add writer trees

1 files changed, 4 insertions, 0 deletions

diff --git a/src/transport/mod.rs b/src/transport/mod.rs
index 9ae8ff2..899f4b8 100644
--- a/src/transport/mod.rs
+++ b/src/transport/mod.rs
@@ -670,6 +670,10 @@ pub(crate) struct SyncEnvelope {
     /// not one it is still filling (joining, rejoining). Only such a peer can tell a
     /// catching-up node that it has everything; an empty document says nothing else.
     pub(crate) ready: bool,
+    /// Whose change it passes on along the writer's tree (`swarm::tree`), by pair key:
+    /// the writer's, on its own push and on every member's after; None otherwise
+    /// (answers, pulls).
+    pub(crate) writer: Option<u64>,
 }
 
 /// What a sync envelope carries.