add migrations

x/bank/keeper/grpc_query.go

@@ -60,7 +60,7 @@ func (k BaseKeeper) AllBalances(ctx context.Context, req *types.QueryAllBalances
 	accountStore := k.getAccountStore(sdkCtx, addr)
 
 	pageRes, err := query.Paginate(accountStore, req.Pagination, func(key, value []byte) error {
-		amount := sdk.ZeroInt()
+		var amount sdk.Int
 		if err := amount.Unmarshal(value); err != nil {
 			return err
 		}

x/bank/keeper/view.go

@@ -98,7 +98,7 @@ func (k BaseViewKeeper) GetAccountsBalances(ctx sdk.Context) []types.Balance {
 // by address.
 func (k BaseViewKeeper) GetBalance(ctx sdk.Context, addr sdk.AccAddress, denom string) sdk.Coin {
 	accountStore := k.getAccountStore(ctx, addr)
-	amount := sdk.ZeroInt()
+	var amount sdk.Int
 	bz := accountStore.Get([]byte(denom))
 	if bz == nil {
 		return sdk.NewCoin(denom, amount)
@@ -121,7 +121,7 @@ func (k BaseViewKeeper) IterateAccountBalances(ctx sdk.Context, addr sdk.AccAddr
 	defer iterator.Close()
 
 	for ; iterator.Valid(); iterator.Next() {
-		amount := sdk.ZeroInt()
+		var amount sdk.Int
 		if err := amount.Unmarshal(iterator.Value()); err != nil {
 			panic(err)
 		}
@@ -151,7 +151,7 @@ func (k BaseViewKeeper) IterateAllBalances(ctx sdk.Context, cb func(sdk.AccAddre
 			panic(err)
 		}
 
-		amount := sdk.ZeroInt()
+		var amount sdk.Int
 		if err := amount.Unmarshal(iterator.Value()); err != nil {
 			panic(err)
 		}

x/bank/migrations/v044/store.go

@@ -6,11 +6,13 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
 	v043 "github.com/cosmos/cosmos-sdk/x/bank/migrations/v043"
+	"github.com/cosmos/cosmos-sdk/x/bank/types"
 )
 
 // MigrateStore performs in-place store migrations from v0.43 to v0.44. The
 // migration includes:
 //
+// - Migrate coin storage to save only amount.
 // - Add an additional reverse index from denomination to address.
 func MigrateStore(ctx sdk.Context, storeKey sdk.StoreKey, cdc codec.BinaryCodec) error {
 	store := ctx.KVStore(storeKey)
@@ -36,6 +38,19 @@ func addDenomReverseIndex(store sdk.KVStore, cdc codec.BinaryCodec) error {
 			return err
 		}
 
+		var coin sdk.DecCoin
+		if err := cdc.Unmarshal(oldBalancesIter.Value(), &coin); err != nil {
+			return err
+		}
+
+		bz, err := coin.Amount.Marshal()
+		if err != nil {
+			return err
+		}
+
+		newStore := prefix.NewStore(store, types.CreateAccountBalancesPrefix(addr))
+		newStore.Set([]byte(coin.Denom), bz)
+
 		denomPrefixStore, ok := denomPrefixStores[balance.Denom]
 		if !ok {
 			denomPrefixStore = prefix.NewStore(store, CreateAddressDenomPrefix(balance.Denom))

x/bank/migrations/v044/store_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/types/address"
 	v043 "github.com/cosmos/cosmos-sdk/x/bank/migrations/v043"
 	v044 "github.com/cosmos/cosmos-sdk/x/bank/migrations/v044"
+	"github.com/cosmos/cosmos-sdk/x/bank/types"
 )
 
 func TestMigrateStore(t *testing.T) {
@@ -37,6 +38,14 @@ func TestMigrateStore(t *testing.T) {
 
 	require.NoError(t, v044.MigrateStore(ctx, bankKey, encCfg.Codec))
 
+	for _, b := range balances {
+		addrPrefixStore := prefix.NewStore(store, types.CreateAccountBalancesPrefix(addr))
+		bz := addrPrefixStore.Get([]byte(b.Denom))
+		var expected sdk.Int
+		require.NoError(t, expected.Unmarshal(bz))
+		require.Equal(t, expected, b.Amount)
+	}
+
 	for _, b := range balances {
 		denomPrefixStore := prefix.NewStore(store, v044.CreateAddressDenomPrefix(b.Denom))
 		bz := denomPrefixStore.Get(address.MustLengthPrefix(addr))