Make bags-list generic over node value and instantiable (#10997)

* make instantiable

* update

* cargo fmt

* Clean up

* bags-list: Make it generic over node value

* Respond to some feedback

* Apply suggestions from code review

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Add back default impl for weight update worst case

* Update to Score in more places'

* Use VoteWeight, not u64 to reduce test diff

* FMT

* FullCodec implies Codec

* formatting

* Fixup bags list remote test

Co-authored-by: doordashcon <jesse.chejieh@gmail.com>
Co-authored-by: Doordashcon <90750465+Doordashcon@users.noreply.github.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

substrate/frame/staking/src/benchmarking.rs

@@ -189,7 +189,7 @@ impl<T: Config> ListScenario<T> {
 
 		// find a destination weight that will trigger the worst case scenario
 		let dest_weight_as_vote =
-			T::SortedListProvider::weight_update_worst_case(&origin_stash1, is_increase);
+			T::SortedListProvider::score_update_worst_case(&origin_stash1, is_increase);
 
 		let total_issuance = T::Currency::total_issuance();
 

substrate/frame/staking/src/mock.rs

@@ -18,7 +18,7 @@
 //! Test utilities
 
 use crate::{self as pallet_staking, *};
-use frame_election_provider_support::{onchain, SortedListProvider};
+use frame_election_provider_support::{onchain, SortedListProvider, VoteWeight};
 use frame_support::{
 	assert_ok, parameter_types,
 	traits::{
@@ -240,8 +240,9 @@ parameter_types! {
 impl pallet_bags_list::Config for Test {
 	type Event = Event;
 	type WeightInfo = ();
-	type VoteWeightProvider = Staking;
+	type ScoreProvider = Staking;
 	type BagThresholds = BagThresholds;
+	type Score = VoteWeight;
 }
 
 impl onchain::Config for Test {

substrate/frame/staking/src/pallet/impls.rs

@@ -18,8 +18,8 @@
 //! Implementations for the Staking FRAME Pallet.
 
 use frame_election_provider_support::{
-	data_provider, ElectionDataProvider, ElectionProvider, SortedListProvider, Supports,
-	VoteWeight, VoteWeightProvider, VoterOf,
+	data_provider, ElectionDataProvider, ElectionProvider, ScoreProvider, SortedListProvider,
+	Supports, VoteWeight, VoterOf,
 };
 use frame_support::{
 	pallet_prelude::*,
@@ -1244,13 +1244,15 @@ where
 	}
 }
 
-impl<T: Config> VoteWeightProvider<T::AccountId> for Pallet<T> {
-	fn vote_weight(who: &T::AccountId) -> VoteWeight {
+impl<T: Config> ScoreProvider<T::AccountId> for Pallet<T> {
+	type Score = VoteWeight;
+
+	fn score(who: &T::AccountId) -> Self::Score {
 		Self::weight_of(who)
 	}
 
 	#[cfg(feature = "runtime-benchmarks")]
-	fn set_vote_weight_of(who: &T::AccountId, weight: VoteWeight) {
+	fn set_score_of(who: &T::AccountId, weight: Self::Score) {
 		// this will clearly results in an inconsistent state, but it should not matter for a
 		// benchmark.
 		let active: BalanceOf<T> = weight.try_into().map_err(|_| ()).unwrap();
@@ -1279,6 +1281,7 @@ impl<T: Config> VoteWeightProvider<T::AccountId> for Pallet<T> {
 pub struct UseNominatorsMap<T>(sp_std::marker::PhantomData<T>);
 impl<T: Config> SortedListProvider<T::AccountId> for UseNominatorsMap<T> {
 	type Error = ();
+	type Score = VoteWeight;
 
 	/// Returns iterator over voter list, which can have `take` called on it.
 	fn iter() -> Box<dyn Iterator<Item = T::AccountId>> {
@@ -1290,11 +1293,11 @@ impl<T: Config> SortedListProvider<T::AccountId> for UseNominatorsMap<T> {
 	fn contains(id: &T::AccountId) -> bool {
 		Nominators::<T>::contains_key(id)
 	}
-	fn on_insert(_: T::AccountId, _weight: VoteWeight) -> Result<(), Self::Error> {
+	fn on_insert(_: T::AccountId, _weight: Self::Score) -> Result<(), Self::Error> {
 		// nothing to do on insert.
 		Ok(())
 	}
-	fn on_update(_: &T::AccountId, _weight: VoteWeight) {
+	fn on_update(_: &T::AccountId, _weight: Self::Score) {
 		// nothing to do on update.
 	}
 	fn on_remove(_: &T::AccountId) {
@@ -1302,7 +1305,7 @@ impl<T: Config> SortedListProvider<T::AccountId> for UseNominatorsMap<T> {
 	}
 	fn unsafe_regenerate(
 		_: impl IntoIterator<Item = T::AccountId>,
-		_: Box<dyn Fn(&T::AccountId) -> VoteWeight>,
+		_: Box<dyn Fn(&T::AccountId) -> Self::Score>,
 	) -> u32 {
 		// nothing to do upon regenerate.
 		0

substrate/frame/staking/src/pallet/mod.rs

@@ -166,7 +166,10 @@ pub mod pallet {
 		/// Something that can provide a sorted list of voters in a somewhat sorted way. The
 		/// original use case for this was designed with `pallet_bags_list::Pallet` in mind. If
 		/// the bags-list is not desired, [`impls::UseNominatorsMap`] is likely the desired option.
-		type SortedListProvider: SortedListProvider<Self::AccountId>;
+		type SortedListProvider: SortedListProvider<
+			Self::AccountId,
+			Score = frame_election_provider_support::VoteWeight,
+		>;
 
 		/// The maximum number of `unlocking` chunks a [`StakingLedger`] can have. Effectively
 		/// determines how many unique eras a staker may be unbonding in.