Adding upstream version 3.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

tarxz.go

@@ -0,0 +1,119 @@
+package archiver
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/ulikunitz/xz"
+	fastxz "github.com/xi2/xz"
+)
+
+// TarXz facilitates xz compression
+// (https://tukaani.org/xz/format.html)
+// of tarball archives.
+type TarXz struct {
+	*Tar
+}
+
+// CheckExt ensures the file extension matches the format.
+func (*TarXz) CheckExt(filename string) error {
+	if !strings.HasSuffix(filename, ".tar.xz") &&
+		!strings.HasSuffix(filename, ".txz") {
+		return fmt.Errorf("filename must have a .tar.xz or .txz extension")
+	}
+	return nil
+}
+
+// Archive creates a compressed tar file at destination
+// containing the files listed in sources. The destination
+// must end with ".tar.xz" or ".txz". File paths can be
+// those of regular files or directories; directories will
+// be recursively added.
+func (txz *TarXz) Archive(sources []string, destination string) error {
+	err := txz.CheckExt(destination)
+	if err != nil {
+		return fmt.Errorf("output %s", err.Error())
+	}
+	txz.wrapWriter()
+	return txz.Tar.Archive(sources, destination)
+}
+
+// Unarchive unpacks the compressed tarball at
+// source to destination. Destination will be
+// treated as a folder name.
+func (txz *TarXz) Unarchive(source, destination string) error {
+	txz.wrapReader()
+	return txz.Tar.Unarchive(source, destination)
+}
+
+// Walk calls walkFn for each visited item in archive.
+func (txz *TarXz) Walk(archive string, walkFn WalkFunc) error {
+	txz.wrapReader()
+	return txz.Tar.Walk(archive, walkFn)
+}
+
+// Create opens txz for writing a compressed
+// tar archive to out.
+func (txz *TarXz) Create(out io.Writer) error {
+	txz.wrapWriter()
+	return txz.Tar.Create(out)
+}
+
+// Open opens t for reading a compressed archive from
+// in. The size parameter is not used.
+func (txz *TarXz) Open(in io.Reader, size int64) error {
+	txz.wrapReader()
+	return txz.Tar.Open(in, size)
+}
+
+// Extract extracts a single file from the tar archive.
+// If the target is a directory, the entire folder will
+// be extracted into destination.
+func (txz *TarXz) Extract(source, target, destination string) error {
+	txz.wrapReader()
+	return txz.Tar.Extract(source, target, destination)
+}
+
+func (txz *TarXz) wrapWriter() {
+	var xzw *xz.Writer
+	txz.Tar.writerWrapFn = func(w io.Writer) (io.Writer, error) {
+		var err error
+		xzw, err = xz.NewWriter(w)
+		return xzw, err
+	}
+	txz.Tar.cleanupWrapFn = func() {
+		xzw.Close()
+	}
+}
+
+func (txz *TarXz) wrapReader() {
+	var xzr *fastxz.Reader
+	txz.Tar.readerWrapFn = func(r io.Reader) (io.Reader, error) {
+		var err error
+		xzr, err = fastxz.NewReader(r, 0)
+		return xzr, err
+	}
+}
+
+func (txz *TarXz) String() string { return "tar.xz" }
+
+// NewTarXz returns a new, default instance ready to be customized and used.
+func NewTarXz() *TarXz {
+	return &TarXz{
+		Tar: NewTar(),
+	}
+}
+
+// Compile-time checks to ensure type implements desired interfaces.
+var (
+	_ = Reader(new(TarXz))
+	_ = Writer(new(TarXz))
+	_ = Archiver(new(TarXz))
+	_ = Unarchiver(new(TarXz))
+	_ = Walker(new(TarXz))
+	_ = Extractor(new(TarXz))
+)
+
+// DefaultTarXz is a convenient archiver ready to use.
+var DefaultTarXz = NewTarXz()