Implement pallet-bags-list and its interfaces with pallet-staking

Cargo.toml

@@ -128,6 +128,7 @@ members = [
 	"frame/uniques",
 	"frame/utility",
 	"frame/vesting",
+	"frame/bags-list",
 	"primitives/api",
 	"primitives/api/proc-macro",
 	"primitives/api/test",
@@ -198,6 +199,8 @@ members = [
 	"utils/frame/try-runtime/cli",
 	"utils/frame/rpc/support",
 	"utils/frame/rpc/system",
+	"utils/frame/generate-bags",
+	"utils/frame/generate-bags/node-runtime",
 	"utils/prometheus",
 	"utils/wasm-builder",
 ]

bin/node/runtime/Cargo.toml

@@ -55,6 +55,7 @@ pallet-assets = { version = "4.0.0-dev", default-features = false, path = "../..
 pallet-authority-discovery = { version = "4.0.0-dev", default-features = false, path = "../../../frame/authority-discovery" }
 pallet-authorship = { version = "4.0.0-dev", default-features = false, path = "../../../frame/authorship" }
 pallet-babe = { version = "4.0.0-dev", default-features = false, path = "../../../frame/babe" }
+pallet-bags-list = { version = "4.0.0-dev", default-features = false, path = "../../../frame/bags-list" }
 pallet-balances = { version = "4.0.0-dev", default-features = false, path = "../../../frame/balances" }
 pallet-bounties = { version = "4.0.0-dev", default-features = false, path = "../../../frame/bounties" }
 pallet-collective = { version = "4.0.0-dev", default-features = false, path = "../../../frame/collective" }
@@ -110,6 +111,7 @@ std = [
 	"pallet-authorship/std",
 	"sp-consensus-babe/std",
 	"pallet-babe/std",
+	"pallet-bags-list/std",
 	"pallet-balances/std",
 	"pallet-bounties/std",
 	"sp-block-builder/std",
@@ -179,6 +181,7 @@ runtime-benchmarks = [
 	"sp-runtime/runtime-benchmarks",
 	"pallet-assets/runtime-benchmarks",
 	"pallet-babe/runtime-benchmarks",
+	"pallet-bags-list/runtime-benchmarks",
 	"pallet-balances/runtime-benchmarks",
 	"pallet-bounties/runtime-benchmarks",
 	"pallet-collective/runtime-benchmarks",

bin/node/runtime/src/lib.rs

@@ -92,6 +92,9 @@ pub mod constants;
 use constants::{currency::*, time::*};
 use sp_runtime::generic::Era;
 
+/// Generated voter bag information.
+mod voter_bags;
+
 // Make the WASM binary available.
 #[cfg(feature = "std")]
 include!(concat!(env!("OUT_DIR"), "/wasm_binary.rs"));
@@ -525,6 +528,9 @@ impl pallet_staking::Config for Runtime {
 	type MaxNominatorRewardedPerValidator = MaxNominatorRewardedPerValidator;
 	type ElectionProvider = ElectionProviderMultiPhase;
 	type GenesisElectionProvider = onchain::OnChainSequentialPhragmen<Self>;
+	// Alternatively, use pallet_staking::UseNominatorsMap<Runtime> to just use the nominators map.
+	// Note that the aforementioned does not scale to a very large number of nominators.
+	type SortedListProvider = BagsList;
 	type WeightInfo = pallet_staking::weights::SubstrateWeight<Runtime>;
 }
 
@@ -552,6 +558,11 @@ parameter_types! {
 		*RuntimeBlockLength::get()
 		.max
 		.get(DispatchClass::Normal);
+
+	// BagsList allows a practically unbounded count of nominators to participate in NPoS elections.
+	// To ensure we respect memory limits when using the BagsList this must be set to a number of
+	// voters we know can fit into a single vec allocation.
+	pub const VoterSnapshotPerBlock: u32 = 10_000;
 }
 
 sp_npos_elections::generate_solution_type!(
@@ -634,6 +645,18 @@ impl pallet_election_provider_multi_phase::Config for Runtime {
 	type WeightInfo = pallet_election_provider_multi_phase::weights::SubstrateWeight<Self>;
 	type ForceOrigin = EnsureRootOrHalfCouncil;
 	type BenchmarkingConfig = BenchmarkConfig;
+	type VoterSnapshotPerBlock = VoterSnapshotPerBlock;
+}
+
+parameter_types! {
+	pub const BagThresholds: &'static [u64] = &voter_bags::THRESHOLDS;
+}
+
+impl pallet_bags_list::Config for Runtime {
+	type Event = Event;
+	type VoteWeightProvider = Staking;
+	type WeightInfo = pallet_bags_list::weights::SubstrateWeight<Runtime>;
+	type BagThresholds = BagThresholds;
 }
 
 parameter_types! {
@@ -1254,6 +1277,7 @@ construct_runtime!(
 		Gilt: pallet_gilt::{Pallet, Call, Storage, Event<T>, Config},
 		Uniques: pallet_uniques::{Pallet, Call, Storage, Event<T>},
 		TransactionStorage: pallet_transaction_storage::{Pallet, Call, Storage, Inherent, Config<T>, Event<T>},
+		BagsList: pallet_bags_list::{Pallet, Call, Storage, Event<T>},
 	}
 );
 
@@ -1581,6 +1605,7 @@ impl_runtime_apis! {
 
 			list_benchmark!(list, extra, pallet_assets, Assets);
 			list_benchmark!(list, extra, pallet_babe, Babe);
+			list_benchmark!(list, extra, pallet_bags_list, BagsList);
 			list_benchmark!(list, extra, pallet_balances, Balances);
 			list_benchmark!(list, extra, pallet_bounties, Bounties);
 			list_benchmark!(list, extra, pallet_collective, Council);
@@ -1655,6 +1680,7 @@ impl_runtime_apis! {
 			add_benchmark!(params, batches, pallet_assets, Assets);
 			add_benchmark!(params, batches, pallet_babe, Babe);
 			add_benchmark!(params, batches, pallet_balances, Balances);
+			add_benchmark!(params, batches, pallet_bags_list, BagsList);
 			add_benchmark!(params, batches, pallet_bounties, Bounties);
 			add_benchmark!(params, batches, pallet_collective, Council);
 			add_benchmark!(params, batches, pallet_contracts, Contracts);