Notification iterator: transform precondition checks to BT_ASSERT_PRE()

[babeltrace.git] / plugins / ctf / fs-src / fs.c

diff --git a/plugins/ctf/fs-src/fs.c b/plugins/ctf/fs-src/fs.c
index 74e9b52aaf9fe04d7418bb6e40e0f3358642fd40..8395c81b0225eca494fac4a5e9d5f2e3e3757c95 100644 (file)
--- a/plugins/ctf/fs-src/fs.c
+++ b/plugins/ctf/fs-src/fs.c
@@ -96,19 +96,52 @@ struct bt_notification_iterator_next_method_return ctf_fs_iterator_next(
 
        BT_ASSERT(notif_iter_data->ds_file);
        next_ret = ctf_fs_ds_file_next(notif_iter_data->ds_file);
-       if (next_ret.status == BT_NOTIFICATION_ITERATOR_STATUS_END) {
-               BT_ASSERT(!next_ret.notification);
+
+       if (next_ret.status == BT_NOTIFICATION_ITERATOR_STATUS_OK &&
+                       bt_notification_get_type(next_ret.notification) ==
+                       BT_NOTIFICATION_TYPE_STREAM_BEGIN) {
+               if (notif_iter_data->skip_stream_begin_notifs) {
+                       /*
+                        * We already emitted a
+                        * BT_NOTIFICATION_TYPE_STREAM_BEGIN
+                        * notification: skip this one, get a new one.
+                        */
+                       BT_PUT(next_ret.notification);
+                       next_ret = ctf_fs_ds_file_next(notif_iter_data->ds_file);
+                       BT_ASSERT(next_ret.status != BT_NOTIFICATION_ITERATOR_STATUS_END);
+                       goto end;
+               } else {
+                       /*
+                        * First BT_NOTIFICATION_TYPE_STREAM_BEGIN
+                        * notification: skip all following.
+                        */
+                       notif_iter_data->skip_stream_begin_notifs = true;
+                       goto end;
+               }
+       }
+
+       if (next_ret.status == BT_NOTIFICATION_ITERATOR_STATUS_OK &&
+                       bt_notification_get_type(next_ret.notification) ==
+                       BT_NOTIFICATION_TYPE_STREAM_END) {
                notif_iter_data->ds_file_info_index++;
 
                if (notif_iter_data->ds_file_info_index ==
                                notif_iter_data->ds_file_group->ds_file_infos->len) {
                        /*
                         * No more stream files to read: we reached the
-                        * real end.
+                        * real end. Emit this
+                        * BT_NOTIFICATION_TYPE_STREAM_END notification.
+                        * The next time ctf_fs_iterator_next() is
+                        * called for this notification iterator,
+                        * ctf_fs_ds_file_next() will return
+                        * BT_NOTIFICATION_ITERATOR_STATUS_END().
                         */
                        goto end;
                }
 
+               BT_PUT(next_ret.notification);
+               bt_notif_iter_reset(notif_iter_data->notif_iter);
+
                /*
                 * Open and start reading the next stream file within
                 * our stream file group.
@@ -122,14 +155,30 @@ struct bt_notification_iterator_next_method_return ctf_fs_iterator_next(
                next_ret = ctf_fs_ds_file_next(notif_iter_data->ds_file);
 
                /*
-                * We should not get BT_NOTIFICATION_ITERATOR_STATUS_END
-                * with a brand new stream file because empty stream
-                * files are not even part of stream file groups, which
-                * means we're sure to get at least one pair of "packet
-                * begin" and "packet end" notifications in the case of
-                * a single, empty packet.
+                * If we get a notification, we expect to get a
+                * BT_NOTIFICATION_TYPE_STREAM_BEGIN notification
+                * because the iterator's state machine emits one before
+                * even requesting the first block of data from the
+                * medium. Skip this notification because we're not
+                * really starting a new stream here, and try getting a
+                * new notification (which, if it works, is a
+                * BT_NOTIFICATION_TYPE_PACKET_BEGIN one). We're sure to
+                * get at least one pair of
+                * BT_NOTIFICATION_TYPE_PACKET_BEGIN and
+                * BT_NOTIFICATION_TYPE_PACKET_END notifications in the
+                * case of a single, empty packet. We know there's at
+                * least one packet because the stream file group does
+                * not contain empty stream files.
                 */
-               BT_ASSERT(next_ret.status != BT_NOTIFICATION_ITERATOR_STATUS_END);
+               BT_ASSERT(notif_iter_data->skip_stream_begin_notifs);
+
+               if (next_ret.status == BT_NOTIFICATION_ITERATOR_STATUS_OK) {
+                       BT_ASSERT(bt_notification_get_type(next_ret.notification) ==
+                               BT_NOTIFICATION_TYPE_STREAM_BEGIN);
+                       BT_PUT(next_ret.notification);
+                       next_ret = ctf_fs_ds_file_next(notif_iter_data->ds_file);
+                       BT_ASSERT(next_ret.status != BT_NOTIFICATION_ITERATOR_STATUS_END);
+               }
        }
 
 end: