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 fb3e1ed68b936e1fd7411273c4b7a9b338f76e0b..a4a6461e69cf218cfa2d573437ada85b12bb3a7d 100644 (file)
--- a/src/bin/lttng-relayd/stream.h
+++ b/src/bin/lttng-relayd/stream.h
@@ -26,16 +26,12 @@
 #include <urcu/list.h>
 
 #include <common/hashtable/hashtable.h>
+#include <common/trace-chunk.h>
 
 #include "session.h"
 #include "stream-fd.h"
 #include "tracefile-array.h"
 
-struct relay_stream_chunk_id {
-       bool is_set;
-       uint64_t value;
-};
-
 /*
  * Represents a stream in the relay
  */
@@ -52,8 +48,12 @@ 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;
@@ -61,6 +61,20 @@ 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. */
@@ -149,23 +163,24 @@ struct relay_stream {
         */
        uint64_t rotate_at_seq_num;
        /*
-        * 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
-        * is the chunk_id we will have after the rotation. It must be updated
-        * atomically with rotate_at_seq_num.
-        *
-        * Always access with stream lock held.
-        *
-        * This attribute is not set if the stream is created by a pre-2.11
-        * consumer.
+        * 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 relay_stream_chunk_id current_chunk_id;
+       struct lttng_trace_chunk *trace_chunk;
 };
 
 struct relay_stream *stream_create(struct ctf_trace *trace,
        uint64_t stream_handle, char *path_name,
        char *channel_name, uint64_t tracefile_size,
-       uint64_t tracefile_count, const struct relay_stream_chunk_id *chunk_id);
+       uint64_t tracefile_count);
 
 struct relay_stream *stream_get_by_id(uint64_t stream_id);
 bool stream_get(struct relay_stream *stream);