Fix: split index and data file rotation logic

[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 151ae25c1ad2be5f3243bc22094c186556a61b29..5e23e7339cf4fcf7495f2ae4825fcdfdd57641d1 100644 (file)
--- a/src/bin/lttng-relayd/stream.h
+++ b/src/bin/lttng-relayd/stream.h
@@ -52,10 +52,12 @@ struct relay_stream {
         * inside the ctf_trace lock.
         */
        pthread_mutex_t lock;
-       uint64_t prev_seq;              /* previous data sequence number encountered. */
+       /* previous data sequence number written to disk. */
+       uint64_t prev_data_seq;
        /* previous index sequence number written to disk. */
        uint64_t prev_index_seq;
-       uint64_t last_net_seq_num;      /* seq num to encounter before closing. */
+       /* 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;
@@ -63,6 +65,20 @@ struct relay_stream {
        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. */
@@ -150,6 +166,14 @@ struct relay_stream {
         * 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;
        /*
         * This is the id of the chunk where we are writing to if no rotation is
         * pending (rotate_at_seq_num == -1ULL). If a rotation is pending, this