X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Fconsumer%2Fconsumer-metadata-cache.hpp;fp=src%2Fcommon%2Fconsumer%2Fconsumer-metadata-cache.hpp;h=6e60e5c15c2eab9852d7b941c9c75b650c494601;hb=c9e313bc594f40a86eed237dce222c0fc99c957f;hp=0000000000000000000000000000000000000000;hpb=4878de5c7deb512bbdac4fdfc498907efa06fb7c;p=lttng-tools.git

diff --git a/src/common/consumer/consumer-metadata-cache.hpp b/src/common/consumer/consumer-metadata-cache.hpp
new file mode 100644
index 000000000..6e60e5c15
--- /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 */