// 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, gdw.uidMaps, gdw.gidMaps) 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 }) }
// DecompressStream decompress the archive and returns a ReaderCloser with the decompressed archive. func DecompressStream(archive io.Reader) (io.ReadCloser, error) { p := pools.BufioReader32KPool buf := p.Get(archive) bs, err := buf.Peek(10) if err != nil { return nil, err } compression := DetectCompression(bs) switch compression { case Uncompressed: readBufWrapper := p.NewReadCloserWrapper(buf, buf) return readBufWrapper, nil case Gzip: gzReader, err := gzip.NewReader(buf) if err != nil { return nil, err } readBufWrapper := p.NewReadCloserWrapper(buf, gzReader) return readBufWrapper, nil case Bzip2: bz2Reader := bzip2.NewReader(buf) readBufWrapper := p.NewReadCloserWrapper(buf, bz2Reader) return readBufWrapper, nil case Xz: xzReader, chdone, err := xzDecompress(buf) if err != nil { return nil, err } readBufWrapper := p.NewReadCloserWrapper(buf, xzReader) return ioutils.NewReadCloserWrapper(readBufWrapper, func() error { <-chdone return readBufWrapper.Close() }), nil default: return nil, fmt.Errorf("Unsupported compression format %s", (&compression).Extension()) } }