Prefix filter optimizations

pkg/eventfilter/filter.go

@@ -23,13 +23,13 @@ import (
 )
 
 const (
-	PassFilter FilterResult = "pass"
-	FailFilter FilterResult = "fail"
-	NoFilter   FilterResult = "no_filter"
+	PassFilter FilterResult = iota
+	FailFilter
+	NoFilter
 )
 
 // FilterResult has the result of the filtering operation.
-type FilterResult string
+type FilterResult int
 
 func (x FilterResult) And(y FilterResult) FilterResult {
 	if x == NoFilter {
@@ -57,6 +57,17 @@ func (x FilterResult) Or(y FilterResult) FilterResult {
 	return FailFilter
 }
 
+func (x FilterResult) String() string {
+	switch x {
+	case PassFilter:
+		return "PassFilter"
+	case FailFilter:
+		return "FailFilter"
+	default:
+		return "NoFilter"
+	}
+}
+
 // Filter is an interface representing an event filter of the trigger filter
 type Filter interface {
 	// Filter compute the predicate on the provided event and returns the result of the matching

pkg/eventfilter/subscriptionsapi/prefix_filter.go

@@ -50,11 +50,6 @@ func (filter *prefixFilter) Filter(ctx context.Context, event cloudevents.Event)
 	if filter == nil {
 		return eventfilter.NoFilter
 	}
-	for attribute, value := range filter.filters {
-		if attribute == "" || value == "" {
-			return eventfilter.NoFilter
-		}
-	}
 	logger := logging.FromContext(ctx)
 	logger.Debugw("Performing a prefix match ", zap.Any("filters", filter.filters), zap.Any("event", event))
 	for k, v := range filter.filters {
@@ -64,7 +59,11 @@ func (filter *prefixFilter) Filter(ctx context.Context, event cloudevents.Event)
 				zap.Any("event", event))
 			return eventfilter.FailFilter
 		}
-		if !strings.HasPrefix(fmt.Sprintf("%v", value), v) {
+		var s string
+		if s, ok = value.(string); !ok {
+			s = fmt.Sprintf("%v", value)
+		}
+		if !strings.HasPrefix(s, v) {
 			return eventfilter.FailFilter
 		}
 	}