Avoid duplicate function definitions

Avoid duplicate function definitions for:
- ensure_owner_or_root()
- ensure_not_halted()
- set_owner()
- set_operating_mode() / set_operational()

Signed-off-by: Serban Iorga <serban@parity.io>

bridges/modules/grandpa/src/lib.rs

@@ -37,12 +37,12 @@
 #![allow(clippy::large_enum_variant)]
 
 use bp_header_chain::{justification::GrandpaJustification, InitializationData};
-use bp_runtime::{BlockNumberOf, Chain, HashOf, HasherOf, HeaderOf};
+use bp_runtime::{BlockNumberOf, Chain, HashOf, HasherOf, HeaderOf, OwnedBridgeModule};
 use finality_grandpa::voter_set::VoterSet;
 use frame_support::{ensure, fail};
-use frame_system::{ensure_signed, RawOrigin};
+use frame_system::ensure_signed;
 use sp_finality_grandpa::{ConsensusLog, GRANDPA_ENGINE_ID};
-use sp_runtime::traits::{BadOrigin, Header as HeaderT, Zero};
+use sp_runtime::traits::{Header as HeaderT, Zero};
 use sp_std::{boxed::Box, convert::TryInto};
 
 mod extension;
@@ -117,6 +117,18 @@ pub mod pallet {
 		}
 	}
 
+	impl<T: Config<I>, I: 'static> OwnedBridgeModule<T> for Pallet<T, I> {
+		const LOG_TARGET: &'static str = "runtime::bridge-grandpa";
+		const OPERATING_MODE_KEY: &'static str = "IsHalted";
+		type OwnerStorage = PalletOwner<T, I>;
+		type OperatingMode = bool;
+		type OperatingModeStorage = IsHalted<T, I>;
+
+		fn is_halted() -> bool {
+			Self::OperatingModeStorage::get()
+		}
+	}
+
 	#[pallet::call]
 	impl<T: Config<I>, I: 'static> Pallet<T, I> {
 		/// Verify a target header is finalized according to the given finality proof.
@@ -135,7 +147,7 @@ pub mod pallet {
 			finality_target: Box<BridgedHeader<T, I>>,
 			justification: GrandpaJustification<BridgedHeader<T, I>>,
 		) -> DispatchResultWithPostInfo {
-			ensure_operational::<T, I>()?;
+			Self::ensure_not_halted().map_err(Error::<T, I>::BridgeModule)?;
 			let _ = ensure_signed(origin)?;
 
 			ensure!(Self::request_count() < T::MaxRequests::get(), <Error<T, I>>::TooManyRequests);
@@ -198,7 +210,7 @@ pub mod pallet {
 			origin: OriginFor<T>,
 			init_data: super::InitializationData<BridgedHeader<T, I>>,
 		) -> DispatchResultWithPostInfo {
-			ensure_owner_or_root::<T, I>(origin)?;
+			Self::ensure_owner_or_root(origin)?;
 
 			let init_allowed = !<BestFinalized<T, I>>::exists();
 			ensure!(init_allowed, <Error<T, I>>::AlreadyInitialized);
@@ -217,43 +229,16 @@ pub mod pallet {
 		///
 		/// May only be called either by root, or by `PalletOwner`.
 		#[pallet::weight((T::DbWeight::get().reads_writes(1, 1), DispatchClass::Operational))]
-		pub fn set_owner(
-			origin: OriginFor<T>,
-			new_owner: Option<T::AccountId>,
-		) -> DispatchResultWithPostInfo {
-			ensure_owner_or_root::<T, I>(origin)?;
-			match new_owner {
-				Some(new_owner) => {
-					PalletOwner::<T, I>::put(&new_owner);
-					log::info!(target: "runtime::bridge-grandpa", "Setting pallet Owner to: {:?}", new_owner);
-				},
-				None => {
-					PalletOwner::<T, I>::kill();
-					log::info!(target: "runtime::bridge-grandpa", "Removed Owner of pallet.");
-				},
-			}
-
-			Ok(().into())
+		pub fn set_owner(origin: OriginFor<T>, new_owner: Option<T::AccountId>) -> DispatchResult {
+			<Self as OwnedBridgeModule<_>>::set_owner(origin, new_owner)
 		}
 
 		/// Halt or resume all pallet operations.
 		///
 		/// May only be called either by root, or by `PalletOwner`.
 		#[pallet::weight((T::DbWeight::get().reads_writes(1, 1), DispatchClass::Operational))]
-		pub fn set_operational(
-			origin: OriginFor<T>,
-			operational: bool,
-		) -> DispatchResultWithPostInfo {
-			ensure_owner_or_root::<T, I>(origin)?;
-			<IsHalted<T, I>>::put(!operational);
-
-			if operational {
-				log::info!(target: "runtime::bridge-grandpa", "Resuming pallet operations.");
-			} else {
-				log::warn!(target: "runtime::bridge-grandpa", "Stopping pallet operations.");
-			}
-
-			Ok(().into())
+		pub fn set_operational(origin: OriginFor<T>, operational: bool) -> DispatchResult {
+			Self::set_operating_mode(origin, !operational)
 		}
 	}
 
@@ -310,7 +295,7 @@ pub mod pallet {
 
 	/// If true, all pallet transactions are failed immediately.
 	#[pallet::storage]
-	pub(super) type IsHalted<T: Config<I>, I: 'static = ()> = StorageValue<_, bool, ValueQuery>;
+	pub type IsHalted<T: Config<I>, I: 'static = ()> = StorageValue<_, bool, ValueQuery>;
 
 	#[pallet::genesis_config]
 	pub struct GenesisConfig<T: Config<I>, I: 'static = ()> {
@@ -364,10 +349,10 @@ pub mod pallet {
 		NotInitialized,
 		/// The pallet has already been initialized.
 		AlreadyInitialized,
-		/// All pallet operations are halted.
-		Halted,
 		/// The storage proof doesn't contains storage root. So it is invalid for given header.
 		StorageRootMismatch,
+		/// Error generated by the `OwnedBridgeModule` trait.
+		BridgeModule(bp_runtime::OwnedBridgeModuleError),
 	}
 
 	/// Check the given header for a GRANDPA scheduled authority set change. If a change
@@ -513,26 +498,6 @@ pub mod pallet {
 			insert_header::<T, I>(header, hash);
 		}
 	}
-
-	/// Ensure that the origin is either root, or `PalletOwner`.
-	fn ensure_owner_or_root<T: Config<I>, I: 'static>(origin: T::Origin) -> Result<(), BadOrigin> {
-		match origin.into() {
-			Ok(RawOrigin::Root) => Ok(()),
-			Ok(RawOrigin::Signed(ref signer))
-				if Some(signer) == <PalletOwner<T, I>>::get().as_ref() =>
-				Ok(()),
-			_ => Err(BadOrigin),
-		}
-	}
-
-	/// Ensure that the pallet is in operational mode (not halted).
-	fn ensure_operational<T: Config<I>, I: 'static>() -> Result<(), Error<T, I>> {
-		if <IsHalted<T, I>>::get() {
-			Err(<Error<T, I>>::Halted)
-		} else {
-			Ok(())
-		}
-	}
 }
 
 impl<T: Config<I>, I: 'static> Pallet<T, I> {
@@ -799,7 +764,10 @@ mod tests {
 			initialize_substrate_bridge();
 
 			assert_ok!(Pallet::<TestRuntime>::set_operational(Origin::root(), false));
-			assert_noop!(submit_finality_proof(1), Error::<TestRuntime>::Halted);
+			assert_noop!(
+				submit_finality_proof(1),
+				Error::<TestRuntime>::BridgeModule(bp_runtime::OwnedBridgeModuleError::Halted)
+			);
 
 			assert_ok!(Pallet::<TestRuntime>::set_operational(Origin::root(), true));
 			assert_ok!(submit_finality_proof(1));