fix: Bank module init genesis optimization (backport #9428) (#9440)

* fix: Bank module init genesis optimization (#9428)

* optimize the bank module genesis initialization

* remove k.setBalances & k.clearBalances and update changelog

* fix lint

Co-authored-by: Aaron Craelius <aaron@regen.network>
(cherry picked from commit 2ae7875)

# Conflicts:
#	CHANGELOG.md
#	x/bank/keeper/genesis.go
#	x/bank/keeper/send.go

* fix conflicts

* Update CHANGELOG.md

Co-authored-by: yys <sw.yunsuk@gmail.com>
Co-authored-by: Amaury M <1293565+amaurym@users.noreply.github.com>

Author: 3 people

CHANGELOG.md

@@ -36,6 +36,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## Unreleased
 
+### Improvements
+
+* [\#9428](https://github.com/cosmos/cosmos-sdk/pull/9428) Optimize bank InitGenesis. Added `k.initBalances`.
+
 ### Bug Fixes
 
 * [\#9401](https://github.com/cosmos/cosmos-sdk/pull/9401) Fixes incorrect export of IBC identifier sequences. Previously, the next identifier sequence for clients/connections/channels was not set during genesis export. This resulted in the next identifiers being generated on the new chain to reuse old identifiers (the sequences began again from 0).

x/bank/keeper/genesis.go

@@ -20,7 +20,7 @@ func (k BaseKeeper) InitGenesis(ctx sdk.Context, genState *types.GenesisState) {
 			panic(err)
 		}
 
-		if err := k.SetBalances(ctx, addr, balance.Coins); err != nil {
+		if err := k.initBalances(ctx, addr, balance.Coins); err != nil {
 			panic(fmt.Errorf("error on setting balances %w", err))
 		}
 

x/bank/keeper/send.go

@@ -258,6 +258,28 @@ func (k BaseSendKeeper) SetBalances(ctx sdk.Context, addr sdk.AccAddress, balanc
 	return nil
 }
 
+// initBalances sets the balance (multiple coins) for an account by address.
+// An error is returned upon failure.
+func (k BaseSendKeeper) initBalances(ctx sdk.Context, addr sdk.AccAddress, balances sdk.Coins) error {
+	store := ctx.KVStore(k.storeKey)
+	balancesStore := prefix.NewStore(store, types.BalancesPrefix)
+	accountStore := prefix.NewStore(balancesStore, addr.Bytes())
+	for i := range balances {
+		balance := balances[i]
+		if !balance.IsValid() {
+			return sdkerrors.Wrap(sdkerrors.ErrInvalidCoins, balance.String())
+		}
+
+		// Bank invariants require to not store zero balances.
+		if !balance.IsZero() {
+			bz := k.cdc.MustMarshalBinaryBare(&balance)
+			accountStore.Set([]byte(balance.Denom), bz)
+		}
+	}
+
+	return nil
+}
+
 // SetBalance sets the coin balance for an account by address.
 func (k BaseSendKeeper) SetBalance(ctx sdk.Context, addr sdk.AccAddress, balance sdk.Coin) error {
 	if !balance.IsValid() {