Refactor some optimizations

Some of the logic in the `checkListsMatch` function does not require the
copies of the inputs to be created or sorted. This does those checks
first, potentially skipping the unnecessary work.

Signed-off-by: Justin Kulikauskas <jkulikau@redhat.com>

controllers/configurationpolicy_utils.go

@@ -300,24 +300,25 @@ func checkListFieldsWithSort(mergedObj []map[string]interface{}, oldObj []map[st
 
 // checkListsMatch is a generic list check that uses an arbitrary sort to ensure it is comparing the right values
 func checkListsMatch(oldVal []interface{}, mergedVal []interface{}) (m bool) {
- oVal := append([]interface{}{}, oldVal...)
- mVal := append([]interface{}{}, mergedVal...)
+ if (oldVal == nil && mergedVal != nil) || (oldVal != nil && mergedVal == nil) {
+ return false
+ }
 
- if (oVal == nil && mVal != nil) || (oVal != nil && mVal == nil) {
+ if len(mergedVal) != len(oldVal) {
  return false
  }
 
+ // Make copies of the lists, so we can sort them without mutating this function's inputs
+ oVal := append([]interface{}{}, oldVal...)
+ mVal := append([]interface{}{}, mergedVal...)
+
  sort.Slice(oVal, func(i, j int) bool {
  return fmt.Sprintf("%v", oVal[i]) < fmt.Sprintf("%v", oVal[j])
  })
  sort.Slice(mVal, func(x, y int) bool {
  return fmt.Sprintf("%v", mVal[x]) < fmt.Sprintf("%v", mVal[y])
  })
 
- if len(mVal) != len(oVal) {
- return false
- }
-
  for idx, oNestedVal := range oVal {
  switch oNestedVal := oNestedVal.(type) {
  case map[string]interface{}: