Implement MaxEncodedLen on pallet-beefy

frame/beefy-mmr/src/mock.rs

@@ -124,6 +124,7 @@ impl pallet_mmr::Config for Test {
 
 impl pallet_beefy::Config for Test {
 	type BeefyId = BeefyId;
+	type MaxAuthorities = ConstU32<100>;
 }
 
 parameter_types! {

frame/beefy/src/lib.rs

@@ -17,9 +17,9 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use codec::Encode;
+use codec::{Encode, MaxEncodedLen};
 
-use frame_support::{traits::OneSessionHandler, Parameter};
+use frame_support::{traits::OneSessionHandler, BoundedSlice, Parameter, WeakBoundedVec};
 
 use sp_runtime::{
 	generic::DigestItem,
@@ -42,28 +42,28 @@ pub use pallet::*;
 pub mod pallet {
 	use super::*;
 	use frame_support::pallet_prelude::*;
-	use frame_system::pallet_prelude::*;
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// Authority identifier type
-		type BeefyId: Member + Parameter + RuntimeAppPublic + MaybeSerializeDeserialize;
+		type BeefyId: Member
+			+ Parameter
+			+ RuntimeAppPublic
+			+ MaybeSerializeDeserialize
+			+ MaxEncodedLen;
+
+		/// The maximum number of authorities that can be added.
+		type MaxAuthorities: Get<u32>;
 	}
 
 	#[pallet::pallet]
-	#[pallet::without_storage_info]
 	pub struct Pallet<T>(PhantomData<T>);
 
-	#[pallet::hooks]
-	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
-
-	#[pallet::call]
-	impl<T: Config> Pallet<T> {}
-
 	/// The current authorities set
 	#[pallet::storage]
 	#[pallet::getter(fn authorities)]
-	pub(super) type Authorities<T: Config> = StorageValue<_, Vec<T::BeefyId>, ValueQuery>;
+	pub(super) type Authorities<T: Config> =
+		StorageValue<_, WeakBoundedVec<T::BeefyId, T::MaxAuthorities>, ValueQuery>;
 
 	/// The current validator set id
 	#[pallet::storage]
@@ -74,7 +74,8 @@ pub mod pallet {
 	/// Authorities set scheduled to be used with the next session
 	#[pallet::storage]
 	#[pallet::getter(fn next_authorities)]
-	pub(super) type NextAuthorities<T: Config> = StorageValue<_, Vec<T::BeefyId>, ValueQuery>;
+	pub(super) type NextAuthorities<T: Config> =
+		StorageValue<_, WeakBoundedVec<T::BeefyId, T::MaxAuthorities>, ValueQuery>;
 
 	#[pallet::genesis_config]
 	pub struct GenesisConfig<T: Config> {
@@ -99,12 +100,15 @@ pub mod pallet {
 impl<T: Config> Pallet<T> {
 	/// Return the current active BEEFY validator set.
 	pub fn validator_set() -> Option<ValidatorSet<T::BeefyId>> {
-		let validators: Vec<T::BeefyId> = Self::authorities();
+		let validators: WeakBoundedVec<T::BeefyId, T::MaxAuthorities> = Self::authorities();
 		let id: beefy_primitives::ValidatorSetId = Self::validator_set_id();
 		ValidatorSet::<T::BeefyId>::new(validators, id)
 	}
 
-	fn change_authorities(new: Vec<T::BeefyId>, queued: Vec<T::BeefyId>) {
+	fn change_authorities(
+		new: WeakBoundedVec<T::BeefyId, T::MaxAuthorities>,
+		queued: WeakBoundedVec<T::BeefyId, T::MaxAuthorities>,
+	) {
 		<Authorities<T>>::put(&new);
 
 		let next_id = Self::validator_set_id() + 1u64;
@@ -127,10 +131,14 @@ impl<T: Config> Pallet<T> {
 
 		assert!(<Authorities<T>>::get().is_empty(), "Authorities are already initialized!");
 
-		<Authorities<T>>::put(authorities);
+		let bounded_authorities =
+			BoundedSlice::<T::BeefyId, T::MaxAuthorities>::try_from(authorities)
+				.expect("Authorities vec too big");
+
+		<Authorities<T>>::put(bounded_authorities);
 		<ValidatorSetId<T>>::put(0);
 		// Like `pallet_session`, initialize the next validator set as well.
-		<NextAuthorities<T>>::put(authorities);
+		<NextAuthorities<T>>::put(bounded_authorities);
 	}
 }
 
@@ -154,11 +162,25 @@ impl<T: Config> OneSessionHandler<T::AccountId> for Pallet<T> {
 		I: Iterator<Item = (&'a T::AccountId, T::BeefyId)>,
 	{
 		let next_authorities = validators.map(|(_, k)| k).collect::<Vec<_>>();
+		let bounded_next_authorities = WeakBoundedVec::<_, T::MaxAuthorities>::force_from(
+			next_authorities,
+			Some(
+				"Warning: The session has more validators than expected. \
+				A runtime configuration adjustment may be needed.",
+			),
+		);
 		let next_queued_authorities = queued_validators.map(|(_, k)| k).collect::<Vec<_>>();
+		let bounded_next_queued_authorities = WeakBoundedVec::<_, T::MaxAuthorities>::force_from(
+			next_queued_authorities,
+			Some(
+				"Warning: The session has more queued validators than expected. \
+				A runtime configuration adjustment may be needed.",
+			),
+		);
 
 		// Always issue a change on each `session`, even if validator set hasn't changed.
 		// We want to have at least one BEEFY mandatory block per session.
-		Self::change_authorities(next_authorities, next_queued_authorities);
+		Self::change_authorities(bounded_next_authorities, bounded_next_queued_authorities);
 	}
 
 	fn on_disabled(i: u32) {

frame/beefy/src/mock.rs

@@ -52,7 +52,7 @@ construct_runtime!(
 		UncheckedExtrinsic = UncheckedExtrinsic,
 	{
 		System: frame_system::{Pallet, Call, Config, Storage, Event<T>},
-		Beefy: pallet_beefy::{Pallet, Call, Config<T>, Storage},
+		Beefy: pallet_beefy::{Pallet, Config<T>, Storage},
 		Session: pallet_session::{Pallet, Call, Storage, Event, Config<T>},
 	}
 );
@@ -86,6 +86,7 @@ impl frame_system::Config for Test {
 
 impl pallet_beefy::Config for Test {
 	type BeefyId = BeefyId;
+	type MaxAuthorities = ConstU32<100>;
 }
 
 parameter_types! {

frame/support/src/storage/bounded_vec.rs

@@ -111,6 +111,15 @@ where
 #[scale_info(skip_type_params(S))]
 pub struct BoundedSlice<'a, T, S>(&'a [T], PhantomData<S>);
 
+impl<'a, T, S> Clone for BoundedSlice<'a, T, S> {
+	fn clone(&self) -> Self {
+		BoundedSlice(self.0, PhantomData)
+	}
+}
+
+// Since a slice `&[]` is always `Copy`, so is `BoundedSlice`.
+impl<'a, T, S> Copy for BoundedSlice<'a, T, S> {}
+
 // `BoundedSlice`s encode to something which will always decode into a `BoundedVec`,
 // `WeakBoundedVec`, or a `Vec`.
 impl<'a, T: Encode + Decode, S: Get<u32>> EncodeLike<BoundedVec<T, S>> for BoundedSlice<'a, T, S> {}