Remove Beast dependency from connect_op.hpp

Summary: resolves T15243

Reviewers: ivica

Reviewed By: ivica

Subscribers: iljazovic, miljen

Maniphest Tasks: T15243

Differential Revision: https://repo.mireo.local/D32561

README.md

@@ -57,7 +57,7 @@ Getting Started
 ---------
 Async.MQTT5 is a header-only library. To use Async.MQTT5 it requires the following: 
 - **C++17 capable compiler**
-- **Boost 1.82 or later**. In addition to Asio, we use other header-only libraries such as Beast, Spirit, and more. 
+- **Boost 1.82 or later**. In addition to Asio, we use other header-only libraries.
 - **OpenSSL**. If you require an SSL connection by using [boost::asio::ssl::stream](https://www.boost.org/doc/libs/1_82_0/doc/html/boost_asio/reference/ssl__stream.html).
 
 Async.MQTT5 has been tested with the following compilers: 

doc/qbk/01_intro.qbk

@@ -154,7 +154,7 @@ __Self__ is a header-only library.
 To use __Self__ it requires the following:
 
 * [*C++17 capable compiler]
-* [*Boost 1.82 or later]. In addition to Asio, we use other header-only libraries such as Beast, Spirit, and more.
+* [*Boost 1.82 or later]. In addition to Asio, we use other header-only libraries.
 * [*OpenSSL]. If you require an SSL connection by using [asioreflink ssl__stream ssl::stream].
 
 __Self__ has been tested with the following compilers:

example/hello_world_over_websocket_tcp.cpp

@@ -15,6 +15,7 @@
 #include <boost/beast/websocket.hpp>
 
 #include <async_mqtt5.hpp>
+#include <async_mqtt5/websocket.hpp> // WebSocket traits
 
 int main() {
 	boost::asio::io_context ioc;

example/hello_world_over_websocket_tls.cpp

@@ -17,6 +17,7 @@
 #include <boost/beast/ssl/ssl_stream.hpp> // async_teardown specialization for websocket ssl stream
 
 #include <async_mqtt5.hpp>
+#include <async_mqtt5/websocket.hpp> // WebSocket traits
 
 // External customization point.
 namespace async_mqtt5 {

include/async_mqtt5/detail/async_traits.hpp

@@ -25,12 +25,19 @@ namespace async_mqtt5 {
 
 namespace asio = boost::asio;
 
+// TLS
+
 template <typename StreamType>
 struct tls_handshake_type {};
 
 template <typename TlsContext, typename TlsStream>
 void assign_tls_sni(const authority_path& ap, TlsContext& ctx, TlsStream& s);
 
+// WebSocket
+
+template <typename Stream>
+struct ws_handshake_traits {};
+
 namespace detail {
 
 // tracking executor

include/async_mqtt5/impl/connect_op.hpp

@@ -27,10 +27,6 @@
 #include <boost/asio/write.hpp>
 #include <boost/asio/ip/tcp.hpp>
 
-#include <boost/beast/http/field.hpp>
-#include <boost/beast/websocket/rfc6455.hpp>
-#include <boost/beast/websocket/stream_base.hpp>
-
 #include <async_mqtt5/error.hpp>
 #include <async_mqtt5/reason_codes.hpp>
 
@@ -171,35 +167,15 @@ public:
 	}
 
 	void do_ws_handshake(endpoint ep, authority_path ap) {
-		if constexpr (has_ws_handshake<Stream>) {
-			using namespace boost::beast;
-
-			// We'll need to turn off read timeouts on the underlying stream
-			// because the websocket stream has its own timeout system.
-
-			// Set suggested timeout settings for the websocket
-			_stream.set_option(
-				websocket::stream_base::timeout::suggested(role_type::client)
-			);
-
-			_stream.binary(true);
-
-			// Set a decorator to change the User-Agent of the handshake
-			_stream.set_option(websocket::stream_base::decorator(
-				[](websocket::request_type& req) {
-					req.set(http::field::sec_websocket_protocol, "mqtt");
-					req.set(http::field::user_agent, "boost.mqtt");
-				})
-			);
-
-			_stream.async_handshake(
-				ap.host + ':' + ap.port, ap.path,
+		if constexpr (has_ws_handshake<Stream>)
+			// If you get a compilation error here,
+			// it might be because of a missing <async_mqtt5/websocket.hpp> include
+			ws_handshake_traits<Stream>::async_handshake(
+				_stream, std::move(ap),
 				asio::append(
-					asio::prepend(std::move(*this), on_ws_handshake {}),
-					ep
+					asio::prepend(std::move(*this), on_ws_handshake {}), ep
 				)
 			);
-		}
 		else
 			(*this)(on_ws_handshake {}, error_code {}, ep);
 	}

include/async_mqtt5/websocket.hpp

@@ -0,0 +1,54 @@
+//
+// Copyright (c) 2023-2024 Ivica Siladic, Bruno Iljazovic, Korina Simicevic
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASYNC_MQTT5_WEBSOCKET_HPP
+#define ASYNC_MQTT5_WEBSOCKET_HPP
+
+#include <boost/beast/http/field.hpp>
+#include <boost/beast/websocket/rfc6455.hpp>
+#include <boost/beast/websocket/stream.hpp>
+
+#include <async_mqtt5/types.hpp>
+
+namespace async_mqtt5 {
+
+// Trait definition for Beast
+template <typename Stream>
+struct ws_handshake_traits<boost::beast::websocket::stream<Stream>> {
+
+	template <typename CompletionToken>
+	static decltype(auto) async_handshake(
+		boost::beast::websocket::stream<Stream>& stream,
+		authority_path ap, CompletionToken&& token
+	) {
+		using namespace boost::beast;
+
+		// Set suggested timeout settings for the websocket
+		stream.set_option(
+			websocket::stream_base::timeout::suggested(role_type::client)
+		);
+
+		stream.binary(true);
+
+		// Set a decorator to change the User-Agent of the handshake
+		stream.set_option(websocket::stream_base::decorator(
+			[](websocket::request_type& req) {
+				req.set(http::field::sec_websocket_protocol, "mqtt");
+				req.set(http::field::user_agent, "boost.mqtt");
+			})
+		);
+
+		stream.async_handshake(
+			ap.host + ':' + ap.port, ap.path,
+			std::forward<CompletionToken>(token)
+		);
+	}
+};
+
+} // end namespace async_mqtt5
+
+#endif // !ASYNC_MQTT5_WEBSOCKET_HPP

test/integration/client.cpp

@@ -25,6 +25,7 @@
 #include <boost/system/error_code.hpp>
 
 #include <async_mqtt5.hpp>
+#include <async_mqtt5/websocket.hpp>
 
 namespace async_mqtt5 {
 

test/integration/mqtt_features.cpp

@@ -26,6 +26,7 @@
 #include <boost/beast/websocket/stream.hpp>
 
 #include <async_mqtt5.hpp>
+#include <async_mqtt5/websocket.hpp>
 
 BOOST_AUTO_TEST_SUITE(mqtt_features/*, *boost::unit_test::disabled()*/)
 

test/unit/default_completion_tokens.cpp

@@ -23,6 +23,7 @@
 #include <boost/beast/websocket/ssl.hpp> // async_teardown for asio::ssl::socket
 
 #include <async_mqtt5.hpp>
+#include <async_mqtt5/websocket.hpp>
 
 namespace async_mqtt5 {
 

test/unit/logger.cpp

@@ -26,6 +26,7 @@
 #include <async_mqtt5/mqtt_client.hpp>
 #include <async_mqtt5/logger.hpp>
 #include <async_mqtt5/logger_traits.hpp>
+#include <async_mqtt5/websocket.hpp>
 
 #include "test_common/message_exchange.hpp"
 #include "test_common/test_service.hpp"