sync: a message carries the signatures of its changes

A sync message carried the signatures its peer wasn't sent yet, by a
cursor per peer. Changes sent again, as after a message taken as
delivered and lost on the way, went without them: the peer was past
them. Under a policy requiring signatures they waited until the
writer's next signed change, or the next session.

A message now carries the signatures of the changes it carries
(Signatures::for_changes), whatever the peer was sent before: changes
sent again arrive vouched for as the first time. Past 256 (a message
carrying the batches of many writers), each writer's latest instead,
as a delta carries. The cursor goes, and with it resetting it after a
failed send or a new session.

1 files changed, 0 insertions, 5 deletions

diff --git a/src/state/peer.rs b/src/state/peer.rs
index f6e4a62..a7c6cc9 100644
--- a/src/state/peer.rs
+++ b/src/state/peer.rs
@@ -98,9 +98,6 @@ pub(crate) struct PeerState {
 
     /// Everything about the current Automerge sync with this peer; a reset replaces it.
     pub(crate) sync: SyncSession,
-    /// The signatures of changes it was sent, up to this stamp
-    /// (`Signatures::newer_than`); a reset sends them again.
-    pub(crate) signatures_sent: u64,
 
     pub(crate) liveness: Liveness,
     pub(crate) added_at: Instant,
@@ -307,7 +304,6 @@ impl PeerState {
             hello_backoff: Backoff::new(HELLO_RETRY, HELLO_RETRY_MAX),
             probe_backoff: timing.probe_backoff(),
             sync: SyncSession::new(timing.sync_reply_backoff()),
-            signatures_sent: 0,
             liveness: Liveness::Unknown,
             added_at: Instant::now(),
             last_seen: None,
@@ -378,7 +374,6 @@ impl PeerState {
         let mut reply_backoff = self.sync.reply_backoff;
         reply_backoff.reset();
         self.sync = SyncSession::new(reply_backoff);
-        self.signatures_sent = 0;
         // Said over the session that ended.
         self.reaches = None;
         self.round_trips = None;