Generate storage info for pallet authority_discovery (#9428)

* Migrate Aura pallet to BoundedVec

Implementing issue #8629

* Fixed aura tests after BoundedVec change

* Moved Vec to BoundedVec in authority-discovery

* Merging into the main branch

* Added MaxEncodedLen to crypto

Need this without full_crypto to be able to add generate_store_info

* Add generate_store_info for aura

* Adding changes to Slot to add MaxEncodedLen

* Adding generate_store_info to authority discovery

* fmt

* removing panics in runtime if vec size too large

* authority-discovery: Remove panics in runtime
Can happen if vec size is too large, so truncate the vec in that case

* Adding logging when I truncate Vecs

* Got the sign the other way around

* Reverting pallet_aura changes
This is already being addressed by PR #9371

* Change BoundedVec to WeakBoundedVec

More robust implementation following @thiolliere recommendation.

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

substrate/bin/node/runtime/src/lib.rs

@@ -883,6 +883,7 @@ parameter_types! {
 	pub const ImOnlineUnsignedPriority: TransactionPriority = TransactionPriority::max_value();
 	/// We prioritize im-online heartbeats over election solution submission.
 	pub const StakingUnsignedPriority: TransactionPriority = TransactionPriority::max_value() / 2;
+	pub const MaxAuthorities: u32 = 100;
 }
 
 impl<LocalCall> frame_system::offchain::CreateSignedTransaction<LocalCall> for Runtime
@@ -955,7 +956,9 @@ impl pallet_offences::Config for Runtime {
 	type OnOffenceHandler = Staking;
 }
 
-impl pallet_authority_discovery::Config for Runtime {}
+impl pallet_authority_discovery::Config for Runtime {
+	type MaxAuthorities = MaxAuthorities;
+}
 
 impl pallet_grandpa::Config for Runtime {
 	type Event = Event;

substrate/frame/authority-discovery/src/lib.rs

@@ -23,10 +23,15 @@
 // Ensure we're `no_std` when compiling for Wasm.
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use frame_support::traits::OneSessionHandler;
+use frame_support::{
+	traits::{Get, OneSessionHandler},
+	WeakBoundedVec,
+};
 use sp_authority_discovery::AuthorityId;
 use sp_std::prelude::*;
 
+use core::convert::TryFrom;
+
 pub use pallet::*;
 
 #[frame_support::pallet]
@@ -36,21 +41,27 @@ pub mod pallet {
 
 	#[pallet::pallet]
 	#[pallet::generate_store(pub(super) trait Store)]
+	#[pallet::generate_storage_info]
 	pub struct Pallet<T>(_);
 
 	#[pallet::config]
 	/// The pallet's config trait.
-	pub trait Config: frame_system::Config + pallet_session::Config {}
+	pub trait Config: frame_system::Config + pallet_session::Config {
+		/// The maximum number of authorities that can be added.
+		type MaxAuthorities: Get<u32>;
+	}
 
 	#[pallet::storage]
 	#[pallet::getter(fn keys)]
 	/// Keys of the current authority set.
-	pub(super) type Keys<T: Config> = StorageValue<_, Vec<AuthorityId>, ValueQuery>;
+	pub(super) type Keys<T: Config> =
+		StorageValue<_, WeakBoundedVec<AuthorityId, T::MaxAuthorities>, ValueQuery>;
 
 	#[pallet::storage]
 	#[pallet::getter(fn next_keys)]
 	/// Keys of the next authority set.
-	pub(super) type NextKeys<T: Config> = StorageValue<_, Vec<AuthorityId>, ValueQuery>;
+	pub(super) type NextKeys<T: Config> =
+		StorageValue<_, WeakBoundedVec<AuthorityId, T::MaxAuthorities>, ValueQuery>;
 
 	#[pallet::genesis_config]
 	pub struct GenesisConfig {
@@ -75,31 +86,36 @@ impl<T: Config> Pallet<T> {
 	/// Retrieve authority identifiers of the current and next authority set
 	/// sorted and deduplicated.
 	pub fn authorities() -> Vec<AuthorityId> {
-		let mut keys = Keys::<T>::get();
-		let next = NextKeys::<T>::get();
+		let mut keys = Keys::<T>::get().to_vec();
+		let next = NextKeys::<T>::get().to_vec();
 
 		keys.extend(next);
 		keys.sort();
 		keys.dedup();
 
-		keys
+		keys.to_vec()
 	}
 
 	/// Retrieve authority identifiers of the current authority set in the original order.
-	pub fn current_authorities() -> Vec<AuthorityId> {
+	pub fn current_authorities() -> WeakBoundedVec<AuthorityId, T::MaxAuthorities> {
 		Keys::<T>::get()
 	}
 
 	/// Retrieve authority identifiers of the next authority set in the original order.
-	pub fn next_authorities() -> Vec<AuthorityId> {
+	pub fn next_authorities() -> WeakBoundedVec<AuthorityId, T::MaxAuthorities> {
 		NextKeys::<T>::get()
 	}
 
-	fn initialize_keys(keys: &[AuthorityId]) {
+	fn initialize_keys(keys: &Vec<AuthorityId>) {
 		if !keys.is_empty() {
 			assert!(Keys::<T>::get().is_empty(), "Keys are already initialized!");
-			Keys::<T>::put(keys);
-			NextKeys::<T>::put(keys);
+
+			let bounded_keys =
+				WeakBoundedVec::<AuthorityId, T::MaxAuthorities>::try_from((*keys).clone())
+					.expect("Keys vec too big");
+
+			Keys::<T>::put(&bounded_keys);
+			NextKeys::<T>::put(&bounded_keys);
 		}
 	}
 }
@@ -124,10 +140,29 @@ impl<T: Config> OneSessionHandler<T::AccountId> for Pallet<T> {
 	{
 		// Remember who the authorities are for the new and next session.
 		if changed {
-			let keys = validators.map(|x| x.1);
-			Keys::<T>::put(keys.collect::<Vec<_>>());
-			let next_keys = queued_validators.map(|x| x.1);
-			NextKeys::<T>::put(next_keys.collect::<Vec<_>>());
+			let keys = validators.map(|x| x.1).collect::<Vec<_>>();
+
+			let bounded_keys = WeakBoundedVec::<_, T::MaxAuthorities>::force_from(
+				keys,
+				Some(
+					"Warning: The session has more validators than expected. \
+				A runtime configuration adjustment may be needed.",
+				),
+			);
+
+			Keys::<T>::put(bounded_keys);
+
+			let next_keys = queued_validators.map(|x| x.1).collect::<Vec<_>>();
+
+			let next_bounded_keys = WeakBoundedVec::<_, T::MaxAuthorities>::force_from(
+				next_keys,
+				Some(
+					"Warning: The session has more queued validators than expected. \
+				A runtime configuration adjustment may be needed.",
+				),
+			);
+
+			NextKeys::<T>::put(next_bounded_keys);
 		}
 	}
 
@@ -166,10 +201,13 @@ mod tests {
 		}
 	);
 
-	impl Config for Test {}
-
 	parameter_types! {
 		pub const DisabledValidatorsThreshold: Perbill = Perbill::from_percent(33);
+		pub const MaxAuthorities: u32 = 100;
+	}
+
+	impl Config for Test {
+		type MaxAuthorities = MaxAuthorities;
 	}
 
 	impl pallet_session::Config for Test {

substrate/primitives/application-crypto/src/lib.rs

@@ -259,6 +259,7 @@ macro_rules! app_crypto_public_not_full_crypto {
 				$crate::codec::Encode,
 				$crate::codec::Decode,
 				$crate::RuntimeDebug,
+				$crate::codec::MaxEncodedLen,
 			)]
 			pub struct Public($public);
 		}

substrate/primitives/consensus/slots/src/lib.rs

@@ -19,10 +19,10 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use codec::{Decode, Encode};
+use codec::{Decode, Encode, MaxEncodedLen};
 
 /// Unit type wrapper that represents a slot.
-#[derive(Debug, Encode, Decode, Eq, Clone, Copy, Default, Ord)]
+#[derive(Debug, Encode, MaxEncodedLen, Decode, Eq, Clone, Copy, Default, Ord)]
 pub struct Slot(u64);
 
 impl core::ops::Deref for Slot {