reduce number of loops

callbacks.go

@@ -187,20 +187,20 @@ func (p *processor) Replace(name string, fn func(*DB)) error {
 
 func (p *processor) compile() (err error) {
 	var (
-		callbacks []*callback
-		removed   []string
+		callbacks  []*callback
+		removedMap map[string]bool
 	)
 	for _, callback := range p.callbacks {
 		if callback.match == nil || callback.match(p.db) {
 			callbacks = append(callbacks, callback)
 		}
 		if callback.remove {
-			removed = append(removed, callback.name)
+			removedMap[callback.name] = true
 		}
 	}
 
-	if len(removed) > 0 {
-		callbacks = removeCallbacks(callbacks, removed)
+	if len(removedMap) > 0 {
+		callbacks = removeCallbacks(callbacks, removedMap)
 	}
 
 	p.callbacks = callbacks
@@ -351,10 +351,10 @@ func sortCallbacks(cs []*callback) (fns []func(*DB), err error) {
 	return
 }
 
-func removeCallbacks(cs []*callback, names []string) []*callback {
+func removeCallbacks(cs []*callback, nameMap map[string]bool) []*callback {
 	callbacks := make([]*callback, 0, len(cs))
 	for _, callback := range cs {
-		if utils.Contains(names, callback.name) {
+		if nameMap[callback.name] {
 			continue
 		}
 		callbacks = append(callbacks, callback)