some more refactoring

Author: rphmeier

Cargo.lock

@@ -26,7 +26,7 @@
 
 use codec::{Decode, Encode};
 use cumulus_client_collator::service::ServiceInterface as CollatorServiceInterface;
-use cumulus_client_consensus_common::{ParachainBlockImportMarker, ParachainCandidate};
+use cumulus_client_consensus_common::{self as consensus_common, ParachainBlockImportMarker, ParachainCandidate};
 use cumulus_client_consensus_proposer::ProposerInterface;
 use cumulus_primitives_core::{
 	relay_chain::Hash as PHash, DigestItem, ParachainBlockData, PersistedValidationData,
@@ -249,6 +249,22 @@ pub struct SlotClaim<Pub> {
 }
 
 impl<Pub> SlotClaim<Pub> {
+	/// Create a slot-claim from the given author public key, slot, and timestamp.
+	///
+	/// This does not check whether the author actually owns the slot or the timestamp
+	/// falls within the slot.
+	pub fn unchecked<P>(author_pub: Pub, slot: Slot, timestamp: Timestamp) -> Self where
+		P: Pair<Public = Pub>,
+		P::Public: Encode + Decode,
+		P::Signature: Encode + Decode
+	{
+		SlotClaim {
+			author_pub,
+			timestamp,
+			pre_digest: aura_internal::pre_digest::<P>(slot),
+		}
+	}
+
 	/// Get the author's public key.
 	pub fn author_pub(&self) -> &Pub {
 		&self.author_pub
@@ -287,17 +303,13 @@ where
 	let authorities = client.runtime_api().authorities(parent_hash).map_err(Box::new)?;
 
 	// Determine the current slot and timestamp based on the relay-parent's.
-	let (slot_now, timestamp) =
-		match sc_consensus_babe::find_pre_digest::<PBlock>(relay_parent_header) {
-			Ok(babe_pre_digest) => {
-				let t =
-					Timestamp::new(relay_chain_slot_duration.as_millis() * *babe_pre_digest.slot());
-				let slot = Slot::from_timestamp(t, slot_duration);
-
-				(slot, t)
-			},
-			Err(_) => return Ok(None),
-		};
+	let (slot_now, timestamp) = match consensus_common::relay_slot_and_timestamp(
+		relay_parent_header,
+		relay_chain_slot_duration,
+	) {
+		Some((_, t)) => (Slot::from_timestamp(t, slot_duration), t),
+		None => return Ok(None),
+	};
 
 	// Try to claim the slot locally.
 	let author_pub = {
@@ -308,10 +320,7 @@ where
 		}
 	};
 
-	// Produce the pre-digest.
-	let pre_digest = aura_internal::pre_digest::<P>(slot_now);
-
-	Ok(Some(SlotClaim { author_pub, pre_digest, timestamp }))
+	Ok(Some(SlotClaim::unchecked::<P>(author_pub, slot_now, timestamp)))
 }
 
 /// Seal a block with a signature in the header.

client/consensus/aura/src/collator.rs

@@ -72,6 +72,8 @@ use sp_state_machine::StorageChanges;
 use sp_timestamp::Timestamp;
 use std::{convert::TryFrom, error::Error, fmt::Debug, hash::Hash, sync::Arc, time::Duration};
 
+use crate::collator as collator_util;
+
 /// Parameters for [`run`].
 pub struct Params<BI, CIDP, Client, RClient, SO, Proposer, CS> {
 	pub create_inherent_data_providers: CIDP,
@@ -129,14 +131,26 @@ pub async fn run<Block, P, BI, CIDP, Client, RClient, SO, Proposer, CS>(
 		},
 	};
 
+	let mut collator = {
+		let params = collator_util::Params {
+			create_inherent_data_providers: params.create_inherent_data_providers,
+			block_import: params.block_import,
+			relay_client: params.relay_client.clone(),
+			keystore: params.keystore.clone(),
+			para_id: params.para_id,
+			proposer: params.proposer,
+			collator_service: params.collator_service,
+		};
+
+		collator_util::Collator::<Block, P, _, _, _, _, _>::new(params)
+	};
+
 	while let Some(relay_parent_header) = import_notifications.next().await {
 		let relay_parent = relay_parent_header.hash();
 
 		// TODO [now]: get asynchronous backing parameters from the relay-chain
 		// runtime. why?
 
-		// TOOD [now]: get slot from relay parent header
-
 		let parent_search_params = ParentSearchParams {
 			relay_parent,
 			para_id: params.para_id,

client/consensus/aura/src/collators/lookahead.rs

@@ -16,10 +16,13 @@ tracing = "0.1.37"
 # Substrate
 sc-client-api = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-consensus = { git = "https://github.com/paritytech/substrate", branch = "master" }
+sc-consensus-babe = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-blockchain = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-consensus = { git = "https://github.com/paritytech/substrate", branch = "master" }
+sp-consensus-slots = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-core = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-runtime = { git = "https://github.com/paritytech/substrate", branch = "master" }
+sp-timestamp = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-trie = { git = "https://github.com/paritytech/substrate", branch = "master" }
 substrate-prometheus-endpoint = { git = "https://github.com/paritytech/substrate", branch = "master" }
 

client/consensus/common/Cargo.toml

@@ -15,13 +15,15 @@
 // along with Cumulus.  If not, see <http://www.gnu.org/licenses/>.
 
 use codec::Decode;
-use polkadot_primitives::{Hash as PHash, PersistedValidationData};
+use polkadot_primitives::{Block as PBlock, Hash as PHash, Header as PHeader, PersistedValidationData};
 
 use cumulus_primitives_core::{relay_chain::OccupiedCoreAssumption, ParaId};
 use cumulus_relay_chain_interface::{RelayChainError, RelayChainInterface};
 
 use sc_client_api::Backend;
 use sc_consensus::{shared_data::SharedData, BlockImport, ImportResult};
+use sp_consensus_slots::{Slot, SlotDuration};
+use sp_timestamp::Timestamp;
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
 
 use std::sync::Arc;
@@ -350,3 +352,16 @@ pub async fn find_potential_parents<B: BlockT>(
 
 	Ok(potential_parents)
 }
+
+/// Get the relay-parent slot and timestamp from a header.
+pub fn relay_slot_and_timestamp(
+	relay_parent_header: &PHeader,
+	relay_chain_slot_duration: SlotDuration,
+) -> Option<(Slot, Timestamp)> {
+	sc_consensus_babe::find_pre_digest::<PBlock>(relay_parent_header).map(|babe_pre_digest| {
+		let slot = babe_pre_digest.slot();
+		let t = Timestamp::new(relay_chain_slot_duration.as_millis() * *slot);
+
+		(slot, t)
+	}).ok()
+}