Common Trace Format 2 generation

[lttng-tools.git] / src / common / trace-chunk-registry.hpp

diff --git a/src/common/trace-chunk-registry.hpp b/src/common/trace-chunk-registry.hpp
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+/*
+ * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#ifndef LTTNG_TRACE_CHUNK_REGISTRY_H
+#define LTTNG_TRACE_CHUNK_REGISTRY_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <common/macros.hpp>
+#include <common/trace-chunk.hpp>
+
+struct lttng_trace_chunk_registry;
+
+/*
+ * Create an lttng_trace_chunk registry.
+ *
+ * A trace chunk registry maintains an association between a
+ * (session_id, chunk_id) tuple and a trace chunk object. The chunk_id can
+ * be "unset" in the case of an anonymous trace chunk.
+ *
+ * Note that a trace chunk registry holds no ownership of its trace
+ * chunks. Trace chunks are unpublished when their last reference is released.
+ * See the documentation of lttng_trace_chunk.
+ *
+ * Returns a trace chunk registry on success, NULL on error.
+ *
+ * Note that a trace chunk registry may only be accessed by an RCU thread.
+ */
+struct lttng_trace_chunk_registry *lttng_trace_chunk_registry_create(void);
+
+/*
+ * Destroy an lttng trace chunk registry. The registry must be emptied
+ * (i.e. all references to the trace chunks it contains must be released) before
+ * it is destroyed.
+ */
+void lttng_trace_chunk_registry_destroy(
+               struct lttng_trace_chunk_registry *registry);
+
+/*
+ * Publish a trace chunk for a given session id.
+ * A reference is acquired on behalf of the caller.
+ *
+ * The trace chunk that is returned is the published version of the trace
+ * chunk. The chunk provided should be discarded on success and it's
+ * published version used in its place.
+ *
+ * See the documentation of lttng_trace_chunk for more information on
+ * the usage of the various parameters.
+ *
+ * Returns an lttng_trace_chunk on success, NULL on error.
+ */
+struct lttng_trace_chunk *lttng_trace_chunk_registry_publish_chunk(
+               struct lttng_trace_chunk_registry *registry,
+               uint64_t session_id, struct lttng_trace_chunk *chunk);
+
+/*
+ * Look-up a trace chunk by session_id and chunk_id.
+ * A reference is acquired on behalf of the caller.
+ *
+ * Returns an lttng_trace_chunk on success, NULL if the chunk does not exist.
+ */
+struct lttng_trace_chunk *
+lttng_trace_chunk_registry_find_chunk(
+               const struct lttng_trace_chunk_registry *registry,
+               uint64_t session_id, uint64_t chunk_id);
+
+/*
+ * Query the existence of a trace chunk by session_id and chunk_id.
+ *
+ * Returns 0 on success, a negative value on error.
+ */
+int lttng_trace_chunk_registry_chunk_exists(
+               const struct lttng_trace_chunk_registry *registry,
+               uint64_t session_id, uint64_t chunk_id, bool *chunk_exists);
+
+/*
+ * Look-up an anonymous trace chunk by session_id.
+ * A reference is acquired on behalf of the caller.
+ *
+ * Returns an lttng_trace_chunk on success, NULL if the chunk does not exist.
+ */
+struct lttng_trace_chunk *
+lttng_trace_chunk_registry_find_anonymous_chunk(
+               const struct lttng_trace_chunk_registry *registry,
+               uint64_t session_id);
+
+unsigned int lttng_trace_chunk_registry_put_each_chunk(
+               const struct lttng_trace_chunk_registry *registry);
+
+#endif /* LTTNG_TRACE_CHUNK_REGISTRY_H */