// updateLocal updates local index and saves it to cache directory.
func (s *synced) updateLocal() error {
dataPath := filepath.Join(s.wd, "data")
cs := s.lidx.Compare(dataPath)
if len(cs) == 0 {
return nil
}
s.lidx.Apply(dataPath, cs)
return index.SaveIndex(s.lidx, filepath.Join(s.wd, LocalIndexName))
}
// loadIdx reads named index from synced working directory. If index file does
// not exist, it is fetched by calling provided `fetchIdx` function and saved to
// provided path.
func (s *synced) loadIdx(name string, fetchIdx idxFunc) (*index.Index, error) {
path := filepath.Join(s.wd, name)
f, err := os.Open(path)
if os.IsNotExist(err) {
idx, err := fetchIdx()
if err != nil {
return nil, err
}
return idx, index.SaveIndex(idx, path)
} else if err != nil {
return nil, err
}
defer f.Close()
idx := index.NewIndex()
return idx, json.NewDecoder(f).Decode(idx)
}