fix(x/slashing/keeper): hoist non-changing addresses parsing out of redelegation loop

This change hoists out, the parsing of non-changing validator address and
delegator address which before were being re-parsed in every loop of
the redelegation entries, parsing them once and reusing the already
parsed addresses.

Fixes #18032

Author: odeke-em

CHANGELOG.md

@@ -50,6 +50,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* (x/staking/keeper) [#18035](https://github.com/cosmos/cosmos-sdk/pull/18035) Hoisted out of the redelegation loop, the non-changing validator and delegator addresses parsing.
 * (keyring) [#17913](https://github.com/cosmos/cosmos-sdk/pull/17913) Add `NewAutoCLIKeyring` for creating an AutoCLI keyring from a SDK keyring.
 * (codec) [#17913](https://github.com/cosmos/cosmos-sdk/pull/17913) `codectypes.NewAnyWithValue` supports proto v2 messages.
 * (client) [#17503](https://github.com/cosmos/cosmos-sdk/pull/17503) Add `client.Context{}.WithAddressCodec`, `WithValidatorAddressCodec`, `WithConsensusAddressCodec` to provide address codecs to the client context. See the [UPGRADING.md](./UPGRADING.md) for more details.

x/staking/keeper/slash.go

@@ -287,6 +287,16 @@ func (k Keeper) SlashRedelegation(ctx context.Context, srcValidator types.Valida
 	totalSlashAmount = math.ZeroInt()
 	bondedBurnedAmount, notBondedBurnedAmount := math.ZeroInt(), math.ZeroInt()
 
+	valDstAddr, err := k.validatorAddressCodec.StringToBytes(redelegation.ValidatorDstAddress)
+	if err != nil {
+		return math.ZeroInt(), fmt.Errorf("SlashRedelegation: could not parse validator destination address: %w", err)
+	}
+
+	delegatorAddress, err := k.authKeeper.AddressCodec().StringToBytes(redelegation.DelegatorAddress)
+	if err != nil {
+		return math.ZeroInt(), fmt.Errorf("SlashRedelegation: could not parse delegator address: %w", err)
+	}
+
 	// perform slashing on all entries within the redelegation
 	for _, entry := range redelegation.Entries {
 		// If redelegation started before this height, stake didn't contribute to infraction
@@ -310,16 +320,7 @@ func (k Keeper) SlashRedelegation(ctx context.Context, srcValidator types.Valida
 			continue
 		}
 
-		valDstAddr, err := k.validatorAddressCodec.StringToBytes(redelegation.ValidatorDstAddress)
-		if err != nil {
-			panic(err)
-		}
-
-		delegatorAddress, err := k.authKeeper.AddressCodec().StringToBytes(redelegation.DelegatorAddress)
-		if err != nil {
-			panic(err)
-		}
-
+		// Delegations can be dynamic hence need to be looked up on every redelegation entry loop.
 		delegation, err := k.Delegations.Get(ctx, collections.Join(sdk.AccAddress(delegatorAddress), sdk.ValAddress(valDstAddr)))
 		if err != nil {
 			// If deleted, delegation has zero shares, and we can't unbond any more