feat(vara,gear-bank): Split gas and fees to author/treasury (#3652)

Co-authored-by: Dmitry Novikov <novikov.dm.al@gmail.com>

pallets/gear-bank/src/lib.rs

@@ -46,6 +46,8 @@ macro_rules! impl_config {
             type Currency = Balances;
             type BankAddress = BankAddress;
             type GasMultiplier = GasMultiplier;
+            type SplitGasFeeRatio = SplitGasFeeRatio;
+            type SplitTxFeeRatio = SplitTxFeeRatio;
         }
     };
 }
@@ -78,7 +80,7 @@ pub mod pallet {
     use pallet_authorship::Pallet as Authorship;
     use parity_scale_codec::{Decode, Encode, EncodeLike, MaxEncodedLen};
     use scale_info::TypeInfo;
-    use sp_runtime::traits::Zero;
+    use sp_runtime::{traits::Zero, Perbill};
 
     // Funds pallet struct itself.
     #[pallet::pallet]
@@ -100,6 +102,11 @@ pub mod pallet {
         #[pallet::constant]
         /// Gas price converter.
         type GasMultiplier: Get<GasMultiplier<Self>>;
+
+        type SplitGasFeeRatio: Get<Option<(Perbill, AccountIdOf<Self>)>>;
+
+        /// The ratio of how much of the tx fees goes to the treasury
+        type SplitTxFeeRatio: Get<Option<u32>>;
     }
 
     // Funds pallets error.
@@ -218,10 +225,28 @@ pub mod pallet {
             while let Some((account_id, value)) = OnFinalizeTransfers::<T>::drain().next() {
                 total = total.saturating_add(value);
 
-                if let Err(e) = Self::withdraw(&account_id, value) {
-                    log::error!(
-                        "Block #{bn:?} ended with unreachable error while performing on-finalize transfer to {account_id:?}: {e:?}"
-                    );
+                if let Some((gas_split, split_dest)) = T::SplitGasFeeRatio::get() {
+                    // split value by `SplitGasFeeRatio`.
+                    let to_split = gas_split.mul_floor(value);
+                    let to_user = value - to_split;
+
+                    // Withdraw value to user.
+                    if let Err(e) = Self::withdraw(&account_id, to_user) {
+                        log::error!(
+                            "Block #{bn:?} ended with unreachable error while performing on-finalize transfer to {account_id:?}: {e:?}"
+                        );
+                    }
+
+                    // Withdraw value to `SplitGasFeeRatio` destination.
+                    if let Err(e) = Self::withdraw(&split_dest, to_split) {
+                        log::error!(
+                            "Block #{bn:?} ended with unreachable error while performing on-finalize transfer to {account_id:?}: {e:?}"
+                        );
+                    }
+                } else {
+                    let _ = Self::withdraw(&account_id, value).map_err(|e| log::error!(
+                                "Block #{bn:?} ended with unreachable error while performing on-finalize transfer to {account_id:?}: {e:?}"
+                            ));
                 }
             }
 
@@ -541,7 +566,7 @@ pub mod pallet {
                 let err_msg = format!(
                     "pallet_gear_bank::withdraw_value: withdraw failed. \
                     Receiver - {account_id:?}, value - {value:?}, receiver reducible balance - {receiver_balance:?}, \
-                    bank reducible balance - {bank_balance:?}, unused value - {unused_value:?}, 
+                    bank reducible balance - {bank_balance:?}, unused value - {unused_value:?},
                     on finalize value - {on_finalize_value:?}. \
                     Got error - {e:?}"
                 );

pallets/gear-bank/src/mock.rs

@@ -21,12 +21,13 @@ use frame_support::{
     construct_runtime, parameter_types,
     traits::{ConstU32, FindAuthor},
     weights::constants::RocksDbWeight,
+    PalletId,
 };
 use primitive_types::H256;
 use sp_io::TestExternalities;
 use sp_runtime::{
-    traits::{BlakeTwo256, IdentityLookup},
-    BuildStorage,
+    traits::{AccountIdConversion, BlakeTwo256, IdentityLookup},
+    BuildStorage, Perbill,
 };
 
 pub type AccountId = u8;
@@ -64,6 +65,9 @@ parameter_types! {
     pub const GasMultiplier: common::GasMultiplier<Balance, u64> = common::GasMultiplier::ValuePerGas(VALUE_PER_GAS);
     pub const BlockHashCount: BlockNumber = 250;
     pub const ExistentialDeposit: Balance = EXISTENTIAL_DEPOSIT;
+    // TODO: Issue #4058
+    pub SplitGasFeeRatio: Option<(Perbill, AccountId)> = Some((Perbill::from_percent(50), PalletId(*b"py/trsry").into_account_truncating()));
+    pub SplitTxFeeRatio: Option<u32> = None;
 }
 
 construct_runtime!(

pallets/gear-bank/src/tests.rs

@@ -499,7 +499,9 @@ fn spend_gas_all_balance_validator_account_deleted() {
 
         assert_bank_balance(0, 0);
 
-        assert_balance(&BLOCK_AUTHOR, gas_price(GAS_AMOUNT));
+        // mul ceil GAS_AMOUNT because of gas fee split.
+        let (gas_split, _) = SplitGasFeeRatio::get().unwrap();
+        assert_balance(&BLOCK_AUTHOR, gas_split.mul_ceil(gas_price(GAS_AMOUNT)));
 
         assert_alice_dec(gas_price(GAS_AMOUNT));
         assert_gas_value(&ALICE, 0, 0);
@@ -1636,7 +1638,12 @@ mod utils {
     // Asserts block author balance inc.
     #[track_caller]
     pub fn assert_block_author_inc(diff: Balance) {
-        assert_balance(&BLOCK_AUTHOR, EXISTENTIAL_DEPOSIT + diff)
+        // mul ceil diff because of gas fee split.
+        let (gas_split, _) = SplitGasFeeRatio::get().unwrap();
+        assert_balance(
+            &BLOCK_AUTHOR,
+            EXISTENTIAL_DEPOSIT + gas_split.mul_ceil(diff),
+        )
     }
 
     // Asserts Charlie balance inc.

pallets/gear-builtin/src/mock.rs

@@ -113,6 +113,8 @@ parameter_types! {
     pub const PerformanceMultiplier: u32 = 100;
     pub const BankAddress: AccountId = 15082001;
     pub const GasMultiplier: common::GasMultiplier<Balance, u64> = common::GasMultiplier::ValuePerGas(25);
+    pub SplitGasFeeRatio: Option<(Perbill, AccountId)> = None;
+    pub SplitTxFeeRatio: Option<u32> = None;
 }
 
 pallet_gear_bank::impl_config!(Test);

pallets/gear-builtin/src/tests/bad_builtin_ids.rs

@@ -82,6 +82,8 @@ parameter_types! {
     pub const PerformanceMultiplier: u32 = 100;
     pub const BankAddress: AccountId = 15082001;
     pub const GasMultiplier: common::GasMultiplier<Balance, u64> = common::GasMultiplier::ValuePerGas(25);
+    pub SplitGasFeeRatio: Option<(Perbill, AccountId)> = None;
+    pub SplitTxFeeRatio: Option<u32> = None;
 }
 
 pallet_gear_bank::impl_config!(Test);

pallets/gear-builtin/src/tests/staking.rs

@@ -704,6 +704,8 @@ mod util {
         pub const PerformanceMultiplier: u32 = 100;
         pub const BankAddress: AccountId = 15082001;
         pub const GasMultiplier: common::GasMultiplier<Balance, u64> = common::GasMultiplier::ValuePerGas(25);
+        pub SplitGasFeeRatio: Option<(Perbill, AccountId)> = None;
+        pub SplitTxFeeRatio: Option<u32> = None;
     }
 
     pub struct TestSessionHandler;

pallets/gear-debug/src/mock.rs

@@ -32,7 +32,7 @@ use primitive_types::H256;
 use sp_core::ConstBool;
 use sp_runtime::{
     traits::{BlakeTwo256, ConstU64, IdentityLookup},
-    BuildStorage,
+    BuildStorage, Perbill,
 };
 use sp_std::convert::{TryFrom, TryInto};
 
@@ -70,6 +70,8 @@ parameter_types! {
     pub ResumeSessionDuration: BlockNumber = 1_000;
     pub const BankAddress: AccountId = 15082001;
     pub const GasMultiplier: common::GasMultiplier<Balance, u64> = common::GasMultiplier::ValuePerGas(25);
+    pub SplitGasFeeRatio: Option<(Perbill, AccountId)> = None;
+    pub SplitTxFeeRatio: Option<u32> = None;
     pub ReserveThreshold: BlockNumber = 1;
 }
 

pallets/gear-eth-bridge/src/mock.rs

@@ -30,7 +30,7 @@ use sp_core::{ed25519::Public, H256};
 use sp_runtime::{
     impl_opaque_keys,
     traits::{BlakeTwo256, IdentityLookup},
-    BuildStorage,
+    BuildStorage, Perbill,
 };
 use sp_std::convert::{TryFrom, TryInto};
 
@@ -160,6 +160,8 @@ parameter_types! {
     pub const PerformanceMultiplier: u32 = 100;
     pub const BankAddress: AccountId = 15082001;
     pub const GasMultiplier: common::GasMultiplier<Balance, u64> = common::GasMultiplier::ValuePerGas(25);
+    pub SplitGasFeeRatio: Option<(Perbill, AccountId)> = None;
+    pub SplitTxFeeRatio: Option<u32> = None;
 }
 
 pallet_gear_bank::impl_config!(Test);

pallets/gear-scheduler/src/mock.rs

@@ -32,7 +32,7 @@ use pallet_gear::GasAllowanceOf;
 use sp_core::{ConstBool, H256};
 use sp_runtime::{
     traits::{BlakeTwo256, IdentityLookup},
-    BuildStorage,
+    BuildStorage, Perbill,
 };
 
 use sp_std::convert::{TryFrom, TryInto};
@@ -94,6 +94,8 @@ parameter_types! {
     pub ResumeSessionDuration: BlockNumber = 1_000;
     pub const BankAddress: AccountId = 15082001;
     pub const GasMultiplier: common::GasMultiplier<Balance, u64> = common::GasMultiplier::ValuePerGas(25);
+    pub SplitGasFeeRatio: Option<(Perbill, AccountId)> = None;
+    pub SplitTxFeeRatio: Option<u32> = None;
 }
 
 // Build genesis storage according to the mock runtime.

pallets/gear/src/mock.rs

@@ -31,7 +31,7 @@ use frame_system::{self as system, limits::BlockWeights, mocking, pallet_prelude
 use sp_core::{ConstU8, H256};
 use sp_runtime::{
     traits::{BlakeTwo256, IdentityLookup},
-    BuildStorage,
+    BuildStorage, Perbill,
 };
 use sp_std::{
     cell::RefCell,
@@ -173,6 +173,8 @@ impl Drop for DynamicScheduleReset {
 parameter_types! {
     pub const BankAddress: AccountId = 15082001;
     pub const GasMultiplier: common::GasMultiplier<Balance, u64> = common::GasMultiplier::ValuePerGas(1);
+    pub SplitGasFeeRatio: Option<(Perbill, AccountId)> = None;
+    pub SplitTxFeeRatio: Option<u32> = None;
     pub const MinVoucherDuration: BlockNumber = 5;
     pub const MaxVoucherDuration: BlockNumber = 100_000_000;
 }

pallets/payment/src/mock.rs

@@ -35,7 +35,7 @@ use primitive_types::H256;
 use sp_runtime::{
     testing::TestXt,
     traits::{BlakeTwo256, ConstBool, ConstU64, IdentityLookup},
-    BuildStorage,
+    BuildStorage, Perbill,
 };
 use sp_std::{
     convert::{TryFrom, TryInto},
@@ -119,6 +119,8 @@ parameter_types! {
     pub ResumeSessionDuration: BlockNumber = 1_000;
     pub const BankAddress: AccountId = 15082001;
     pub const GasMultiplier: common::GasMultiplier<Balance, u64> = common::GasMultiplier::ValuePerGas(25);
+    pub SplitGasFeeRatio: Option<(Perbill, AccountId)> = None;
+    pub SplitTxFeeRatio: Option<u32> = None;
 }
 
 type NegativeImbalance = <Balances as Currency<u64>>::NegativeImbalance;

runtime/common/Cargo.toml

@@ -17,6 +17,7 @@ frame-system.workspace = true
 pallet-authorship.workspace = true
 pallet-balances.workspace = true
 pallet-session.workspace = true
+pallet-treasury.workspace = true
 sp-runtime.workspace = true
 sp-std.workspace = true
 

runtime/common/src/constants.rs

@@ -42,3 +42,9 @@ pub const RENT_FREE_PERIOD_MONTH_FACTOR: BlockNumber = 6;
 /// The amount of blocks on which tasks of pausing program shifted
 /// in a case of disabled program rent logic, represented as a factor of weeks.
 pub const RENT_DISABLED_DELTA_WEEK_FACTOR: BlockNumber = 1;
+
+/// The percentage of the transaction fee that will go to the treasury
+pub const SPLIT_TX_FEE_PERCENT: u32 = 0;
+
+/// The percentage of the gas fee that will go to the specified destination
+pub const SPLIT_GAS_PERCENT: u32 = 0;

runtime/common/src/lib.rs

@@ -22,10 +22,12 @@ mod apis;
 pub mod constants;
 pub mod weights;
 
+use sp_runtime::traits::Get;
+
 use frame_support::{
     pallet_prelude::DispatchClass,
     parameter_types,
-    traits::{Currency, OnUnbalanced},
+    traits::{Currency, Imbalance, OnUnbalanced},
     weights::{
         constants::{BlockExecutionWeight, ExtrinsicBaseWeight},
         Weight,
@@ -85,22 +87,54 @@ pub type NegativeImbalance<T> = <pallet_balances::Pallet<T> as Currency<
     <T as frame_system::Config>::AccountId,
 >>::NegativeImbalance;
 
+/// Logic for the author to get a portion of fees.
+pub struct ToAuthor<R>(sp_std::marker::PhantomData<R>);
+impl<R> OnUnbalanced<NegativeImbalance<R>> for ToAuthor<R>
+where
+    R: pallet_balances::Config + pallet_authorship::Config,
+    <R as frame_system::Config>::AccountId: From<AccountId>,
+    <R as frame_system::Config>::AccountId: Into<AccountId>,
+{
+    fn on_nonzero_unbalanced(amount: NegativeImbalance<R>) {
+        if let Some(author) = <pallet_authorship::Pallet<R>>::author() {
+            <pallet_balances::Pallet<R>>::resolve_creating(&author, amount);
+        }
+    }
+}
+
 pub struct DealWithFees<R>(sp_std::marker::PhantomData<R>);
 impl<R> OnUnbalanced<NegativeImbalance<R>> for DealWithFees<R>
 where
-    R: pallet_balances::Config + pallet_authorship::Config,
+    R: pallet_balances::Config
+        + pallet_treasury::Config
+        + pallet_authorship::Config
+        + pallet_gear_bank::Config,
+    pallet_treasury::Pallet<R>: OnUnbalanced<NegativeImbalance<R>>,
     <R as frame_system::Config>::AccountId: From<AccountId>,
     <R as frame_system::Config>::AccountId: Into<AccountId>,
 {
     fn on_unbalanceds<B>(mut fees_then_tips: impl Iterator<Item = NegativeImbalance<R>>) {
+        use pallet_treasury::Pallet as Treasury;
+
         if let Some(fees) = fees_then_tips.next() {
-            if let Some(author) = <pallet_authorship::Pallet<R>>::author() {
-                <pallet_balances::Pallet<R>>::resolve_creating(&author, fees);
-            }
-            if let Some(tips) = fees_then_tips.next() {
-                if let Some(author) = <pallet_authorship::Pallet<R>>::author() {
-                    <pallet_balances::Pallet<R>>::resolve_creating(&author, tips);
+            let split_tx_fee_ratio = R::SplitTxFeeRatio::get();
+            if let Some(split_tx_fee_ratio) = split_tx_fee_ratio {
+                // for fees, SplitTxFeeRatio to treasury else to author
+                let (mut to_author, to_treasury) =
+                    fees.ration(100 - split_tx_fee_ratio, split_tx_fee_ratio);
+                if let Some(tips) = fees_then_tips.next() {
+                    // for tips, if any, 100% to author
+                    tips.merge_into(&mut to_author);
+                }
+                <Treasury<R> as OnUnbalanced<_>>::on_unbalanced(to_treasury);
+                <ToAuthor<R> as OnUnbalanced<_>>::on_unbalanced(to_author);
+            } else {
+                let mut to_author = fees;
+                if let Some(tips) = fees_then_tips.next() {
+                    // for tips, if any, 100% to author
+                    tips.merge_into(&mut to_author);
                 }
+                <ToAuthor<R> as OnUnbalanced<_>>::on_unbalanced(to_author);
             }
         }
     }

runtime/vara/src/integration_tests.rs

@@ -861,3 +861,48 @@ fn fungible_api_works() {
             );
         });
 }
+
+#[test]
+fn test_fees_and_tip_split() {
+    init_logger();
+
+    let alice = AccountKeyring::Alice;
+    let charlie = AccountKeyring::Charlie;
+
+    ExtBuilder::default()
+        .initial_authorities(vec![(
+            alice.into(),
+            charlie.into(),
+            alice.public(),
+            ed25519::Pair::from_string("//Alice", None)
+                .unwrap()
+                .public(),
+            alice.public(),
+            alice.public(),
+        )])
+        .stash(STASH)
+        .endowment(ENDOWMENT)
+        .endowed_accounts(vec![])
+        .root(alice.into())
+        .build()
+        .execute_with(|| {
+            let fee = Balances::issue(10);
+            let tip = Balances::issue(20);
+
+            assert_eq!(
+                Balances::free_balance(Treasury::account_id()),
+                EXISTENTIAL_DEPOSIT
+            );
+            assert_eq!(Balances::free_balance(alice.to_account_id()), STASH);
+
+            DealWithFees::on_unbalanceds(vec![fee, tip].into_iter());
+
+            // Author gets 100% of the tip and 100% of the fee = 30
+            assert_eq!(Balances::free_balance(alice.to_account_id()), STASH + 30);
+            // Treasury gets 0% of the fee
+            assert_eq!(
+                Balances::free_balance(Treasury::account_id()),
+                EXISTENTIAL_DEPOSIT
+            );
+        });
+}