Prepare syncing for parallel sync strategies

substrate/client/network/sync/src/engine.rs

@@ -33,7 +33,7 @@ use crate::{
 	},
 	strategy::{
 		warp::{EncodedProof, WarpProofRequest, WarpSyncParams},
-		SyncingAction, SyncingConfig, SyncingStrategy,
+		Key, SyncingAction, SyncingConfig, SyncingStrategy,
 	},
 	types::{
 		BadPeer, ExtendedPeerInfo, OpaqueStateRequest, OpaqueStateResponse, PeerRequest, SyncEvent,
@@ -214,9 +214,6 @@ pub struct SyncingEngine<B: BlockT, Client> {
 	/// Syncing strategy.
 	strategy: SyncingStrategy<B, Client>,
 
-	/// Syncing configuration for startegies.
-	syncing_config: SyncingConfig,
-
 	/// Blockchain client.
 	client: Arc<Client>,
 
@@ -441,8 +438,7 @@ where
 			.map_or(futures::future::pending().boxed().fuse(), |rx| rx.boxed().fuse());
 
 		// Initialize syncing strategy.
-		let strategy =
-			SyncingStrategy::new(syncing_config.clone(), client.clone(), warp_sync_config)?;
+		let strategy = SyncingStrategy::new(syncing_config, client.clone(), warp_sync_config)?;
 
 		let block_announce_protocol_name = block_announce_config.protocol_name().clone();
 		let (tx, service_rx) = tracing_unbounded("mpsc_chain_sync", 100_000);
@@ -471,7 +467,6 @@ where
 				roles,
 				client,
 				strategy,
-				syncing_config,
 				network_service,
 				peers: HashMap::new(),
 				block_announce_data_cache: LruMap::new(ByLength::new(cache_capacity)),
@@ -661,8 +656,15 @@ where
 					Some(event) => self.process_notification_event(event),
 					None => return,
 				},
-				warp_target_block_header = &mut self.warp_sync_target_block_header_rx_fused =>
-					self.pass_warp_sync_target_block_header(warp_target_block_header),
+				warp_target_block_header = &mut self.warp_sync_target_block_header_rx_fused => {
+					if let Err(_) = self.pass_warp_sync_target_block_header(warp_target_block_header) {
+						error!(
+							target: LOG_TARGET,
+							"Failed to set warp sync target block header, terminating `SyncingEngine`.",
+						);
+						return
+					}
+				},
 				response_event = self.pending_responses.select_next_some() =>
 					self.process_response_event(response_event),
 				validation_result = self.block_announce_validator.select_next_some() =>
@@ -675,21 +677,23 @@ where
 
 			// Process actions requested by a syncing strategy.
 			if let Err(e) = self.process_strategy_actions() {
-				error!("Terminating `SyncingEngine` due to fatal error: {e:?}");
+				error!(
+					target: LOG_TARGET,
+					"Terminating `SyncingEngine` due to fatal error: {e:?}.",
+				);
 				return
 			}
 		}
 	}
 
 	fn process_strategy_actions(&mut self) -> Result<(), ClientError> {
-		for action in self.strategy.actions() {
+		for action in self.strategy.actions()? {
 			match action {
-				SyncingAction::SendBlockRequest { peer_id, request } => {
+				SyncingAction::SendBlockRequest { peer_id, key, request } => {
 					// Sending block request implies dropping obsolete pending response as we are
 					// not interested in it anymore (see [`SyncingAction::SendBlockRequest`]).
-					// Furthermore, only one request at a time is allowed to any peer.
-					let removed = self.pending_responses.remove(&peer_id);
-					self.send_block_request(peer_id, request.clone());
+					let removed = self.pending_responses.remove(peer_id, key);
+					self.send_block_request(peer_id, key, request.clone());
 
 					trace!(
 						target: LOG_TARGET,
@@ -699,24 +703,24 @@ where
 						removed,
 					)
 				},
-				SyncingAction::CancelBlockRequest { peer_id } => {
-					let removed = self.pending_responses.remove(&peer_id);
+				SyncingAction::CancelRequest { peer_id, key } => {
+					let removed = self.pending_responses.remove(peer_id, key);
 
 					trace!(
 						target: LOG_TARGET,
 						"Processed {action:?}, response removed: {removed}.",
 					);
 				},
-				SyncingAction::SendStateRequest { peer_id, request } => {
-					self.send_state_request(peer_id, request);
+				SyncingAction::SendStateRequest { peer_id, key, request } => {
+					self.send_state_request(peer_id, key, request);
 
 					trace!(
 						target: LOG_TARGET,
 						"Processed `ChainSyncAction::SendBlockRequest` to {peer_id}.",
 					);
 				},
-				SyncingAction::SendWarpProofRequest { peer_id, request } => {
-					self.send_warp_proof_request(peer_id, request.clone());
+				SyncingAction::SendWarpProofRequest { peer_id, key, request } => {
+					self.send_warp_proof_request(peer_id, key, request.clone());
 
 					trace!(
 						target: LOG_TARGET,
@@ -726,7 +730,7 @@ where
 					);
 				},
 				SyncingAction::DropPeer(BadPeer(peer_id, rep)) => {
-					self.pending_responses.remove(&peer_id);
+					self.pending_responses.remove_all(&peer_id);
 					self.network_service
 						.disconnect_peer(peer_id, self.block_announce_protocol_name.clone());
 					self.network_service.report_peer(peer_id, rep);
@@ -753,20 +757,8 @@ where
 						number,
 					)
 				},
-				SyncingAction::Finished => {
-					let connected_peers = self.peers.iter().filter_map(|(peer_id, peer)| {
-						peer.info.roles.is_full().then_some((
-							*peer_id,
-							peer.info.best_hash,
-							peer.info.best_number,
-						))
-					});
-					self.strategy.switch_to_next(
-						self.syncing_config.clone(),
-						self.client.clone(),
-						connected_peers,
-					)?;
-				},
+				// Nothing to do, this is handled internally by `SyncingStrategy`.
+				SyncingAction::Finished => {},
 			}
 		}
 
@@ -948,23 +940,18 @@ where
 		}
 	}
 
-	fn pass_warp_sync_target_block_header(&mut self, header: Result<B::Header, oneshot::Canceled>) {
+	fn pass_warp_sync_target_block_header(
+		&mut self,
+		header: Result<B::Header, oneshot::Canceled>,
+	) -> Result<(), ()> {
 		match header {
-			Ok(header) =>
-				if let SyncingStrategy::WarpSyncStrategy(warp_sync) = &mut self.strategy {
-					warp_sync.set_target_block(header);
-				} else {
-					error!(
-						target: LOG_TARGET,
-						"Cannot set warp sync target block: no warp sync strategy is active."
-					);
-					debug_assert!(false);
-				},
+			Ok(header) => self.strategy.set_warp_sync_target_block_header(header),
 			Err(err) => {
 				error!(
 					target: LOG_TARGET,
 					"Failed to get target block for warp sync. Error: {err:?}",
 				);
+				Err(())
 			},
 		}
 	}
@@ -1002,7 +989,7 @@ where
 		}
 
 		self.strategy.remove_peer(&peer_id);
-		self.pending_responses.remove(&peer_id);
+		self.pending_responses.remove_all(&peer_id);
 		self.event_streams
 			.retain(|stream| stream.unbounded_send(SyncEvent::PeerDisconnected(peer_id)).is_ok());
 	}
@@ -1167,7 +1154,7 @@ where
 		Ok(())
 	}
 
-	fn send_block_request(&mut self, peer_id: PeerId, request: BlockRequest<B>) {
+	fn send_block_request(&mut self, peer_id: PeerId, key: Key, request: BlockRequest<B>) {
 		if !self.peers.contains_key(&peer_id) {
 			trace!(target: LOG_TARGET, "Cannot send block request to unknown peer {peer_id}");
 			debug_assert!(false);
@@ -1178,12 +1165,13 @@ where
 
 		self.pending_responses.insert(
 			peer_id,
+			key,
 			PeerRequest::Block(request.clone()),
 			async move { downloader.download_blocks(peer_id, request).await }.boxed(),
 		);
 	}
 
-	fn send_state_request(&mut self, peer_id: PeerId, request: OpaqueStateRequest) {
+	fn send_state_request(&mut self, peer_id: PeerId, key: Key, request: OpaqueStateRequest) {
 		if !self.peers.contains_key(&peer_id) {
 			trace!(target: LOG_TARGET, "Cannot send state request to unknown peer {peer_id}");
 			debug_assert!(false);
@@ -1192,7 +1180,7 @@ where
 
 		let (tx, rx) = oneshot::channel();
 
-		self.pending_responses.insert(peer_id, PeerRequest::State, rx.boxed());
+		self.pending_responses.insert(peer_id, key, PeerRequest::State, rx.boxed());
 
 		match Self::encode_state_request(&request) {
 			Ok(data) => {
@@ -1213,7 +1201,7 @@ where
 		}
 	}
 
-	fn send_warp_proof_request(&mut self, peer_id: PeerId, request: WarpProofRequest<B>) {
+	fn send_warp_proof_request(&mut self, peer_id: PeerId, key: Key, request: WarpProofRequest<B>) {
 		if !self.peers.contains_key(&peer_id) {
 			trace!(target: LOG_TARGET, "Cannot send warp proof request to unknown peer {peer_id}");
 			debug_assert!(false);
@@ -1222,7 +1210,7 @@ where
 
 		let (tx, rx) = oneshot::channel();
 
-		self.pending_responses.insert(peer_id, PeerRequest::WarpProof, rx.boxed());
+		self.pending_responses.insert(peer_id, key, PeerRequest::WarpProof, rx.boxed());
 
 		match &self.warp_sync_protocol_name {
 			Some(name) => self.network_service.start_request(
@@ -1259,14 +1247,14 @@ where
 	}
 
 	fn process_response_event(&mut self, response_event: ResponseEvent<B>) {
-		let ResponseEvent { peer_id, request, response } = response_event;
+		let ResponseEvent { peer_id, key, request, response } = response_event;
 
 		match response {
 			Ok(Ok((resp, _))) => match request {
 				PeerRequest::Block(req) => {
 					match self.block_downloader.block_response_into_blocks(&req, resp) {
 						Ok(blocks) => {
-							self.strategy.on_block_response(peer_id, req, blocks);
+							self.strategy.on_block_response(peer_id, key, req, blocks);
 						},
 						Err(BlockResponseError::DecodeFailed(e)) => {
 							debug!(
@@ -1311,10 +1299,10 @@ where
 						},
 					};
 
-					self.strategy.on_state_response(peer_id, response);
+					self.strategy.on_state_response(peer_id, key, response);
 				},
 				PeerRequest::WarpProof => {
-					self.strategy.on_warp_proof_response(&peer_id, EncodedProof(resp));
+					self.strategy.on_warp_proof_response(&peer_id, key, EncodedProof(resp));
 				},
 			},
 			Ok(Err(e)) => {

substrate/client/network/sync/src/extra_requests.rs → substrate/client/network/sync/src/justification_requests.rs

@@ -16,6 +16,10 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
+//! Justification requests scheduling. [`ExtraRequests`] manages requesting justifications
+//! from peers taking into account forks and their finalization (dropping pending requests
+//! that don't make sense after one of the forks is finalized).
+
 use crate::{
 	request_metrics::Metrics,
 	strategy::chain_sync::{PeerSync, PeerSyncState},

substrate/client/network/sync/src/lib.rs

@@ -23,8 +23,8 @@ pub use strategy::warp::{WarpSyncParams, WarpSyncPhase, WarpSyncProgress};
 pub use types::{SyncEvent, SyncEventStream, SyncState, SyncStatus, SyncStatusProvider};
 
 mod block_announce_validator;
-mod extra_requests;
 mod futures_stream;
+mod justification_requests;
 mod pending_responses;
 mod request_metrics;
 mod schema;

substrate/client/network/sync/src/pending_responses.rs

@@ -19,7 +19,7 @@
 //! [`PendingResponses`] is responsible for keeping track of pending responses and
 //! polling them. [`Stream`] implemented by [`PendingResponses`] never terminates.
 
-use crate::{types::PeerRequest, LOG_TARGET};
+use crate::{strategy::Key, types::PeerRequest, LOG_TARGET};
 use futures::{
 	channel::oneshot,
 	future::BoxFuture,
@@ -42,14 +42,16 @@ type ResponseFuture = BoxFuture<'static, ResponseResult>;
 /// An event we receive once a pending response future resolves.
 pub(crate) struct ResponseEvent<B: BlockT> {
 	pub peer_id: PeerId,
+	pub key: Key,
 	pub request: PeerRequest<B>,
 	pub response: ResponseResult,
 }
 
 /// Stream taking care of polling pending responses.
 pub(crate) struct PendingResponses<B: BlockT> {
 	/// Pending responses
-	pending_responses: StreamMap<PeerId, BoxStream<'static, (PeerRequest<B>, ResponseResult)>>,
+	pending_responses:
+		StreamMap<(PeerId, Key), BoxStream<'static, (PeerRequest<B>, ResponseResult)>>,
 	/// Waker to implement never terminating stream
 	waker: Option<Waker>,
 }
@@ -62,6 +64,7 @@ impl<B: BlockT> PendingResponses<B> {
 	pub fn insert(
 		&mut self,
 		peer_id: PeerId,
+		key: Key,
 		request: PeerRequest<B>,
 		response_future: ResponseFuture,
 	) {
@@ -70,7 +73,7 @@ impl<B: BlockT> PendingResponses<B> {
 		if self
 			.pending_responses
 			.insert(
-				peer_id,
+				(peer_id, key),
 				Box::pin(async move { (request, response_future.await) }.into_stream()),
 			)
 			.is_some()
@@ -87,8 +90,20 @@ impl<B: BlockT> PendingResponses<B> {
 		}
 	}
 
-	pub fn remove(&mut self, peer_id: &PeerId) -> bool {
-		self.pending_responses.remove(peer_id).is_some()
+	pub fn remove(&mut self, peer_id: PeerId, key: Key) -> bool {
+		self.pending_responses.remove(&(peer_id, key)).is_some()
+	}
+
+	pub fn remove_all(&mut self, peer_id: &PeerId) {
+		let to_remove = self
+			.pending_responses
+			.keys()
+			.filter(|(peer, _key)| peer == peer_id)
+			.cloned()
+			.collect::<Vec<_>>();
+		to_remove.iter().for_each(|k| {
+			self.pending_responses.remove(k);
+		});
 	}
 
 	pub fn len(&self) -> usize {
@@ -104,13 +119,13 @@ impl<B: BlockT> Stream for PendingResponses<B> {
 		cx: &mut Context<'_>,
 	) -> Poll<Option<Self::Item>> {
 		match self.pending_responses.poll_next_unpin(cx) {
-			Poll::Ready(Some((peer_id, (request, response)))) => {
+			Poll::Ready(Some(((peer_id, key), (request, response)))) => {
 				// We need to manually remove the stream, because `StreamMap` doesn't know yet that
 				// it's going to yield `None`, so may not remove it before the next request is made
 				// to the same peer.
-				self.pending_responses.remove(&peer_id);
+				self.pending_responses.remove(&(peer_id, key));
 
-				Poll::Ready(Some(ResponseEvent { peer_id, request, response }))
+				Poll::Ready(Some(ResponseEvent { peer_id, key, request, response }))
 			},
 			Poll::Ready(None) | Poll::Pending => {
 				self.waker = Some(cx.waker().clone());