package keeper import ( "fmt" errorsmod "cosmossdk.io/errors" sdkmath "cosmossdk.io/math" sdk "github.com/cosmos/cosmos-sdk/types" sdkerrors "github.com/cosmos/cosmos-sdk/types/errors" evmtypes "github.com/evmos/ethermint/x/evm/types" "github.com/0glabs/0g-chain/chaincfg" "github.com/0glabs/0g-chain/x/evmutil/types" ) // ConversionMultiplier is the conversion multiplier between base denom and auxiliary denom var ConversionMultiplier = sdkmath.NewInt(chaincfg.AuxiliaryDenomConversionMultiplier) var _ evmtypes.BankKeeper = EvmBankKeeper{} // EvmBankKeeper is a BankKeeper wrapper for the x/evm module to allow the use // of the 18 decimal base denom coin on the evm. // x/evm consumes gas and send coins by minting and burning base denom coins in its module // account and then sending the funds to the target account. // This keeper uses both the auxiliary denom coin and a separate base denom balance to manage the // extra percision needed by the evm. type EvmBankKeeper struct { baseDenomKeeper Keeper bk types.BankKeeper ak types.AccountKeeper } func NewEvmBankKeeper(baseKeeper Keeper, bk types.BankKeeper, ak types.AccountKeeper) EvmBankKeeper { return EvmBankKeeper{ baseDenomKeeper: baseKeeper, bk: bk, ak: ak, } } // GetBalance returns the total **spendable** balance of base denom for a given account by address. func (k EvmBankKeeper) GetBalance(ctx sdk.Context, addr sdk.AccAddress, denom string) sdk.Coin { if denom != chaincfg.BaseDenom { panic(fmt.Errorf("only evm denom %s is supported by EvmBankKeeper", chaincfg.BaseDenom)) } spendableCoins := k.bk.SpendableCoins(ctx, addr) auxiliaryDenomFromBank := spendableCoins.AmountOf(chaincfg.AuxiliaryDenom) baseDenomFromBank := spendableCoins.AmountOf(chaincfg.BaseDenom) baseDenomFromEvmBank := k.baseDenomKeeper.GetBalance(ctx, addr) var total sdkmath.Int if auxiliaryDenomFromBank.IsPositive() { total = auxiliaryDenomFromBank.Mul(ConversionMultiplier).Add(baseDenomFromBank).Add(baseDenomFromEvmBank) } else { total = baseDenomFromBank.Add(baseDenomFromEvmBank) } return sdk.NewCoin(chaincfg.BaseDenom, total) } // SendCoins transfers base denom coins from a AccAddress to an AccAddress. func (k EvmBankKeeper) SendCoins(ctx sdk.Context, senderAddr sdk.AccAddress, recipientAddr sdk.AccAddress, amt sdk.Coins) error { // SendCoins method is not used by the evm module, but is required by the // evmtypes.BankKeeper interface. This must be updated if the evm module // is updated to use SendCoins. panic("not implemented") } // SendCoinsFromModuleToAccount transfers base denom coins from a ModuleAccount to an AccAddress. // It will panic if the module account does not exist. An error is returned if the recipient // address is black-listed or if sending the tokens fails. func (k EvmBankKeeper) SendCoinsFromModuleToAccount(ctx sdk.Context, senderModule string, recipientAddr sdk.AccAddress, amt sdk.Coins) error { auxiliaryDenomCoin, baseDemonCnt, err := SplitBaseDenomCoins(amt) if err != nil { return err } if auxiliaryDenomCoin.Amount.IsPositive() { if err := k.bk.SendCoinsFromModuleToAccount(ctx, senderModule, recipientAddr, sdk.NewCoins(auxiliaryDenomCoin)); err != nil { return err } } senderAddr := k.GetModuleAddress(senderModule) if err := k.ConvertOneAuxiliaryDenomToBaseDenomIfNeeded(ctx, senderAddr, baseDemonCnt); err != nil { return err } if err := k.baseDenomKeeper.SendBalance(ctx, senderAddr, recipientAddr, baseDemonCnt); err != nil { return err } return k.ConvertBaseDenomToAuxiliaryDenom(ctx, recipientAddr) } // SendCoinsFromAccountToModule transfers base denom coins from an AccAddress to a ModuleAccount. // It will panic if the module account does not exist. func (k EvmBankKeeper) SendCoinsFromAccountToModule(ctx sdk.Context, senderAddr sdk.AccAddress, recipientModule string, amt sdk.Coins) error { auxiliaryDenomCoin, baseDenomCnt, err := SplitBaseDenomCoins(amt) if err != nil { return err } if auxiliaryDenomCoin.IsPositive() { if err := k.bk.SendCoinsFromAccountToModule(ctx, senderAddr, recipientModule, sdk.NewCoins(auxiliaryDenomCoin)); err != nil { return err } } if err := k.ConvertOneAuxiliaryDenomToBaseDenomIfNeeded(ctx, senderAddr, baseDenomCnt); err != nil { return err } recipientAddr := k.GetModuleAddress(recipientModule) if err := k.baseDenomKeeper.SendBalance(ctx, senderAddr, recipientAddr, baseDenomCnt); err != nil { return err } return k.ConvertBaseDenomToAuxiliaryDenom(ctx, recipientAddr) } // MintCoins mints base denom coins by minting the equivalent auxiliary denom coins and any remaining base denom coins. // It will panic if the module account does not exist or is unauthorized. func (k EvmBankKeeper) MintCoins(ctx sdk.Context, moduleName string, amt sdk.Coins) error { auxiliaryDenomCoin, baseDemonCnt, err := SplitBaseDenomCoins(amt) if err != nil { return err } if auxiliaryDenomCoin.IsPositive() { if err := k.bk.MintCoins(ctx, moduleName, sdk.NewCoins(auxiliaryDenomCoin)); err != nil { return err } } recipientAddr := k.GetModuleAddress(moduleName) if err := k.baseDenomKeeper.AddBalance(ctx, recipientAddr, baseDemonCnt); err != nil { return err } return k.ConvertBaseDenomToAuxiliaryDenom(ctx, recipientAddr) } // BurnCoins burns base denom coins by burning the equivalent auxiliary denom coins and any remaining base denom coins. // It will panic if the module account does not exist or is unauthorized. func (k EvmBankKeeper) BurnCoins(ctx sdk.Context, moduleName string, amt sdk.Coins) error { auxiliaryDenomCoin, baseDemonCnt, err := SplitBaseDenomCoins(amt) if err != nil { return err } if auxiliaryDenomCoin.IsPositive() { if err := k.bk.BurnCoins(ctx, moduleName, sdk.NewCoins(auxiliaryDenomCoin)); err != nil { return err } } moduleAddr := k.GetModuleAddress(moduleName) if err := k.ConvertOneAuxiliaryDenomToBaseDenomIfNeeded(ctx, moduleAddr, baseDemonCnt); err != nil { return err } return k.baseDenomKeeper.RemoveBalance(ctx, moduleAddr, baseDemonCnt) } // ConvertOneauxiliaryDenomToBaseDenomIfNeeded converts 1 auxiliary denom to base denom for an address if // its base denom balance is smaller than the baseDenomCnt amount. func (k EvmBankKeeper) ConvertOneAuxiliaryDenomToBaseDenomIfNeeded(ctx sdk.Context, addr sdk.AccAddress, baseDenomCnt sdkmath.Int) error { baseDenomBal := k.baseDenomKeeper.GetBalance(ctx, addr) if baseDenomBal.GTE(baseDenomCnt) { return nil } auxiliaryDenomToStore := sdk.NewCoins(sdk.NewCoin(chaincfg.AuxiliaryDenom, sdk.OneInt())) if err := k.bk.SendCoinsFromAccountToModule(ctx, addr, types.ModuleName, auxiliaryDenomToStore); err != nil { return err } // add 1 auxiliary denom equivalent of base denom to addr baseDenomToReceive := ConversionMultiplier if err := k.baseDenomKeeper.AddBalance(ctx, addr, baseDenomToReceive); err != nil { return err } return nil } // ConvertBaseDenomToauxiliaryDenom converts all available base denom to auxiliary denom for a given AccAddress. func (k EvmBankKeeper) ConvertBaseDenomToAuxiliaryDenom(ctx sdk.Context, addr sdk.AccAddress) error { totalBaseDenom := k.baseDenomKeeper.GetBalance(ctx, addr) auxiliaryDenomCoin, _, err := SplitBaseDenomCoins(sdk.NewCoins(sdk.NewCoin(chaincfg.BaseDenom, totalBaseDenom))) if err != nil { return err } // do nothing if account does not have enough base denom for a single auxiliary denom auxiliaryDenomToReceive := auxiliaryDenomCoin.Amount if !auxiliaryDenomToReceive.IsPositive() { return nil } // remove base denom used for converting to auxiliary denom baseDenomToBurn := auxiliaryDenomToReceive.Mul(ConversionMultiplier) finalBal := totalBaseDenom.Sub(baseDenomToBurn) if err := k.baseDenomKeeper.SetBalance(ctx, addr, finalBal); err != nil { return err } fromAddr := k.GetModuleAddress(types.ModuleName) if err := k.bk.SendCoins(ctx, fromAddr, addr, sdk.NewCoins(auxiliaryDenomCoin)); err != nil { return err } return nil } func (k EvmBankKeeper) GetModuleAddress(moduleName string) sdk.AccAddress { addr := k.ak.GetModuleAddress(moduleName) if addr == nil { panic(errorsmod.Wrapf(sdkerrors.ErrUnknownAddress, "module account %s does not exist", moduleName)) } return addr } // SplitBaseDenomCoins splits base denom coins to the equivalent auxiliary denom coins and any remaining base denom balance. // An error will be returned if the coins are not valid or if the coins are not the base denom. func SplitBaseDenomCoins(coins sdk.Coins) (sdk.Coin, sdkmath.Int, error) { baseDemonCnt := sdk.ZeroInt() auxiliaryDenomAmt := sdk.NewCoin(chaincfg.AuxiliaryDenom, sdk.ZeroInt()) if len(coins) == 0 { return auxiliaryDenomAmt, baseDemonCnt, nil } if err := ValidateEvmCoins(coins); err != nil { return auxiliaryDenomAmt, baseDemonCnt, err } // note: we should always have len(coins) == 1 here since coins cannot have dup denoms after we validate. coin := coins[0] remainingBalance := coin.Amount.Mod(ConversionMultiplier) if remainingBalance.IsPositive() { baseDemonCnt = remainingBalance } auxiliaryDenomAmount := coin.Amount.Quo(ConversionMultiplier) if auxiliaryDenomAmount.IsPositive() { auxiliaryDenomAmt = sdk.NewCoin(chaincfg.AuxiliaryDenom, auxiliaryDenomAmount) } return auxiliaryDenomAmt, baseDemonCnt, nil } // ValidateEvmCoins validates the coins from evm is valid and is the base denom. func ValidateEvmCoins(coins sdk.Coins) error { if len(coins) == 0 { return nil } // validate that coins are non-negative, sorted, and no dup denoms if err := coins.Validate(); err != nil { return errorsmod.Wrap(sdkerrors.ErrInvalidCoins, coins.String()) } // validate that coin denom is base denom if len(coins) != 1 || coins[0].Denom != chaincfg.BaseDenom { errMsg := fmt.Sprintf("invalid evm coin denom, only %s is supported", chaincfg.BaseDenom) return errorsmod.Wrap(sdkerrors.ErrInvalidCoins, errMsg) } return nil }