// Diff produces an archive of the changes between the specified // layer and its parent layer which may be "". func (gdw *naiveDiffDriver) Diff(id, parent string) (arch archive.Archive, err error) { driver := gdw.ProtoDriver layerFs, err := driver.Get(id, "") if err != nil { return nil, err } defer func() { if err != nil { driver.Put(id) } }() if parent == "" { archive, err := archive.Tar(layerFs, archive.Uncompressed) if err != nil { return nil, err } return ioutils.NewReadCloserWrapper(archive, func() error { err := archive.Close() driver.Put(id) return err }), nil } parentFs, err := driver.Get(parent, "") if err != nil { return nil, err } defer driver.Put(parent) changes, err := archive.ChangesDirs(layerFs, parentFs) if err != nil { return nil, err } archive, err := archive.ExportChanges(layerFs, changes) if err != nil { return nil, err } return ioutils.NewReadCloserWrapper(archive, func() error { err := archive.Close() driver.Put(id) return err }), nil }
func (bufPool *BufioReaderPool) NewReadCloserWrapper(buf *bufio.Reader, r io.Reader) io.ReadCloser { return ioutils.NewReadCloserWrapper(r, func() error { if readCloser, ok := r.(io.ReadCloser); ok { return readCloser.Close() } return nil }) }