add chat server

src/base/base.h

@@ -0,0 +1,6 @@
+#ifndef BASE_BASE_H
+#define BASE_BASE_H
+
+#define foreach BOOST_FOREACH
+
+#endif  // BASE_BASE_H

src/experimental/SConscript

@@ -6,8 +6,10 @@ experimental_env.Append(LIBS=[
 	'gflags',
 	'glog',
 	'gtest',
-	'boost_system'
+	'boost_system',
+	'boost_thread'
 ])
 
-experimental_env.Program('boost_function_test.cc')
-#experimental_env.Program('boost_asio_test.cc')
+#experimental_env.Program('boost_function_test.cc')
+experimental_env.Program('chat/chat_message.cc')
+experimental_env.Program('chat/chat_server.cc')

src/experimental/chat/chat_message.cc

@@ -0,0 +1,177 @@
+//
+// chat_client.cc
+// ~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2010 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 <boost/bind.hpp>
+#include <boost/asio.hpp>
+#include <boost/thread.hpp>
+#include "experimental/chat/chat_message.h"
+
+using boost::asio::ip::tcp;
+
+typedef std::deque<chat_message> chat_message_queue;
+
+class chat_client
+{
+public:
+	chat_client(boost::asio::io_service& io_service, tcp::resolver::iterator endpoint_iterator) :
+		io_service_(io_service), socket_(io_service)
+	{
+		tcp::endpoint endpoint = *endpoint_iterator;
+		socket_.async_connect(endpoint, boost::bind(&chat_client::handle_connect, this,
+		        boost::asio::placeholders::error, ++endpoint_iterator));
+	}
+
+	void write(const chat_message& msg)
+	{
+		io_service_.post(boost::bind(&chat_client::do_write, this, msg));
+	}
+
+	void close()
+	{
+		io_service_.post(boost::bind(&chat_client::do_close, this));
+	}
+
+private:
+
+	void handle_connect(const boost::system::error_code& error,
+	        tcp::resolver::iterator endpoint_iterator)
+	{
+		if(!error)
+		{
+			boost::asio::async_read(socket_, boost::asio::buffer(read_msg_.data(),
+			        chat_message::header_length), boost::bind(&chat_client::handle_read_header,
+			        this, boost::asio::placeholders::error));
+		}
+		else if(endpoint_iterator != tcp::resolver::iterator())
+		{
+			socket_.close();
+			tcp::endpoint endpoint = *endpoint_iterator;
+			socket_.async_connect(endpoint, boost::bind(&chat_client::handle_connect, this,
+			        boost::asio::placeholders::error, ++endpoint_iterator));
+		}
+	}
+
+	void handle_read_header(const boost::system::error_code& error)
+	{
+		if(!error && read_msg_.decode_header())
+		{
+			boost::asio::async_read(socket_, boost::asio::buffer(read_msg_.body(),
+			        read_msg_.body_length()), boost::bind(&chat_client::handle_read_body, this,
+			        boost::asio::placeholders::error));
+		}
+		else
+		{
+			do_close();
+		}
+	}
+
+	void handle_read_body(const boost::system::error_code& error)
+	{
+		if(!error)
+		{
+			std::cout.write(read_msg_.body(), read_msg_.body_length());
+			std::cout << "\n";
+			boost::asio::async_read(socket_, boost::asio::buffer(read_msg_.data(),
+			        chat_message::header_length), boost::bind(&chat_client::handle_read_header,
+			        this, boost::asio::placeholders::error));
+		}
+		else
+		{
+			do_close();
+		}
+	}
+
+	void do_write(chat_message msg)
+	{
+		bool write_in_progress = !write_msgs_.empty();
+		write_msgs_.push_back(msg);
+		if(!write_in_progress)
+		{
+			boost::asio::async_write(socket_, boost::asio::buffer(write_msgs_.front().data(),
+			        write_msgs_.front().length()), boost::bind(&chat_client::handle_write, this,
+			        boost::asio::placeholders::error));
+		}
+	}
+
+	void handle_write(const boost::system::error_code& error)
+	{
+		if(!error)
+		{
+			write_msgs_.pop_front();
+			if(!write_msgs_.empty())
+			{
+				boost::asio::async_write(socket_, boost::asio::buffer(write_msgs_.front().data(),
+				        write_msgs_.front().length()), boost::bind(&chat_client::handle_write,
+				        this, boost::asio::placeholders::error));
+			}
+		}
+		else
+		{
+			do_close();
+		}
+	}
+
+	void do_close()
+	{
+		socket_.close();
+	}
+
+private:
+	boost::asio::io_service& io_service_;
+	tcp::socket socket_;
+	chat_message read_msg_;
+	chat_message_queue write_msgs_;
+};
+
+int main(int argc, char* argv[])
+{
+	try
+	{
+		if(argc != 3)
+		{
+			std::cerr << "Usage: chat_client <host> <port>\n";
+			return 1;
+		}
+
+		boost::asio::io_service io_service;
+
+		tcp::resolver resolver(io_service);
+		tcp::resolver::query query(argv[1], argv[2]);
+		tcp::resolver::iterator iterator = resolver.resolve(query);
+
+		chat_client c(io_service, iterator);
+
+		boost::thread t(boost::bind(&boost::asio::io_service::run, &io_service));
+
+		char line[chat_message::max_body_length + 1];
+		while(std::cin.getline(line, chat_message::max_body_length + 1))
+		{
+			using namespace std;
+			// For strlen and memcpy.
+			chat_message msg;
+			msg.body_length(strlen(line));
+			memcpy(msg.body(), line, msg.body_length());
+			msg.encode_header();
+			c.write(msg);
+		}
+
+		c.close();
+		t.join();
+	}
+	catch(std::exception& e)
+	{
+		std::cerr << "Exception: " << e.what() << "\n";
+	}
+
+	return 0;
+}

src/experimental/chat/chat_message.h

@@ -0,0 +1,101 @@
+//
+// chat_message.hpp
+// ~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2010 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 EXPERIMENTAL_CHAT_MESSAGE_H
+#define EXPERIMENTAL_CHAT_MESSAGE_H
+
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+
+class chat_message
+{
+public:
+	enum
+	{
+		header_length = 4
+	};
+	enum
+	{
+		max_body_length = 512
+	};
+
+	chat_message():
+		body_length_(0)
+	{
+	}
+
+	const char* data() const
+	{
+		return data_;
+	}
+
+	char* data()
+	{
+		return data_;
+	}
+
+	size_t length() const
+	{
+		return header_length + body_length_;
+	}
+
+	const char* body() const
+	{
+		return data_ + header_length;
+	}
+
+	char* body()
+	{
+		return data_ + header_length;
+	}
+
+	size_t body_length() const
+	{
+		return body_length_;
+	}
+
+	void body_length(size_t length)
+	{
+		body_length_ = length;
+		if(body_length_ > max_body_length)
+			body_length_ = max_body_length;
+	}
+
+	bool decode_header()
+	{
+		using namespace std;
+		// For strncat and atoi.
+		char header[header_length + 1] = "";
+		strncat(header, data_, header_length);
+		body_length_ = atoi(header);
+		if(body_length_ > max_body_length)
+		{
+			body_length_ = 0;
+			return false;
+		}
+		return true;
+	}
+
+	void encode_header()
+	{
+		using namespace std;
+		// For sprintf and memcpy.
+		char header[header_length + 1] = "";
+		sprintf(header, "%4d", body_length_);
+		memcpy(data_, header, header_length);
+	}
+
+private:
+	char data_[header_length + max_body_length];
+	size_t body_length_;
+};
+
+#endif // EXPERIMENTAL_CHAT_MESSAGE_H

src/experimental/chat/chat_server.cc

@@ -0,0 +1,247 @@
+//
+// chat_server.cpp
+// ~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2010 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 <algorithm>
+#include <cstdlib>
+#include <deque>
+#include <iostream>
+#include <list>
+#include <set>
+#include <boost/bind.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/enable_shared_from_this.hpp>
+#include <boost/asio.hpp>
+#include "experimental/chat/chat_message.h"
+
+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 boost::shared_ptr<chat_participant> chat_participant_ptr;
+
+//----------------------------------------------------------------------
+
+class chat_room
+{
+public:
+	void join(chat_participant_ptr participant)
+	{
+		participants_.insert(participant);
+		std::for_each(recent_msgs_.begin(), recent_msgs_.end(), boost::bind(
+		        &chat_participant::deliver, participant, _1));
+	}
+
+	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();
+
+		std::for_each(participants_.begin(), participants_.end(), boost::bind(
+		        &chat_participant::deliver, _1, boost::ref(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 boost::enable_shared_from_this<chat_session>
+{
+public:
+	chat_session(boost::asio::io_service& io_service, chat_room& room) :
+		socket_(io_service), room_(room)
+	{
+	}
+
+	tcp::socket& socket()
+	{
+		return socket_;
+	}
+
+	void start()
+	{
+		room_.join(shared_from_this());
+		boost::asio::async_read(socket_, boost::asio::buffer(read_msg_.data(),
+		        chat_message::header_length), boost::bind(
+		        &chat_session::handle_read_header, shared_from_this(),
+		        boost::asio::placeholders::error));
+	}
+
+	void deliver(const chat_message& msg)
+	{
+		bool write_in_progress = !write_msgs_.empty();
+		write_msgs_.push_back(msg);
+		if(!write_in_progress)
+		{
+			boost::asio::async_write(socket_, boost::asio::buffer(
+			        write_msgs_.front().data(), write_msgs_.front().length()),
+			        boost::bind(&chat_session::handle_write,
+			                shared_from_this(),
+			                boost::asio::placeholders::error));
+		}
+	}
+
+	void handle_read_header(const boost::system::error_code& error)
+	{
+		if(!error && read_msg_.decode_header())
+		{
+			boost::asio::async_read(socket_, boost::asio::buffer(
+			        read_msg_.body(), read_msg_.body_length()), boost::bind(
+			        &chat_session::handle_read_body, shared_from_this(),
+			        boost::asio::placeholders::error));
+		}
+		else
+		{
+			room_.leave(shared_from_this());
+		}
+	}
+
+	void handle_read_body(const boost::system::error_code& error)
+	{
+		if(!error)
+		{
+			room_.deliver(read_msg_);
+			boost::asio::async_read(socket_, boost::asio::buffer(
+			        read_msg_.data(), chat_message::header_length),
+			        boost::bind(&chat_session::handle_read_header,
+			                shared_from_this(),
+			                boost::asio::placeholders::error));
+		}
+		else
+		{
+			room_.leave(shared_from_this());
+		}
+	}
+
+	void handle_write(const boost::system::error_code& error)
+	{
+		if(!error)
+		{
+			write_msgs_.pop_front();
+			if(!write_msgs_.empty())
+			{
+				boost::asio::async_write(socket_, boost::asio::buffer(
+				        write_msgs_.front().data(),
+				        write_msgs_.front().length()), boost::bind(
+				        &chat_session::handle_write, shared_from_this(),
+				        boost::asio::placeholders::error));
+			}
+		}
+		else
+		{
+			room_.leave(shared_from_this());
+		}
+	}
+
+private:
+	tcp::socket socket_;
+	chat_room& room_;
+	chat_message read_msg_;
+	chat_message_queue write_msgs_;
+};
+
+typedef boost::shared_ptr<chat_session> chat_session_ptr;
+
+//----------------------------------------------------------------------
+
+class chat_server
+{
+public:
+	chat_server(boost::asio::io_service& io_service,
+	        const tcp::endpoint& endpoint) :
+		io_service_(io_service), acceptor_(io_service, endpoint)
+	{
+		chat_session_ptr new_session(new chat_session(io_service_, room_));
+		acceptor_.async_accept(new_session->socket(), boost::bind(
+		        &chat_server::handle_accept, this, new_session,
+		        boost::asio::placeholders::error));
+	}
+
+	void handle_accept(chat_session_ptr session,
+	        const boost::system::error_code& error)
+	{
+		if(!error)
+		{
+			session->start();
+			chat_session_ptr new_session(new chat_session(io_service_, room_));
+			acceptor_.async_accept(new_session->socket(), boost::bind(
+			        &chat_server::handle_accept, this, new_session,
+			        boost::asio::placeholders::error));
+		}
+	}
+
+private:
+	boost::asio::io_service& io_service_;
+	tcp::acceptor acceptor_;
+	chat_room room_;
+};
+
+typedef boost::shared_ptr<chat_server> chat_server_ptr;
+typedef std::list<chat_server_ptr> chat_server_list;
+
+//----------------------------------------------------------------------
+
+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;
+
+		chat_server_list servers;
+		for(int i = 1; i < argc; ++i)
+		{
+			using namespace std;
+			// For atoi.
+			tcp::endpoint endpoint(tcp::v4(), atoi(argv[i]));
+			chat_server_ptr server(new chat_server(io_service, endpoint));
+			servers.push_back(server);
+		}
+
+		io_service.run();
+	}
+	catch(std::exception& e)
+	{
+		std::cerr << "Exception: " << e.what() << "\n";
+	}
+
+	return 0;
+}