--- /dev/null
+/*
+ * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#ifndef LTTNG_CTF2_TRACE_CLASS_VISITOR_H
+#define LTTNG_CTF2_TRACE_CLASS_VISITOR_H
+
+#include "trace-class.hpp"
+#include "stream-class.hpp"
+#include "event-class.hpp"
+
+#include <vendor/optional.hpp>
+#include <vendor/nlohmann/json.hpp>
+
+#include <functional>
+
+namespace lttng {
+namespace sessiond {
+namespace ctf2 {
+
+using append_metadata_fragment_function = std::function<void(const std::string& fragment)>;
+
+class trace_class_visitor : public lttng::sessiond::trace::trace_class_visitor {
+public:
+ trace_class_visitor(const lttng::sessiond::trace::abi& trace_abi,
+ append_metadata_fragment_function append_metadata);
+
+ virtual void visit(const lttng::sessiond::trace::trace_class& trace_class) override final;
+ virtual void visit(const lttng::sessiond::trace::clock_class& clock_class) override final;
+ virtual void visit(const lttng::sessiond::trace::stream_class& stream_class) override final;
+ virtual void visit(const lttng::sessiond::trace::event_class& event_class) override final;
+
+private:
+ void append_metadata_fragment(const nlohmann::json& fragment) const;
+
+ const lttng::sessiond::trace::abi& _trace_abi;
+ const append_metadata_fragment_function _append_metadata_fragment;
+};
+
+} /* namespace ctf2 */
+} /* namespace sessiond */
+} /* namespace lttng */
+
+#endif /* LTTNG_CTF2_TRACE_CLASS_VISITOR_H */