Issue #5689: Add support for lzma compression to the tarfile module.
diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index 1789828..39dc1f1 100644
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -420,10 +420,11 @@
self.crc = zlib.crc32(b"")
if mode == "r":
self._init_read_gz()
+ self.exception = zlib.error
else:
self._init_write_gz()
- if comptype == "bz2":
+ elif comptype == "bz2":
try:
import bz2
except ImportError:
@@ -431,8 +432,25 @@
if mode == "r":
self.dbuf = b""
self.cmp = bz2.BZ2Decompressor()
+ self.exception = IOError
else:
self.cmp = bz2.BZ2Compressor()
+
+ elif comptype == "xz":
+ try:
+ import lzma
+ except ImportError:
+ raise CompressionError("lzma module is not available")
+ if mode == "r":
+ self.dbuf = b""
+ self.cmp = lzma.LZMADecompressor()
+ self.exception = lzma.LZMAError
+ else:
+ self.cmp = lzma.LZMACompressor()
+
+ elif comptype != "tar":
+ raise CompressionError("unknown compression type %r" % comptype)
+
except:
if not self._extfileobj:
self.fileobj.close()
@@ -584,7 +602,7 @@
break
try:
buf = self.cmp.decompress(buf)
- except IOError:
+ except self.exception:
raise ReadError("invalid compressed data")
self.dbuf += buf
c += len(buf)
@@ -622,11 +640,14 @@
return self.buf
def getcomptype(self):
- if self.buf.startswith(b"\037\213\010"):
+ if self.buf.startswith(b"\x1f\x8b\x08"):
return "gz"
- if self.buf[0:3] == b"BZh" and self.buf[4:10] == b"1AY&SY":
+ elif self.buf[0:3] == b"BZh" and self.buf[4:10] == b"1AY&SY":
return "bz2"
- return "tar"
+ elif self.buf.startswith((b"\x5d\x00\x00\x80", b"\xfd7zXZ")):
+ return "xz"
+ else:
+ return "tar"
def close(self):
self.fileobj.close()
@@ -1651,18 +1672,22 @@
'r:' open for reading exclusively uncompressed
'r:gz' open for reading with gzip compression
'r:bz2' open for reading with bzip2 compression
+ 'r:xz' open for reading with lzma compression
'a' or 'a:' open for appending, creating the file if necessary
'w' or 'w:' open for writing without compression
'w:gz' open for writing with gzip compression
'w:bz2' open for writing with bzip2 compression
+ 'w:xz' open for writing with lzma compression
'r|*' open a stream of tar blocks with transparent compression
'r|' open an uncompressed stream of tar blocks for reading
'r|gz' open a gzip compressed stream of tar blocks
'r|bz2' open a bzip2 compressed stream of tar blocks
+ 'r|xz' open an lzma compressed stream of tar blocks
'w|' open an uncompressed stream for writing
'w|gz' open a gzip compressed stream for writing
'w|bz2' open a bzip2 compressed stream for writing
+ 'w|xz' open an lzma compressed stream for writing
"""
if not name and not fileobj:
@@ -1780,11 +1805,40 @@
t._extfileobj = False
return t
+ @classmethod
+ def xzopen(cls, name, mode="r", fileobj=None, preset=9, **kwargs):
+ """Open lzma compressed tar archive name for reading or writing.
+ Appending is not allowed.
+ """
+ if mode not in ("r", "w"):
+ raise ValueError("mode must be 'r' or 'w'")
+
+ try:
+ import lzma
+ except ImportError:
+ raise CompressionError("lzma module is not available")
+
+ if mode == "r":
+ # LZMAFile complains about a preset argument in read mode.
+ preset = None
+
+ fileobj = lzma.LZMAFile(filename=name if fileobj is None else None,
+ mode=mode, fileobj=fileobj, preset=preset)
+
+ try:
+ t = cls.taropen(name, mode, fileobj, **kwargs)
+ except (lzma.LZMAError, EOFError):
+ fileobj.close()
+ raise ReadError("not an lzma file")
+ t._extfileobj = False
+ return t
+
# All *open() methods are registered here.
OPEN_METH = {
"tar": "taropen", # uncompressed tar
"gz": "gzopen", # gzip compressed tar
- "bz2": "bz2open" # bzip2 compressed tar
+ "bz2": "bz2open", # bzip2 compressed tar
+ "xz": "xzopen" # lzma compressed tar
}
#--------------------------------------------------------------------------