Disabled validators runtime API (#1257)

Exposes disabled validators list via a runtime API.

---------

Co-authored-by: ordian <noreply@reusable.software>
Co-authored-by: ordian <write@reusable.software>

polkadot/node/core/runtime-api/src/cache.rs

@@ -64,6 +64,7 @@ pub(crate) struct RequestResultCache {
 	unapplied_slashes: LruMap<Hash, Vec<(SessionIndex, CandidateHash, slashing::PendingSlashes)>>,
 	key_ownership_proof: LruMap<(Hash, ValidatorId), Option<slashing::OpaqueKeyOwnershipProof>>,
 	minimum_backing_votes: LruMap<SessionIndex, u32>,
+	disabled_validators: LruMap<Hash, Vec<ValidatorIndex>>,
 	para_backing_state: LruMap<(Hash, ParaId), Option<async_backing::BackingState>>,
 	async_backing_params: LruMap<Hash, async_backing::AsyncBackingParams>,
 }
@@ -96,6 +97,7 @@ impl Default for RequestResultCache {
 			unapplied_slashes: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 			key_ownership_proof: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 			minimum_backing_votes: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
+			disabled_validators: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 			para_backing_state: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 			async_backing_params: LruMap::new(ByLength::new(DEFAULT_CACHE_CAP)),
 		}
@@ -444,6 +446,21 @@ impl RequestResultCache {
 		self.minimum_backing_votes.insert(session_index, minimum_backing_votes);
 	}
 
+	pub(crate) fn disabled_validators(
+		&mut self,
+		relay_parent: &Hash,
+	) -> Option<&Vec<ValidatorIndex>> {
+		self.disabled_validators.get(relay_parent).map(|v| &*v)
+	}
+
+	pub(crate) fn cache_disabled_validators(
+		&mut self,
+		relay_parent: Hash,
+		disabled_validators: Vec<ValidatorIndex>,
+	) {
+		self.disabled_validators.insert(relay_parent, disabled_validators);
+	}
+
 	pub(crate) fn para_backing_state(
 		&mut self,
 		key: (Hash, ParaId),
@@ -520,6 +537,7 @@ pub(crate) enum RequestResult {
 		slashing::OpaqueKeyOwnershipProof,
 		Option<()>,
 	),
+	DisabledValidators(Hash, Vec<ValidatorIndex>),
 	ParaBackingState(Hash, ParaId, Option<async_backing::BackingState>),
 	AsyncBackingParams(Hash, async_backing::AsyncBackingParams),
 }

polkadot/node/core/runtime-api/src/lib.rs

@@ -166,6 +166,8 @@ where
 				.requests_cache
 				.cache_key_ownership_proof((relay_parent, validator_id), key_ownership_proof),
 			SubmitReportDisputeLost(_, _, _, _) => {},
+			DisabledValidators(relay_parent, disabled_validators) =>
+				self.requests_cache.cache_disabled_validators(relay_parent, disabled_validators),
 			ParaBackingState(relay_parent, para_id, constraints) => self
 				.requests_cache
 				.cache_para_backing_state((relay_parent, para_id), constraints),
@@ -296,6 +298,8 @@ where
 						Request::SubmitReportDisputeLost(dispute_proof, key_ownership_proof, sender)
 					},
 				),
+			Request::DisabledValidators(sender) => query!(disabled_validators(), sender)
+				.map(|sender| Request::DisabledValidators(sender)),
 			Request::ParaBackingState(para, sender) => query!(para_backing_state(para), sender)
 				.map(|sender| Request::ParaBackingState(para, sender)),
 			Request::AsyncBackingParams(sender) => query!(async_backing_params(), sender)
@@ -565,6 +569,12 @@ where
 			ver = Request::MINIMUM_BACKING_VOTES_RUNTIME_REQUIREMENT,
 			sender
 		),
+		Request::DisabledValidators(sender) => query!(
+			DisabledValidators,
+			disabled_validators(),
+			ver = Request::DISABLED_VALIDATORS_RUNTIME_REQUIREMENT,
+			sender
+		),
 		Request::ParaBackingState(para, sender) => {
 			query!(
 				ParaBackingState,

polkadot/node/core/runtime-api/src/tests.rs

@@ -268,6 +268,10 @@ impl RuntimeApiSubsystemClient for MockSubsystemClient {
 	async fn minimum_backing_votes(&self, _: Hash, _: SessionIndex) -> Result<u32, ApiError> {
 		todo!("Not required for tests")
 	}
+
+	async fn disabled_validators(&self, _: Hash) -> Result<Vec<ValidatorIndex>, ApiError> {
+		todo!("Not required for tests")
+	}
 }
 
 #[test]