add basic http server (using boost.asio example)

Change-Id: I02bbc161ec7f89ade999b92ed99ef71fec83af32
diff --git a/server/connection.cpp b/server/connection.cpp
new file mode 100644
index 0000000..e379043
--- /dev/null
+++ b/server/connection.cpp
@@ -0,0 +1,99 @@
+//
+// connection.cpp
+// ~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2012 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 "connection.hpp"
+#include <vector>
+#include <boost/bind.hpp>
+#include "connection_manager.hpp"
+#include "request_handler.hpp"
+
+namespace http {
+namespace server {
+
+connection::connection(boost::asio::io_service& io_service,
+    connection_manager& manager, request_handler& handler)
+  : socket_(io_service),
+    connection_manager_(manager),
+    request_handler_(handler)
+{
+}
+
+boost::asio::ip::tcp::socket& connection::socket()
+{
+  return socket_;
+}
+
+void connection::start()
+{
+  socket_.async_read_some(boost::asio::buffer(buffer_),
+      boost::bind(&connection::handle_read, shared_from_this(),
+        boost::asio::placeholders::error,
+        boost::asio::placeholders::bytes_transferred));
+}
+
+void connection::stop()
+{
+  socket_.close();
+}
+
+void connection::handle_read(const boost::system::error_code& e,
+    std::size_t bytes_transferred)
+{
+  if (!e)
+  {
+    boost::tribool result;
+    boost::tie(result, boost::tuples::ignore) = request_parser_.parse(
+        request_, buffer_.data(), buffer_.data() + bytes_transferred);
+
+    if (result)
+    {
+      request_handler_.handle_request(request_, reply_);
+      boost::asio::async_write(socket_, reply_.to_buffers(),
+          boost::bind(&connection::handle_write, shared_from_this(),
+            boost::asio::placeholders::error));
+    }
+    else if (!result)
+    {
+      reply_ = reply::stock_reply(reply::bad_request);
+      boost::asio::async_write(socket_, reply_.to_buffers(),
+          boost::bind(&connection::handle_write, shared_from_this(),
+            boost::asio::placeholders::error));
+    }
+    else
+    {
+      socket_.async_read_some(boost::asio::buffer(buffer_),
+          boost::bind(&connection::handle_read, shared_from_this(),
+            boost::asio::placeholders::error,
+            boost::asio::placeholders::bytes_transferred));
+    }
+  }
+  else if (e != boost::asio::error::operation_aborted)
+  {
+    connection_manager_.stop(shared_from_this());
+  }
+}
+
+void connection::handle_write(const boost::system::error_code& e)
+{
+  if (!e)
+  {
+    // Initiate graceful connection closure.
+    boost::system::error_code ignored_ec;
+    socket_.shutdown(boost::asio::ip::tcp::socket::shutdown_both, ignored_ec);
+  }
+
+  if (e != boost::asio::error::operation_aborted)
+  {
+    connection_manager_.stop(shared_from_this());
+  }
+}
+
+} // namespace server
+} // namespace http