2 * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
3 * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
5 * SPDX-License-Identifier: GPL-2.0-only
9 #ifndef CONSUMER_METADATA_CACHE_H
10 #define CONSUMER_METADATA_CACHE_H
12 #include <common/consumer/consumer.h>
13 #include <common/dynamic-buffer.h>
15 enum consumer_metadata_cache_write_status
{
16 CONSUMER_METADATA_CACHE_WRITE_STATUS_ERROR
= -1,
18 * New metadata content was appended to the cache successfully.
19 * Previously available content remains valid.
21 CONSUMER_METADATA_CACHE_WRITE_STATUS_APPENDED_CONTENT
= 0,
23 * The new content pushed to the cache invalidated the content that
24 * was already present. The contents of the cache should be re-read.
26 CONSUMER_METADATA_CACHE_WRITE_STATUS_INVALIDATED
,
28 * A metadata cache write can simply overwrite an already existing
29 * section of the cache (and it should be a write-through with identical
30 * data). From the caller's standpoint, there is no change to the state
33 CONSUMER_METADATA_CACHE_WRITE_STATUS_NO_CHANGE
,
36 struct consumer_metadata_cache
{
37 /* Current version of the metadata cache. */
40 * Size is the upper-limit of data written inside the buffer.
41 * All cached data is contiguous.
43 struct lttng_dynamic_buffer contents
;
45 * Lock to update the metadata cache and push into the ring_buffer
46 * (lttng_ust_ctl_write_metadata_to_channel).
48 * This is nested INSIDE the consumer_data lock.
53 enum consumer_metadata_cache_write_status
54 consumer_metadata_cache_write(struct consumer_metadata_cache
*cache
,
55 unsigned int offset
, unsigned int len
, uint64_t version
,
57 int consumer_metadata_cache_allocate(struct lttng_consumer_channel
*channel
);
58 void consumer_metadata_cache_destroy(struct lttng_consumer_channel
*channel
);
59 int consumer_metadata_cache_flushed(struct lttng_consumer_channel
*channel
,
60 uint64_t offset
, int timer
);
62 #endif /* CONSUMER_METADATA_CACHE_H */