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| 1 | +#![cfg_attr(not(feature = "std"), no_std)] |
| 2 | + |
| 3 | +use frame_support::pallet_prelude::*; |
| 4 | +use frame_support::{ |
| 5 | + traits::{ |
| 6 | + Imbalance, OnUnbalanced, |
| 7 | + fungible::{Balanced, Credit, Debt, Inspect}, |
| 8 | + tokens::{Precision, WithdrawConsequence}, |
| 9 | + }, |
| 10 | + weights::{WeightToFeeCoefficient, WeightToFeeCoefficients, WeightToFeePolynomial}, |
| 11 | +}; |
| 12 | + |
| 13 | +use sp_runtime::{ |
| 14 | + Perbill, Saturating, |
| 15 | + traits::{DispatchInfoOf, PostDispatchInfoOf}, |
| 16 | +}; |
| 17 | +// use substrate_fixed::types::U96F32; |
| 18 | +// use subtensor_runtime_common::{AlphaCurrency, NetUid}; |
| 19 | +use pallet_transaction_payment::Config as PTPConfig; |
| 20 | + |
| 21 | +use smallvec::smallvec; |
| 22 | +use subtensor_runtime_common::Balance; |
| 23 | + |
| 24 | +pub use pallet_transaction_payment::OnChargeTransaction; |
| 25 | + |
| 26 | +pub struct LinearWeightToFee; |
| 27 | + |
| 28 | +impl WeightToFeePolynomial for LinearWeightToFee { |
| 29 | + type Balance = Balance; |
| 30 | + |
| 31 | + fn polynomial() -> WeightToFeeCoefficients<Self::Balance> { |
| 32 | + let coefficient = WeightToFeeCoefficient { |
| 33 | + coeff_integer: 0, |
| 34 | + coeff_frac: Perbill::from_parts(500_000), // 0.5 unit per weight |
| 35 | + negative: false, |
| 36 | + degree: 1, |
| 37 | + }; |
| 38 | + |
| 39 | + smallvec![coefficient] |
| 40 | + } |
| 41 | +} |
| 42 | + |
| 43 | +/// Custom FungibleAdapter based on standard FungibleAdapter from transsaction_payment |
| 44 | +/// FRAME pallet |
| 45 | +/// |
| 46 | +pub struct FungibleAdapter<F, OU>(PhantomData<(F, OU)>); |
| 47 | + |
| 48 | +impl<T, F, OU> OnChargeTransaction<T> for FungibleAdapter<F, OU> |
| 49 | +where |
| 50 | + T: PTPConfig, |
| 51 | + F: Balanced<T::AccountId>, |
| 52 | + OU: OnUnbalanced<Credit<T::AccountId, F>>, |
| 53 | +{ |
| 54 | + type LiquidityInfo = Option<Credit<T::AccountId, F>>; |
| 55 | + type Balance = <F as Inspect<<T as frame_system::Config>::AccountId>>::Balance; |
| 56 | + |
| 57 | + fn withdraw_fee( |
| 58 | + who: &<T>::AccountId, |
| 59 | + call: &<T>::RuntimeCall, |
| 60 | + _dispatch_info: &DispatchInfoOf<<T>::RuntimeCall>, |
| 61 | + fee: Self::Balance, |
| 62 | + _tip: Self::Balance, |
| 63 | + ) -> Result<Self::LiquidityInfo, TransactionValidityError> { |
| 64 | + log::error!("====================== withdraw_fee. Call = {:?}", call); |
| 65 | + |
| 66 | + if fee.is_zero() { |
| 67 | + return Ok(None); |
| 68 | + } |
| 69 | + |
| 70 | + match F::withdraw( |
| 71 | + who, |
| 72 | + fee, |
| 73 | + Precision::Exact, |
| 74 | + frame_support::traits::tokens::Preservation::Preserve, |
| 75 | + frame_support::traits::tokens::Fortitude::Polite, |
| 76 | + ) { |
| 77 | + Ok(imbalance) => Ok(Some(imbalance)), |
| 78 | + Err(_) => Err(InvalidTransaction::Payment.into()), |
| 79 | + } |
| 80 | + } |
| 81 | + |
| 82 | + fn can_withdraw_fee( |
| 83 | + who: &T::AccountId, |
| 84 | + _call: &T::RuntimeCall, |
| 85 | + _dispatch_info: &DispatchInfoOf<T::RuntimeCall>, |
| 86 | + fee: Self::Balance, |
| 87 | + _tip: Self::Balance, |
| 88 | + ) -> Result<(), TransactionValidityError> { |
| 89 | + if fee.is_zero() { |
| 90 | + return Ok(()); |
| 91 | + } |
| 92 | + |
| 93 | + match F::can_withdraw(who, fee) { |
| 94 | + WithdrawConsequence::Success => Ok(()), |
| 95 | + _ => Err(InvalidTransaction::Payment.into()), |
| 96 | + } |
| 97 | + } |
| 98 | + |
| 99 | + fn correct_and_deposit_fee( |
| 100 | + who: &<T>::AccountId, |
| 101 | + _dispatch_info: &DispatchInfoOf<<T>::RuntimeCall>, |
| 102 | + _post_info: &PostDispatchInfoOf<<T>::RuntimeCall>, |
| 103 | + corrected_fee: Self::Balance, |
| 104 | + tip: Self::Balance, |
| 105 | + already_withdrawn: Self::LiquidityInfo, |
| 106 | + ) -> Result<(), TransactionValidityError> { |
| 107 | + if let Some(paid) = already_withdrawn { |
| 108 | + // Calculate how much refund we should return |
| 109 | + let refund_amount = paid.peek().saturating_sub(corrected_fee); |
| 110 | + // refund to the the account that paid the fees if it exists. otherwise, don't refind |
| 111 | + // anything. |
| 112 | + let refund_imbalance = if F::total_balance(who) > F::Balance::zero() { |
| 113 | + F::deposit(who, refund_amount, Precision::BestEffort) |
| 114 | + .unwrap_or_else(|_| Debt::<T::AccountId, F>::zero()) |
| 115 | + } else { |
| 116 | + Debt::<T::AccountId, F>::zero() |
| 117 | + }; |
| 118 | + // merge the imbalance caused by paying the fees and refunding parts of it again. |
| 119 | + let adjusted_paid: Credit<T::AccountId, F> = paid |
| 120 | + .offset(refund_imbalance) |
| 121 | + .same() |
| 122 | + .map_err(|_| TransactionValidityError::Invalid(InvalidTransaction::Payment))?; |
| 123 | + // Call someone else to handle the imbalance (fee and tip separately) |
| 124 | + let (tip, fee) = adjusted_paid.split(tip); |
| 125 | + OU::on_unbalanceds(Some(fee).into_iter().chain(Some(tip))); |
| 126 | + } |
| 127 | + |
| 128 | + Ok(()) |
| 129 | + } |
| 130 | + |
| 131 | + #[cfg(feature = "runtime-benchmarks")] |
| 132 | + fn endow_account(who: &T::AccountId, amount: Self::Balance) { |
| 133 | + let _ = F::deposit(who, amount, Precision::BestEffort); |
| 134 | + } |
| 135 | + |
| 136 | + #[cfg(feature = "runtime-benchmarks")] |
| 137 | + fn minimum_balance() -> Self::Balance { |
| 138 | + F::minimum_balance() |
| 139 | + } |
| 140 | +} |
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