func (s *v3Manager) Status(dbPath string) (ds Status, err error) {
	if _, err = os.Stat(dbPath); err != nil {
		return ds, err
	}

	db, err := bolt.Open(dbPath, 0400, &bolt.Options{ReadOnly: true})
	if err != nil {
		return ds, err
	}
	defer db.Close()

	h := crc32.New(crc32.MakeTable(crc32.Castagnoli))

	if err = db.View(func(tx *bolt.Tx) error {
		// check snapshot file integrity first
		var dbErrStrings []string
		for dbErr := range tx.Check() {
			dbErrStrings = append(dbErrStrings, dbErr.Error())
		}
		if len(dbErrStrings) > 0 {
			return fmt.Errorf("snapshot file integrity check failed. %d errors found.\n"+strings.Join(dbErrStrings, "\n"), len(dbErrStrings))
		}
		ds.TotalSize = tx.Size()
		c := tx.Cursor()
		for next, _ := c.First(); next != nil; next, _ = c.Next() {
			b := tx.Bucket(next)
			if b == nil {
				return fmt.Errorf("cannot get hash of bucket %s", string(next))
			}
			h.Write(next)
			iskeyb := (string(next) == "key")
			b.ForEach(func(k, v []byte) error {
				h.Write(k)
				h.Write(v)
				if iskeyb {
					rev := bytesToRev(k)
					ds.Revision = rev.main
				}
				ds.TotalKey++
				return nil
			})
		}
		return nil
	}); err != nil {
		return ds, err
	}

	ds.Hash = h.Sum32()
	return ds, nil
}
func (s *v3Manager) Status(dbPath string) (ds Status, err error) {
	if _, err = os.Stat(dbPath); err != nil {
		return ds, err
	}

	db, err := bolt.Open(dbPath, 0400, &bolt.Options{ReadOnly: true})
	if err != nil {
		return ds, err
	}
	defer db.Close()

	h := crc32.New(crc32.MakeTable(crc32.Castagnoli))

	if err = db.View(func(tx *bolt.Tx) error {
		// check snapshot file integrity first
		var dbErrStrings []string
		for dbErr := range tx.Check() {
			dbErrStrings = append(dbErrStrings, dbErr.Error())
		}
		if len(dbErrStrings) > 0 {
			return fmt.Errorf("snapshot file integrity check failed. %d errors found.\n"+strings.Join(dbErrStrings, "\n"), len(dbErrStrings))
		}
		ds.TotalSize = tx.Size()
		c := tx.Cursor()
		for next, _ := c.First(); next != nil; next, _ = c.Next() {
			b := tx.Bucket(next)
			if b == nil {
				return fmt.Errorf("cannot get hash of bucket %s", string(next))
			}
			h.Write(next)
			iskeyb := (string(next) == "key")
			b.ForEach(func(k, v []byte) error {
				h.Write(k)
				h.Write(v)
				if iskeyb {
					rev := bytesToRev(k)
					ds.Revision = rev.main
				}
				ds.TotalKey++
				return nil
			})
		}
		return nil
	}); err != nil {
		return ds, err
	}

	ds.Hash = h.Sum32()
	return ds, nil
}
// Status returns the snapshot file information.