difftreelog
doc(pallet-evm-transaction-payment): document public api
in: master
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pallets/evm-transaction-payment/README.mddiffbeforeafterboth--- /dev/null
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+# Evm transaction payment pallet
+
+pallet-evm-transaction-payment is a bridge between pallet-evm substrate calls and pallet-sponsoring.
+It doesn't provide any sponsoring logic by itself, instead all sponsoring handlers
+are loosly coupled via [`Config::EvmSponsorshipHandler`] trait.
\ No newline at end of file
pallets/evm-transaction-payment/src/lib.rsdiffbeforeafterboth1// 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::IsSubType;22pub use pallet::*;23use pallet_evm::{EnsureAddressOrigin, account::CrossAccountId};24use sp_core::H160;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}4546pub struct TransactionValidityHack<T: Config>(PhantomData<*const T>);47impl<T: Config> fp_evm::TransactionValidityHack<T::CrossAccountId> for TransactionValidityHack<T> {48 fn who_pays_fee(origin: H160, reason: &WithdrawReason) -> Option<T::CrossAccountId> {49 match reason {50 WithdrawReason::Call { target, input } => {51 let origin_sub = T::CrossAccountId::from_eth(origin);52 T::EvmSponsorshipHandler::get_sponsor(&origin_sub, &(*target, input.clone()))53 }54 _ => None,55 }56 }57}5859/// Implements sponsoring for evm calls performed from pallet-evm (via api.tx.ethereum.transact/api.tx.evm.call)60pub struct BridgeSponsorshipHandler<T>(PhantomData<T>);61impl<T, C> SponsorshipHandler<T::AccountId, C> for BridgeSponsorshipHandler<T>62where63 T: Config + pallet_evm::Config,64 C: IsSubType<pallet_evm::Call<T>>,65{66 fn get_sponsor(who: &T::AccountId, call: &C) -> Option<T::AccountId> {67 match call.is_sub_type()? {68 pallet_evm::Call::call {69 source,70 target,71 input,72 ..73 } => {74 let _ = T::CallOrigin::ensure_address_origin(75 source,76 <frame_system::RawOrigin<T::AccountId>>::Signed(who.clone()).into(),77 )78 .ok()?;79 let who = T::CrossAccountId::from_sub(who.clone());80 // Effects from EvmSponsorshipHandler are applied by pallet_evm::runner81 // TODO: Should we implement simulation mode (test, but do not apply effects) in `up-sponsorship`?82 let sponsor = frame_support::storage::with_transaction(|| {83 TransactionOutcome::Rollback(Ok::<_, DispatchError>(84 T::EvmSponsorshipHandler::get_sponsor(&who, &(*target, input.clone())),85 ))86 })87 // FIXME: it may fail with DispatchError in case of depth limit88 .ok()??;89 Some(sponsor.as_sub().clone())90 }91 _ => None,92 }93 }94}