| // |
| // chat_server.cpp |
| // ~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2015 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 <cstdlib> |
| #include <deque> |
| #include <iostream> |
| #include <list> |
| #include <memory> |
| #include <set> |
| #include <utility> |
| #include <boost/asio.hpp> |
| #include "chat_message.hpp" |
| |
| using boost::asio::ip::tcp; |
| |
| //---------------------------------------------------------------------- |
| |
| typedef std::deque<chat_message> chat_message_queue; |
| |
| //---------------------------------------------------------------------- |
| |
| class chat_participant |
| { |
| public: |
| virtual ~chat_participant() {} |
| virtual void deliver(const chat_message& msg) = 0; |
| }; |
| |
| typedef std::shared_ptr<chat_participant> chat_participant_ptr; |
| |
| //---------------------------------------------------------------------- |
| |
| class chat_room |
| { |
| public: |
| void join(chat_participant_ptr participant) |
| { |
| participants_.insert(participant); |
| for (auto msg: recent_msgs_) |
| participant->deliver(msg); |
| } |
| |
| void leave(chat_participant_ptr participant) |
| { |
| participants_.erase(participant); |
| } |
| |
| void deliver(const chat_message& msg) |
| { |
| recent_msgs_.push_back(msg); |
| while (recent_msgs_.size() > max_recent_msgs) |
| recent_msgs_.pop_front(); |
| |
| for (auto participant: participants_) |
| participant->deliver(msg); |
| } |
| |
| private: |
| std::set<chat_participant_ptr> participants_; |
| enum { max_recent_msgs = 100 }; |
| chat_message_queue recent_msgs_; |
| }; |
| |
| //---------------------------------------------------------------------- |
| |
| class chat_session |
| : public chat_participant, |
| public std::enable_shared_from_this<chat_session> |
| { |
| public: |
| chat_session(tcp::socket socket, chat_room& room) |
| : socket_(std::move(socket)), |
| room_(room) |
| { |
| } |
| |
| void start() |
| { |
| room_.join(shared_from_this()); |
| do_read_header(); |
| } |
| |
| void deliver(const chat_message& msg) |
| { |
| bool write_in_progress = !write_msgs_.empty(); |
| write_msgs_.push_back(msg); |
| if (!write_in_progress) |
| { |
| do_write(); |
| } |
| } |
| |
| private: |
| void do_read_header() |
| { |
| auto self(shared_from_this()); |
| boost::asio::async_read(socket_, |
| boost::asio::buffer(read_msg_.data(), chat_message::header_length), |
| [this, self](boost::system::error_code ec, std::size_t /*length*/) |
| { |
| if (!ec && read_msg_.decode_header()) |
| { |
| do_read_body(); |
| } |
| else |
| { |
| room_.leave(shared_from_this()); |
| } |
| }); |
| } |
| |
| void do_read_body() |
| { |
| auto self(shared_from_this()); |
| boost::asio::async_read(socket_, |
| boost::asio::buffer(read_msg_.body(), read_msg_.body_length()), |
| [this, self](boost::system::error_code ec, std::size_t /*length*/) |
| { |
| if (!ec) |
| { |
| room_.deliver(read_msg_); |
| do_read_header(); |
| } |
| else |
| { |
| room_.leave(shared_from_this()); |
| } |
| }); |
| } |
| |
| void do_write() |
| { |
| auto self(shared_from_this()); |
| boost::asio::async_write(socket_, |
| boost::asio::buffer(write_msgs_.front().data(), |
| write_msgs_.front().length()), |
| [this, self](boost::system::error_code ec, std::size_t /*length*/) |
| { |
| if (!ec) |
| { |
| write_msgs_.pop_front(); |
| if (!write_msgs_.empty()) |
| { |
| do_write(); |
| } |
| } |
| else |
| { |
| room_.leave(shared_from_this()); |
| } |
| }); |
| } |
| |
| tcp::socket socket_; |
| chat_room& room_; |
| chat_message read_msg_; |
| chat_message_queue write_msgs_; |
| }; |
| |
| //---------------------------------------------------------------------- |
| |
| class chat_server |
| { |
| public: |
| chat_server(boost::asio::io_service& io_service, |
| const tcp::endpoint& endpoint) |
| : acceptor_(io_service, endpoint), |
| socket_(io_service) |
| { |
| do_accept(); |
| } |
| |
| private: |
| void do_accept() |
| { |
| acceptor_.async_accept(socket_, |
| [this](boost::system::error_code ec) |
| { |
| if (!ec) |
| { |
| std::make_shared<chat_session>(std::move(socket_), room_)->start(); |
| } |
| |
| do_accept(); |
| }); |
| } |
| |
| tcp::acceptor acceptor_; |
| tcp::socket socket_; |
| chat_room room_; |
| }; |
| |
| //---------------------------------------------------------------------- |
| |
| int main(int argc, char* argv[]) |
| { |
| try |
| { |
| if (argc < 2) |
| { |
| std::cerr << "Usage: chat_server <port> [<port> ...]\n"; |
| return 1; |
| } |
| |
| boost::asio::io_service io_service; |
| |
| std::list<chat_server> servers; |
| for (int i = 1; i < argc; ++i) |
| { |
| tcp::endpoint endpoint(tcp::v4(), std::atoi(argv[i])); |
| servers.emplace_back(io_service, endpoint); |
| } |
| |
| io_service.run(); |
| } |
| catch (std::exception& e) |
| { |
| std::cerr << "Exception: " << e.what() << "\n"; |
| } |
| |
| return 0; |
| } |