feat: add block rewards to altair and centrifuge runtimes

pallets/block-rewards/src/benchmarking.rs

@@ -44,8 +44,11 @@ benchmarks! {
 
 	}: _(RawOrigin::Signed(caller), beneficiary.clone())
 	verify {
+		let num_collators: u128 = BlockRewards::<T>::next_session_changes().collator_count.unwrap_or(
+			BlockRewards::<T>::active_session_data().collator_count
+		).into();
 		// Does not get entire reward since another collator is auto-staked via genesis config
-		assert_eq!(<T as Config>::Currency::balance(CurrencyId::Native.into(), &beneficiary).saturating_sub(before), (REWARD / 2).into());
+		assert_eq!(<T as Config>::Currency::balance(CurrencyId::Native.into(), &beneficiary).saturating_sub(before), (REWARD / (num_collators + 1)).into());
 	}
 
 	set_collator_reward {

pallets/block-rewards/src/migrations.rs

@@ -101,8 +101,7 @@ where
 			weight.saturating_accrue(T::DbWeight::get().writes(1));
 
 			for collator in collators.iter() {
-				// TODO: Benching preferred to be precise.
-				// However, not necessarily needed as num of collators <= 10.
+				// NOTE: Benching not required as num of collators <= 10.
 				Pallet::<T>::do_init_collator(collator)
 					.map_err(|e| {
 						log::error!("Failed to init genesis collators for rewards: {:?}", e);

pallets/block-rewards/src/mock.rs

@@ -115,7 +115,7 @@ impl pallet_session::Config for Test {
 }
 
 parameter_types! {
-	pub const ExistentialDeposit: Balance = 0;
+	pub const ExistentialDeposit: Balance = 1;
 }
 impl pallet_balances::Config for Test {
 	type AccountStore = System;
@@ -378,6 +378,13 @@ impl ExtBuilder {
 		.assimilate_storage(&mut storage)
 		.expect("Session pallet's storage can be assimilated");
 
+		pallet_rewards::GenesisConfig::<Test, pallet_rewards::Instance1> {
+			currency_id: CurrencyId::Native,
+			amount: ExistentialDeposit::get(),
+		}
+		.assimilate_storage(&mut storage)
+		.expect("Rewards pallet's storage can be assimilated");
+
 		let mut ext = sp_io::TestExternalities::new(storage);
 
 		ext.execute_with(|| {

pallets/block-rewards/src/tests.rs

@@ -287,7 +287,10 @@ fn single_claim_reward() {
 				},
 			));
 			assert_eq!(Balances::total_balance(&TREASURY_ADDRESS), 9 * REWARD);
-			assert_eq!(Balances::total_issuance(), 10 * REWARD);
+			assert_eq!(
+				Balances::total_issuance(),
+				10 * REWARD + ExistentialDeposit::get()
+			);
 			assert_eq!(Balances::free_balance(&1), REWARD);
 		});
 }
@@ -314,7 +317,10 @@ fn collator_rewards_greater_than_remainder() {
 				),
 				Ok(REWARD)
 			);
-			assert_eq!(Balances::total_issuance(), 2 * REWARD);
+			assert_eq!(
+				Balances::total_issuance(),
+				2 * REWARD + ExistentialDeposit::get()
+			);
 			assert_eq!(Balances::total_balance(&TREASURY_ADDRESS), REWARD);
 
 			// EPOCH 1 -> EPOCH 2
@@ -333,7 +339,10 @@ fn collator_rewards_greater_than_remainder() {
 				Ok(2 * REWARD)
 			);
 			assert_eq!(Balances::total_balance(&TREASURY_ADDRESS), 2 * REWARD);
-			assert_eq!(Balances::total_issuance(), 4 * REWARD);
+			assert_eq!(
+				Balances::total_issuance(),
+				4 * REWARD + ExistentialDeposit::get()
+			);
 
 			// EPOCH 2 -> EPOCH 3
 			advance_session();
@@ -364,7 +373,10 @@ fn collator_rewards_greater_than_remainder() {
 				);
 			}
 			assert_eq!(Balances::total_balance(&TREASURY_ADDRESS), 2 * REWARD);
-			assert_eq!(Balances::total_issuance(), 6 * REWARD);
+			assert_eq!(
+				Balances::total_issuance(),
+				6 * REWARD + ExistentialDeposit::get()
+			);
 
 			// EPOCH 3 -> EPOCH 4
 			advance_session();
@@ -403,7 +415,10 @@ fn collator_rewards_greater_than_remainder() {
 				Ok(2 * REWARD / 3)
 			);
 			assert_eq!(Balances::total_balance(&TREASURY_ADDRESS), 2 * REWARD);
-			assert_eq!(Balances::total_issuance(), 8 * REWARD);
+			assert_eq!(
+				Balances::total_issuance(),
+				8 * REWARD + ExistentialDeposit::get()
+			);
 		});
 }
 

pallets/rewards/Cargo.toml

@@ -17,6 +17,7 @@ cfg-types = { path = "../../libs/types", default-features = false }
 codec = { package = "parity-scale-codec", version = "3.0.0", default-features = false, features = ["derive"] }
 frame-support = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "polkadot-v0.9.37" }
 frame-system = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "polkadot-v0.9.37" }
+log = { version = "0.4.17", default-features = false }
 num-traits = { version = "0.2", default-features = false }
 scale-info = { version = "2.3.0", default-features = false, features = ["derive"] }
 sp-runtime = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "polkadot-v0.9.37" }
@@ -42,6 +43,7 @@ std = [
   "codec/std",
   "frame-support/std",
   "frame-system/std",
+  "log/std",
   "sp-runtime/std",
   "sp-std/std",
   "cfg-traits/std",

pallets/rewards/src/lib.rs

@@ -69,13 +69,16 @@ mod tests;
 
 pub mod issuance;
 pub mod mechanism;
+pub mod migrations {
+	pub mod new_instance;
+}
 
 use cfg_traits::rewards::{AccountRewards, CurrencyGroupChange, GroupRewards, RewardIssuance};
 use codec::FullCodec;
 use frame_support::{
 	pallet_prelude::*,
 	traits::{
-		fungibles::{InspectHold, Mutate, MutateHold, Transfer},
+		fungibles::{Inspect, InspectHold, Mutate, MutateHold, Transfer},
 		tokens::AssetId,
 	},
 	PalletId,
@@ -110,7 +113,7 @@ pub mod pallet {
 		type DomainId: TypeInfo + MaxEncodedLen + FullCodec + Copy + PartialEq + Debug;
 
 		/// Type used to identify currencies.
-		type CurrencyId: AssetId + MaxEncodedLen;
+		type CurrencyId: AssetId + MaxEncodedLen + MaybeSerializeDeserialize + Default;
 
 		/// Identifier for the currency used to give the reward.
 		type RewardCurrency: Get<Self::CurrencyId>;
@@ -120,7 +123,8 @@ pub mod pallet {
 
 		/// Type used to handle currency transfers and reservations.
 		type Currency: MutateHold<Self::AccountId, AssetId = Self::CurrencyId, Balance = BalanceOf<Self, I>>
-			+ Mutate<Self::AccountId, AssetId = Self::CurrencyId, Balance = BalanceOf<Self, I>>;
+			+ Mutate<Self::AccountId, AssetId = Self::CurrencyId, Balance = BalanceOf<Self, I>>
+			+ Inspect<Self::AccountId, AssetId = Self::CurrencyId, Balance = BalanceOf<Self, I>>;
 
 		/// Specify the internal reward mechanism used by this pallet.
 		/// Check available mechanisms at [`mechanism`] module.
@@ -138,6 +142,44 @@ pub mod pallet {
 	#[pallet::generate_store(pub(super) trait Store)]
 	pub struct Pallet<T, I = ()>(_);
 
+	#[pallet::genesis_config]
+	pub struct GenesisConfig<T: Config<I>, I: 'static = ()>
+	where
+		BalanceOf<T, I>: MaybeSerializeDeserialize,
+	{
+		pub currency_id: T::CurrencyId,
+		pub amount: BalanceOf<T, I>,
+	}
+
+	#[cfg(feature = "std")]
+	impl<T: Config<I>, I: 'static> Default for GenesisConfig<T, I>
+	where
+		BalanceOf<T, I>: MaybeSerializeDeserialize,
+	{
+		fn default() -> Self {
+			Self {
+				currency_id: Default::default(),
+				amount: Default::default(),
+			}
+		}
+	}
+
+	#[pallet::genesis_build]
+	impl<T: Config<I>, I: 'static> GenesisBuild<T, I> for GenesisConfig<T, I>
+	where
+		BalanceOf<T, I>: MaybeSerializeDeserialize,
+	{
+		fn build(&self) {
+			T::Currency::mint_into(
+				self.currency_id,
+				&T::PalletId::get().into_account_truncating(),
+				self.amount,
+			)
+			.map_err(|_| log::error!("Failed to mint ED for sovereign pallet account",))
+			.ok();
+		}
+	}
+
 	// --------------------------
 	//          Storage
 	// --------------------------

pallets/rewards/src/migrations/new_instance.rs

@@ -0,0 +1,82 @@
+// Copyright 2021 Centrifuge Foundation (centrifuge.io).
+//
+// This file is part of the Centrifuge chain project.
+// Centrifuge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version (see http://www.gnu.org/licenses).
+// Centrifuge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+use frame_support::traits::{
+	fungibles::{Inspect, Mutate},
+	Get, OnRuntimeUpgrade,
+};
+use sp_runtime::traits::AccountIdConversion;
+use sp_std::marker::PhantomData;
+#[cfg(feature = "try-runtime")]
+use {frame_support::inherent::Vec, sp_std::vec};
+
+use crate::{BalanceOf, Config};
+
+pub struct FundExistentialDeposit<T, I, Currency, ED>(PhantomData<(T, I, Currency, ED)>);
+
+fn pallet_is_funded<T, I, Currency, ED>() -> bool
+where
+	T: Config<I>,
+	I: 'static,
+	Currency: Get<<T as Config<I>>::CurrencyId>,
+	ED: Get<BalanceOf<T, I>>,
+{
+	let balance = <<T as Config<I>>::Currency as Inspect<T::AccountId>>::balance(
+		Currency::get(),
+		&<T as Config<I>>::PalletId::get().into_account_truncating(),
+	);
+	balance >= ED::get()
+}
+
+impl<T, I, Currency, ED> OnRuntimeUpgrade for FundExistentialDeposit<T, I, Currency, ED>
+where
+	T: frame_system::Config + Config<I>,
+	I: 'static,
+	Currency: Get<<T as Config<I>>::CurrencyId>,
+	ED: Get<BalanceOf<T, I>>,
+{
+	#[cfg(feature = "try-runtime")]
+	fn pre_upgrade() -> Result<Vec<u8>, &'static str> {
+		assert!(!pallet_is_funded::<T, I, Currency, ED>());
+
+		log::info!("💶 Rewards: Pre funding ED checks successful");
+		Ok(vec![])
+	}
+
+	fn on_runtime_upgrade() -> frame_support::weights::Weight {
+		if !pallet_is_funded::<T, I, Currency, ED>() {
+			log::info!("💶 Rewards: Initiating ED funding to sovereign pallet account");
+			T::Currency::mint_into(
+				Currency::get(),
+				&T::PalletId::get().into_account_truncating(),
+				ED::get(),
+			)
+			.map_err(|_| log::error!("💶 Rewards: Failed to mint ED for sovereign pallet account",))
+			.ok();
+
+			T::DbWeight::get().reads_writes(1, 1)
+		} else {
+			log::info!(
+				"💶 Rewards: ED funding for sovereign pallet account not required anymore. This probably should be removed"
+			);
+			T::DbWeight::get().reads_writes(1, 0)
+		}
+	}
+
+	#[cfg(feature = "try-runtime")]
+	fn post_upgrade(_pre_state: Vec<u8>) -> Result<(), &'static str> {
+		assert!(pallet_is_funded::<T, I, Currency, ED>());
+
+		log::info!("💶 Rewards: Post funding ED checks successful");
+		Ok(())
+	}
+}

pallets/rewards/src/mock.rs

@@ -94,6 +94,12 @@ pub enum CurrencyId {
 	M,
 }
 
+impl Default for CurrencyId {
+	fn default() -> Self {
+		CurrencyId::Reward
+	}
+}
+
 #[derive(Clone, Copy, PartialEq, Eq, Encode, Decode, TypeInfo, MaxEncodedLen, RuntimeDebug)]
 pub enum DomainId {
 	D1,