BabeApi functions return a StandaloneEpoch

bin/node/runtime/src/lib.rs

@@ -1205,11 +1205,11 @@ impl_runtime_apis! {
 			Babe::current_epoch_start()
 		}
 
-		fn current_epoch() -> sp_consensus_babe::Epoch {
+		fn current_epoch() -> sp_consensus_babe::StandaloneEpoch {
 			Babe::current_epoch()
 		}
 
-		fn next_epoch() -> sp_consensus_babe::Epoch {
+		fn next_epoch() -> sp_consensus_babe::StandaloneEpoch {
 			Babe::next_epoch()
 		}
 

frame/babe/src/lib.rs

@@ -43,7 +43,8 @@ use sp_timestamp::OnTimestampSet;
 use sp_consensus_babe::{
 	digests::{NextConfigDescriptor, NextEpochDescriptor, PreDigest},
 	inherents::{BabeInherentData, INHERENT_IDENTIFIER},
-	BabeAuthorityWeight, ConsensusLog, Epoch, EquivocationProof, Slot, BABE_ENGINE_ID,
+	BabeAuthorityWeight, ConsensusLog, EquivocationProof, Slot, BABE_ENGINE_ID, StandaloneEpoch,
+	BabeEpochConfiguration,
 };
 use sp_consensus_vrf::schnorrkel;
 use sp_inherents::{InherentData, InherentIdentifier, MakeFatalError, ProvideInherent};
@@ -188,6 +189,9 @@ decl_storage! {
 		// variable to its underlying value.
 		pub Randomness get(fn randomness): schnorrkel::Randomness;
 
+		/// The Current epoch configuration.
+		EpochConfig: Option<BabeEpochConfiguration>;
+
 		/// Next epoch configuration, if changed.
 		NextEpochConfig: Option<NextConfigDescriptor>;
 
@@ -486,6 +490,8 @@ impl<T: Config> Module<T> {
 		Self::deposit_consensus(ConsensusLog::NextEpochData(next_epoch));
 
 		if let Some(next_config) = NextEpochConfig::take() {
+			let config: BabeEpochConfiguration = next_config.clone().into();
+			EpochConfig::put(config);
 			Self::deposit_consensus(ConsensusLog::NextConfigData(next_config));
 		}
 	}
@@ -498,30 +504,38 @@ impl<T: Config> Module<T> {
 	}
 
 	/// Produces information about the current epoch.
-	pub fn current_epoch() -> Epoch {
-		Epoch {
+	pub fn current_epoch() -> StandaloneEpoch {
+		let epoch_config = EpochConfig::get().unwrap();
+
+		StandaloneEpoch {
 			epoch_index: EpochIndex::get(),
 			start_slot: Self::current_epoch_start(),
 			duration: T::EpochDuration::get(),
 			authorities: Self::authorities(),
 			randomness: Self::randomness(),
+			c: epoch_config.c,
+			allowed_slots: epoch_config.allowed_slots,
 		}
 	}
 
 	/// Produces information about the next epoch (which was already previously
 	/// announced).
-	pub fn next_epoch() -> Epoch {
+	pub fn next_epoch() -> StandaloneEpoch {
 		let next_epoch_index = EpochIndex::get().checked_add(1).expect(
 			"epoch index is u64; it is always only incremented by one; \
 			 if u64 is not enough we should crash for safety; qed.",
 		);
 
-		Epoch {
+		let epoch_config = EpochConfig::get().unwrap();
+
+		StandaloneEpoch {
 			epoch_index: next_epoch_index,
 			start_slot: Self::epoch_start(next_epoch_index),
 			duration: T::EpochDuration::get(),
 			authorities: NextAuthorities::get(),
 			randomness: NextRandomness::get(),
+			c: epoch_config.c,
+			allowed_slots: epoch_config.allowed_slots,
 		}
 	}
 

primitives/consensus/babe/src/lib.rs

@@ -364,6 +364,31 @@ pub struct Epoch {
 	pub randomness: [u8; VRF_OUTPUT_LENGTH],
 }
 
+/// BABE epoch information with `c` and `allowed_slots`
+#[derive(Decode, Encode, PartialEq, Eq, Clone, Debug)]
+pub struct StandaloneEpoch {
+	/// The epoch index.
+	pub epoch_index: u64,
+	/// The starting slot of the epoch.
+	pub start_slot: Slot,
+	/// The duration of this epoch.
+	pub duration: u64,
+	/// The authorities and their weights.
+	pub authorities: Vec<(AuthorityId, BabeAuthorityWeight)>,
+	/// Randomness for this epoch.
+	pub randomness: [u8; VRF_OUTPUT_LENGTH],
+	/// A constant value that is used in the threshold calculation formula.
+	/// Expressed as a rational where the first member of the tuple is the
+	/// numerator and the second is the denominator. The rational should
+	/// represent a value between 0 and 1.
+	/// In the threshold formula calculation, `1 - c` represents the probability
+	/// of a slot being empty.
+	pub c: (u64, u64),
+	/// Whether this chain should run with secondary slots, which are assigned
+	/// in round-robin manner.
+	pub allowed_slots: AllowedSlots,
+}
+
 sp_api::decl_runtime_apis! {
 	/// API necessary for block authorship with BABE.
 	#[api_version(2)]
@@ -379,11 +404,11 @@ sp_api::decl_runtime_apis! {
 		fn current_epoch_start() -> Slot;
 
 		/// Returns information regarding the current epoch.
-		fn current_epoch() -> Epoch;
+		fn current_epoch() -> StandaloneEpoch;
 
 		/// Returns information regarding the next epoch (which was already
 		/// previously announced).
-		fn next_epoch() -> Epoch;
+		fn next_epoch() -> StandaloneEpoch;
 
 		/// Generates a proof of key ownership for the given authority in the
 		/// current epoch. An example usage of this module is coupled with the

test-utils/runtime/src/lib.rs

@@ -743,11 +743,11 @@ cfg_if! {
 					<pallet_babe::Module<Runtime>>::current_epoch_start()
 				}
 
-				fn current_epoch() -> sp_consensus_babe::Epoch {
+				fn current_epoch() -> sp_consensus_babe::StandaloneEpoch {
 					<pallet_babe::Module<Runtime>>::current_epoch()
 				}
 
-				fn next_epoch() -> sp_consensus_babe::Epoch {
+				fn next_epoch() -> sp_consensus_babe::StandaloneEpoch {
 					<pallet_babe::Module<Runtime>>::next_epoch()
 				}
 
@@ -1002,11 +1002,11 @@ cfg_if! {
 					<pallet_babe::Module<Runtime>>::current_epoch_start()
 				}
 
-				fn current_epoch() -> sp_consensus_babe::Epoch {
+				fn current_epoch() -> sp_consensus_babe::StandaloneEpoch {
 					<pallet_babe::Module<Runtime>>::current_epoch()
 				}
 
-				fn next_epoch() -> sp_consensus_babe::Epoch {
+				fn next_epoch() -> sp_consensus_babe::StandaloneEpoch {
 					<pallet_babe::Module<Runtime>>::next_epoch()
 				}