Fix: don't access missing ctf trace when getting metadata

[babeltrace.git] / formats / lttng-live / lttng-live-comm.c

diff --git a/formats/lttng-live/lttng-live-comm.c b/formats/lttng-live/lttng-live-comm.c
index 77bf34ac377156a39fb60aa276873a2659655f24..8059b338b095dd4672021946ae497b3f8a45f7dd 100644 (file)
--- a/formats/lttng-live/lttng-live-comm.c
+++ b/formats/lttng-live/lttng-live-comm.c
@@ -607,6 +607,11 @@ int append_metadata(struct lttng_live_ctx *ctx,
        struct lttng_live_viewer_stream *metadata;
        char *metadata_buf = NULL;
 
+       if (!viewer_stream->ctf_trace->handle) {
+               printf_verbose("append_metadata: trace handle not ready yet.\n");
+               return 0;
+       }
+
        printf_verbose("get_next_index: new metadata needed\n");
        ret = get_new_metadata(ctx, viewer_stream, &metadata_buf);
        if (ret < 0) {
@@ -1276,14 +1281,30 @@ retry:
        }
 
        if (cur_index->content_size == 0) {
+               /* Beacon packet index */
                if (file_stream->parent.stream_class) {
                        file_stream->parent.cycles_timestamp =
                                cur_index->ts_cycles.timestamp_end;
                        file_stream->parent.real_timestamp = ctf_get_real_timestamp(
                                        &file_stream->parent,
                                        cur_index->ts_cycles.timestamp_end);
+
+                       /*
+                        * Duplicate the data from the previous index, because
+                        * the one we just received is only a beacon with no
+                        * relevant information except the timestamp_end. We
+                        * don't need to keep this timestamp_end because we already
+                        * updated the file_stream timestamps, so we only need
+                        * to keep the last real index data as prev_index. That
+                        * way, we keep the original prev timestamps and
+                        * discarded events counter. This is the same behaviour
+                        * as if we were reading a local trace, we would not
+                        * have fake indexes between real indexes.
+                        */
+                       memcpy(cur_index, prev_index, sizeof(struct packet_index));
                }
        } else {
+               /* Real packet index */
                if (file_stream->parent.stream_class) {
                        /* Convert the timestamps and append to the real_index. */
                        cur_index->ts_real.timestamp_begin = ctf_get_real_timestamp(