`dd8a13dfd6b6`

source

pallets/evm-transaction-payment/src/lib.rs5.2 KiBsource history
1// Copyright 2019-2022 Unique Network (Gibraltar) Ltd.2// This file is part of Unique Network.34// Unique Network is free software: you can redistribute it and/or modify5// it under the terms of the GNU General Public License as published by6// the Free Software Foundation, either version 3 of the License, or7// (at your option) any later version.89// Unique Network is distributed in the hope that it will be useful,10// but WITHOUT ANY WARRANTY; without even the implied warranty of11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the12// GNU General Public License for more details.1314// You should have received a copy of the GNU General Public License15// along with Unique Network. If not, see <http://www.gnu.org/licenses/>.1617#![cfg_attr(not(feature = "std"), no_std)]1819use core::marker::PhantomData;20use fp_evm::WithdrawReason;21use frame_support::traits::{Currency, IsSubType};22pub use pallet::*;23use pallet_evm::{EVMCurrencyAdapter, EnsureAddressOrigin, account::CrossAccountId};24use sp_core::{H160, U256};25use sp_runtime::{TransactionOutcome, DispatchError};26use up_sponsorship::SponsorshipHandler;2728#[frame_support::pallet]29pub mod pallet {30	use super::*;3132	use frame_support::traits::Currency;33	use sp_std::vec::Vec;3435	#[pallet::config]36	pub trait Config: frame_system::Config + pallet_evm::account::Config {37		type EvmSponsorshipHandler: SponsorshipHandler<Self::CrossAccountId, (H160, Vec<u8>)>;38		type Currency: Currency<Self::AccountId>;39	}4041	#[pallet::pallet]42	#[pallet::generate_store(pub(super) trait Store)]43	pub struct Pallet<T>(_);44}4546type NegativeImbalanceOf<C, T> =47	<C as Currency<<T as frame_system::Config>::AccountId>>::NegativeImbalance;4849pub struct ChargeEvmLiquidityInfo<T>50where51	T: Config,52	T: pallet_evm::Config,53{54	who: H160,55	negative_imbalance: NegativeImbalanceOf<<T as Config>::Currency, T>,56}5758pub struct TransactionValidityHack<T: Config>(PhantomData<*const T>);59impl<T: Config> fp_evm::TransactionValidityHack<T::CrossAccountId> for TransactionValidityHack<T> {60	fn who_pays_fee(origin: H160, reason: &WithdrawReason) -> Option<T::CrossAccountId> {61		match reason {62			WithdrawReason::Call { target, input } => {63				// This method is only used for checking, we shouldn't touch storage in it64				frame_support::storage::with_transaction(|| {65					let origin_sub = T::CrossAccountId::from_eth(origin);66					TransactionOutcome::Rollback(Ok::<_, DispatchError>(T::EvmSponsorshipHandler::get_sponsor(67						&origin_sub,68						&(*target, input.clone()),69					)))70				})71				// FIXME: it may fail with DispatchError in case of depth limit72				.ok()?73			}74			_ => None,75		}76	}77}78pub struct OnChargeTransaction<T: Config>(PhantomData<*const T>);79impl<T> pallet_evm::OnChargeEVMTransaction<T> for OnChargeTransaction<T>80where81	T: Config,82	T: pallet_evm::Config,83{84	type LiquidityInfo = Option<ChargeEvmLiquidityInfo<T>>;8586	fn withdraw_fee(87		who: &T::CrossAccountId,88		reason: WithdrawReason,89		fee: U256,90	) -> core::result::Result<Self::LiquidityInfo, pallet_evm::Error<T>> {91		let who_pays_fee = if let WithdrawReason::Call { target, input } = &reason {92			T::EvmSponsorshipHandler::get_sponsor(who, &(*target, input.clone()))93				.unwrap_or(who.clone())94		} else {95			who.clone()96		};9798		let negative_imbalance = EVMCurrencyAdapter::<<T as Config>::Currency, ()>::withdraw_fee(99			&who_pays_fee,100			reason,101			fee,102		)?;103104		Ok(negative_imbalance.map(|i| ChargeEvmLiquidityInfo {105			who: who_pays_fee.as_eth().clone(),106			negative_imbalance: i,107		}))108	}109110	fn correct_and_deposit_fee(111		who: &T::CrossAccountId,112		corrected_fee: U256,113		already_withdrawn: Self::LiquidityInfo,114	) {115		<EVMCurrencyAdapter<<T as Config>::Currency, ()> as pallet_evm::OnChargeEVMTransaction<T>>::correct_and_deposit_fee(116			&already_withdrawn.as_ref().map(|e| T::CrossAccountId::from_eth(e.who)).unwrap_or(who.clone()),117			corrected_fee,118			already_withdrawn.map(|e| e.negative_imbalance),119		)120	}121122	fn pay_priority_fee(tip: U256) {123		<EVMCurrencyAdapter<<T as Config>::Currency, ()> as pallet_evm::OnChargeEVMTransaction<T>>::pay_priority_fee(tip)124	}125}126127/// Implements sponsoring for evm calls performed from pallet-evm (via api.tx.ethereum.transact/api.tx.evm.call)128pub struct BridgeSponsorshipHandler<T>(PhantomData<T>);129impl<T, C> SponsorshipHandler<T::AccountId, C> for BridgeSponsorshipHandler<T>130where131	T: Config + pallet_evm::Config,132	C: IsSubType<pallet_evm::Call<T>>,133{134	fn get_sponsor(who: &T::AccountId, call: &C) -> Option<T::AccountId> {135		match call.is_sub_type()? {136			pallet_evm::Call::call {137				source,138				target,139				input,140				..141			} => {142				let _ = T::CallOrigin::ensure_address_origin(143					source,144					<frame_system::RawOrigin<T::AccountId>>::Signed(who.clone()).into(),145				)146				.ok()?;147				let who = T::CrossAccountId::from_sub(who.clone());148				// Effects from EvmSponsorshipHandler are applied in OnChargeEvmTransaction by pallet_evm::runner149				// TODO: Should we implement simulation mode (test, but do not apply effects) in `up-sponsorship`?150				let sponsor = frame_support::storage::with_transaction(|| {151					TransactionOutcome::Rollback(Ok::<_, DispatchError>(T::EvmSponsorshipHandler::get_sponsor(152						&who,153						&(*target, input.clone()),154					)))155				})156				// FIXME: it may fail with DispatchError in case of depth limit157				.ok()??;158				Some(sponsor.as_sub().clone())159			}160			_ => None,161		}162	}163}