Merge pull request #5086 from ignazio-bovo/luxor/reward-curve-proposal

Luxor/reward-curve-proposal

bin/node/src/chain_spec/council_config.rs

@@ -2,6 +2,7 @@ use node_runtime::{
  constants::currency, council::CouncilStageUpdate, days, dollars, hours,
  monthly_dollars_to_per_block, Balance, CouncilConfig, ExpectedBlockTime,
 };
+use sp_runtime::Percent;
 
 pub fn create_council_config() -> CouncilConfig {
  CouncilConfig {
@@ -12,5 +13,6 @@ pub fn create_council_config() -> CouncilConfig {
  next_budget_refill: 1,
  budget_increment: dollars!(22_000),
  councilor_reward: monthly_dollars_to_per_block!(10_000),
+ era_payout_damping_factor: Percent::from_percent(100),
  }
 }

runtime-modules/council/src/benchmarking.rs

@@ -716,6 +716,16 @@ benchmarks! {
  );
  }
 
+ set_era_payout_damping_factor {
+ let new_value = Percent::from_percent(80);
+
+ }: _ (RawOrigin::Root, new_value)
+ verify {
+ assert_eq!(Council::<T>::era_payout_damping_factor(), Percent::from_percent(80), "Budget not updated");
+ assert_last_event::<T>(
+ RawEvent::EraPayoutDampingFactorSet(new_value).into()
+ );
+ }
 
  candidate_remark {
  let msg = b"test".to_vec();
@@ -900,4 +910,12 @@ mod tests {
  assert_ok!(Council::<Runtime>::test_benchmark_candidate_remark());
  })
  }
+
+ #[test]
+ fn test_set_era_payout_damping_factor() {
+ let config = default_genesis_config();
+ build_test_externalities(config).execute_with(|| {
+ assert_ok!(Council::<Runtime>::test_benchmark_set_era_payout_damping_factor());
+ })
+ }
 }

runtime-modules/council/src/lib.rs

@@ -79,6 +79,7 @@ use scale_info::TypeInfo;
 #[cfg(feature = "std")]
 use serde::{Deserialize, Serialize};
 use sp_runtime::traits::{Hash, One, SaturatedConversion, Saturating, Zero};
+use sp_runtime::Percent;
 use sp_std::convert::TryInto;
 use sp_std::{vec, vec::Vec};
 use staking_handler::StakingHandler;
@@ -367,6 +368,10 @@ decl_storage! { generate_storage_info
 
  /// Councilor reward per block
  pub CouncilorReward get(fn councilor_reward) config(): Balance<T>;
+
+ /// Era payou damping factor: a parameter in [0,1] that can be used to reduce the era
+ /// payout without changing the reward curve directly
+ pub EraPayoutDampingFactor get(fn era_payout_damping_factor) config(): Percent = Percent::from_percent(100);
  }
 }
 
@@ -443,6 +448,9 @@ decl_event! {
 
  /// Candidate remark message
  CandidateRemarked(MemberId, Vec<u8>),
+
+ /// Era payou damping factor set
+ EraPayoutDampingFactorSet(Percent),
  }
 }
 
@@ -851,6 +859,33 @@ decl_module! {
  Ok(())
  }
 
+ /// Set the era payout damping factor
+ ///
+ /// # <weight>
+ ///
+ /// ## weight
+ /// `O (1)`
+ /// - db:
+ /// - `O(1)` doesn't depend on the state or parameters
+ /// # </weight>
+ #[weight = CouncilWeightInfo::<T>::set_era_payout_damping_factor()] // TODO: adjust
+ pub fn set_era_payout_damping_factor(origin, new_parameter: Percent) -> Result<(), Error<T>> {
+ // ensure action can be started
+ EnsureChecks::<T>::can_set_era_payout_damping_factor(origin)?;
+
+ //
+ // == MUTATION SAFE ==
+ //
+
+ // update state
+ Mutations::<T>::set_era_payout_damping_factor(new_parameter);
+
+ // emit event
+ Self::deposit_event(RawEvent::EraPayoutDampingFactorSet(new_parameter));
+
+ Ok(())
+ }
+
  /// Decrease the council total budget
  ///
  /// # <weight>
@@ -1653,6 +1688,10 @@ impl<T: Config> Mutations<T> {
  let next_reward_block = now + T::ElectedMemberRewardPeriod::get();
  NextRewardPayments::<T>::put(next_reward_block);
  }
+
+ fn set_era_payout_damping_factor(new_parameter: Percent) {
+ EraPayoutDampingFactor::put(new_parameter);
+ }
 }
 
 /////////////////// Ensure checks //////////////////////////////////////////////
@@ -1835,6 +1874,12 @@ impl<T: Config> EnsureChecks<T> {
 
  Ok(())
  }
+
+ fn can_set_era_payout_damping_factor(origin: T::RuntimeOrigin) -> Result<(), Error<T>> {
+ ensure_root(origin)?;
+
+ Ok(())
+ }
 }
 
 impl<T: Config + common::membership::MembershipTypes>

runtime-modules/council/src/mock.rs

@@ -27,6 +27,7 @@ use sp_runtime::traits::Hash;
 use sp_runtime::{
  testing::Header,
  traits::{BlakeTwo256, IdentityLookup, Zero},
+ Percent,
 };
 use staking_handler::{LockComparator, StakingHandler, StakingManager};
 use std::boxed::Box;
@@ -538,6 +539,7 @@ pub fn default_genesis_config() -> council::GenesisConfig<Runtime> {
  next_budget_refill: <Runtime as Config>::BudgetRefillPeriod::get(),
  budget_increment: 1,
  councilor_reward: 100,
+ era_payout_damping_factor: Percent::from_percent(100),
  }
 }
 

runtime-modules/council/src/weights.rs

@@ -62,6 +62,7 @@ pub trait WeightInfo {
  fn decrease_council_budget() -> Weight;
  fn candidate_remark() -> Weight;
  fn councilor_remark() -> Weight;
+ fn set_era_payout_damping_factor() -> Weight;
 }
 
 /// Weights for council using the Substrate node and recommended hardware.
@@ -348,6 +349,11 @@ impl<T: frame_system::Config> WeightInfo for SubstrateWeight<T> {
  .saturating_add(Weight::from_parts(0, 5400))
  .saturating_add(T::DbWeight::get().reads(2_u64))
  }
+
+ fn set_era_payout_damping_factor() -> Weight {
+ Weight::from_parts(0, 0u64)
+ }
+
 }
 
 // Default implementation for tests
@@ -406,5 +412,8 @@ impl WeightInfo for () {
  fn decrease_council_budget() -> Weight {
  Weight::from_parts(0, 0u64)
  }
+ fn set_era_payout_damping_factor() -> Weight {
+ Weight::from_parts(0, 0u64)
+ }
 
 }

runtime-modules/proposals/codex/src/lib.rs

@@ -287,6 +287,11 @@ pub trait Config:
  ProposalParameters<Self::BlockNumber, BalanceOf<Self>>,
  >;
 
+ /// `Set Era Payout Damping Factor` proposal parameters
+ type SetEraPayoutDampingFactorProposalParameters: Get<
+ ProposalParameters<Self::BlockNumber, BalanceOf<Self>>,
+ >;
+
  /// `Decrease Council Budget` proposal parameters
  type DecreaseCouncilBudgetProposalParameters: Get<
  ProposalParameters<Self::BlockNumber, BalanceOf<Self>>,
@@ -530,6 +535,11 @@ decl_module! {
  const UpdateTokenPalletTokenConstraints:
  ProposalParameters<T::BlockNumber, BalanceOf<T>> = T::UpdateTokenPalletTokenConstraints::get();
 
+ /// Era payout damping factor
+ const SetEraPayoutDampingFactorProposalParameters:
+ ProposalParameters<T::BlockNumber, BalanceOf<T>> = T::SetEraPayoutDampingFactorProposalParameters::get();
+
+
  /// Create a proposal, the type of proposal depends on the `proposal_details` variant
  ///
  /// <weight>
@@ -900,15 +910,18 @@ impl<T: Config> Module<T> {
  ProposalDetails::SetPalletFozenStatus(..) => {
  // Note: No checks for this proposal for now
  }
- ProposalDetails::UpdateTokenPalletTokenConstraints(..) => {
- // Note: No checks for this proposal for now
- }
  ProposalDetails::DecreaseCouncilBudget(reduction_amount) => {
  ensure!(
  !(*reduction_amount).is_zero(),
  Error::<T>::ReductionAmountZero
  );
  }
+ ProposalDetails::UpdateTokenPalletTokenConstraints(..) => {
+ // Note: No checks for this proposal for now
+ }
+ ProposalDetails::SetEraPayoutDampingFactor(..) => {
+ // Note: No checks for this proposal for now
+ }
  }
 
  Ok(())
@@ -979,11 +992,14 @@ impl<T: Config> Module<T> {
  ProposalDetails::SetPalletFozenStatus(..) => {
  T::SetPalletFozenStatusProposalParameters::get()
  }
+ ProposalDetails::DecreaseCouncilBudget(..) => {
+ T::DecreaseCouncilBudgetProposalParameters::get()
+ }
  ProposalDetails::UpdateTokenPalletTokenConstraints(..) => {
  T::UpdateTokenPalletTokenConstraints::get()
  }
- ProposalDetails::DecreaseCouncilBudget(..) => {
- T::DecreaseCouncilBudgetProposalParameters::get()
+ ProposalDetails::SetEraPayoutDampingFactor(..) => {
+ T::SetEraPayoutDampingFactorProposalParameters::get()
  }
  }
  }
@@ -1152,14 +1168,20 @@ impl<T: Config> Module<T> {
  to_kb(description_length.saturated_into()),
  )
  }
+ ProposalDetails::DecreaseCouncilBudget(..) => {
+ WeightInfoCodex::<T>::create_proposal_decrease_council_budget(
+ to_kb(title_length.saturated_into()),
+ to_kb(description_length.saturated_into()),
+ )
+ }
  ProposalDetails::UpdateTokenPalletTokenConstraints(..) => {
- WeightInfoCodex::<T>::create_proposal_update_token_pallet_governance_parameters(
+ WeightInfoCodex::<T>::create_proposal_update_token_pallet_token_constraints(
  to_kb(title_length.saturated_into()),
  to_kb(description_length.saturated_into()),
  )
  }
- ProposalDetails::DecreaseCouncilBudget(..) => {
- WeightInfoCodex::<T>::create_proposal_decrease_council_budget(
+ ProposalDetails::SetEraPayoutDampingFactor(..) => {
+ WeightInfoCodex::<T>::create_proposal_set_era_payout_damping_factor(
  to_kb(title_length.saturated_into()),
  to_kb(description_length.saturated_into()),
  )

runtime-modules/proposals/codex/src/tests/mock.rs

@@ -786,6 +786,7 @@ impl crate::Config for Test {
  type SetMaxValidatorCountProposalMaxValidators = SetMaxValidatorCountProposalMaxValidators;
  type SetPalletFozenStatusProposalParameters = DefaultProposalParameters;
  type UpdateTokenPalletTokenConstraints = DefaultProposalParameters;
+ type SetEraPayoutDampingFactorProposalParameters = DefaultProposalParameters;
  type DecreaseCouncilBudgetProposalParameters = DefaultProposalParameters;
 }
 

runtime-modules/proposals/codex/src/types.rs

@@ -10,6 +10,7 @@ use sp_std::vec::Vec;
 use common::working_group::WorkingGroup;
 use common::BalanceKind;
 use common::FundingRequestParameters;
+use sp_runtime::Percent;
 
 use content::NftLimitPeriod;
 use working_group::StakePolicy;
@@ -128,6 +129,9 @@ pub enum ProposalDetails<
  /// Update token constraints
  UpdateTokenPalletTokenConstraints(TokenConstraints),
 
+ /// `SetEraPayoutDampingFactor` proposal
+ SetEraPayoutDampingFactor(Percent),
+
  /// `DecreaseCouncilBudget` proposal
  DecreaseCouncilBudget(Balance),
 }

runtime-modules/proposals/codex/src/weights.rs

@@ -68,7 +68,8 @@ pub trait WeightInfo {
  fn create_proposal_update_global_nft_limit(_t: u32, _d: u32, ) -> Weight;
  fn create_proposal_update_channel_payouts(_t: u32, _d: u32, _i: u32, ) -> Weight;
  fn create_proposal_freeze_pallet(_t: u32, _d: u32, ) -> Weight;
- fn create_proposal_update_token_pallet_governance_parameters(_t: u32, _d: u32, ) -> Weight;
+ fn create_proposal_update_token_pallet_token_constraints(_t: u32, _d: u32, ) -> Weight;
+ fn create_proposal_set_era_payout_damping_factor(_t: u32, _d: u32) -> Weight;
  fn create_proposal_decrease_council_budget(_t: u32, _d: u32, ) -> Weight;
 }
 
@@ -1021,9 +1022,12 @@ impl<T: frame_system::Config> WeightInfo for SubstrateWeight<T> {
  .saturating_add(T::DbWeight::get().reads(7_u64))
  .saturating_add(T::DbWeight::get().writes(9_u64))
  }
- fn create_proposal_update_token_pallet_governance_parameters(_t: u32, _d: u32) -> Weight {
+ fn create_proposal_update_token_pallet_token_constraints(_t: u32, _d: u32, ) -> Weight { 
  Weight::from_parts(0, 0)
  }
+ fn create_proposal_set_era_payout_damping_factor(_t: u32, _d: u32) -> Weight {
+ Weight::from_parts(0,0)
+ }
 
  fn create_proposal_decrease_council_budget(t: u32, d: u32, ) -> Weight {
  Weight::from_parts(0, 0)
@@ -1104,9 +1108,13 @@ impl WeightInfo for () {
  fn create_proposal_freeze_pallet(t: u32, d: u32, ) -> Weight {
  Weight::from_parts(0, 0)
  }
- fn create_proposal_update_token_pallet_governance_parameters(_t: u32, _d: u32, ) -> Weight {
+ fn create_proposal_update_token_pallet_token_constraints(_t: u32, _d: u32, ) -> Weight { 
  Weight::from_parts(0, 0)
  }
+
+ fn create_proposal_set_era_payout_damping_factor(_t: u32, _d: u32) -> Weight {
+ Weight::from_parts(0,0)
+ }
  fn create_proposal_decrease_council_budget(t: u32, d: u32, ) -> Weight {
  Weight::from_parts(0, 0)
  }

runtime/src/integration/proposals/proposal_encoder.rs

@@ -176,6 +176,9 @@ impl ProposalEncoder<Runtime> for ExtrinsicProposalEncoder {
  RuntimeCall::ProjectToken(project_token::Call::set_frozen_status { freeze })
  }
  },
+ ProposalDetails::SetEraPayoutDampingFactor(new_parameter) => {
+ RuntimeCall::Council(council::Call::set_era_payout_damping_factor { new_parameter })
+ }
  ProposalDetails::DecreaseCouncilBudget(reduction_amount) => {
  RuntimeCall::Council(council::Call::decrease_council_budget { reduction_amount })
  }

runtime/src/lib.rs

@@ -53,6 +53,7 @@ mod weights;
 extern crate lazy_static; // for proposals_configuration module
 
 use codec::Decode;
+use core::ops::Div;
 use frame_election_provider_support::{
  onchain, BalancingConfig, ElectionDataProvider, SequentialPhragmen, VoteWeight,
 };
@@ -536,11 +537,21 @@ impl EraPayout<Balance> for NoInflationIfNoEras {
  // PoA mode: no inflation.
  (0, 0)
  } else {
- <pallet_staking::ConvertCurve<RewardCurve> as EraPayout<Balance>>::era_payout(
- total_staked,
- total_issuance,
- era_duration_millis,
- )
+ // rescale the era payout according to the damping factor while keeping the invariant
+ // era_payou + rest = max_payout
+ let (era_payout_unscaled, rest_unscaled) =
+ <pallet_staking::ConvertCurve<RewardCurve> as EraPayout<Balance>>::era_payout(
+ total_staked,
+ total_issuance,
+ era_duration_millis,
+ );
+ let max_payout = era_payout_unscaled.saturating_add(rest_unscaled);
+ let damping_factor_parts = Council::era_payout_damping_factor().deconstruct();
+ let era_payout_scaled = era_payout_unscaled
+ .saturating_mul(damping_factor_parts.into())
+ .div(100u128);
+ let rest_scaled = max_payout.saturating_sub(era_payout_scaled);
+ (era_payout_scaled, rest_scaled)
  }
  }
 }
@@ -1709,6 +1720,7 @@ impl proposals_codex::Config for Runtime {
  type SetMaxValidatorCountProposalMaxValidators = SetMaxValidatorCountProposalMaxValidators;
  type UpdateTokenPalletTokenConstraints = UpdateTokenPalletTokenConstraints;
  type SetPalletFozenStatusProposalParameters = SetPalletFozenStatusProposalParameters;
+ type SetEraPayoutDampingFactorProposalParameters = SetEraPayoutDampingFactorProposalParameters;
  type WeightInfo = proposals_codex::weights::SubstrateWeight<Runtime>;
 }