Change behaviour of stream-intersection with multiple traces

[babeltrace.git] / formats / ctf / iterator.c

diff --git a/formats/ctf/iterator.c b/formats/ctf/iterator.c
index 0534d013acc601220dd41986aea26805a7169d88..7ef3e0b1537479941193a26708ef42f605e03563 100644 (file)
--- a/formats/ctf/iterator.c
+++ b/formats/ctf/iterator.c
@@ -63,6 +63,53 @@ struct bt_ctf_iter *bt_ctf_iter_create(struct bt_context *ctx,
        return iter;
 }
 
+struct bt_ctf_iter *bt_ctf_iter_create_intersect(struct bt_context *ctx,
+               struct bt_iter_pos **inter_begin_pos,
+               struct bt_iter_pos **inter_end_pos)
+{
+       int ret;
+       uint64_t begin, end;
+
+       /*
+        * The iterator's range is the union of each trace's intersection of
+        * streams. This means that we determine the "active" region of each
+        * trace (that is the region where all of its streams are active), and
+        * use the TraceCollection to merge all of these active regions.
+        *
+        * This results in a union of the traces' active regions.
+        */
+       ret = ctf_find_tc_stream_packet_intersection_union(ctx, &begin, &end);
+       if (ret == 1) {
+               fprintf(stderr, "[error] No intersection found between trace files.\n");
+               goto error;
+       } else if (ret != 0) {
+               goto error;
+       }
+       *inter_begin_pos = bt_iter_create_time_pos(NULL, begin);
+       if (!(*inter_begin_pos)) {
+               goto error;
+       }
+       *inter_end_pos = bt_iter_create_time_pos(NULL, end);
+       if (!(*inter_end_pos)) {
+               goto error;
+       }
+
+       ret = ctf_tc_set_stream_intersection_mode(ctx);
+       if (ret) {
+               goto error;
+       }
+
+       /*
+        * bt_ctf_iter does not take ownership of begin and end positions,
+        * so we return them to the caller who must still assume their ownership
+        * until the iterator is destroyed.
+        */
+       return bt_ctf_iter_create(ctx, *inter_begin_pos,
+                       *inter_end_pos);
+error:
+       return NULL;
+}
+
 void bt_ctf_iter_destroy(struct bt_ctf_iter *iter)
 {
        struct bt_stream_callbacks *bt_stream_cb;
@@ -119,22 +166,43 @@ struct bt_ctf_event *bt_ctf_iter_read_event_flags(struct bt_ctf_iter *iter,
         */
        assert(iter);
 
+       if (flags)
+               *flags = 0;
+
        ret = &iter->current_ctf_event;
-       file_stream = heap_maximum(iter->parent.stream_heap);
+       file_stream = bt_heap_maximum(iter->parent.stream_heap);
        if (!file_stream) {
                /* end of file for all streams */
                goto stop;
        }
+
+       /*
+        * If the packet is empty (contains only headers or is of size 0), the
+        * caller has to know that we can't read the current event and we need
+        * to do a bt_iter_next.
+        */
+       if (file_stream->pos.data_offset == file_stream->pos.content_size
+                       || file_stream->pos.content_size == 0) {
+               /* More events may come. */
+               ret = NULL;
+               if (flags)
+                       *flags |= BT_ITER_FLAG_RETRY;
+               goto end;
+       }
+
        stream = &file_stream->parent;
+       if (iter->parent.end_pos &&
+               iter->parent.end_pos->type == BT_SEEK_TIME &&
+               stream->real_timestamp > iter->parent.end_pos->u.seek_time) {
+               goto stop;
+       }
        ret->parent = g_ptr_array_index(stream->events_by_id,
                        stream->event_id);
 
-       if (flags)
-               *flags = 0;
-       if (!file_stream->pos.packet_cycles_index)
+       if (!file_stream->pos.packet_index)
                packet_index = NULL;
        else
-               packet_index = &g_array_index(file_stream->pos.packet_cycles_index,
+               packet_index = &g_array_index(file_stream->pos.packet_index,
                                struct packet_index, file_stream->pos.cur_index);
        iter->events_lost = 0;
        if (packet_index && packet_index->events_discarded >