func writeTarFromLayer(r hcsshim.LayerReader, w io.Writer) error {
t := tar.NewWriter(w)
for {
name, size, fileInfo, err := r.Next()
if err == io.EOF {
break
}
if err != nil {
return err
}
if fileInfo == nil {
// Write a whiteout file.
hdr := &tar.Header{
Name: filepath.ToSlash(filepath.Join(filepath.Dir(name), archive.WhiteoutPrefix+filepath.Base(name))),
}
err := t.WriteHeader(hdr)
if err != nil {
return err
}
} else {
err = backuptar.WriteTarFileFromBackupStream(t, r, name, size, fileInfo)
if err != nil {
return err
}
}
}
return t.Close()
}
func TestRoundTrip(t *testing.T) {
f, err := ioutil.TempFile("", "tst")
if err != nil {
t.Fatal(err)
}
defer f.Close()
defer os.Remove(f.Name())
if _, err = f.Write([]byte("testing 1 2 3\n")); err != nil {
t.Fatal(err)
}
if _, err = f.Seek(0, 0); err != nil {
t.Fatal(err)
}
fi, err := f.Stat()
if err != nil {
t.Fatal(err)
}
bi, err := winio.GetFileBasicInfo(f)
if err != nil {
t.Fatal(err)
}
br := winio.NewBackupFileReader(f, true)
defer br.Close()
var buf bytes.Buffer
tw := tar.NewWriter(&buf)
err = WriteTarFileFromBackupStream(tw, br, f.Name(), fi.Size(), bi)
if err != nil {
t.Fatal(err)
}
tr := tar.NewReader(&buf)
hdr, err := tr.Next()
if err != nil {
t.Fatal(err)
}
name, size, bi2, err := FileInfoFromHeader(hdr)
if err != nil {
t.Fatal(err)
}
if name != filepath.ToSlash(f.Name()) {
t.Errorf("got name %s, expected %s", name, filepath.ToSlash(f.Name()))
}
if size != fi.Size() {
t.Errorf("got size %d, expected %d", size, fi.Size())
}
if !reflect.DeepEqual(*bi, *bi2) {
t.Errorf("got %#v, expected %#v", *bi, *bi2)
}
ensurePresent(t, hdr.Winheaders, "fileattr", "sd")
}