Allow changing the behavior for imported blocks

client/network/src/protocol.rs

@@ -1446,6 +1446,11 @@ impl<B: BlockT, H: ExHashT> Protocol<B, H> {
 			return;
 		}
 
+		// blocks are announced by default
+		if !self.config.default_block_announce {
+			return;
+		}
+
 		// send out block announcements
 		self.send_announcement(header, data, is_best, false);
 	}

client/service/src/builder.rs

@@ -1221,6 +1221,7 @@ ServiceBuilder<
 				network_status_sinks.clone(),
 				system_rpc_rx,
 				has_bootnodes,
+				config.default_announce_block,
 			),
 		);
 

client/service/src/config.rs

@@ -127,6 +127,8 @@ pub struct Configuration<G, E = NoExtension> {
 	///
 	/// The default value is 8.
 	pub max_runtime_instances: usize,
+	/// Use default block announcement
+	pub default_announce_block: bool,
 }
 
 /// Configuration of the client keystore.
@@ -229,6 +231,7 @@ impl<G, E> Default for Configuration<G, E> {
 			tracing_targets: Default::default(),
 			tracing_receiver: Default::default(),
 			max_runtime_instances: 8,
+			default_announce_block: true,
 		}
 	}
 }

client/service/src/lib.rs

@@ -326,16 +326,19 @@ fn build_network_future<
 	status_sinks: Arc<Mutex<status_sinks::StatusSinks<(NetworkStatus<B>, NetworkState)>>>,
 	mut rpc_rx: mpsc::UnboundedReceiver<sc_rpc::system::Request<B>>,
 	should_have_peers: bool,
+	default_announce_block: bool,
 ) -> impl Future<Output = ()> {
 	let mut imported_blocks_stream = client.import_notification_stream().fuse();
 	let mut finality_notification_stream = client.finality_notification_stream().fuse();
 
 	futures::future::poll_fn(move |cx| {
 		let before_polling = Instant::now();
 
-		// We poll `imported_blocks_stream`.
-		while let Poll::Ready(Some(notification)) = Pin::new(&mut imported_blocks_stream).poll_next(cx) {
-			network.on_block_imported(notification.header, Vec::new(), notification.is_new_best);
+		if default_announce_block {
+			// We poll `imported_blocks_stream`.
+			while let Poll::Ready(Some(notification)) = Pin::new(&mut imported_blocks_stream).poll_next(cx) {
+				network.on_block_imported(notification.header, Vec::new(), notification.is_new_best);
+			}
 		}
 
 		// We poll `finality_notification_stream`, but we only take the last event.

client/service/test/src/lib.rs

@@ -211,6 +211,7 @@ fn node_config<G, E: Clone> (
 		tracing_targets: None,
 		tracing_receiver: Default::default(),
 		max_runtime_instances: 8,
+		default_announce_block: true,
 	}
 }