
 144   /// bytes written to the next layer on the last write operation, or 0 if an
 145   /// error occurred.
 146   std::size_t flush(boost::system::error_code& ec);
 147
 148   /// Start an asynchronous flush.
 149   template <typename WriteHandler>
 150   BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
 151       void (boost::system::error_code, std::size_t))
 152   async_flush(BOOST_ASIO_MOVE_ARG(WriteHandler) handler);
 153
 154   /// Write the given data to the stream. Returns the number of bytes written.
 155   /// Throws an exception on failure.
 156   template <typename ConstBufferSequence>
 157   std::size_t write_some(const ConstBufferSequence& buffers);
 158
 159   /// Write the given data to the stream. Returns the number of bytes written,
 160   /// or 0 if an error occurred and the error handler did not throw.
 161   template <typename ConstBufferSequence>
 162   std::size_t write_some(const ConstBufferSequence& buffers,
 163       boost::system::error_code& ec);
 164
 165   /// Start an asynchronous write. The data being written must be valid for the
 166   /// lifetime of the asynchronous operation.
 167   template <typename ConstBufferSequence, typename WriteHandler>
 168   BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
 169       void (boost::system::error_code, std::size_t))
 170   async_write_some(const ConstBufferSequence& buffers,
 171       BOOST_ASIO_MOVE_ARG(WriteHandler) handler);
 172
 173   /// Read some data from the stream. Returns the number of bytes read. Throws
 174   /// an exception on failure.
 175   template <typename MutableBufferSequence>
 176   std::size_t read_some(const MutableBufferSequence& buffers)
 177   {
 178     return next_layer_.read_some(buffers);
 179   }
 180
 181   /// Read some data from the stream. Returns the number of bytes read or 0 if
 182   /// an error occurred.
 183   template <typename MutableBufferSequence>
 184   std::size_t read_some(const MutableBufferSequence& buffers,
 185       boost::system::error_code& ec)
 186   {
 187     return next_layer_.read_some(buffers, ec);
 188   }
 189
 190   /// Start an asynchronous read. The buffer into which the data will be read
 191   /// must be valid for the lifetime of the asynchronous operation.
 192   template <typename MutableBufferSequence, typename ReadHandler>
 193   BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
 194       void (boost::system::error_code, std::size_t))
 195   async_read_some(const MutableBufferSequence& buffers,
 196       BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
 197   {
 198     return next_layer_.async_read_some(buffers,
 199         BOOST_ASIO_MOVE_CAST(ReadHandler)(handler));
 200   }
 201
 202   /// Peek at the incoming data on the stream. Returns the number of bytes read.
 203   /// Throws an exception on failure.
 204   template <typename MutableBufferSequence>
 205   std::size_t peek(const MutableBufferSequence& buffers)
 206   {
 207     return next_layer_.peek(buffers);
 208   }
 209
 210   /// Peek at the incoming data on the stream. Returns the number of bytes read,
 211   /// or 0 if an error occurred.
 212   template <typename MutableBufferSequence>
 213   std::size_t peek(const MutableBufferSequence& buffers,
 214       boost::system::error_code& ec)
 215   {
 216     return next_layer_.peek(buffers, ec);
 217   }
 218
 219   /// Determine the amount of data that may be read without blocking.
 220   std::size_t in_avail()
 221   {
 222     return next_layer_.in_avail();
 223   }
 224
 225   /// Determine the amount of data that may be read without blocking.
 226   std::size_t in_avail(boost::system::error_code& ec)
 227   {
 228     return next_layer_.in_avail(ec);
 229   }
 230
 231 private:
 232   /// Copy data into the internal buffer from the specified source buffer.
 233   /// Returns the number of bytes copied.
 234   template <typename ConstBufferSequence>
 235   std::size_t copy(const ConstBufferSequence& buffers);
 236
 237   /// The next layer.
 238   Stream next_layer_;
 239
 240   // The data in the buffer.
 241   detail::buffered_stream_storage storage_;
 242 };
 243
 244 } // namespace asio
 245 } // namespace boost
 246
 247 #include <boost/asio/detail/pop_options.hpp>
 248
 249 #include <boost/asio/impl/buffered_write_stream.hpp>
 250
 251 #endif // BOOST_ASIO_BUFFERED_WRITE_STREAM_HPP