| // |
| // reference_counted.cpp |
| // ~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // 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) |
| // |
| |
| #include <boost/asio.hpp> |
| #include <iostream> |
| #include <memory> |
| #include <utility> |
| #include <vector> |
| #include <ctime> |
| |
| using boost::asio::ip::tcp; |
| |
| // A reference-counted non-modifiable buffer class. |
| class shared_const_buffer |
| { |
| public: |
| // Construct from a std::string. |
| explicit shared_const_buffer(const std::string& data) |
| : data_(new std::vector<char>(data.begin(), data.end())), |
| buffer_(boost::asio::buffer(*data_)) |
| { |
| } |
| |
| // Implement the ConstBufferSequence requirements. |
| typedef boost::asio::const_buffer value_type; |
| typedef const boost::asio::const_buffer* const_iterator; |
| const boost::asio::const_buffer* begin() const { return &buffer_; } |
| const boost::asio::const_buffer* end() const { return &buffer_ + 1; } |
| |
| private: |
| std::shared_ptr<std::vector<char> > data_; |
| boost::asio::const_buffer buffer_; |
| }; |
| |
| class session |
| : public std::enable_shared_from_this<session> |
| { |
| public: |
| session(tcp::socket socket) |
| : socket_(std::move(socket)) |
| { |
| } |
| |
| void start() |
| { |
| do_write(); |
| } |
| |
| private: |
| void do_write() |
| { |
| std::time_t now = std::time(0); |
| shared_const_buffer buffer(std::ctime(&now)); |
| |
| auto self(shared_from_this()); |
| boost::asio::async_write(socket_, buffer, |
| [self](boost::system::error_code /*ec*/, std::size_t /*length*/) |
| { |
| }); |
| } |
| |
| // The socket used to communicate with the client. |
| tcp::socket socket_; |
| }; |
| |
| class server |
| { |
| public: |
| server(boost::asio::io_context& io_context, short port) |
| : acceptor_(io_context, tcp::endpoint(tcp::v4(), port)) |
| { |
| do_accept(); |
| } |
| |
| private: |
| void do_accept() |
| { |
| acceptor_.async_accept( |
| [this](boost::system::error_code ec, tcp::socket socket) |
| { |
| if (!ec) |
| { |
| std::make_shared<session>(std::move(socket))->start(); |
| } |
| |
| do_accept(); |
| }); |
| } |
| |
| tcp::acceptor acceptor_; |
| }; |
| |
| int main(int argc, char* argv[]) |
| { |
| try |
| { |
| if (argc != 2) |
| { |
| std::cerr << "Usage: reference_counted <port>\n"; |
| return 1; |
| } |
| |
| boost::asio::io_context io_context; |
| |
| server s(io_context, std::atoi(argv[1])); |
| |
| io_context.run(); |
| } |
| catch (std::exception& e) |
| { |
| std::cerr << "Exception: " << e.what() << "\n"; |
| } |
| |
| return 0; |
| } |