Problem: no efficient bank api to support evm add/sub balances

CHANGELOG.md

@@ -41,8 +41,9 @@ Ref: https://keepachangelog.com/en/1.0.0/
 ### Features
 
 * (baseapp) [#205](https://github.com/crypto-org-chain/cosmos-sdk/pull/205) Add `TxExecutor` baseapp option, add `TxIndex`/`TxCount`/`MsgIndex`/`BlockGasUsed` fields to `Context, to support tx parallel execution.
-* (baseapp) [#206](https://github.com/crypto-org-chain/cosmos-sdk/pull/206) Support mount object store in baseapp, add `ObjectStore` api in context..
+* (baseapp) [#206](https://github.com/crypto-org-chain/cosmos-sdk/pull/206) Support mount object store in baseapp, add `ObjectStore` api in context.
 * (bank) [#237](https://github.com/crypto-org-chain/cosmos-sdk/pull/237) Support virtual accounts in sending coins.
+* (x/bank) [#239](https://github.com/crypto-org-chain/cosmos-sdk/pull/239) Add low level `AddBalance`,`SubBalance` APIs to bank keeper.
 
 ## [Unreleased-Upstream]
 

x/bank/keeper/keeper.go

@@ -419,6 +419,33 @@ func (k BaseKeeper) BurnCoins(ctx context.Context, moduleName string, amounts sd
 	return nil
 }
 
+// AddBalance is low level api to update balance directly, mainly used by evm integration,
+// caller should make sure the total supply of the denom not changed and the account exists.
+// it's for evm integration, call at your own risk.
+// it emits mint event.
+func (k BaseKeeper) AddBalance(ctx context.Context, addr sdk.AccAddress, coin sdk.Coin) error {
+	sdkCtx := sdk.UnwrapSDKContext(ctx)
+	// emit mint event
+	sdkCtx.EventManager().EmitEvent(
+		types.NewCoinMintEvent(addr, sdk.NewCoins(coin)),
+	)
+	return k.addCoin(ctx, addr, coin)
+}
+
+// SubBalance is low level api to update balance directly, mainly used by evm integration,
+// caller should make sure the total supply of the denom not changed.
+// it's for evm integration, call at your own risk.
+// it emits burn event.
+func (k BaseKeeper) SubBalance(ctx context.Context, addr sdk.AccAddress, coin sdk.Coin) error {
+	sdkCtx := sdk.UnwrapSDKContext(ctx)
+	// emit burn event
+	sdkCtx.EventManager().EmitEvent(
+		types.NewCoinBurnEvent(addr, sdk.NewCoins(coin)),
+	)
+	lockedCoins := k.LockedCoins(ctx, addr)
+	return k.subCoin(ctx, addr, coin, lockedCoins)
+}
+
 // setSupply sets the supply for the given coin
 func (k BaseKeeper) setSupply(ctx context.Context, coin sdk.Coin) {
 	// Bank invariants and IBC requires to remove zero coins.

x/bank/keeper/send.go

@@ -8,7 +8,6 @@ import (
 	"cosmossdk.io/core/store"
 	errorsmod "cosmossdk.io/errors"
 	"cosmossdk.io/log"
-	"cosmossdk.io/math"
 	storetypes "cosmossdk.io/store/types"
 
 	"github.com/cosmos/cosmos-sdk/codec"
@@ -273,29 +272,7 @@ func (k BaseSendKeeper) subUnlockedCoins(ctx context.Context, addr sdk.AccAddres
 	lockedCoins := k.LockedCoins(ctx, addr)
 
 	for _, coin := range amt {
-		balance := k.GetBalance(ctx, addr, coin.Denom)
-		locked := sdk.NewCoin(coin.Denom, lockedCoins.AmountOf(coin.Denom))
-
-		spendable, hasNeg := sdk.Coins{balance}.SafeSub(locked)
-		if hasNeg {
-			return errorsmod.Wrapf(sdkerrors.ErrInsufficientFunds,
-				"locked amount exceeds account balance funds: %s > %s", locked, balance)
-		}
-
-		if _, hasNeg := spendable.SafeSub(coin); hasNeg {
-			if len(spendable) == 0 {
-				spendable = sdk.Coins{sdk.NewCoin(coin.Denom, math.ZeroInt())}
-			}
-			return errorsmod.Wrapf(
-				sdkerrors.ErrInsufficientFunds,
-				"spendable balance %s is smaller than %s",
-				spendable, coin,
-			)
-		}
-
-		newBalance := balance.Sub(coin)
-
-		if err := k.setBalance(ctx, addr, newBalance); err != nil {
+		if err := k.subCoin(ctx, addr, coin, lockedCoins); err != nil {
 			return err
 		}
 	}
@@ -308,6 +285,32 @@ func (k BaseSendKeeper) subUnlockedCoins(ctx context.Context, addr sdk.AccAddres
 	return nil
 }
 
+func (k BaseSendKeeper) subCoin(ctx context.Context, addr sdk.AccAddress, coin sdk.Coin, lockedCoins sdk.Coins) error {
+	var (
+		spendable sdk.Coin
+		err       error
+	)
+	balance := k.GetBalance(ctx, addr, coin.Denom)
+	locked := sdk.NewCoin(coin.Denom, lockedCoins.AmountOf(coin.Denom))
+	if locked.IsZero() {
+		spendable = balance
+	} else {
+		spendable, err = balance.SafeSub(locked)
+		if err != nil {
+			return errorsmod.Wrapf(sdkerrors.ErrInsufficientFunds,
+				"locked amount exceeds account balance funds: %s > %s", locked, balance)
+		}
+	}
+	if spendable.Amount.LT(coin.Amount) {
+		return errorsmod.Wrapf(
+			sdkerrors.ErrInsufficientFunds,
+			"spendable balance %s is smaller than %s",
+			spendable, coin,
+		)
+	}
+	return k.setBalance(ctx, addr, balance.Sub(coin))
+}
+
 // addCoins increase the addr balance by the given amt. Fails if the provided
 // amt is invalid. It emits a coin received event.
 func (k BaseSendKeeper) addCoins(ctx context.Context, addr sdk.AccAddress, amt sdk.Coins) error {
@@ -316,11 +319,7 @@ func (k BaseSendKeeper) addCoins(ctx context.Context, addr sdk.AccAddress, amt s
 	}
 
 	for _, coin := range amt {
-		balance := k.GetBalance(ctx, addr, coin.Denom)
-		newBalance := balance.Add(coin)
-
-		err := k.setBalance(ctx, addr, newBalance)
-		if err != nil {
+		if err := k.addCoin(ctx, addr, coin); err != nil {
 			return err
 		}
 	}
@@ -334,6 +333,12 @@ func (k BaseSendKeeper) addCoins(ctx context.Context, addr sdk.AccAddress, amt s
 	return nil
 }
 
+func (k BaseSendKeeper) addCoin(ctx context.Context, addr sdk.AccAddress, coin sdk.Coin) error {
+	balance := k.GetBalance(ctx, addr, coin.Denom)
+	newBalance := balance.Add(coin)
+	return k.setBalance(ctx, addr, newBalance)
+}
+
 // setBalance sets the coin balance for an account by address.
 func (k BaseSendKeeper) setBalance(ctx context.Context, addr sdk.AccAddress, balance sdk.Coin) error {
 	if !balance.IsValid() {