code: func (m *model) NeedSize(folder string) db.Counts {
  	m.fmut.RLock()
  	rf, ok := m.folderFiles[folder]
  	cfg := m.folderCfgs[folder]
  	m.fmut.RUnlock()
  
  	var result db.Counts
  	if ok {
  		rf.WithNeedTruncated(protocol.LocalDeviceID, func(f db.FileIntf) bool {
  			if cfg.IgnoreDelete && f.IsDeleted() {
  				return true
  			}
  
  			addSizeOfFile(&result, f)
  			return true
  		})
  	}
  	result.Bytes -= m.progressEmitter.BytesCompleted(folder)
  	l.Debugf("%v NeedSize(%q): %v", m, folder, result)
  	return result
  }
docs: // NeedSize returns the number and total size of currently needed files.