parachain-template: Simplify it (#3801)

Also while doing this, move slot duration fetching into the AURA code.

cumulus/client/consensus/aura/src/collators/basic.rs

@@ -42,7 +42,7 @@ use sp_api::{CallApiAt, ProvideRuntimeApi};
 use sp_application_crypto::AppPublic;
 use sp_blockchain::HeaderBackend;
 use sp_consensus::SyncOracle;
-use sp_consensus_aura::{AuraApi, SlotDuration};
+use sp_consensus_aura::AuraApi;
 use sp_core::crypto::Pair;
 use sp_inherents::CreateInherentDataProviders;
 use sp_keystore::KeystorePtr;
@@ -74,8 +74,6 @@ pub struct Params<BI, CIDP, Client, RClient, SO, Proposer, CS> {
 	pub para_id: ParaId,
 	/// A handle to the relay-chain client's "Overseer" or task orchestrator.
 	pub overseer_handle: OverseerHandle,
-	/// The length of slots in this chain.
-	pub slot_duration: SlotDuration,
 	/// The length of slots in the relay chain.
 	pub relay_chain_slot_duration: Duration,
 	/// The underlying block proposer this should call into.
@@ -197,11 +195,16 @@ where
 					Ok(Some(h)) => h,
 				};
 
+			let slot_duration = match params.para_client.runtime_api().slot_duration(parent_hash) {
+				Ok(d) => d,
+				Err(e) => reject_with_error!(e),
+			};
+
 			let claim = match collator_util::claim_slot::<_, _, P>(
 				&*params.para_client,
 				parent_hash,
 				&relay_parent_header,
-				params.slot_duration,
+				slot_duration,
 				params.relay_chain_slot_duration,
 				&params.keystore,
 			)

cumulus/client/consensus/aura/src/equivocation_import_queue.rs

@@ -70,7 +70,6 @@ impl NaiveEquivocationDefender {
 struct Verifier<P, Client, Block, CIDP> {
 	client: Arc<Client>,
 	create_inherent_data_providers: CIDP,
-	slot_duration: SlotDuration,
 	defender: NaiveEquivocationDefender,
 	telemetry: Option<TelemetryHandle>,
 	_phantom: std::marker::PhantomData<fn() -> (Block, P)>,
@@ -110,7 +109,13 @@ where
 				format!("Could not fetch authorities at {:?}: {}", parent_hash, e)
 			})?;
 
-			let slot_now = slot_now(self.slot_duration);
+			let slot_duration = self
+				.client
+				.runtime_api()
+				.slot_duration(parent_hash)
+				.map_err(|e| e.to_string())?;
+
+			let slot_now = slot_now(slot_duration);
 			let res = aura_internal::check_header_slot_and_seal::<Block, P>(
 				slot_now,
 				block_params.header,
@@ -218,7 +223,6 @@ pub fn fully_verifying_import_queue<P, Client, Block: BlockT, I, CIDP>(
 	client: Arc<Client>,
 	block_import: I,
 	create_inherent_data_providers: CIDP,
-	slot_duration: SlotDuration,
 	spawner: &impl sp_core::traits::SpawnEssentialNamed,
 	registry: Option<&substrate_prometheus_endpoint::Registry>,
 	telemetry: Option<TelemetryHandle>,
@@ -240,7 +244,6 @@ where
 		client,
 		create_inherent_data_providers,
 		defender: NaiveEquivocationDefender::default(),
-		slot_duration,
 		telemetry,
 		_phantom: std::marker::PhantomData,
 	};