Add TCP_NODELAY to disable Nagle's algorithm in Boost.ASIO-based http_client (#1310)

* Add TCP_NODELAY to disable Nagle's algorithm to avoid waiting for ACK for HTTP request headers before transmitting the request body, in order to significantly improve performance for requests with bodies (see #1201)

* Also add TCP_NODELAY on the server-side, to disable Nagle's algorithm to avoid waiting for ACK for HTTP response headers before transmitting the response body (see #1201)

Author: garethsb

Release/src/http/client/http_client_asio.cpp

@@ -330,6 +330,12 @@ class asio_connection
 
     void start_reuse() { m_is_reused = true; }
 
+    void enable_no_delay()
+    {
+        boost::asio::ip::tcp::no_delay option(true);
+        m_socket.set_option(option);
+    }
+
 private:
     // Guards concurrent access to socket/ssl::stream. This is necessary
     // because timeouts and cancellation can touch the socket at the same time
@@ -610,6 +616,7 @@ class asio_context final : public request_context, public std::enable_shared_fro
             if (!ec)
             {
                 m_context->m_timer.reset();
+                m_context->m_connection->enable_no_delay();
                 m_context->m_connection->async_write(m_request,
                                                      boost::bind(&ssl_proxy_tunnel::handle_write_request,
                                                                  shared_from_this(),
@@ -1006,6 +1013,7 @@ class asio_context final : public request_context, public std::enable_shared_fro
         m_timer.reset();
         if (!ec)
         {
+            m_connection->enable_no_delay();
             write_request();
         }
         else if (ec.value() == boost::system::errc::operation_canceled ||

Release/src/http/listener/http_server_asio.cpp

@@ -593,6 +593,9 @@ void hostport_listener::on_accept(std::unique_ptr<ip::tcp::socket> socket, const
     // Handle successful accept
     if (!ec)
     {
+        boost::asio::ip::tcp::no_delay option(true);
+        socket->set_option(option);
+
         auto conn = asio_server_connection::create(std::move(socket), m_p_server, this);
 
         m_connections.insert(conn.get());