companion for substrate/pull/7929 (24 nominators)

runtime/common/Cargo.toml

@@ -21,6 +21,7 @@ sp-runtime = { git = "https://github.com/paritytech/substrate", branch = "master
 sp-session = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-staking = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-core = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-npos-elections = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 
 pallet-authorship = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 pallet-balances = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
@@ -84,6 +85,7 @@ std = [
 	"pallet-transaction-payment/std",
 	"runtime-parachains/std",
 	"xcm/std",
+	"sp-npos-elections/std",
 ]
 runtime-benchmarks = [
 	"libsecp256k1/hmac",

runtime/common/src/lib.rs

@@ -129,6 +129,22 @@ pub type SlowAdjustingFeeUpdate<R> = TargetedFeeAdjustment<
 pub type CurrencyToVote = frame_support::traits::U128CurrencyToVote;
 static_assertions::assert_eq_size!(primitives::v1::Balance, u128);
 
+/// The a solution for staking solutions that allows 24 nominators per validator.
+pub mod npos_solution {
+	use sp_std::prelude::*;
+
+	/// The nominator index type.
+	pub type NominatorIndex = u32;
+	/// The validator index type.
+	pub type ValidatorIndex = u16;
+	/// The accuracy type of the solution.
+	pub type Accuracy = sp_runtime::PerU16;
+
+	sp_npos_elections::generate_solution_type!{
+		pub struct CompactSolution24::<NominatorIndex, ValidatorIndex, Accuracy>(24)
+	}
+}
+
 /// A placeholder since there is currently no provided session key handler for parachain validator
 /// keys.
 pub struct ParachainSessionKeyPlaceholder<T>(sp_std::marker::PhantomData<T>);

runtime/common/src/paras_registrar.rs

@@ -422,6 +422,7 @@ mod tests {
 		type MaxIterations = ();
 		type MinSolutionScoreBump = ();
 		type OffchainSolutionWeightLimit = ();
+		type CompactSolution = pallet_staking::default_solution::CompactSolution24;
 		type WeightInfo = ();
 	}
 

runtime/kusama/src/lib.rs

@@ -390,6 +390,7 @@ impl pallet_staking::Config for Runtime {
 	// The unsigned solution weight targeted by the OCW. We set it to the maximum possible value of
 	// a single extrinsic.
 	type OffchainSolutionWeightLimit = OffchainSolutionWeightLimit;
+	type CompactSolution = runtime_common::npos_solution::CompactSolution24;
 	type WeightInfo = weights::pallet_staking::WeightInfo<Runtime>;
 }
 

runtime/polkadot/src/lib.rs

@@ -398,6 +398,7 @@ impl pallet_staking::Config for Runtime {
 	// The unsigned solution weight targeted by the OCW. We set it to the maximum possible value of
 	// a single extrinsic.
 	type OffchainSolutionWeightLimit = OffchainSolutionWeightLimit;
+	type CompactSolution = runtime_common::npos_solution::CompactSolution24;
 	type WeightInfo = weights::pallet_staking::WeightInfo<Runtime>;
 }
 

runtime/test-runtime/src/lib.rs

@@ -332,6 +332,7 @@ impl pallet_staking::Config for Runtime {
 	type MaxIterations = MaxIterations;
 	type OffchainSolutionWeightLimit = ();
 	type MinSolutionScoreBump = MinSolutionScoreBump;
+	type CompactSolution = pallet_staking::default_solution::CompactSolution24;
 	type WeightInfo = ();
 
 }

runtime/westend/src/lib.rs

@@ -368,6 +368,7 @@ impl pallet_staking::Config for Runtime {
 	type MaxIterations = MaxIterations;
 	type MinSolutionScoreBump = MinSolutionScoreBump;
 	type OffchainSolutionWeightLimit = OffchainSolutionWeightLimit;
+	type CompactSolution = runtime_common::npos_solution::CompactSolution24;
 	type WeightInfo = weights::pallet_staking::WeightInfo<Runtime>;
 }