cache: use badgerdb (#15)

cache/delete.go

@@ -2,12 +2,12 @@ package cache
 
 import (
 	"fmt"
-	"github.com/xujiajun/nutsdb"
+	"github.com/dgraph-io/badger/v3"
 )
 
 func (c *Client) Delete(bucket string, key string) error {
-	if err := c.db.Update(func(tx *nutsdb.Tx) error {
-		return tx.Delete(bucket, []byte(key))
+	if err := c.db.Update(func(txn *badger.Txn) error {
+		return txn.Delete([]byte(fmt.Sprintf("%s_%v", bucket, key)))
 	}); err != nil {
 		return fmt.Errorf("%v: %v; delete: %w", bucket, key, err)
 	}