relayd: create stream files relative to a session's trace chunk

[lttng-tools.git] / src / bin / lttng-relayd / stream.h

diff --git a/src/bin/lttng-relayd/stream.h b/src/bin/lttng-relayd/stream.h
index 5030e5d4c47e03291b22102aaef1b50a093bd33a..a4a6461e69cf218cfa2d573437ada85b12bb3a7d 100644 (file)
--- a/src/bin/lttng-relayd/stream.h
+++ b/src/bin/lttng-relayd/stream.h
@@ -26,6 +26,7 @@
 #include <urcu/list.h>
 
 #include <common/hashtable/hashtable.h>
+#include <common/trace-chunk.h>
 
 #include "session.h"
 #include "stream-fd.h"
@@ -37,12 +38,6 @@
 struct relay_stream {
        uint64_t stream_handle;
 
-       /*
-        * reflock used to synchronize the closing of this stream.
-        * stream reflock nests inside viewer stream reflock.
-        * stream reflock nests inside index reflock.
-        */
-       pthread_mutex_t reflock;
        struct urcu_ref ref;
        /* Back reference to trace. Protected by refcount on trace object. */
        struct ctf_trace *trace;
@@ -53,15 +48,33 @@ struct relay_stream {
         * inside the ctf_trace lock.
         */
        pthread_mutex_t lock;
-       uint64_t prev_seq;              /* previous data sequence number encountered. */
-       uint64_t last_net_seq_num;      /* seq num to encounter before closing. */
+       /* previous data sequence number written to disk. */
+       uint64_t prev_data_seq;
+       /* previous index sequence number written to disk. */
+       uint64_t prev_index_seq;
+       /* seq num to encounter before closing. */
+       uint64_t last_net_seq_num;
 
        /* FD on which to write the stream data. */
        struct stream_fd *stream_fd;
-       /* FD on which to write the index data. */
-       struct stream_fd *index_fd;
+       /* index file on which to write the index data. */
+       struct lttng_index_file *index_file;
 
        char *path_name;
+       /*
+        * prev_path_name is only used for session rotation support.
+        * It is essentially used to work around the fact that index
+        * files are always created from the 'data' connection.
+        *
+        * Hence, it is possible to receive a ROTATE_STREAM command
+        * which affects the stream's path_name before the creation of
+        * an index file. In this situation, the index file of the
+        * 'previous' chunk would be created in the new destination folder.
+        *
+        * It would then be unlinked when the actual index of the new chunk
+        * is created.
+        */
+       char *prev_path_name;
        char *channel_name;
 
        /* On-disk circular buffer of tracefiles. */
@@ -69,6 +82,11 @@ struct relay_stream {
        uint64_t tracefile_size_current;
        uint64_t tracefile_count;
 
+       /*
+        * Position in the tracefile where we have the full index also on disk.
+        */
+       uint64_t pos_after_last_complete_data_index;
+
        /*
         * Counts the number of received indexes. The "tag" associated
         * with an index is taken before incrementing this seqcount.
@@ -135,6 +153,28 @@ struct relay_stream {
        struct lttng_ht_node_u64 node;
        bool in_stream_ht;              /* is stream in stream hash table. */
        struct rcu_head rcu_node;       /* For call_rcu teardown. */
+       /*
+        * When we have written the data and index corresponding to this
+        * seq_num, rotate the tracefile (session rotation). The path_name is
+        * already up-to-date.
+        * This is set to -1ULL when no rotation is pending.
+        *
+        * Always access with stream lock held.
+        */
+       uint64_t rotate_at_seq_num;
+       /*
+        * When rotate_at_seq_num != -1ULL, meaning that a rotation is ongoing,
+        * data_rotated and index_rotated respectively indicate if the stream's
+        * data and index have been rotated. A rotation is considered completed
+        * when both rotations have occurred.
+        */
+       bool data_rotated;
+       bool index_rotated;
+       /*
+        * `trace_chunk` is the trace chunk to which the file currently
+        * being produced (if any) belongs.
+        */
+       struct lttng_trace_chunk *trace_chunk;
 };
 
 struct relay_stream *stream_create(struct ctf_trace *trace,