avoid using layout_watch in System directly

src/table/replication/fullcopy.rs

@@ -27,11 +27,11 @@ impl TableReplication for TableFullReplication {
 	}
 
 	fn write_nodes(&self, _hash: &Hash) -> Vec<Uuid> {
-		let layout = self.system.layout_watch.borrow();
+		let layout = self.system.cluster_layout();
 		layout.node_ids().to_vec()
 	}
 	fn write_quorum(&self) -> usize {
-		let nmembers = self.system.layout_watch.borrow().node_ids().len();
+		let nmembers = self.system.cluster_layout().node_ids().len();
 		if nmembers > self.max_faults {
 			nmembers - self.max_faults
 		} else {

src/table/replication/sharded.rs

@@ -26,7 +26,7 @@ pub struct TableShardedReplication {
 
 impl TableReplication for TableShardedReplication {
 	fn read_nodes(&self, hash: &Hash) -> Vec<Uuid> {
-		let layout = self.system.layout_watch.borrow();
+		let layout = self.system.cluster_layout();
 		layout.nodes_of(hash, self.replication_factor)
 	}
 	fn read_quorum(&self) -> usize {
@@ -34,7 +34,7 @@ impl TableReplication for TableShardedReplication {
 	}
 
 	fn write_nodes(&self, hash: &Hash) -> Vec<Uuid> {
-		let layout = self.system.layout_watch.borrow();
+		let layout = self.system.cluster_layout();
 		layout.nodes_of(hash, self.replication_factor)
 	}
 	fn write_quorum(&self) -> usize {
@@ -45,9 +45,9 @@ impl TableReplication for TableShardedReplication {
 	}
 
 	fn partition_of(&self, hash: &Hash) -> Partition {
-		self.system.layout_watch.borrow().partition_of(hash)
+		self.system.cluster_layout().partition_of(hash)
 	}
 	fn partitions(&self) -> Vec<(Partition, Hash)> {
-		self.system.layout_watch.borrow().partitions()
+		self.system.cluster_layout().partitions()
 	}
 }

src/table/sync.rs

@@ -92,7 +92,7 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 		bg.spawn_worker(SyncWorker {
 			syncer: self.clone(),
 			layout_watch: self.system.layout_watch.clone(),
-			layout: self.system.layout_watch.borrow().clone(),
+			layout: self.system.cluster_layout().clone(),
 			add_full_sync_rx,
 			todo: vec![],
 			next_full_sync: Instant::now() + Duration::from_secs(20),