func makeTestLayer(paths []string) (rc io.ReadCloser, err error) {
tmpDir, err := ioutil.TempDir("", "graphdriver-test-mklayer")
if err != nil {
return
}
defer func() {
if err != nil {
os.RemoveAll(tmpDir)
}
}()
for _, p := range paths {
if p[len(p)-1] == filepath.Separator {
if err = os.MkdirAll(filepath.Join(tmpDir, p), 0700); err != nil {
return
}
} else {
if err = ioutil.WriteFile(filepath.Join(tmpDir, p), nil, 0600); err != nil {
return
}
}
}
archive, err := Tar(tmpDir, Uncompressed)
if err != nil {
return
}
return ioutils.NewReadCloserWrapper(archive, func() error {
err := archive.Close()
os.RemoveAll(tmpDir)
return err
}), nil
}
// NewReadCloserWrapper returns a wrapper which puts the bufio.Reader back
// into the pool and closes the reader if it's an io.ReadCloser.
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 {
readCloser.Close()
}
bufPool.Put(buf)
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 && err != io.EOF {
// Note: we'll ignore any io.EOF error because there are some odd
// cases where the layer.tar file will be empty (zero bytes) and
// that results in an io.EOF from the Peek() call. So, in those
// cases we'll just treat it as a non-compressed stream and
// that means just create an empty layer.
// See Issue 18170
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())
}
}