// // buffered_write_stream.hpp // ~~~~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2021 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 ASIO_BUFFERED_WRITE_STREAM_HPP #define ASIO_BUFFERED_WRITE_STREAM_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include "asio/detail/config.hpp" #include #include "asio/buffered_write_stream_fwd.hpp" #include "asio/buffer.hpp" #include "asio/completion_condition.hpp" #include "asio/detail/bind_handler.hpp" #include "asio/detail/buffered_stream_storage.hpp" #include "asio/detail/noncopyable.hpp" #include "asio/detail/type_traits.hpp" #include "asio/error.hpp" #include "asio/write.hpp" #include "asio/detail/push_options.hpp" namespace asio { /// Adds buffering to the write-related operations of a stream. /** * The buffered_write_stream class template can be used to add buffering to the * synchronous and asynchronous write 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 class buffered_write_stream : private noncopyable { public: /// The type of the next layer. typedef typename remove_reference::type next_layer_type; /// The type of the lowest layer. typedef typename next_layer_type::lowest_layer_type lowest_layer_type; /// The type of the executor associated with the object. typedef typename lowest_layer_type::executor_type executor_type; #if defined(GENERATING_DOCUMENTATION) /// The default buffer size. static const std::size_t default_buffer_size = implementation_defined; #else ASIO_STATIC_CONSTANT(std::size_t, default_buffer_size = 1024); #endif /// Construct, passing the specified argument to initialise the next layer. template explicit buffered_write_stream(Arg& a) : next_layer_(a), storage_(default_buffer_size) { } /// Construct, passing the specified argument to initialise the next layer. template buffered_write_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 executor associated with the object. executor_type get_executor() ASIO_NOEXCEPT { return next_layer_.lowest_layer().get_executor(); } /// Close the stream. void close() { next_layer_.close(); } /// Close the stream. ASIO_SYNC_OP_VOID close(asio::error_code& ec) { next_layer_.close(ec); ASIO_SYNC_OP_VOID_RETURN(ec); } /// Flush all data from the buffer to the next layer. Returns the number of /// bytes written to the next layer on the last write operation. Throws an /// exception on failure. std::size_t flush(); /// Flush all data from the buffer to the next layer. Returns the number of /// bytes written to the next layer on the last write operation, or 0 if an /// error occurred. std::size_t flush(asio::error_code& ec); /// Start an asynchronous flush. template < ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code, std::size_t)) WriteHandler ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)> ASIO_INITFN_AUTO_RESULT_TYPE(WriteHandler, void (asio::error_code, std::size_t)) async_flush( ASIO_MOVE_ARG(WriteHandler) handler ASIO_DEFAULT_COMPLETION_TOKEN(executor_type)); /// Write the given data to the stream. Returns the number of bytes written. /// Throws an exception on failure. template std::size_t write_some(const ConstBufferSequence& buffers); /// Write the given data to the stream. Returns the number of bytes written, /// or 0 if an error occurred and the error handler did not throw. template std::size_t write_some(const ConstBufferSequence& buffers, asio::error_code& ec); /// Start an asynchronous write. The data being written must be valid for the /// lifetime of the asynchronous operation. template ASIO_INITFN_AUTO_RESULT_TYPE(WriteHandler, void (asio::error_code, std::size_t)) async_write_some(const ConstBufferSequence& buffers, ASIO_MOVE_ARG(WriteHandler) handler ASIO_DEFAULT_COMPLETION_TOKEN(executor_type)); /// Read some data from the stream. Returns the number of bytes read. Throws /// an exception on failure. template std::size_t read_some(const MutableBufferSequence& buffers) { return next_layer_.read_some(buffers); } /// Read some data from the stream. Returns the number of bytes read or 0 if /// an error occurred. template std::size_t read_some(const MutableBufferSequence& buffers, asio::error_code& ec) { return next_layer_.read_some(buffers, 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 ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler, void (asio::error_code, std::size_t)) async_read_some(const MutableBufferSequence& buffers, ASIO_MOVE_ARG(ReadHandler) handler ASIO_DEFAULT_COMPLETION_TOKEN(executor_type)) { return next_layer_.async_read_some(buffers, ASIO_MOVE_CAST(ReadHandler)(handler)); } /// Peek at the incoming data on the stream. Returns the number of bytes read. /// Throws an exception on failure. template std::size_t peek(const MutableBufferSequence& buffers) { return next_layer_.peek(buffers); } /// Peek at the incoming data on the stream. Returns the number of bytes read, /// or 0 if an error occurred. template std::size_t peek(const MutableBufferSequence& buffers, asio::error_code& ec) { return next_layer_.peek(buffers, ec); } /// Determine the amount of data that may be read without blocking. std::size_t in_avail() { return next_layer_.in_avail(); } /// Determine the amount of data that may be read without blocking. std::size_t in_avail(asio::error_code& ec) { return next_layer_.in_avail(ec); } private: /// Copy data into the internal buffer from the specified source buffer. /// Returns the number of bytes copied. template std::size_t copy(const ConstBufferSequence& buffers); /// The next layer. Stream next_layer_; // The data in the buffer. detail::buffered_stream_storage storage_; }; } // namespace asio #include "asio/detail/pop_options.hpp" #include "asio/impl/buffered_write_stream.hpp" #endif // ASIO_BUFFERED_WRITE_STREAM_HPP