Extend the rotation API to provide network trace archive locations

[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 7e2b1334ec9c54e3e3ca3c5229b4e664c31c06b8..47ae2e8f9927fdcd672a595bf3c20902fd375846 100644 (file)
--- a/src/bin/lttng-relayd/stream.h
+++ b/src/bin/lttng-relayd/stream.h
@@ -29,6 +29,7 @@
 
 #include "session.h"
 #include "stream-fd.h"
+#include "tracefile-array.h"
 
 /*
  * Represents a stream in the relay
@@ -36,12 +37,6 @@
 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;
@@ -57,8 +52,8 @@ struct relay_stream {
 
        /* 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;
        char *channel_name;
@@ -67,17 +62,30 @@ struct relay_stream {
        uint64_t tracefile_size;
        uint64_t tracefile_size_current;
        uint64_t tracefile_count;
-       uint64_t current_tracefile_id;
 
-       uint64_t current_tracefile_seq; /* Free-running counter. */
-       uint64_t oldest_tracefile_seq;  /* Free-running counter. */
+       /*
+        * Position in the tracefile where we have the full index also on disk.
+        */
+       uint64_t pos_after_last_complete_data_index;
 
-       /* To inform the viewer up to where it can go back in time. */
-       uint64_t oldest_tracefile_id;
+       /*
+        * Counts the number of received indexes. The "tag" associated
+        * with an index is taken before incrementing this seqcount.
+        * Therefore, the sequence tag associated with the last index
+        * received is always index_received_seqcount - 1.
+        */
+       uint64_t index_received_seqcount;
 
-       uint64_t total_index_received;
+       /*
+        * Tracefile array is an index of the stream trace files,
+        * indexed by position. It allows keeping track of the oldest
+        * available indexes when overwriting trace files in tracefile
+        * rotation.
+        */
+       struct tracefile_array *tfa;
 
-       bool closed;    /* Stream is closed. */
+       bool closed;            /* Stream is closed. */
+       bool close_requested;   /* Close command has been received. */
 
        /*
         * Counts number of indexes in indexes_ht. Redundant info.
@@ -124,7 +132,26 @@ struct relay_stream {
         * Node of stream within global stream hash table.
         */
        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;
+       /*
+        * 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.
+        */
+       uint64_t chunk_id;
 };
 
 struct relay_stream *stream_create(struct ctf_trace *trace,
@@ -135,7 +162,7 @@ struct relay_stream *stream_create(struct ctf_trace *trace,
 struct relay_stream *stream_get_by_id(uint64_t stream_id);
 bool stream_get(struct relay_stream *stream);
 void stream_put(struct relay_stream *stream);
-void stream_close(struct relay_stream *stream);
+void try_stream_close(struct relay_stream *stream);
 void stream_publish(struct relay_stream *stream);
 void print_relay_streams(void);