func writer(t *testing.T, tname string, w io.Writer, atype string) archive.WriteCloser {
switch atype {
case gzipType:
return gzip.NewWriter(w)
case tarType:
return tar.NewWriter(w)
case zipType:
return zip.NewWriter(w)
}
t.Fatalf("%s: unrecognized archive type: %s", tname, atype)
panic("execution continued after (*testing.T).Fatalf")
}
fi, err := f.Stat()
if err != nil {
return nil, err
}
r, err := zip.NewReader(f, fi.Size())
if err != nil {
return nil, err
}
return archive.NopCloser(r), nil
},
},
rollingArchiveGzip: {
extension: ".gz",
handleMultipleEntries: false,
archiver: func(f *os.File, exploded bool) archive.WriteCloser {
gw := gzip.NewWriter(f)
if exploded {
return gw
}
return tar.NewWriteMultiCloser(gw, gw)
},
unarchiver: func(f *os.File) (archive.ReadCloser, error) {
gr, err := gzip.NewReader(f, f.Name())
if err != nil {
return nil, err
}
// Determine if the gzip is a tar
tr := tar.NewReader(gr)
_, err = tr.Next()
isTar := err == nil
