Rename C++ header files to .hpp

[lttng-tools.git] / src / common / consumer / consumer-metadata-cache.hpp

diff --git a/src/common/consumer/consumer-metadata-cache.hpp b/src/common/consumer/consumer-metadata-cache.hpp
new file mode 100644 (file)
index 0000000..6e60e5c
--- /dev/null
+++ b/src/common/consumer/consumer-metadata-cache.hpp
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
+ * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#ifndef CONSUMER_METADATA_CACHE_H
+#define CONSUMER_METADATA_CACHE_H
+
+#include <common/consumer/consumer.hpp>
+#include <common/dynamic-buffer.hpp>
+
+enum consumer_metadata_cache_write_status {
+       CONSUMER_METADATA_CACHE_WRITE_STATUS_ERROR = -1,
+       /*
+        * New metadata content was appended to the cache successfully.
+        * Previously available content remains valid.
+        */
+       CONSUMER_METADATA_CACHE_WRITE_STATUS_APPENDED_CONTENT = 0,
+       /*
+        * The new content pushed to the cache invalidated the content that
+        * was already present. The contents of the cache should be re-read.
+        */
+       CONSUMER_METADATA_CACHE_WRITE_STATUS_INVALIDATED,
+       /*
+        * A metadata cache write can simply overwrite an already existing
+        * section of the cache (and it should be a write-through with identical
+        * data). From the caller's standpoint, there is no change to the state
+        * of the cache.
+        */
+       CONSUMER_METADATA_CACHE_WRITE_STATUS_NO_CHANGE,
+};
+
+struct consumer_metadata_cache {
+       /* Current version of the metadata cache. */
+       uint64_t version;
+       /*
+        * Size is the upper-limit of data written inside the buffer.
+        * All cached data is contiguous.
+        */
+       struct lttng_dynamic_buffer contents;
+       /*
+        * Lock to update the metadata cache and push into the ring_buffer
+        * (lttng_ust_ctl_write_metadata_to_channel).
+        *
+        * This is nested INSIDE the consumer_data lock.
+        */
+       pthread_mutex_t lock;
+};
+
+enum consumer_metadata_cache_write_status
+consumer_metadata_cache_write(struct consumer_metadata_cache *cache,
+               unsigned int offset, unsigned int len, uint64_t version,
+               const char *data);
+int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel);
+void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel);
+int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
+               uint64_t offset, int timer);
+
+#endif /* CONSUMER_METADATA_CACHE_H */