feat: introduce pallet-parameters to Westend to parameterize inflation

polkadot/runtime/westend/Cargo.toml

@@ -72,6 +72,7 @@ pallet-multisig = { workspace = true }
 pallet-nomination-pools = { workspace = true }
 pallet-conviction-voting = { workspace = true }
 pallet-offences = { workspace = true }
+pallet-parameters = { workspace = true }
 pallet-preimage = { workspace = true }
 pallet-proxy = { workspace = true }
 pallet-recovery = { workspace = true }
@@ -174,6 +175,7 @@ std = [
 	"pallet-nomination-pools/std",
 	"pallet-offences-benchmarking?/std",
 	"pallet-offences/std",
+	"pallet-parameters/std",
 	"pallet-preimage/std",
 	"pallet-proxy/std",
 	"pallet-recovery/std",
@@ -261,6 +263,7 @@ runtime-benchmarks = [
 	"pallet-nomination-pools/runtime-benchmarks",
 	"pallet-offences-benchmarking/runtime-benchmarks",
 	"pallet-offences/runtime-benchmarks",
+	"pallet-parameters/runtime-benchmarks",
 	"pallet-preimage/runtime-benchmarks",
 	"pallet-proxy/runtime-benchmarks",
 	"pallet-recovery/runtime-benchmarks",
@@ -319,6 +322,7 @@ try-runtime = [
 	"pallet-multisig/try-runtime",
 	"pallet-nomination-pools/try-runtime",
 	"pallet-offences/try-runtime",
+	"pallet-parameters/try-runtime",
 	"pallet-preimage/try-runtime",
 	"pallet-proxy/try-runtime",
 	"pallet-recovery/try-runtime",
@@ -348,7 +352,10 @@ metadata-hash = ["substrate-wasm-builder/metadata-hash"]
 # Set timing constants (e.g. session period) to faster versions to speed up testing.
 fast-runtime = []
 
-runtime-metrics = ["polkadot-runtime-parachains/runtime-metrics", "sp-io/with-tracing"]
+runtime-metrics = [
+	"polkadot-runtime-parachains/runtime-metrics",
+	"sp-io/with-tracing",
+]
 
 # A feature that should be enabled when the runtime should be built for on-chain
 # deployment. This will disable stuff that shouldn't be part of the on-chain wasm

polkadot/runtime/westend/src/lib.rs

@@ -24,12 +24,14 @@ use codec::{Decode, Encode, MaxEncodedLen};
 use frame_election_provider_support::{bounds::ElectionBoundsBuilder, onchain, SequentialPhragmen};
 use frame_support::{
 	derive_impl,
+	dynamic_params::{dynamic_pallet_params, dynamic_params},
 	genesis_builder_helper::{build_state, get_preset},
 	parameter_types,
 	traits::{
 		fungible::HoldConsideration, tokens::UnityOrOuterConversion, ConstU32, Contains, EitherOf,
-		EitherOfDiverse, EverythingBut, FromContains, InstanceFilter, KeyOwnerProofSystem,
-		LinearStoragePrice, ProcessMessage, ProcessMessageError, VariantCountOf, WithdrawReasons,
+		EitherOfDiverse, EnsureOriginWithArg, EverythingBut, FromContains, InstanceFilter,
+		KeyOwnerProofSystem, LinearStoragePrice, ProcessMessage, ProcessMessageError,
+		VariantCountOf, WithdrawReasons,
 	},
 	weights::{ConstantMultiplier, WeightMeter, WeightToFee as _},
 	PalletId,
@@ -241,6 +243,56 @@ parameter_types! {
 	pub const PreimageHoldReason: RuntimeHoldReason = RuntimeHoldReason::Preimage(pallet_preimage::HoldReason::Preimage);
 }
 
+/// Dynamic params that can be adjusted at runtime.
+#[dynamic_params(RuntimeParameters, pallet_parameters::Parameters::<Runtime>)]
+pub mod dynamic_params {
+	use super::*;
+
+	#[dynamic_pallet_params]
+	#[codec(index = 0)]
+	pub mod staking_reward_curve {
+		#[codec(index = 0)]
+		pub static MinInflation: u32 = 0_025_000;
+		#[codec(index = 1)]
+		pub static MaxInflation: u32 = 0_100_000;
+		#[codec(index = 2)]
+		pub static IdealStake: u32 = 0_500_000;
+		#[codec(index = 3)]
+		pub static Falloff: u32 = 0_050_000;
+		#[codec(index = 4)]
+		pub static MaxPieceCount: u32 = 40;
+		#[codec(index = 5)]
+		pub static TestPrecision: u32 = 0_005_000;
+	}
+}
+
+impl pallet_parameters::Config for Runtime {
+	type RuntimeEvent = RuntimeEvent;
+	type RuntimeParameters = RuntimeParameters;
+	type AdminOrigin = DynamicParameterOrigin;
+	// TODO: add benchmarking and update weight info
+	type WeightInfo = ();
+}
+
+/// Defines what origin can modify which dynamic parameters.
+pub struct DynamicParameterOrigin;
+impl EnsureOriginWithArg<RuntimeOrigin, RuntimeParametersKey> for DynamicParameterOrigin {
+	type Success = ();
+
+	fn try_origin(
+		origin: RuntimeOrigin,
+		key: &RuntimeParametersKey,
+	) -> Result<Self::Success, RuntimeOrigin> {
+		use crate::{dynamic_params::*, governance::*, RuntimeParametersKey::*};
+		// TODO: update to correct origin
+
+		match key {
+			StakingRewardCurve(_) => frame_system::ensure_root(origin.clone()),
+		}
+		.map_err(|_| origin)
+	}
+}
+
 impl pallet_preimage::Config for Runtime {
 	type WeightInfo = weights::pallet_preimage::WeightInfo<Runtime>;
 	type RuntimeEvent = RuntimeEvent;
@@ -598,12 +650,12 @@ impl pallet_bags_list::Config<VoterBagsListInstance> for Runtime {
 
 pallet_staking_reward_curve::build! {
 	const REWARD_CURVE: PiecewiseLinear<'static> = curve!(
-		min_inflation: 0_025_000,
-		max_inflation: 0_100_000,
-		ideal_stake: 0_500_000,
-		falloff: 0_050_000,
-		max_piece_count: 40,
-		test_precision: 0_005_000,
+		min_inflation: 0_025_000, // dynamic_params::staking_reward_curve::MinInflation,
+		max_inflation: 0_100_000, // dynamic_params::staking_reward_curve::MaxInflation::get(),
+		ideal_stake: 0_500_000, // dynamic_params::staking_reward_curve::IdealStake::get(),
+		falloff: 0_050_000, // dynamic_params::staking_reward_curve::Falloff::get(),
+		max_piece_count: 40, // dynamic_params::staking_reward_curve::MaxPieceCount::get(),
+		test_precision: 0_005_000, // dynamic_params::staking_reward_curve::TestPrecision::get(),
 	);
 }
 
@@ -1008,7 +1060,8 @@ impl InstanceFilter<RuntimeCall> for ProxyType {
 				matches!(
 					c,
 					RuntimeCall::Staking(..) |
-						RuntimeCall::Session(..) | RuntimeCall::Utility(..) |
+						RuntimeCall::Session(..) |
+						RuntimeCall::Utility(..) |
 						RuntimeCall::FastUnstake(..) |
 						RuntimeCall::VoterList(..) |
 						RuntimeCall::NominationPools(..)
@@ -1475,6 +1528,8 @@ mod runtime {
 	pub type Offences = pallet_offences;
 	#[runtime::pallet_index(27)]
 	pub type Historical = session_historical;
+	#[runtime::pallet_index(70)]
+	pub type Parameters = pallet_parameters;
 
 	#[runtime::pallet_index(8)]
 	pub type Session = pallet_session;