ceph/src/boost/boost/beast/_experimental/http/icy_stream.hpp

   1 //
   2 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // Official repository: https://github.com/boostorg/beast
   8 //
   9
  10 #ifndef BOOST_BEAST_HTTP_ICY_STREAM_HPP
  11 #define BOOST_BEAST_HTTP_ICY_STREAM_HPP
  12
  13 #include <boost/beast/core/detail/config.hpp>
  14 #include <boost/beast/core/error.hpp>
  15 #include <boost/asio/async_result.hpp>
  16 #include <boost/asio/buffer.hpp>
  17 #include <boost/logic/tribool.hpp>
  18 #include <type_traits>
  19
  20 namespace boost {
  21 namespace beast {
  22 namespace http {
  23
  24 /** Stream wrapper to process Shoutcast HTTP responses
  25
  26     This wrapper replaces the word "ICY" in the first
  27     HTTP response received on the connection, with "HTTP/1.1".
  28     This allows the Beast parser to be used with Shoutcast
  29     servers, which send a non-standard HTTP message as the
  30     response.
  31
  32     For asynchronous operations, the application must ensure
  33     that they are are all performed within the same implicit
  34     or explicit strand.
  35
  36     @par Thread Safety
  37     @e Distinct @e objects: Safe.@n
  38     @e Shared @e objects: Unsafe.
  39     The application must also ensure that all asynchronous
  40     operations are performed within the same implicit or explicit strand.
  41
  42     @par Example
  43     To use the @ref icy_stream template with an @ref tcp_stream
  44     you would write:
  45     @code
  46     http::icy_stream<tcp_stream> is(ioc);
  47     @endcode
  48
  49     @tparam NextLayer The type representing the next layer, to which
  50     data will be read and written during operations. For synchronous
  51     operations, the type must support the <em>SyncStream</em> concept.
  52     For asynchronous operations, the type must support the
  53     <em>AsyncStream</em> concept.
  54
  55     @note A stream object must not be moved or destroyed while there
  56     are pending asynchronous operations associated with it.
  57
  58     @par Concepts
  59     <em>AsyncStream</em>, <em>SyncStream</em>
  60 */
  61 template<class NextLayer>
  62 class icy_stream
  63 {
  64     NextLayer stream_;
  65     char buf_[8];
  66     unsigned char n_ = 0;
  67     bool detect_ = true;
  68
  69     struct ops;
  70
  71     static
  72     net::const_buffer
  73     version()
  74     {
  75         return {"HTTP/1.1", 8};
  76     }
  77
  78 public:
  79     /// The type of the next layer.
  80     using next_layer_type =
  81         typename std::remove_reference<NextLayer>::type;
  82
  83     /// The type of the executor associated with the object.
  84     using executor_type = typename next_layer_type::executor_type;
  85
  86     icy_stream(icy_stream&&) = default;
  87     icy_stream(icy_stream const&) = default;
  88     icy_stream& operator=(icy_stream&&) = default;
  89     icy_stream& operator=(icy_stream const&) = default;
  90
  91     /** Destructor
  92
  93         The treatment of pending operations will be the same as that
  94         of the next layer.
  95     */
  96     ~icy_stream() = default;
  97
  98     /** Constructor
  99
 100         Arguments, if any, are forwarded to the next layer's constructor.
 101     */
 102     template<class... Args>
 103     explicit
 104     icy_stream(Args&&... args);
 105
 106     //--------------------------------------------------------------------------
 107
 108     /** Get the executor associated with the object.
 109
 110         This function may be used to obtain the executor object that the
 111         stream uses to dispatch handlers for asynchronous operations.
 112
 113         @return A copy of the executor that stream will use to dispatch handlers.
 114     */
 115     executor_type
 116     get_executor() noexcept
 117     {
 118         return stream_.get_executor();
 119     }
 120
 121     /** Get a reference to the next layer
 122
 123         This function returns a reference to the next layer
 124         in a stack of stream layers.
 125
 126         @return A reference to the next layer in the stack of
 127         stream layers.
 128     */
 129     next_layer_type&
 130     next_layer()
 131     {
 132         return stream_;
 133     }
 134
 135     /** Get a reference to the next layer
 136
 137         This function returns a reference to the next layer in a
 138         stack of stream layers.
 139
 140         @return A reference to the next layer in the stack of
 141         stream layers.
 142     */
 143     next_layer_type const&
 144     next_layer() const
 145     {
 146         return stream_;
 147     }
 148
 149     //--------------------------------------------------------------------------
 150
 151     /** Read some data from the stream.
 152
 153         This function is used to read data from the stream. The function call will
 154         block until one or more bytes of data has been read successfully, or until
 155         an error occurs.
 156
 157         @param buffers The buffers into which the data will be read.
 158
 159         @returns The number of bytes read.
 160
 161         @throws system_error Thrown on failure.
 162
 163         @note The `read_some` operation may not read all of the requested number of
 164         bytes. Consider using the function `net::read` if you need to ensure
 165         that the requested amount of data is read before the blocking operation
 166         completes.
 167     */
 168     template<class MutableBufferSequence>
 169     std::size_t
 170     read_some(MutableBufferSequence const& buffers);
 171
 172     /** Read some data from the stream.
 173
 174         This function is used to read data from the stream. The function call will
 175         block until one or more bytes of data has been read successfully, or until
 176         an error occurs.
 177
 178         @param buffers The buffers into which the data will be read.
 179
 180         @param ec Set to indicate what error occurred, if any.
 181
 182         @returns The number of bytes read.
 183
 184         @note The `read_some` operation may not read all of the requested number of
 185         bytes. Consider using the function `net::read` if you need to ensure
 186         that the requested amount of data is read before the blocking operation
 187         completes.
 188     */
 189     template<class MutableBufferSequence>
 190     std::size_t
 191     read_some(
 192         MutableBufferSequence const& buffers,
 193         error_code& ec);
 194
 195     /** Start an asynchronous read.
 196
 197         This function is used to asynchronously read one or more bytes of data from
 198         the stream. The function call always returns immediately.
 199
 200         @param buffers The buffers into which the data will be read. Although the
 201         buffers object may be copied as necessary, ownership of the underlying
 202         buffers is retained by the caller, which must guarantee that they remain
 203         valid until the handler is called.
 204
 205         @param handler The completion handler to invoke when the operation
 206         completes. The implementation takes ownership of the handler by
 207         performing a decay-copy. The equivalent function signature of
 208         the handler must be:
 209         @code
 210         void handler(
 211           const boost::system::error_code& error, // Result of operation.
 212           std::size_t bytes_transferred           // Number of bytes read.
 213         );
 214         @endcode
 215         Regardless of whether the asynchronous operation completes
 216         immediately or not, the handler will not be invoked from within
 217         this function. Invocation of the handler will be performed in a
 218         manner equivalent to using `net::post`.
 219
 220         @note The `async_read_some` operation may not read all of the requested number of
 221         bytes. Consider using the function `net::async_read` if you need
 222         to ensure that the requested amount of data is read before the asynchronous
 223         operation completes.
 224     */
 225     template<
 226         class MutableBufferSequence,
 227         BOOST_BEAST_ASYNC_TPARAM2 ReadHandler =
 228             net::default_completion_token_t<executor_type>
 229     >
 230     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
 231     async_read_some(
 232         MutableBufferSequence const& buffers,
 233         ReadHandler&& handler =
 234             net::default_completion_token_t<executor_type>{});
 235
 236     /** Write some data to the stream.
 237
 238         This function is used to write data on the stream. The function call will
 239         block until one or more bytes of data has been written successfully, or
 240         until an error occurs.
 241
 242         @param buffers The data to be written.
 243
 244         @returns The number of bytes written.
 245
 246         @throws system_error Thrown on failure.
 247
 248         @note The `write_some` operation may not transmit all of the data to the
 249         peer. Consider using the function `net::write` if you need to
 250         ensure that all data is written before the blocking operation completes.
 251     */
 252     template<class ConstBufferSequence>
 253     std::size_t
 254     write_some(ConstBufferSequence const& buffers);
 255
 256     /** Write some data to the stream.
 257
 258         This function is used to write data on the stream. The function call will
 259         block until one or more bytes of data has been written successfully, or
 260         until an error occurs.
 261
 262         @param buffers The data to be written.
 263
 264         @param ec Set to indicate what error occurred, if any.
 265
 266         @returns The number of bytes written.
 267
 268         @note The `write_some` operation may not transmit all of the data to the
 269         peer. Consider using the function `net::write` if you need to
 270         ensure that all data is written before the blocking operation completes.
 271     */
 272     template<class ConstBufferSequence>
 273     std::size_t
 274     write_some(
 275         ConstBufferSequence const& buffers,
 276         error_code& ec);
 277
 278     /** Start an asynchronous write.
 279
 280         This function is used to asynchronously write one or more bytes of data to
 281         the stream. The function call always returns immediately.
 282
 283         @param buffers The data to be written to the stream. Although the buffers
 284         object may be copied as necessary, ownership of the underlying buffers is
 285         retained by the caller, which must guarantee that they remain valid until
 286         the handler is called.
 287
 288         @param handler The completion handler to invoke when the operation
 289         completes. The implementation takes ownership of the handler by
 290         performing a decay-copy. The equivalent function signature of
 291         the handler must be:
 292         @code
 293         void handler(
 294           error_code const& error,          // Result of operation.
 295           std::size_t bytes_transferred     // Number of bytes written.
 296         );
 297         @endcode
 298         Regardless of whether the asynchronous operation completes
 299         immediately or not, the handler will not be invoked from within
 300         this function. Invocation of the handler will be performed in a
 301         manner equivalent to using `net::post`.
 302
 303         @note The `async_write_some` operation may not transmit all of the data to
 304         the peer. Consider using the function `net::async_write` if you need
 305         to ensure that all data is written before the asynchronous operation completes.
 306     */
 307     template<
 308         class ConstBufferSequence,
 309         BOOST_BEAST_ASYNC_TPARAM2 WriteHandler =
 310             net::default_completion_token_t<executor_type>
 311     >
 312     BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
 313     async_write_some(
 314         ConstBufferSequence const& buffers,
 315         WriteHandler&& handler =
 316             net::default_completion_token_t<executor_type>{});
 317 };
 318
 319 } // http
 320 } // beast
 321 } // boost
 322
 323 #include <boost/beast/_experimental/http/impl/icy_stream.hpp>
 324
 325 #endif