Added backup machinery

storage/bolt/bolt.go

@@ -4,6 +4,7 @@ import (
 	bolt "go.etcd.io/bbolt"
 	"net/url"
 	"time"
+	"os"
 )
 
 type BoltStorage struct {
@@ -26,3 +27,17 @@ func New(u *url.URL) (*BoltStorage, error) {
 	}
 	return &BoltStorage{DB: db}, nil
 }
+
+func (stor *BoltStorage) Backup(bpath string) error {
+	tx, err := stor.DB.Begin(false)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	err = tx.CopyFile(bpath, os.FileMode(0600))
+	if err != nil {
+		return err
+	}
+	return nil
+}

storage/storage.go

@@ -13,6 +13,7 @@ type Storage interface {
 	//	GetQURL(uint64) (*qurl.QURL, error)
 	GetQURLByURL(string) (*qurl.QURL, error)
 	SetQURLSequence(uint64) error
+	Backup(string) error
 	Shutdown()
 }