use 23/WAKU2-TOPICS format for content topics (#2281)

wakuv2/api.go

@@ -247,7 +247,7 @@ func (api *PublicWakuAPI) Post(ctx context.Context, req NewMessage) (hexutil.Byt
 	wakuMsg := &pb.WakuMessage{
 		Payload:      payload,
 		Version:      version,
-		ContentTopic: req.Topic.String(),
+		ContentTopic: req.Topic.ContentTopic(),
 		Timestamp:    utils.GetUnixEpoch(),
 	}
 

wakuv2/common/filter.go

@@ -165,7 +165,13 @@ func (fs *Filters) NotifyWatchers(recvMessage *ReceivedMessage) {
 	fs.mutex.RLock()
 	defer fs.mutex.RUnlock()
 
-	candidates := fs.GetWatchersByTopic(StringToTopic(recvMessage.Envelope.Message().ContentTopic))
+	topic, err := ExtractTopicFromContentTopic(recvMessage.Envelope.Message().ContentTopic)
+	if err != nil {
+		log.Trace(err.Error(), "topic", recvMessage.Envelope.Message().ContentTopic)
+		return
+	}
+
+	candidates := fs.GetWatchersByTopic(*topic)
 	for _, watcher := range candidates {
 		match := true
 		if decodedMsg == nil {

wakuv2/common/topic.go

@@ -19,6 +19,9 @@
 package common
 
 import (
+	"errors"
+	"strings"
+
 	"github.com/ethereum/go-ethereum/common/hexutil"
 )
 
@@ -43,7 +46,6 @@ func BytesToTopic(b []byte) (t TopicType) {
 func StringToTopic(s string) (t TopicType) {
 	str, _ := hexutil.Decode(s)
 	return BytesToTopic(str)
-
 }
 
 // String converts a topic byte array to a string representation.
@@ -60,3 +62,25 @@ func (t TopicType) MarshalText() ([]byte, error) {
 func (t *TopicType) UnmarshalText(input []byte) error {
 	return hexutil.UnmarshalFixedText("Topic", input, t[:])
 }
+
+// Converts a topic to its 23/WAKU2-TOPICS representation
+func (t TopicType) ContentTopic() string {
+	enc := hexutil.Encode(t[:])
+	return "/waku/1/" + enc + "/rfc26"
+}
+
+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")
+	}
+
+	str, err := hexutil.Decode(p[3])
+	if err != nil {
+		return nil, err
+	}
+
+	result := BytesToTopic(str)
+	return &result, nil
+}