--- /dev/null
+/*
+ * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#ifndef SESSIOND_TRACE_CHUNK_REGISTRY_H
+#define SESSIOND_TRACE_CHUNK_REGISTRY_H
+
+#include <common/uuid.hpp>
+#include <common/trace-chunk.hpp>
+#include <stdint.h>
+
+/*
+ * A session trace chunk registry allows the relay daemon to share trace chunks
+ * used by different "relay sessions" when they were created for the same
+ * user-visible session daemon session. Tracing multiple domains (e.g. ust and
+ * kernel) results in per-domain relay sessions being created.
+ *
+ * Sharing trace chunks, and their output directory more specifically, is
+ * essential to properly implement session rotations. The sharing of output
+ * directory handles allows directory renames to be performed once and without
+ * races that would stem from from multiple renames.
+ */
+struct sessiond_trace_chunk_registry;
+
+struct sessiond_trace_chunk_registry *
+sessiond_trace_chunk_registry_create(void);
+
+void sessiond_trace_chunk_registry_destroy(
+ struct sessiond_trace_chunk_registry *sessiond_registry);
+
+int sessiond_trace_chunk_registry_session_created(
+ struct sessiond_trace_chunk_registry *sessiond_registry,
+ const lttng_uuid sessiond_uuid);
+
+int sessiond_trace_chunk_registry_session_destroyed(
+ struct sessiond_trace_chunk_registry *sessiond_registry,
+ const lttng_uuid sessiond_uuid);
+
+struct lttng_trace_chunk *sessiond_trace_chunk_registry_publish_chunk(
+ struct sessiond_trace_chunk_registry *sessiond_registry,
+ const lttng_uuid sessiond_uuid, uint64_t session_id,
+ struct lttng_trace_chunk *chunk);
+
+struct lttng_trace_chunk *
+sessiond_trace_chunk_registry_get_anonymous_chunk(
+ struct sessiond_trace_chunk_registry *sessiond_registry,
+ const lttng_uuid sessiond_uuid,
+ uint64_t session_id);
+
+struct lttng_trace_chunk *
+sessiond_trace_chunk_registry_get_chunk(
+ struct sessiond_trace_chunk_registry *sessiond_registry,
+ const lttng_uuid sessiond_uuid,
+ uint64_t session_id, uint64_t chunk_id);
+
+int sessiond_trace_chunk_registry_chunk_exists(
+ struct sessiond_trace_chunk_registry *sessiond_registry,
+ const lttng_uuid sessiond_uuid,
+ uint64_t session_id, uint64_t chunk_id, bool *chunk_exists);
+
+#endif /* SESSIOND_TRACE_CHUNK_REGISTRY_H */