Optimize Validator Roots Computation (#12585)

* add changes

* change it

beacon-chain/state/fieldtrie/field_trie_helpers.go

@@ -207,7 +207,7 @@ func handle32ByteArrays(val [][32]byte, indices []uint64, convertAll bool) ([][3
 func handleValidatorSlice(val []*ethpb.Validator, indices []uint64, convertAll bool) ([][32]byte, error) {
 	length := len(indices)
 	if convertAll {
-		length = len(val)
+		return stateutil.OptimizedValidatorRoots(val)
 	}
 	roots := make([][32]byte, 0, length)
 	rootCreator := func(input *ethpb.Validator) error {
@@ -218,15 +218,6 @@ func handleValidatorSlice(val []*ethpb.Validator, indices []uint64, convertAll b
 		roots = append(roots, newRoot)
 		return nil
 	}
-	if convertAll {
-		for i := range val {
-			err := rootCreator(val[i])
-			if err != nil {
-				return nil, err
-			}
-		}
-		return roots, nil
-	}
 	if len(val) > 0 {
 		for _, idx := range indices {
 			if idx > uint64(len(val))-1 {

beacon-chain/state/stateutil/field_root_validator.go

@@ -30,7 +30,7 @@ func ValidatorRegistryRoot(vals []*ethpb.Validator) ([32]byte, error) {
 }
 
 func validatorRegistryRoot(validators []*ethpb.Validator) ([32]byte, error) {
-	roots, err := optimizedValidatorRoots(validators)
+	roots, err := OptimizedValidatorRoots(validators)
 	if err != nil {
 		return [32]byte{}, err
 	}
@@ -51,7 +51,9 @@ func validatorRegistryRoot(validators []*ethpb.Validator) ([32]byte, error) {
 	return res, nil
 }
 
-func optimizedValidatorRoots(validators []*ethpb.Validator) ([][32]byte, error) {
+// OptimizedValidatorRoots uses an optimized routine with gohashtree in order to
+// derive a list of validator roots from a list of validator objects.
+func OptimizedValidatorRoots(validators []*ethpb.Validator) ([][32]byte, error) {
 	// Exit early if no validators are provided.
 	if len(validators) == 0 {
 		return [][32]byte{}, nil