fix: convert TopicType to stack variable and use recvMessage.Topic instead of extracting content topic from WakuMessage

wakuv2/common/filter.go

@@ -165,18 +165,11 @@ func (fs *Filters) NotifyWatchers(recvMessage *ReceivedMessage) bool {
 	fs.mutex.RLock()
 	defer fs.mutex.RUnlock()
 
-	topic, err := ExtractTopicFromContentTopic(recvMessage.Envelope.Message().ContentTopic)
-	if err != nil {
-		log.Trace(err.Error(), "topic", recvMessage.Envelope.Message().ContentTopic)
-		return false
-	}
-
 	var matched bool
-
-	candidates := fs.GetWatchersByTopic(*topic)
+	candidates := fs.GetWatchersByTopic(recvMessage.Topic)
 
 	if len(candidates) == 0 {
-		log.Debug("no filters available for this topic", "message", recvMessage.Hash().Hex(), "topic", (*topic).String())
+		log.Debug("no filters available for this topic", "message", recvMessage.Hash().Hex(), "topic", recvMessage.Topic.String())
 	}
 
 	for _, watcher := range candidates {

wakuv2/common/message.go

@@ -154,14 +154,14 @@ type MemoryMessageStore struct {
 func NewReceivedMessage(env *protocol.Envelope, msgType MessageType) *ReceivedMessage {
 	ct, err := ExtractTopicFromContentTopic(env.Message().ContentTopic)
 	if err != nil {
-		ct = new(TopicType)
+		log.Error("failed to extract content topic from message", "topic", env.Message().ContentTopic, "err", err)
 	}
 
 	return &ReceivedMessage{
 		Envelope: env,
 		MsgType:  msgType,
 		Sent:     uint32(env.Message().Timestamp / int64(time.Second)),
-		Topic:    *ct,
+		Topic:    ct,
 	}
 }
 
@@ -241,7 +241,7 @@ func (msg *ReceivedMessage) Open(watcher *Filter) (result *ReceivedMessage) {
 		return nil
 	}
 
-	result.Topic = *ct
+	result.Topic = ct
 
 	return result
 }

wakuv2/common/topic.go

@@ -69,18 +69,18 @@ func (t TopicType) ContentTopic() string {
 	return "/waku/1/" + enc + "/rfc26"
 }
 
-func ExtractTopicFromContentTopic(s string) (*TopicType, error) {
+func ExtractTopicFromContentTopic(s string) (TopicType, error) {
 	p := strings.Split(s, "/")
 
 	if len(p) != 5 || p[1] != "waku" || p[2] != "1" || p[4] != "rfc26" {
-		return nil, errors.New("invalid content topic format")
+		return TopicType{}, errors.New("invalid content topic format")
 	}
 
 	str, err := hexutil.Decode(p[3])
 	if err != nil {
-		return nil, err
+		return TopicType{}, err
 	}
 
 	result := BytesToTopic(str)
-	return &result, nil
+	return result, nil
 }