Dispute distribution implementation (#3282)

* Dispute protocol.

* Dispute distribution protocol.

* Get network requests routed.

* WIP: Basic dispute sender logic.

* Basic validator determination logic.

* WIP: Getting things to typecheck.

* Slightly larger timeout.

* More typechecking stuff.

* Cleanup.

* Finished most of the sending logic.

* Handle active leaves updates

- Cleanup dead disputes
- Update sends for new sessions
- Retry on errors

* Pass sessions in already.

* Startup dispute sending.

* Provide incoming decoding facilities

and use them in statement-distribution.

* Relaxed runtime util requirements.

We only need a `SubsystemSender` not a full `SubsystemContext`.

* Better usability of incoming requests.

Make it possible to consume stuff without clones.

* Add basic receiver functionality.

* Cleanup + fixes for sender.

* One more sender fix.

* Start receiver.

* Make sure to send responses back.

* WIP: Exposed authority discovery

* Make tests pass.

* Fully featured receiver.

* Decrease cost of `NotAValidator`.

* Make `RuntimeInfo` LRU cache size configurable.

* Cache more sessions.

* Fix collator protocol.

* Disable metrics for now.

* Make dispute-distribution a proper subsystem.

* Fix naming.

* Code style fixes.

* Factored out 4x copied mock function.

* WIP: Tests.

* Whitespace cleanup.

* Accessor functions.

* More testing.

* More Debug instances.

* Fix busy loop.

* Working tests.

* More tests.

* Cleanup.

* Fix build.

* Basic receiving test.

* Non validator message gets dropped.

* More receiving tests.

* Test nested and subsequent imports.

* Fix spaces.

* Better formatted imports.

* Import cleanup.

* Metrics.

* Message -> MuxedMessage

* Message -> MuxedMessage

* More review remarks.

* Add missing metrics.rs.

* Fix flaky test.

* Dispute coordinator - deliver confirmations.

* Send out `DisputeMessage` on issue local statement.

* Unwire dispute distribution.

* Review remarks.

* Review remarks.

* Better docs.

polkadot/node/network/statement-distribution/src/error.rs

@@ -60,11 +60,11 @@ impl From<runtime::Error> for Error {
 #[derive(Debug, Error)]
 pub enum Fatal {
 	/// Requester channel is never closed.
-	#[error("Requester receiver stream finished.")]
+	#[error("Requester receiver stream finished")]
 	RequesterReceiverFinished,
 
 	/// Responder channel is never closed.
-	#[error("Responder receiver stream finished.")]
+	#[error("Responder receiver stream finished")]
 	ResponderReceiverFinished,
 
 	/// Spawning a running task failed.

polkadot/node/network/statement-distribution/src/lib.rs

@@ -580,7 +580,7 @@ struct FetchingInfo {
 }
 
 /// Messages to be handled in this subsystem.
-enum Message {
+enum MuxedMessage {
 	/// Messages from other subsystems.
 	Subsystem(FatalResult<FromOverseer<StatementDistributionMessage>>),
 	/// Messages from spawned requester background tasks.
@@ -589,12 +589,12 @@ enum Message {
 	Responder(Option<ResponderMessage>)
 }
 
-impl Message {
+impl MuxedMessage {
 	async fn receive(
 		ctx: &mut (impl SubsystemContext<Message = StatementDistributionMessage> + overseer::SubsystemContext<Message = StatementDistributionMessage>),
 		from_requester: &mut mpsc::Receiver<RequesterMessage>,
 		from_responder: &mut mpsc::Receiver<ResponderMessage>,
-	) -> Message {
+	) -> MuxedMessage {
 		// We are only fusing here to make `select` happy, in reality we will quit if one of those
 		// streams end:
 		let from_overseer = ctx.recv().fuse();
@@ -602,9 +602,9 @@ impl Message {
 		let from_responder = from_responder.next();
 		futures::pin_mut!(from_overseer, from_requester, from_responder);
 		futures::select! {
-			msg = from_overseer => Message::Subsystem(msg.map_err(Fatal::SubsystemReceive)),
-			msg = from_requester => Message::Requester(msg),
-			msg = from_responder => Message::Responder(msg),
+			msg = from_overseer => MuxedMessage::Subsystem(msg.map_err(Fatal::SubsystemReceive)),
+			msg = from_requester => MuxedMessage::Requester(msg),
+			msg = from_responder => MuxedMessage::Responder(msg),
 		}
 	}
 }
@@ -1614,9 +1614,9 @@ impl StatementDistribution {
 		let (res_sender, mut res_receiver) = mpsc::channel(1);
 
 		loop {
-			let message = Message::receive(&mut ctx, &mut req_receiver, &mut res_receiver).await;
+			let message = MuxedMessage::receive(&mut ctx, &mut req_receiver, &mut res_receiver).await;
 			match message {
-				Message::Subsystem(result) => {
+				MuxedMessage::Subsystem(result) => {
 					let result = self.handle_subsystem_message(
 						&mut ctx,
 						&mut runtime,
@@ -1637,7 +1637,7 @@ impl StatementDistribution {
 							tracing::debug!(target: LOG_TARGET, ?error)
 					}
 				}
-				Message::Requester(result) => {
+				MuxedMessage::Requester(result) => {
 					let result = self.handle_requester_message(
 						&mut ctx,
 						&gossip_peers,
@@ -1649,7 +1649,7 @@ impl StatementDistribution {
 					.await;
 					log_error(result.map_err(From::from), "handle_requester_message")?;
 				}
-				Message::Responder(result) => {
+				MuxedMessage::Responder(result) => {
 					let result = self.handle_responder_message(
 						&peers,
 						&mut active_heads,
@@ -1856,8 +1856,8 @@ impl StatementDistribution {
 						"New active leaf",
 					);
 
-					let session_index = runtime.get_session_index(ctx, relay_parent).await?;
-					let info = runtime.get_session_info_by_index(ctx, relay_parent, session_index).await?;
+					let session_index = runtime.get_session_index(ctx.sender(), relay_parent).await?;
+					let info = runtime.get_session_info_by_index(ctx.sender(), relay_parent, session_index).await?;
 					let session_info = &info.session_info;
 
 					active_heads.entry(relay_parent)
@@ -1899,7 +1899,7 @@ impl StatementDistribution {
 						}
 					}
 
-					let info = runtime.get_session_info(ctx, relay_parent).await?;
+					let info = runtime.get_session_info(ctx.sender(), relay_parent).await?;
 					let session_info = &info.session_info;
 					let validator_info = &info.validator_info;
 

polkadot/node/network/statement-distribution/src/responder.rs

@@ -16,8 +16,6 @@
 
 use futures::{SinkExt, StreamExt, channel::{mpsc, oneshot}, stream::FuturesUnordered};
 
-use parity_scale_codec::Decode;
-
 use polkadot_node_network_protocol::{
 	PeerId, UnifiedReputationChange as Rep,
 	request_response::{
@@ -85,35 +83,26 @@ pub async fn respond(
 			Some(v) => v,
 		};
 
-		let sc_network::config::IncomingRequest {
-			payload,
-			peer,
-			pending_response,
-		} = raw;
-
-		let payload = match StatementFetchingRequest::decode(&mut payload.as_ref()) {
+		let req =
+			match IncomingRequest::<StatementFetchingRequest>::try_from_raw(
+				raw,
+				vec![COST_INVALID_REQUEST],
+			) {
 			Err(err) => {
 				tracing::debug!(
 					target: LOG_TARGET,
 					?err,
 					"Decoding request failed"
 				);
-				report_peer(pending_response, COST_INVALID_REQUEST);
 				continue
 			}
 			Ok(payload) => payload,
 		};
 
-		let req = IncomingRequest::new(
-			peer,
-			payload,
-			pending_response
-		);
-
 		let (tx, rx) = oneshot::channel();
 		if let Err(err) = sender.feed(
 			ResponderMessage::GetData {
-				requesting_peer: peer,
+				requesting_peer: req.peer,
 				relay_parent: req.payload.relay_parent,
 				candidate_hash: req.payload.candidate_hash,
 				tx,
@@ -152,20 +141,3 @@ pub async fn respond(
 		}
 	}
 }
-
-/// Report peer who sent us a request.
-fn report_peer(
-	tx: oneshot::Sender<sc_network::config::OutgoingResponse>,
-	rep: Rep,
-) {
-	if let Err(_) = tx.send(sc_network::config::OutgoingResponse {
-		result: Err(()),
-		reputation_changes: vec![rep.into_base_rep()],
-		sent_feedback: None,
-	}) {
-		tracing::debug!(
-			target: LOG_TARGET,
-			"Reporting peer failed."
-		);
-	}
-}

polkadot/node/network/statement-distribution/src/tests.rs

@@ -18,6 +18,7 @@ use std::time::Duration;
 use std::sync::Arc;
 use std::iter::FromIterator as _;
 use parity_scale_codec::{Decode, Encode};
+use polkadot_node_subsystem_test_helpers::mock::make_ferdie_keystore;
 use super::*;
 use sp_keyring::Sr25519Keyring;
 use sp_application_crypto::{AppKey, sr25519::Pair, Pair as TraitPair};
@@ -1704,14 +1705,3 @@ fn make_session_info(validators: Vec<Pair>, groups: Vec<Vec<u32>>) -> SessionInf
 		needed_approvals: 0,
 	}
 }
-
-pub fn make_ferdie_keystore() -> SyncCryptoStorePtr {
-	let keystore: SyncCryptoStorePtr = Arc::new(LocalKeystore::in_memory());
-	SyncCryptoStore::sr25519_generate_new(
-		&*keystore,
-		ValidatorId::ID,
-		Some(&Sr25519Keyring::Ferdie.to_seed()),
-		)
-		.expect("Insert key into keystore");
-	keystore
-}