msg: add message translation node for ROS

msg/translation_node/src/pub_sub_graph.h

@@ -0,0 +1,58 @@
+/****************************************************************************
+ * Copyright (c) 2024 PX4 Development Team.
+ * SPDX-License-Identifier: BSD-3-Clause
+ ****************************************************************************/
+#pragma once
+
+#include <rclcpp/rclcpp.hpp>
+#include <utility>
+#include "translations.h"
+#include "translation_util.h"
+#include "graph.h"
+
+class PubSubGraph {
+public:
+	struct TopicInfo {
+		std::string topic_name; ///< fully qualified topic name (with namespace)
+		int num_subscribers; ///< does not include this node's subscribers
+		int num_publishers; ///< does not include this node's publishers
+	};
+
+	PubSubGraph(rclcpp::Node& node, const TopicTranslations& translations);
+
+	void updateCurrentTopics(const std::vector<TopicInfo>& topics);
+
+private:
+	struct NodeDataPubSub {
+		explicit NodeDataPubSub(SubscriptionFactoryCB subscription_factory, PublicationFactoryCB publication_factory,
+								const MessageIdentifier& id, size_t max_serialized_message_size)
+				: subscription_factory(std::move(subscription_factory)), publication_factory(std::move(publication_factory)),
+				topic_name(id.topic_name), version(id.version), max_serialized_message_size(max_serialized_message_size)
+		{ }
+
+		const SubscriptionFactoryCB subscription_factory;
+		const PublicationFactoryCB publication_factory;
+		const std::string topic_name;
+		const MessageVersionType version;
+		const size_t max_serialized_message_size;
+
+		// Keep track if there's currently a publisher/subscriber
+		bool has_external_publisher{false};
+		bool has_external_subscriber{false};
+
+		rclcpp::SubscriptionBase::SharedPtr subscription;
+		rclcpp::PublisherBase::SharedPtr publication;
+
+		bool visited{false};
+	};
+
+	void onSubscriptionUpdate(const Graph<NodeDataPubSub>::MessageNodePtr& node);
+	void printTopicInfo(const std::unordered_map<std::string, std::set<MessageVersionType>>& known_versions) const;
+	void handleLargestTopic(const std::unordered_map<std::string, std::set<MessageVersionType>>& known_versions);
+
+	rclcpp::Node& _node;
+	Graph<NodeDataPubSub> _pub_sub_graph;
+	std::unordered_map<std::string, bool> _known_topics_warned;
+
+	std::vector<rclcpp::PublisherBase::SharedPtr> _largest_topic_publications;
+};