make lmdb and badger backends use a binary encoding instead of nson.

badger/delete.go

@@ -0,0 +1,78 @@
+package badger
+
+import (
+	"context"
+	"encoding/hex"
+
+	"github.com/dgraph-io/badger/v4"
+	"github.com/nbd-wtf/go-nostr"
+	nostr_binary "github.com/nbd-wtf/go-nostr/binary"
+)
+
+func (b *BadgerBackend) DeleteEvent(ctx context.Context, evt *nostr.Event) error {
+	deletionHappened := false
+
+	err := b.Update(func(txn *badger.Txn) error {
+		idx := make([]byte, 1, 5)
+		idx[0] = rawEventStorePrefix
+
+		// query event by id to get its idx
+		id, _ := hex.DecodeString(evt.ID)
+		prefix := make([]byte, 1+32)
+		copy(prefix[1:], id)
+		opts := badger.DefaultIteratorOptions
+		opts.PrefetchValues = false
+		it := txn.NewIterator(opts)
+		it.Seek(prefix)
+		if it.ValidForPrefix(prefix) {
+			// the key is the last 32 bytes
+			idx = append(idx, it.Item().Key()[1+32:]...)
+		}
+		it.Close()
+
+		// if no idx was found, end here, this event doesn't exist
+		if len(idx) == 1 {
+			return nil
+		}
+
+		// fetch the event
+		item, err := txn.Get(idx)
+		if err != nil {
+			return err
+		}
+
+		item.Value(func(val []byte) error {
+			evt := &nostr.Event{}
+			if err := nostr_binary.Unmarshal(val, evt); err != nil {
+				return err
+			}
+
+			// set this so we'll run the GC later
+			deletionHappened = true
+
+			// calculate all index keys we have for this event and delete them
+			for _, k := range getIndexKeysForEvent(evt, idx[1:]) {
+				if err := txn.Delete(k); err != nil {
+					return err
+				}
+			}
+
+			// delete the raw event
+			return txn.Delete(idx)
+		})
+
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	// after deleting, run garbage collector
+	if deletionHappened {
+		if err := b.RunValueLogGC(0.8); err != nil {
+			panic(err)
+		}
+	}
+
+	return nil
+}