func main() {
dec, er := xz.NewReader(os.Stdin)
if er != nil {
fmt.Println(er)
os.Exit(1)
}
io.Copy(os.Stdout, dec)
}
func OpenPackage(name string) (x ReadCloser, err error) {
f, err := os.Open(name)
if err != nil {
return x, err
}
var rd io.ReadCloser
switch filepath.Ext(name) {
case ".xz":
rd, err = xz.NewReader(f)
case ".gz":
rd, err = gzip.NewReader(f)
default:
return x, fmt.Errorf("not a package name: %s", name)
}
if err != nil {
f.Close()
return x, err
}
return ReadCloser{rd, []io.Closer{rd, f}}, nil
}
// return the uncompressed data associated with this article
func (a *Article) Data() ([]byte, error) {
// ensure we have data to read
if a.EntryType == RedirectEntry || a.EntryType == LinkTargetEntry || a.EntryType == DeletedEntry {
return nil, nil
}
start, end, err := a.z.clusterOffsetsAtIdx(a.cluster)
if err != nil {
return nil, err
}
s, err := a.z.bytesRangeAt(start, start+1)
if err != nil {
return nil, err
}
compression := uint8(s[0])
// blob starts at offset, blob ends at offset
var bs, be uint32
// LZMA
if compression == 4 {
b, err := a.z.bytesRangeAt(start+1, end+1)
if err != nil {
return nil, err
}
bbuf := bytes.NewBuffer(b)
dec, err := xz.NewReader(bbuf)
defer dec.Close()
if err != nil {
return nil, err
}
// the decoded chunk are around 1MB
// TODO: on smaller devices need to read stream rather than ReadAll
blob, err := ioutil.ReadAll(dec)
if err != nil {
return nil, err
}
bs, err = readInt32(blob[a.blob*4:a.blob*4+4], nil)
if err != nil {
return nil, err
}
be, err = readInt32(blob[a.blob*4+4:a.blob*4+4+4], nil)
if err != nil {
return nil, err
}
// avoid retaining all the chunk
c := make([]byte, be-bs)
copy(c, blob[bs:be])
return c, nil
} else if compression == 0 || compression == 1 {
// un compresssed
startPos := start + 1
blobOffset := uint64(a.blob * 4)
bs, err := readInt32(a.z.bytesRangeAt(startPos+blobOffset, startPos+blobOffset+4))
if err != nil {
return nil, err
}
be, err := readInt32(a.z.bytesRangeAt(startPos+blobOffset+4, startPos+blobOffset+4+4))
if err != nil {
return nil, err
}
return a.z.bytesRangeAt(startPos+uint64(bs), startPos+uint64(be))
}
return nil, errors.New("Unhandled compression")
}
func (c *XZDecompressor) NewReader(src io.Reader) (io.Reader, error) {
return xz.NewReader(src)
}