|
|
|
@ -18,10 +18,12 @@ import (
|
|
|
|
|
"archive/tar"
|
|
|
|
|
"bufio"
|
|
|
|
|
"bytes"
|
|
|
|
|
"compress/bzip2"
|
|
|
|
|
"compress/gzip"
|
|
|
|
|
"errors"
|
|
|
|
|
"io"
|
|
|
|
|
"io/ioutil"
|
|
|
|
|
"os/exec"
|
|
|
|
|
"strings"
|
|
|
|
|
)
|
|
|
|
|
|
|
|
|
@ -32,19 +34,75 @@ var (
|
|
|
|
|
// ErrExtractedFileTooBig occurs when a file to extract is too big.
|
|
|
|
|
ErrExtractedFileTooBig = errors.New("utils: could not extract one or more files from the archive: file too big")
|
|
|
|
|
|
|
|
|
|
gzipHeader = []byte{0x1f, 0x8b}
|
|
|
|
|
readLen = 6 // max bytes to sniff
|
|
|
|
|
|
|
|
|
|
gzipHeader = []byte{0x1f, 0x8b}
|
|
|
|
|
bzip2Header = []byte{0x42, 0x5a, 0x68}
|
|
|
|
|
xzHeader = []byte{0xfd, 0x37, 0x7a, 0x58, 0x5a, 0x00}
|
|
|
|
|
)
|
|
|
|
|
|
|
|
|
|
// XzReader is an io.ReadCloser which decompresses xz compressed data.
|
|
|
|
|
type XzReader struct {
|
|
|
|
|
io.ReadCloser
|
|
|
|
|
cmd *exec.Cmd
|
|
|
|
|
closech chan error
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// NewXzReader shells out to a command line xz executable (if
|
|
|
|
|
// available) to decompress the given io.Reader using the xz
|
|
|
|
|
// compression format and returns an *XzReader.
|
|
|
|
|
// It is the caller's responsibility to call Close on the XzReader when done.
|
|
|
|
|
func NewXzReader(r io.Reader) (*XzReader, error) {
|
|
|
|
|
rpipe, wpipe := io.Pipe()
|
|
|
|
|
ex, err := exec.LookPath("xz")
|
|
|
|
|
if err != nil {
|
|
|
|
|
return nil, err
|
|
|
|
|
}
|
|
|
|
|
cmd := exec.Command(ex, "--decompress", "--stdout")
|
|
|
|
|
|
|
|
|
|
closech := make(chan error)
|
|
|
|
|
|
|
|
|
|
cmd.Stdin = r
|
|
|
|
|
cmd.Stdout = wpipe
|
|
|
|
|
|
|
|
|
|
go func() {
|
|
|
|
|
err := cmd.Run()
|
|
|
|
|
wpipe.CloseWithError(err)
|
|
|
|
|
closech <- err
|
|
|
|
|
}()
|
|
|
|
|
|
|
|
|
|
return &XzReader{rpipe, cmd, closech}, nil
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
func (r *XzReader) Close() error {
|
|
|
|
|
r.ReadCloser.Close()
|
|
|
|
|
r.cmd.Process.Kill()
|
|
|
|
|
return <-r.closech
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// TarReadCloser embeds a *tar.Reader and the related io.Closer
|
|
|
|
|
// It is the caller's responsibility to call Close on TarReadCloser when
|
|
|
|
|
// done.
|
|
|
|
|
type TarReadCloser struct {
|
|
|
|
|
*tar.Reader
|
|
|
|
|
io.Closer
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
func (r *TarReadCloser) Close() error {
|
|
|
|
|
return r.Closer.Close()
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// SelectivelyExtractArchive extracts the specified files and folders
|
|
|
|
|
// from targz data read from the given reader and store them in a map indexed by file paths
|
|
|
|
|
func SelectivelyExtractArchive(r io.Reader, prefix string, toExtract []string, maxFileSize int64) (map[string][]byte, error) {
|
|
|
|
|
data := make(map[string][]byte)
|
|
|
|
|
|
|
|
|
|
// Create a tar or tar/tar-gzip reader
|
|
|
|
|
// Create a tar or tar/tar-gzip/tar-bzip2/tar-xz reader
|
|
|
|
|
tr, err := getTarReader(r)
|
|
|
|
|
if err != nil {
|
|
|
|
|
return data, ErrCouldNotExtract
|
|
|
|
|
}
|
|
|
|
|
defer tr.Close()
|
|
|
|
|
|
|
|
|
|
// For each element in the archive
|
|
|
|
|
for {
|
|
|
|
@ -89,22 +147,35 @@ func SelectivelyExtractArchive(r io.Reader, prefix string, toExtract []string, m
|
|
|
|
|
return data, nil
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// getTarReader returns a tar.Reader associated with the specified io.Reader,
|
|
|
|
|
// optionally backed by a gzip.Reader if gzip compression is detected.
|
|
|
|
|
// getTarReader returns a TarReaderCloser associated with the specified io.Reader.
|
|
|
|
|
//
|
|
|
|
|
// Gzip detection is done by using the magic numbers defined in the RFC1952 :
|
|
|
|
|
// the first two bytes should be 0x1f and 0x8b..
|
|
|
|
|
func getTarReader(r io.Reader) (*tar.Reader, error) {
|
|
|
|
|
// Gzip/Bzip2/XZ detection is done by using the magic numbers:
|
|
|
|
|
// Gzip: the first two bytes should be 0x1f and 0x8b. Defined in the RFC1952.
|
|
|
|
|
// Bzip2: the first three bytes should be 0x42, 0x5a and 0x68. No RFC.
|
|
|
|
|
// XZ: the first three bytes should be 0xfd, 0x37, 0x7a, 0x58, 0x5a, 0x00. No RFC.
|
|
|
|
|
func getTarReader(r io.Reader) (*TarReadCloser, error) {
|
|
|
|
|
br := bufio.NewReader(r)
|
|
|
|
|
header, err := br.Peek(2)
|
|
|
|
|
|
|
|
|
|
if err == nil && bytes.Equal(header, gzipHeader) {
|
|
|
|
|
gr, err := gzip.NewReader(br)
|
|
|
|
|
if err != nil {
|
|
|
|
|
return nil, err
|
|
|
|
|
header, err := br.Peek(readLen)
|
|
|
|
|
if err == nil {
|
|
|
|
|
switch {
|
|
|
|
|
case bytes.HasPrefix(header, gzipHeader):
|
|
|
|
|
gr, err := gzip.NewReader(br)
|
|
|
|
|
if err != nil {
|
|
|
|
|
return nil, err
|
|
|
|
|
}
|
|
|
|
|
return &TarReadCloser{tar.NewReader(gr), gr}, nil
|
|
|
|
|
case bytes.HasPrefix(header, bzip2Header):
|
|
|
|
|
bzip2r := ioutil.NopCloser(bzip2.NewReader(br))
|
|
|
|
|
return &TarReadCloser{tar.NewReader(bzip2r), bzip2r}, nil
|
|
|
|
|
case bytes.HasPrefix(header, xzHeader):
|
|
|
|
|
xzr, err := NewXzReader(br)
|
|
|
|
|
if err != nil {
|
|
|
|
|
return nil, err
|
|
|
|
|
}
|
|
|
|
|
return &TarReadCloser{tar.NewReader(xzr), xzr}, nil
|
|
|
|
|
}
|
|
|
|
|
return tar.NewReader(gr), nil
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return tar.NewReader(br), nil
|
|
|
|
|
dr := ioutil.NopCloser(br)
|
|
|
|
|
return &TarReadCloser{tar.NewReader(dr), dr}, nil
|
|
|
|
|
}
|
|
|
|
|