change: ETCM-12424 remove dependency on slots from pallet-block-producer-fees (#1085)

Author: AmbientTea

Cargo.lock

@@ -39,6 +39,8 @@ runtime APIs `sp_sidechain::GetEpochDurationApi` instead of deprecated `sp_sidec
 implement the new API in their runtime. Backward compatibility option can be switched on by enabling `legacy-slotapi-compat`
 feature in the crate, which will cause legacy chain nodes to still use `SlotApi` where present and include the
 `sidechain.slot` as an optional field.
+* `pallet-block-producer-fees` no longer uses slots and is instead configured with a `Moment` type used for identifying
+when an SPO's fee configuration has changed
 
 ## Removed
 

changelog.md

@@ -556,7 +556,9 @@ impl pallet_block_producer_fees::Config for Runtime {
 
 	type HistoricalChangesPerProducer = ConstU16<5>;
 
-	fn current_slot() -> sp_consensus_slots::Slot {
+	type Moment = Slot;
+
+	fn current_moment() -> Slot {
 		let slot: u64 = pallet_aura::CurrentSlot::<Runtime>::get().into();
 		sp_consensus_slots::Slot::from(slot)
 	}

demo/runtime/src/lib.rs

@@ -17,7 +17,6 @@ frame-system = { workspace = true }
 parity-scale-codec = { workspace = true }
 scale-info = { workspace = true }
 sp-block-producer-fees = { workspace = true }
-sp-consensus-slots = { workspace = true }
 sp-std = { workspace = true }
 
 [dev-dependencies]

toolkit/block-producer-fees/pallet/Cargo.toml

@@ -11,20 +11,25 @@ pub trait BenchmarkHelper<T> {
 	fn account_id(i: u8) -> T;
 }
 
-#[benchmarks]
+#[benchmarks(where <T as crate::Config>::Moment: From<u64>)]
 mod benchmarks {
 	use super::*;
 	use frame_support::traits::Get;
 	use frame_system::RawOrigin;
 	use frame_system::pallet_prelude::OriginFor;
-	use sp_consensus_slots::Slot;
 	use sp_std::collections::vec_deque::VecDeque;
 
 	// Pessimistic storage for the ID
-	fn setup_storage<T: Config>() {
+	fn setup_storage<T: Config>()
+	where
+		<T as crate::Config>::Moment: From<u64>,
+	{
 		let size = T::HistoricalChangesPerProducer::get();
 		// Pessimistic storage content for is full, because it requires additional removal from the vecdeque.
-		let data = (0..size).into_iter().map(|_| (Slot::from(0), 0u16)).collect::<VecDeque<_>>();
+		let data = (0..size)
+			.into_iter()
+			.map(|_| (T::Moment::from(0u64), 0u16))
+			.collect::<VecDeque<_>>();
 		for i in 0u8..100u8 {
 			let id = T::BenchmarkHelper::account_id(i);
 			FeesChanges::<T>::insert(id, data.clone());

toolkit/block-producer-fees/pallet/src/benchmarking.rs

@@ -4,7 +4,7 @@
 //! distributing the rest of rewards to his stakers. Precision of the margin fee setting is bounded
 //! to 1/100 of a percent.
 //!
-//! The margin fees are stored together with the slot at which change occurred, so this data can be
+//! The margin fees are stored together with the time at which change occurred, so this data can be
 //! exposed to rewards calculation.
 //!
 //! Log of changes per account is bounded. The oldest entries are dropped when new ones are added.
@@ -31,7 +31,6 @@ pub mod pallet {
 	use frame_support::pallet_prelude::*;
 	use frame_system::pallet_prelude::*;
 	use sp_block_producer_fees::PerTenThousands;
-	use sp_consensus_slots::Slot;
 	use sp_std::collections::vec_deque::VecDeque;
 
 	/// Current version of the pallet
@@ -49,23 +48,26 @@ pub mod pallet {
 		/// Weight information on extrinsic in the pallet. For convenience weights in [weights] module can be used.
 		type WeightInfo: WeightInfo;
 
-		/// Should provide the slot number of the current block.
-		fn current_slot() -> Slot;
+		/// Moment in time when a change in fees occured
+		type Moment: Parameter + Default + MaxEncodedLen + PartialOrd;
+
+		/// Should provide the moment for the current block.
+		fn current_moment() -> Self::Moment;
 
 		#[cfg(feature = "runtime-benchmarks")]
 		/// Benchmark helper type used for running benchmarks
 		type BenchmarkHelper: benchmarking::BenchmarkHelper<Self::AccountId>;
 	}
 
-	type FeeChange = (Slot, PerTenThousands);
+	type FeeChangeOf<T> = (<T as Config>::Moment, PerTenThousands);
 
 	/// Stores bounded amount of fee changes per account
 	#[pallet::storage]
 	#[pallet::unbounded]
 	pub type FeesChanges<T: Config> = StorageMap<
 		Hasher = Twox64Concat,
 		Key = T::AccountId,
-		Value = VecDeque<FeeChange>,
+		Value = VecDeque<FeeChangeOf<T>>,
 		QueryKind = ValueQuery,
 	>;
 
@@ -83,7 +85,7 @@ pub mod pallet {
 				if fees_log.len() > T::HistoricalChangesPerProducer::get().into() {
 					let _ = fees_log.pop_back();
 				}
-				fees_log.push_front((T::current_slot(), fee_numerator));
+				fees_log.push_front((T::current_moment(), fee_numerator));
 			});
 			Ok(())
 		}
@@ -96,25 +98,28 @@ pub mod pallet {
 		}
 
 		/// Retrieves all stored block producer fees settings. The most recent fees are in front of vecdeque.
-		pub fn get_all() -> impl Iterator<Item = (T::AccountId, VecDeque<FeeChange>)> {
+		pub fn get_all() -> impl Iterator<Item = (T::AccountId, VecDeque<FeeChangeOf<T>>)> {
 			FeesChanges::<T>::iter()
 		}
 
 		/// Retrieves the latest fee settings for all accounts.
-		pub fn get_all_latest() -> impl Iterator<Item = (T::AccountId, FeeChange)> {
+		pub fn get_all_latest() -> impl Iterator<Item = (T::AccountId, FeeChangeOf<T>)> {
 			Self::get_all().map(|(account_id, changes)| {
-				(account_id, *changes.front().expect("There are no empty collections in storage"))
+				(
+					account_id,
+					changes.front().expect("There are no empty collections in storage").clone(),
+				)
 			})
 		}
 
 		/// Retrieves fees settings for the given account id.
 		/// Empty collection is returned if there are no settings stored for given id.
-		pub fn get(id: T::AccountId) -> VecDeque<FeeChange> {
+		pub fn get(id: T::AccountId) -> VecDeque<FeeChangeOf<T>> {
 			FeesChanges::<T>::get(id)
 		}
 
 		/// Gets the latest fee setting for the given account.
-		pub fn get_latest(id: T::AccountId) -> Option<FeeChange> {
+		pub fn get_latest(id: T::AccountId) -> Option<FeeChangeOf<T>> {
 			FeesChanges::<T>::get(id).front().cloned()
 		}
 	}

toolkit/block-producer-fees/pallet/src/lib.rs

@@ -4,13 +4,14 @@ use frame_support::{
 	traits::{ConstU16, ConstU32, ConstU64, Everything},
 };
 use frame_system::mocking::MockBlock;
-use sp_consensus_slots::Slot;
 use sp_io::TestExternalities;
 use sp_runtime::{
 	AccountId32, BuildStorage,
 	traits::{BlakeTwo256, IdentityLookup},
 };
 
+type Moment = u64;
+
 #[frame_support::pallet]
 pub mod mock_pallet {
 	use super::*;
@@ -22,7 +23,7 @@ pub mod mock_pallet {
 	pub trait Config: frame_system::Config {}
 
 	#[pallet::storage]
-	pub type CurrentSlot<T: Config> = StorageValue<_, Slot, ValueQuery>;
+	pub type CurrentMoment<T: Config> = StorageValue<_, Moment, ValueQuery>;
 }
 
 construct_runtime! {
@@ -84,8 +85,10 @@ impl crate::pallet::Config for Test {
 	// Stores the current and one historical value, two in total
 	type HistoricalChangesPerProducer = ConstU16<1>;
 
-	fn current_slot() -> Slot {
-		mock_pallet::CurrentSlot::<Test>::get()
+	type Moment = Moment;
+
+	fn current_moment() -> Moment {
+		mock_pallet::CurrentMoment::<Test>::get()
 	}
 
 	#[cfg(feature = "runtime-benchmarks")]

toolkit/block-producer-fees/pallet/src/mock.rs

@@ -2,7 +2,6 @@ use super::*;
 use frame_support::{assert_err, assert_ok};
 use frame_system::pallet_prelude::OriginFor;
 use mock::*;
-use sp_consensus_slots::Slot;
 use sp_runtime::{AccountId32, DispatchError};
 use sp_std::collections::vec_deque::VecDeque;
 
@@ -13,21 +12,21 @@ fn stores_the_configured_number_of_fee_changes() {
 		let bob = AccountId32::new([2u8; 32]);
 		let charlie = AccountId32::new([3u8; 32]);
 
-		mock_pallet::CurrentSlot::<Test>::set(Slot::from(1));
+		mock_pallet::CurrentMoment::<Test>::set(1);
 		assert_ok!(Pallet::<Test>::set_fee(OriginFor::<Test>::signed(alice.clone()), 101));
 		assert_ok!(Pallet::<Test>::set_fee(OriginFor::<Test>::signed(bob.clone()), 201));
 
-		mock_pallet::CurrentSlot::<Test>::set(Slot::from(2));
+		mock_pallet::CurrentMoment::<Test>::set(2);
 		assert_ok!(Pallet::<Test>::set_fee(OriginFor::<Test>::signed(alice.clone()), 102));
 
-		mock_pallet::CurrentSlot::<Test>::set(Slot::from(3));
+		mock_pallet::CurrentMoment::<Test>::set(3);
 		// Setting third fee causes drop of the first one
 		assert_ok!(Pallet::<Test>::set_fee(OriginFor::<Test>::signed(alice.clone()), 103));
 
-		let alice_entry_2 = (Slot::from(2), 102);
-		let alice_entry_3 = (Slot::from(3), 103);
+		let alice_entry_2 = (2, 102);
+		let alice_entry_3 = (3, 103);
 		let alice_entries = VecDeque::from(vec![alice_entry_3, alice_entry_2]);
-		let bob_entry_1 = (Slot::from(1), 201);
+		let bob_entry_1 = (1, 201);
 		let bob_entries = VecDeque::from(vec![bob_entry_1]);
 
 		assert_eq!(Pallet::<Test>::get(alice.clone()), alice_entries);