Distribute a PoV after seconding it (#1924)

We need to distribute the PoV after we have seconded it. Other nodes
that will receive our `Secondded` statement and want to validate the
candidate another time will request this PoV from us.

polkadot/node/collation-generation/src/lib.rs

@@ -318,7 +318,7 @@ fn erasure_root(
 ) -> crate::error::Result<Hash> {
 	let available_data = AvailableData {
 		validation_data: persisted_validation,
-		pov,
+		pov: Arc::new(pov),
 	};
 
 	let chunks = polkadot_erasure_coding::obtain_chunks_v1(n_validators, &available_data)?;

polkadot/node/core/av-store/src/tests.rs

@@ -282,7 +282,7 @@ fn store_block_works() {
 		};
 
 		let available_data = AvailableData {
-			pov,
+			pov: Arc::new(pov),
 			validation_data: test_state.persisted_validation_data,
 		};
 
@@ -335,7 +335,7 @@ fn store_pov_and_query_chunk_works() {
 		};
 
 		let available_data = AvailableData {
-			pov,
+			pov: Arc::new(pov),
 			validation_data: test_state.persisted_validation_data,
 		};
 
@@ -433,7 +433,7 @@ fn stored_but_not_included_data_is_pruned() {
 		};
 
 		let available_data = AvailableData {
-			pov,
+			pov: Arc::new(pov),
 			validation_data: test_state.persisted_validation_data,
 		};
 
@@ -487,7 +487,7 @@ fn stored_data_kept_until_finalized() {
 		let candidate_hash = candidate.hash();
 
 		let available_data = AvailableData {
-			pov,
+			pov: Arc::new(pov),
 			validation_data: test_state.persisted_validation_data,
 		};
 
@@ -726,12 +726,12 @@ fn forkfullness_works() {
 		let candidate_2_hash = candidate_2.hash();
 
 		let available_data_1 = AvailableData {
-			pov: pov_1,
+			pov: Arc::new(pov_1),
 			validation_data: test_state.persisted_validation_data.clone(),
 		};
 
 		let available_data_2 = AvailableData {
-			pov: pov_2,
+			pov: Arc::new(pov_2),
 			validation_data: test_state.persisted_validation_data,
 		};
 

polkadot/node/core/backing/src/lib.rs

@@ -24,10 +24,7 @@ use std::pin::Pin;
 use std::sync::Arc;
 
 use bitvec::vec::BitVec;
-use futures::{
-	channel::{mpsc, oneshot},
-	Future, FutureExt, SinkExt, StreamExt,
-};
+use futures::{channel::{mpsc, oneshot}, Future, FutureExt, SinkExt, StreamExt};
 
 use sp_keystore::SyncCryptoStorePtr;
 use polkadot_primitives::v1::{
@@ -314,7 +311,7 @@ impl CandidateBackingJob {
 	async fn validate_and_second(
 		&mut self,
 		candidate: &CandidateReceipt,
-		pov: PoV,
+		pov: Arc<PoV>,
 	) -> Result<bool, Error> {
 		// Check that candidate is collated by the right collator.
 		if self.required_collator.as_ref()
@@ -326,7 +323,7 @@ impl CandidateBackingJob {
 
 		let valid = self.request_candidate_validation(
 			candidate.descriptor().clone(),
-			Arc::new(pov.clone()),
+			pov.clone(),
 		).await?;
 
 		let candidate_hash = candidate.hash();
@@ -491,14 +488,16 @@ impl CandidateBackingJob {
 				if self.seconded.is_none() {
 					// This job has not seconded a candidate yet.
 					let candidate_hash = candidate.hash();
+					let pov = Arc::new(pov);
 
 					if !self.issued_statements.contains(&candidate_hash) {
 						if let Ok(true) = self.validate_and_second(
 							&candidate,
-							pov,
+							pov.clone(),
 						).await {
 							self.metrics.on_candidate_seconded();
 							self.seconded = Some(candidate_hash);
+							self.distribute_pov(candidate.descriptor, pov).await?;
 						}
 					}
 				}
@@ -559,7 +558,7 @@ impl CandidateBackingJob {
 			ValidationResult::Valid(outputs, validation_data) => {
 				// If validation produces a new set of commitments, we vote the candidate as invalid.
 				let commitments_check = self.make_pov_available(
-					(&*pov).clone(),
+					pov,
 					candidate_hash,
 					validation_data,
 					outputs,
@@ -633,6 +632,16 @@ impl CandidateBackingJob {
 		Ok(())
 	}
 
+	async fn distribute_pov(
+		&mut self,
+		descriptor: CandidateDescriptor,
+		pov: Arc<PoV>,
+	) -> Result<(), Error> {
+		self.tx_from.send(FromJob::PoVDistribution(
+			PoVDistributionMessage::DistributePoV(self.parent, descriptor, pov),
+		)).await.map_err(Into::into)
+	}
+
 	async fn request_pov_from_distribution(
 		&mut self,
 		descriptor: CandidateDescriptor,
@@ -696,7 +705,7 @@ impl CandidateBackingJob {
 	// early without making the PoV available.
 	async fn make_pov_available<T, E>(
 		&mut self,
-		pov: PoV,
+		pov: Arc<PoV>,
 		candidate_hash: CandidateHash,
 		validation_data: polkadot_primitives::v1::PersistedValidationData,
 		outputs: ValidationOutputs,
@@ -1068,7 +1077,7 @@ mod tests {
 	fn make_erasure_root(test: &TestState, pov: PoV) -> Hash {
 		let available_data = AvailableData {
 			validation_data: test.validation_data.persisted.clone(),
-			pov,
+			pov: Arc::new(pov),
 		};
 
 		let chunks = erasure_coding::obtain_chunks_v1(test.validators.len(), &available_data).unwrap();
@@ -1232,6 +1241,15 @@ mod tests {
 				}
 			);
 
+			assert_matches!(
+				virtual_overseer.recv().await,
+				AllMessages::PoVDistribution(PoVDistributionMessage::DistributePoV(hash, descriptor, pov_received)) => {
+					assert_eq!(test_state.relay_parent, hash);
+					assert_eq!(candidate.descriptor, descriptor);
+					assert_eq!(pov, *pov_received);
+				}
+			);
+
 			virtual_overseer.send(FromOverseer::Signal(
 				OverseerSignal::ActiveLeaves(ActiveLeavesUpdate::stop_work(test_state.relay_parent)))
 			).await;

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

@@ -23,7 +23,7 @@ use polkadot_primitives::v1::{
 	AvailableData, BlockData, CandidateCommitments, CandidateDescriptor, GroupIndex,
 	GroupRotationInfo, HeadData, OccupiedCore, PersistedValidationData, PoV, ScheduledCore,
 };
-use polkadot_subsystem_testhelpers::{self as test_helpers};
+use polkadot_subsystem_testhelpers as test_helpers;
 
 use futures::{executor, future, Future};
 use futures_timer::Delay;
@@ -241,7 +241,7 @@ impl Default for TestState {
 fn make_available_data(test: &TestState, pov: PoV) -> AvailableData {
 	AvailableData {
 		validation_data: test.persisted_validation_data.clone(),
-		pov,
+		pov: Arc::new(pov),
 	}
 }
 

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

@@ -30,12 +30,8 @@ use polkadot_subsystem::{
 		PoVDistributionMessage, RuntimeApiMessage, RuntimeApiRequest, AllMessages, NetworkBridgeMessage,
 	},
 };
-use polkadot_node_subsystem_util::{
-	metrics::{self, prometheus},
-};
-use polkadot_node_network_protocol::{
-	v1 as protocol_v1, ReputationChange as Rep, NetworkBridgeEvent, PeerId, View,
-};
+use polkadot_node_subsystem_util::metrics::{self, prometheus};
+use polkadot_node_network_protocol::{v1 as protocol_v1, ReputationChange as Rep, NetworkBridgeEvent, PeerId, View};
 
 use futures::prelude::*;
 use futures::channel::oneshot;
@@ -43,6 +39,9 @@ use futures::channel::oneshot;
 use std::collections::{hash_map::{Entry, HashMap}, HashSet};
 use std::sync::Arc;
 
+#[cfg(test)]
+mod tests;
+
 const COST_APPARENT_FLOOD: Rep = Rep::new(-500, "Peer appears to be flooding us with PoV requests");
 const COST_UNEXPECTED_POV: Rep = Rep::new(-500, "Peer sent us an unexpected PoV");
 const COST_AWAITED_NOT_IN_VIEW: Rep
@@ -616,6 +615,3 @@ impl metrics::Metrics for Metrics {
 		Ok(Metrics(Some(metrics)))
 	}
 }
-
-#[cfg(test)]
-mod tests;