Request based collation fetching (#2621)

* Introduce collation fetching protocol

also move to mod.rs

* Allow `PeerId`s in requests to network bridge.

* Fix availability distribution tests.

* Move CompressedPoV to primitives.

* Request based collator protocol: validator side

- Missing: tests
- Collator side
- don't connect, if not connected

* Fixes.

* Basic request based collator side.

* Minor fix on collator side.

* Don't connect in requests in collation protocol.

Also some cleanup.

* Fix PoV distribution

* Bump substrate

* Add back metrics + whitespace fixes.

* Add back missing spans.

* More cleanup.

* Guide update.

* Fix tests

* Handle results in tests.

* Fix weird compilation issue.

* Add missing )

* Get rid of dead code.

* Get rid of redundant import.

* Fix runtime build.

* Cleanup.

* Fix wasm build.

* Format fixes.

Thanks @andronik !

polkadot/node/network/bridge/src/action.rs

@@ -24,7 +24,7 @@ use polkadot_node_network_protocol::{
 use polkadot_primitives::v1::{AuthorityDiscoveryId, BlockNumber};
 use polkadot_subsystem::messages::{AllMessages, NetworkBridgeMessage};
 use polkadot_subsystem::{ActiveLeavesUpdate, FromOverseer, OverseerSignal};
-use sc_network::Event as NetworkEvent;
+use sc_network::{Event as NetworkEvent, IfDisconnected};
 
 use polkadot_node_network_protocol::{request_response::Requests, ObservedRole};
 
@@ -45,7 +45,7 @@ pub(crate) enum Action {
 	SendCollationMessages(Vec<(Vec<PeerId>, protocol_v1::CollationProtocol)>),
 
 	/// Ask network to send requests.
-	SendRequests(Vec<Requests>),
+	SendRequests(Vec<Requests>, IfDisconnected),
 
 	/// Ask network to connect to validators.
 	ConnectToValidators {
@@ -125,7 +125,7 @@ impl From<polkadot_subsystem::SubsystemResult<FromOverseer<NetworkBridgeMessage>
 				NetworkBridgeMessage::SendCollationMessage(peers, msg) => {
 					Action::SendCollationMessages(vec![(peers, msg)])
 				}
-				NetworkBridgeMessage::SendRequests(reqs) => Action::SendRequests(reqs),
+				NetworkBridgeMessage::SendRequests(reqs, if_disconnected) => Action::SendRequests(reqs, if_disconnected),
 				NetworkBridgeMessage::SendValidationMessages(msgs) => {
 					Action::SendValidationMessages(msgs)
 				}

polkadot/node/network/bridge/src/lib.rs

@@ -235,11 +235,11 @@ where
 				}
 			}
 
-			Action::SendRequests(reqs) => {
+			Action::SendRequests(reqs, if_disconnected) => {
 				for req in reqs {
 					bridge
 						.network_service
-						.start_request(&mut bridge.authority_discovery_service, req)
+						.start_request(&mut bridge.authority_discovery_service, req, if_disconnected)
 						.await;
 				}
 			},
@@ -604,7 +604,7 @@ mod tests {
 	use parking_lot::Mutex;
 	use assert_matches::assert_matches;
 
-	use sc_network::Event as NetworkEvent;
+	use sc_network::{Event as NetworkEvent, IfDisconnected};
 
 	use polkadot_subsystem::{ActiveLeavesUpdate, FromOverseer, OverseerSignal};
 	use polkadot_subsystem::messages::{
@@ -681,7 +681,7 @@ mod tests {
 			Box::pin((&mut self.action_tx).sink_map_err(Into::into))
 		}
 
-		async fn start_request<AD: AuthorityDiscovery>(&self, _: &mut AD, _: Requests) {
+		async fn start_request<AD: AuthorityDiscovery>(&self, _: &mut AD, _: Requests, _: IfDisconnected) {
 		}
 	}
 

polkadot/node/network/bridge/src/multiplexer.rs

@@ -136,6 +136,11 @@ fn multiplex_single(
 			decode_with_peer::<v1::AvailabilityFetchingRequest>(peer, payload)?,
 			pending_response,
 		)),
+		Protocol::CollationFetching => From::from(IncomingRequest::new(
+			peer,
+			decode_with_peer::<v1::CollationFetchingRequest>(peer, payload)?,
+			pending_response,
+		)),
 	};
 	Ok(r)
 }

polkadot/node/network/bridge/src/network.rs

@@ -29,7 +29,7 @@ use sc_network::{IfDisconnected, NetworkService, OutboundFailure, RequestFailure
 
 use polkadot_node_network_protocol::{
 	peer_set::PeerSet,
-	request_response::{OutgoingRequest, Requests},
+	request_response::{OutgoingRequest, Requests, Recipient},
 	PeerId, UnifiedReputationChange as Rep,
 };
 use polkadot_primitives::v1::{Block, Hash};
@@ -113,6 +113,7 @@ pub trait Network: Send + 'static {
 		&self,
 		authority_discovery: &mut AD,
 		req: Requests,
+		if_disconnected: IfDisconnected,
 	);
 
 	/// Report a given peer as either beneficial (+) or costly (-) according to the given scalar.
@@ -202,6 +203,7 @@ impl Network for Arc<NetworkService<Block, Hash>> {
 		&self,
 		authority_discovery: &mut AD,
 		req: Requests,
+		if_disconnected: IfDisconnected,
 	) {
 		let (
 			protocol,
@@ -212,14 +214,18 @@ impl Network for Arc<NetworkService<Block, Hash>> {
 			},
 		) = req.encode_request();
 
-		let peer_id = authority_discovery
-			.get_addresses_by_authority_id(peer)
-			.await
-			.and_then(|addrs| {
-				addrs
-					.into_iter()
-					.find_map(|addr| peer_id_from_multiaddr(&addr))
-			});
+		let peer_id = match peer {
+			Recipient::Peer(peer_id) =>  Some(peer_id),
+			Recipient::Authority(authority) =>
+				authority_discovery
+				.get_addresses_by_authority_id(authority)
+				.await
+				.and_then(|addrs| {
+					addrs
+						.into_iter()
+						.find_map(|addr| peer_id_from_multiaddr(&addr))
+				}),
+			};
 
 		let peer_id = match peer_id {
 			None => {
@@ -244,7 +250,7 @@ impl Network for Arc<NetworkService<Block, Hash>> {
 			protocol.into_protocol_name(),
 			payload,
 			pending_response,
-			IfDisconnected::TryConnect,
+			if_disconnected,
 		);
 	}
 }