message: Log purged deploy hashes from the synchronizer
diff: @@ -41,11 +41,20 @@ impl<I, C: Context> Default for PendingVertices<I, C> {
  impl<I: NodeIdT, C: Context> PendingVertices<I, C> {
  /// Removes expired vertices.
  - fn remove_expired(&mut self, oldest: Timestamp) {
  + fn remove_expired(&mut self, oldest: Timestamp) -> Vec<C::Hash> {
  + let mut removed = vec![];
  for time_by_sender in self.0.values_mut() {
  time_by_sender.retain(|_, time_received| *time_received >= oldest);
  }
  - self.0.retain(|_, time_by_peer| !time_by_peer.is_empty())
  + self.0.retain(|pvv, time_by_peer| {
  + if time_by_peer.is_empty() {
  + removed.extend(pvv.inner().unit_hash().into_iter());
  + false
  + } else {
  + true
  + }
  + });
  + removed
  }
  /// Adds a vertex, or updates its timestamp.
  @@ -200,10 +209,17 @@ impl<I: NodeIdT, C: Context + 'static> Synchronizer<I, C> {
  /// Removes expired pending vertices from the queues, and schedules the next purge.
  pub(crate) fn purge_vertices(&mut self, oldest: Timestamp) {
  info!("purging synchronizer queues");
  - self.vertices_no_deps.remove_expired(oldest);
  + let no_deps_expired = self.vertices_no_deps.remove_expired(oldest);
  + debug!(?no_deps_expired, "expired no dependencies");
  self.requests_sent.clear();
  + let to_be_added_later_expired =
  Self::remove_expired(&mut self.vertices_to_be_added_later, oldest);
  - Self::remove_expired(&mut self.vertices_awaiting_deps, oldest);
  + debug!(
  + ?to_be_added_later_expired,
  + "expired to be added later dependencies"
  + );
  + let awaiting_deps_expired = Self::remove_expired(&mut self.vertices_awaiting_deps, oldest);
  + debug!(?awaiting_deps_expired, "expired awaiting dependencies");
  }
  // Returns number of elements in the `vertices_to_be_added_later` queue.
  @@ -526,9 +542,10 @@ impl<I: NodeIdT, C: Context + 'static> Synchronizer<I, C> {
  fn remove_expired<T: Ord + Clone>(
  map: &mut BTreeMap<T, PendingVertices<I, C>>,
  oldest: Timestamp,
  - ) {
  + )-> Vec<C::Hash> {
  + let mut expired = vec![];
  for pvs in map.values_mut() {
  - pvs.remove_expired(oldest);
  + expired.extend(pvs.remove_expired(oldest));
  }
  let keys = map
  .iter()
  @@ -538,5 +555,6 @@ impl<I: NodeIdT, C: Context + 'static> Synchronizer<I, C> {
  for key in keys {
  map.remove(&key);
  }
  + expired
  }
  }
  