support large publish packets

Reviewers: ivica

Reviewed By: ivica

Subscribers: korina

Differential Revision: https://repo.mireo.local/D26763

include/async_mqtt5/detail/async_traits.hpp

@@ -28,19 +28,22 @@ void assign_tls_sni(const authority_path& ap, TlsContext& ctx, TlsStream& s);
 namespace detail {
 
 template <typename Handler, typename DfltExecutor>
-decltype(auto) tracking_executor(const Handler& handler, const DfltExecutor& ex) {
+using tracking_type = std::decay_t<
+	typename asio::prefer_result<
+		asio::associated_executor_t<Handler, DfltExecutor>,
+		asio::execution::outstanding_work_t::tracked_t
+	>::type
+>;
+
+template <typename Handler, typename DfltExecutor>
+tracking_type<Handler, DfltExecutor>
+tracking_executor(const Handler& handler, const DfltExecutor& ex) {
 	return asio::prefer(
 		asio::get_associated_executor(handler, ex),
 		asio::execution::outstanding_work.tracked
 	);
 }
 
-template <typename Handler, typename DfltExecutor>
-using tracking_type = typename asio::prefer_result<
-	asio::associated_executor_t<Handler, DfltExecutor>,
-	asio::execution::outstanding_work_t::tracked_t
->::type;
-
 template <typename T, typename B>
 concept has_async_write = requires(T a) {
 	a.async_write(

include/async_mqtt5/impl/internal/codecs/base_encoders.hpp

@@ -75,7 +75,7 @@ public:
 		return flag_def<bits, repr> { val };
 	}
 
-	uint16_t byte_size() const { return sizeof(repr); }
+	size_t byte_size() const { return sizeof(repr); }
 
 	template <size_t rhs_bits, typename rhs_repr>
 	auto operator|(const flag_def<rhs_bits, rhs_repr>& rhs) const {
@@ -103,13 +103,13 @@ class int_val : public encoder {
 public:
 	int_val(T val) : _val(val) {}
 
-	uint16_t byte_size() const { 
+	size_t byte_size() const {
 		if constexpr (is_optional<T>) {
-			if (_val) return uint16_t(val_length(*_val));
-			return uint16_t(0);
+			if (_val) return val_length(*_val);
+			return 0;
 		}
 		else
-			return uint16_t(val_length(_val));
+			return val_length(_val);
 	}
 
 	std::string& encode(std::string& s) const {
@@ -185,11 +185,11 @@ public:
 		static_assert(std::is_reference_v<T> || std::is_same_v<T, std::string_view>);
 	}
 
-	uint16_t byte_size() const { 
+	size_t byte_size() const {
 		if constexpr (is_optional<T>)
-			return uint16_t(_val ? _with_length * 2 + val_length(*_val) : 0); 
+			return _val ? _with_length * 2 + val_length(*_val) : 0;
 		else
-		 	return uint16_t(_with_length * 2 + val_length(_val));
+			return _with_length * 2 + val_length(_val);
 	}
 
 	std::string& encode(std::string& s) const {
@@ -215,12 +215,12 @@ private:
 	template <typename U>
 	std::string& encode_val(std::string& s, U&& u) const {
 		using namespace boost::endian;
-		int16_t byte_len = int16_t(val_length(std::forward<U>(u)));
+		auto byte_len = val_length(std::forward<U>(u));
 		if (byte_len == 0 && !_with_length) return s;
 		if (_with_length) {
 			size_t sz = s.size(); s.resize(sz + 2);
 			auto p = reinterpret_cast<uint8_t*>(s.data() + sz);
-			endian_store<int16_t, sizeof(int16_t), order::big>(p, byte_len);
+			endian_store<int16_t, sizeof(int16_t), order::big>(p, int16_t(byte_len));
 		}
 		s.append(std::begin(u), std::begin(u) + byte_len);
 		return s;
@@ -266,8 +266,8 @@ public:
 	composed_val(T lhs, U rhs) : 
 		_lhs(std::forward<T>(lhs)), _rhs(std::forward<U>(rhs)) {}
 
-	uint16_t byte_size() const { 
-		return uint16_t(_lhs.byte_size() + _rhs.byte_size()); 
+	size_t byte_size() const {
+		return _lhs.byte_size() + _rhs.byte_size();
 	}
 
 	std::string& encode(std::string& s) const {

test/unit/test/serialization.cpp

@@ -114,13 +114,40 @@ BOOST_AUTO_TEST_CASE(test_publish) {
 	BOOST_CHECK(packet_id);
 	BOOST_CHECK_EQUAL(*packet_id_, packet_id);
 	BOOST_CHECK_EQUAL(topic_, topic);
-	BOOST_CHECK_EQUAL(payload_, payload_);
+	BOOST_CHECK_EQUAL(payload_, payload);
 	BOOST_CHECK_EQUAL(*pprops[prop::message_expiry_interval], message_expiry);
 	BOOST_CHECK_EQUAL(*pprops[prop::content_type], content_type);
 	BOOST_CHECK_EQUAL(pprops[prop::user_property][0], publish_prop_1);
 	BOOST_CHECK_EQUAL(pprops[prop::user_property][1], publish_prop_2);
 }
 
+BOOST_AUTO_TEST_CASE(test_large_publish) {
+	// testing variables
+	uint16_t packet_id = 40001;
+	std::string_view topic = "publish_topic";
+	std::string large_payload(1'000'000, 'a');
+
+	auto msg = encoders::encode_publish(
+		packet_id, topic, large_payload,
+		qos_e::at_least_once, retain_e::yes, dup_e::no,
+		publish_props{}
+	);
+
+	byte_citer it = msg.cbegin(), last = msg.cend();
+	auto header = decoders::decode_fixed_header(it, last);
+	BOOST_CHECK_MESSAGE(header, "Parsing PUBLISH fixed header failed.");
+
+	const auto& [control_byte, remain_length] = *header;
+	auto rv = decoders::decode_publish(control_byte, remain_length, it);
+	BOOST_CHECK_MESSAGE(rv, "Parsing PUBLISH failed.");
+
+	const auto& [topic_, packet_id_, flags, pprops, payload_] = *rv;
+	BOOST_CHECK(packet_id);
+	BOOST_CHECK_EQUAL(*packet_id_, packet_id);
+	BOOST_CHECK_EQUAL(topic_, topic);
+	BOOST_CHECK_EQUAL(payload_, large_payload);
+}
+
 BOOST_AUTO_TEST_CASE(test_puback) {
 	// testing variables
 	uint16_t packet_id = 9199;