badger: allow custom tag indexing and skipping.

badger/delete.go

@@ -42,7 +42,7 @@ func (b *BadgerBackend) DeleteEvent(ctx context.Context, evt *nostr.Event) error
 		deletionHappened = true
 
 		// calculate all index keys we have for this event and delete them
-		for _, k := range getIndexKeysForEvent(evt, idx[1:]) {
+		for _, k := range b.getIndexKeysForEvent(evt, idx[1:]) {
 			if err := txn.Delete(k); err != nil {
 				return err
 			}

badger/helpers.go

@@ -38,7 +38,7 @@ func getTagIndexPrefix(tagValue string) ([]byte, int) {
 	return k, offset
 }
 
-func getIndexKeysForEvent(evt *nostr.Event, idx []byte) [][]byte {
+func (b BadgerBackend) getIndexKeysForEvent(evt *nostr.Event, idx []byte) [][]byte {
 	keys := make([][]byte, 0, 18)
 
 	// indexes
@@ -86,17 +86,28 @@ func getIndexKeysForEvent(evt *nostr.Event, idx []byte) [][]byte {
 	}
 
 	// ~ by tagvalue+date
+	customIndex := b.IndexLongerTag != nil
+	customSkip := b.SkipIndexingTag != nil
+
 	for i, tag := range evt.Tags {
 		if len(tag) < 2 || len(tag[0]) != 1 || len(tag[1]) == 0 || len(tag[1]) > 100 {
-			// not indexable
-			continue
+			if !customIndex || !b.IndexLongerTag(evt, tag[0], tag[1]) {
+				// not indexable
+				continue
+			}
 		}
+
 		firstIndex := slices.IndexFunc(evt.Tags, func(t nostr.Tag) bool { return len(t) >= 2 && t[1] == tag[1] })
 		if firstIndex != i {
 			// duplicate
 			continue
 		}
 
+		if customSkip && b.SkipIndexingTag(evt, tag[0], tag[1]) {
+			// purposefully skipped
+			continue
+		}
+
 		// get key prefix (with full length) and offset where to write the last parts
 		k, offset := getTagIndexPrefix(tag[1])
 

badger/lib.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/dgraph-io/badger/v4"
 	"github.com/fiatjaf/eventstore"
+	"github.com/nbd-wtf/go-nostr"
 )
 
 const (
@@ -27,6 +28,11 @@ type BadgerBackend struct {
 	Path     string
 	MaxLimit int
 
+	// Experimental
+	SkipIndexingTag func(event *nostr.Event, tagName string, tagValue string) bool
+	// Experimental
+	IndexLongerTag func(event *nostr.Event, tagName string, tagValue string) bool
+
 	*badger.DB
 	seq *badger.Sequence
 }

badger/save.go

@@ -37,7 +37,7 @@ func (b *BadgerBackend) SaveEvent(ctx context.Context, evt *nostr.Event) error {
 			return err
 		}
 
-		for _, k := range getIndexKeysForEvent(evt, idx[1:]) {
+		for _, k := range b.getIndexKeysForEvent(evt, idx[1:]) {
 			if err := txn.Set(k, nil); err != nil {
 				return err
 			}