First commit

author: Shubham Saini <shubham6405@gmail.com> 2018-12-11 10:01:23 +0000
committer: Shubham Saini <shubham6405@gmail.com> 2018-12-11 10:01:23 +0000
commit: 68df54d6629ec019142eb149dd037774f2d11e7c (patch)
tree: 345bc22d46b4e01a4ba8303b94278952a4ed2b9e /venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/distlib/_backport/tarfile.py
1 files changed, 2607 insertions, 0 deletions
diff --git a/venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/distlib/_backport/tarfile.py b/venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/distlib/_backport/tarfile.py
new file mode 100644
index 0000000..b0599bc
--- /dev/null
+++ b/venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/distlib/_backport/tarfile.py
@@ -0,0 +1,2607 @@
+#-------------------------------------------------------------------
+# tarfile.py
+#-------------------------------------------------------------------
+# Copyright (C) 2002 Lars Gustaebel <lars@gustaebel.de>
+# All rights reserved.
+#
+# Permission  is  hereby granted,  free  of charge,  to  any person
+# obtaining a  copy of  this software  and associated documentation
+# files  (the  "Software"),  to   deal  in  the  Software   without
+# restriction,  including  without limitation  the  rights to  use,
+# copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies  of  the  Software,  and to  permit  persons  to  whom the
+# Software  is  furnished  to  do  so,  subject  to  the  following
+# conditions:
+#
+# The above copyright  notice and this  permission notice shall  be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS  IS", WITHOUT WARRANTY OF ANY  KIND,
+# EXPRESS OR IMPLIED, INCLUDING  BUT NOT LIMITED TO  THE WARRANTIES
+# OF  MERCHANTABILITY,  FITNESS   FOR  A  PARTICULAR   PURPOSE  AND
+# NONINFRINGEMENT.  IN  NO  EVENT SHALL  THE  AUTHORS  OR COPYRIGHT
+# HOLDERS  BE LIABLE  FOR ANY  CLAIM, DAMAGES  OR OTHER  LIABILITY,
+# WHETHER  IN AN  ACTION OF  CONTRACT, TORT  OR OTHERWISE,  ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+#
+from __future__ import print_function
+"""Read from and write to tar format archives.
+"""
+__version__ = "$Revision$"
+version     = "0.9.0"
+__author__  = "Lars Gust\u00e4bel (lars@gustaebel.de)"
+__date__    = "$Date: 2011-02-25 17:42:01 +0200 (Fri, 25 Feb 2011) $"
+__cvsid__   = "$Id: tarfile.py 88586 2011-02-25 15:42:01Z marc-andre.lemburg $"
+__credits__ = "Gustavo Niemeyer, Niels Gust\u00e4bel, Richard Townsend."
+#---------
+# Imports
+#---------
+import sys
+import os
+import stat
+import errno
+import time
+import struct
+import copy
+import re
+try:
+    import grp, pwd
+except ImportError:
+    grp = pwd = None
+# os.symlink on Windows prior to 6.0 raises NotImplementedError
+symlink_exception = (AttributeError, NotImplementedError)
+try:
+    # WindowsError (1314) will be raised if the caller does not hold the
+    # SeCreateSymbolicLinkPrivilege privilege
+    symlink_exception += (WindowsError,)
+except NameError:
+    pass
+# from tarfile import *
+__all__ = ["TarFile", "TarInfo", "is_tarfile", "TarError"]
+if sys.version_info[0] < 3:
+    import __builtin__ as builtins
+else:
+    import builtins
+_open = builtins.open   # Since 'open' is TarFile.open
+#---------------------------------------------------------
+# tar constants
+#---------------------------------------------------------
+NUL = b"\0"                     # the null character
+BLOCKSIZE = 512                 # length of processing blocks
+RECORDSIZE = BLOCKSIZE * 20     # length of records
+GNU_MAGIC = b"ustar  \0"        # magic gnu tar string
+POSIX_MAGIC = b"ustar\x0000"    # magic posix tar string
+LENGTH_NAME = 100               # maximum length of a filename
+LENGTH_LINK = 100               # maximum length of a linkname
+LENGTH_PREFIX = 155             # maximum length of the prefix field
+REGTYPE = b"0"                  # regular file
+AREGTYPE = b"\0"                # regular file
+LNKTYPE = b"1"                  # link (inside tarfile)
+SYMTYPE = b"2"                  # symbolic link
+CHRTYPE = b"3"                  # character special device
+BLKTYPE = b"4"                  # block special device
+DIRTYPE = b"5"                  # directory
+FIFOTYPE = b"6"                 # fifo special device
+CONTTYPE = b"7"                 # contiguous file
+GNUTYPE_LONGNAME = b"L"         # GNU tar longname
+GNUTYPE_LONGLINK = b"K"         # GNU tar longlink
+GNUTYPE_SPARSE = b"S"           # GNU tar sparse file
+XHDTYPE = b"x"                  # POSIX.1-2001 extended header
+XGLTYPE = b"g"                  # POSIX.1-2001 global header
+SOLARIS_XHDTYPE = b"X"          # Solaris extended header
+USTAR_FORMAT = 0                # POSIX.1-1988 (ustar) format
+GNU_FORMAT = 1                  # GNU tar format
+PAX_FORMAT = 2                  # POSIX.1-2001 (pax) format
+DEFAULT_FORMAT = GNU_FORMAT
+#---------------------------------------------------------
+# tarfile constants
+#---------------------------------------------------------
+# File types that tarfile supports:
+SUPPORTED_TYPES = (REGTYPE, AREGTYPE, LNKTYPE,
+                   SYMTYPE, DIRTYPE, FIFOTYPE,
+                   CONTTYPE, CHRTYPE, BLKTYPE,
+                   GNUTYPE_LONGNAME, GNUTYPE_LONGLINK,
+                   GNUTYPE_SPARSE)
+# File types that will be treated as a regular file.
+REGULAR_TYPES = (REGTYPE, AREGTYPE,
+                 CONTTYPE, GNUTYPE_SPARSE)
+# File types that are part of the GNU tar format.
+GNU_TYPES = (GNUTYPE_LONGNAME, GNUTYPE_LONGLINK,
+             GNUTYPE_SPARSE)
+# Fields from a pax header that override a TarInfo attribute.
+PAX_FIELDS = ("path", "linkpath", "size", "mtime",
+              "uid", "gid", "uname", "gname")
+# Fields from a pax header that are affected by hdrcharset.
+PAX_NAME_FIELDS = set(("path", "linkpath", "uname", "gname"))
+# Fields in a pax header that are numbers, all other fields
+# are treated as strings.
+PAX_NUMBER_FIELDS = {
+    "atime": float,
+    "ctime": float,
+    "mtime": float,
+    "uid": int,
+    "gid": int,
+    "size": int
+}
+#---------------------------------------------------------
+# Bits used in the mode field, values in octal.
+#---------------------------------------------------------
+S_IFLNK = 0o120000        # symbolic link
+S_IFREG = 0o100000        # regular file
+S_IFBLK = 0o060000        # block device
+S_IFDIR = 0o040000        # directory
+S_IFCHR = 0o020000        # character device
+S_IFIFO = 0o010000        # fifo
+TSUID   = 0o4000          # set UID on execution
+TSGID   = 0o2000          # set GID on execution
+TSVTX   = 0o1000          # reserved
+TUREAD  = 0o400           # read by owner
+TUWRITE = 0o200           # write by owner
+TUEXEC  = 0o100           # execute/search by owner
+TGREAD  = 0o040           # read by group
+TGWRITE = 0o020           # write by group
+TGEXEC  = 0o010           # execute/search by group
+TOREAD  = 0o004           # read by other
+TOWRITE = 0o002           # write by other
+TOEXEC  = 0o001           # execute/search by other
+#---------------------------------------------------------
+# initialization
+#---------------------------------------------------------
+if os.name in ("nt", "ce"):
+    ENCODING = "utf-8"
+else:
+    ENCODING = sys.getfilesystemencoding()
+#---------------------------------------------------------
+# Some useful functions
+#---------------------------------------------------------
+def stn(s, length, encoding, errors):
+    """Convert a string to a null-terminated bytes object.
+    """
+    s = s.encode(encoding, errors)
+    return s[:length] + (length - len(s)) * NUL
+def nts(s, encoding, errors):
+    """Convert a null-terminated bytes object to a string.
+    """
+    p = s.find(b"\0")
+    if p != -1:
+        s = s[:p]
+    return s.decode(encoding, errors)
+def nti(s):
+    """Convert a number field to a python number.
+    """
+    # There are two possible encodings for a number field, see
+    # itn() below.
+    if s[0] != chr(0o200):
+        try:
+            n = int(nts(s, "ascii", "strict") or "0", 8)
+        except ValueError:
+            raise InvalidHeaderError("invalid header")
+    else:
+        n = 0
+        for i in range(len(s) - 1):
+            n <<= 8
+            n += ord(s[i + 1])
+    return n
+def itn(n, digits=8, format=DEFAULT_FORMAT):
+    """Convert a python number to a number field.
+    """
+    # POSIX 1003.1-1988 requires numbers to be encoded as a string of
+    # octal digits followed by a null-byte, this allows values up to
+    # (8**(digits-1))-1. GNU tar allows storing numbers greater than
+    # that if necessary. A leading 0o200 byte indicates this particular
+    # encoding, the following digits-1 bytes are a big-endian
+    # representation. This allows values up to (256**(digits-1))-1.
+    if 0 <= n < 8 ** (digits - 1):
+        s = ("%0*o" % (digits - 1, n)).encode("ascii") + NUL
+    else:
+        if format != GNU_FORMAT or n >= 256 ** (digits - 1):
+            raise ValueError("overflow in number field")
+        if n < 0:
+            # XXX We mimic GNU tar's behaviour with negative numbers,
+            # this could raise OverflowError.
+            n = struct.unpack("L", struct.pack("l", n))[0]
+        s = bytearray()
+        for i in range(digits - 1):
+            s.insert(0, n & 0o377)
+            n >>= 8
+        s.insert(0, 0o200)
+    return s
+def calc_chksums(buf):
+    """Calculate the checksum for a member's header by summing up all
+       characters except for the chksum field which is treated as if
+       it was filled with spaces. According to the GNU tar sources,
+       some tars (Sun and NeXT) calculate chksum with signed char,
+       which will be different if there are chars in the buffer with
+       the high bit set. So we calculate two checksums, unsigned and
+       signed.
+    """
+    unsigned_chksum = 256 + sum(struct.unpack("148B", buf[:148]) + struct.unpack("356B", buf[156:512]))
+    signed_chksum = 256 + sum(struct.unpack("148b", buf[:148]) + struct.unpack("356b", buf[156:512]))
+    return unsigned_chksum, signed_chksum
+def copyfileobj(src, dst, length=None):
+    """Copy length bytes from fileobj src to fileobj dst.
+       If length is None, copy the entire content.
+    """
+    if length == 0:
+        return
+    if length is None:
+        while True:
+            buf = src.read(16*1024)
+            if not buf:
+                break
+            dst.write(buf)
+        return
+    BUFSIZE = 16 * 1024
+    blocks, remainder = divmod(length, BUFSIZE)
+    for b in range(blocks):
+        buf = src.read(BUFSIZE)
+        if len(buf) < BUFSIZE:
+            raise IOError("end of file reached")
+        dst.write(buf)
+    if remainder != 0:
+        buf = src.read(remainder)
+        if len(buf) < remainder:
+            raise IOError("end of file reached")
+        dst.write(buf)
+    return
+filemode_table = (
+    ((S_IFLNK,      "l"),
+     (S_IFREG,      "-"),
+     (S_IFBLK,      "b"),
+     (S_IFDIR,      "d"),
+     (S_IFCHR,      "c"),
+     (S_IFIFO,      "p")),
+    ((TUREAD,       "r"),),
+    ((TUWRITE,      "w"),),
+    ((TUEXEC|TSUID, "s"),
+     (TSUID,        "S"),
+     (TUEXEC,       "x")),
+    ((TGREAD,       "r"),),
+    ((TGWRITE,      "w"),),
+    ((TGEXEC|TSGID, "s"),
+     (TSGID,        "S"),
+     (TGEXEC,       "x")),
+    ((TOREAD,       "r"),),
+    ((TOWRITE,      "w"),),
+    ((TOEXEC|TSVTX, "t"),
+     (TSVTX,        "T"),
+     (TOEXEC,       "x"))
+)
+def filemode(mode):
+    """Convert a file's mode to a string of the form
+       -rwxrwxrwx.
+       Used by TarFile.list()
+    """
+    perm = []
+    for table in filemode_table:
+        for bit, char in table:
+            if mode & bit == bit:
+                perm.append(char)
+                break
+        else:
+            perm.append("-")
+    return "".join(perm)
+class TarError(Exception):
+    """Base exception."""
+    pass
+class ExtractError(TarError):
+    """General exception for extract errors."""
+    pass
+class ReadError(TarError):
+    """Exception for unreadable tar archives."""
+    pass
+class CompressionError(TarError):
+    """Exception for unavailable compression methods."""
+    pass
+class StreamError(TarError):
+    """Exception for unsupported operations on stream-like TarFiles."""
+    pass
+class HeaderError(TarError):
+    """Base exception for header errors."""
+    pass
+class EmptyHeaderError(HeaderError):
+    """Exception for empty headers."""
+    pass
+class TruncatedHeaderError(HeaderError):
+    """Exception for truncated headers."""
+    pass
+class EOFHeaderError(HeaderError):
+    """Exception for end of file headers."""
+    pass
+class InvalidHeaderError(HeaderError):
+    """Exception for invalid headers."""
+    pass
+class SubsequentHeaderError(HeaderError):
+    """Exception for missing and invalid extended headers."""
+    pass
+#---------------------------
+# internal stream interface
+#---------------------------
+class _LowLevelFile(object):
+    """Low-level file object. Supports reading and writing.
+       It is used instead of a regular file object for streaming
+       access.
+    """
+    def __init__(self, name, mode):
+        mode = {
+            "r": os.O_RDONLY,
+            "w": os.O_WRONLY | os.O_CREAT | os.O_TRUNC,
+        }[mode]
+        if hasattr(os, "O_BINARY"):
+            mode |= os.O_BINARY
+        self.fd = os.open(name, mode, 0o666)
+    def close(self):
+        os.close(self.fd)
+    def read(self, size):
+        return os.read(self.fd, size)
+    def write(self, s):
+        os.write(self.fd, s)
+class _Stream(object):
+    """Class that serves as an adapter between TarFile and
+       a stream-like object.  The stream-like object only
+       needs to have a read() or write() method and is accessed
+       blockwise.  Use of gzip or bzip2 compression is possible.
+       A stream-like object could be for example: sys.stdin,
+       sys.stdout, a socket, a tape device etc.
+       _Stream is intended to be used only internally.
+    """
+    def __init__(self, name, mode, comptype, fileobj, bufsize):
+        """Construct a _Stream object.
+        """
+        self._extfileobj = True
+        if fileobj is None:
+            fileobj = _LowLevelFile(name, mode)
+            self._extfileobj = False
+        if comptype == '*':
+            # Enable transparent compression detection for the
+            # stream interface
+            fileobj = _StreamProxy(fileobj)
+            comptype = fileobj.getcomptype()
+        self.name     = name or ""
+        self.mode     = mode
+        self.comptype = comptype
+        self.fileobj  = fileobj
+        self.bufsize  = bufsize
+        self.buf      = b""
+        self.pos      = 0
+        self.closed   = False
+        try:
+            if comptype == "gz":
+                try:
+                    import zlib
+                except ImportError:
+                    raise CompressionError("zlib module is not available")
+                self.zlib = zlib
+                self.crc = zlib.crc32(b"")
+                if mode == "r":
+                    self._init_read_gz()
+                else:
+                    self._init_write_gz()
+            if comptype == "bz2":
+                try:
+                    import bz2
+                except ImportError:
+                    raise CompressionError("bz2 module is not available")
+                if mode == "r":
+                    self.dbuf = b""
+                    self.cmp = bz2.BZ2Decompressor()
+                else:
+                    self.cmp = bz2.BZ2Compressor()
+        except:
+            if not self._extfileobj:
+                self.fileobj.close()
+            self.closed = True
+            raise
+    def __del__(self):
+        if hasattr(self, "closed") and not self.closed:
+            self.close()
+    def _init_write_gz(self):
+        """Initialize for writing with gzip compression.
+        """
+        self.cmp = self.zlib.compressobj(9, self.zlib.DEFLATED,
+                                            -self.zlib.MAX_WBITS,
+                                            self.zlib.DEF_MEM_LEVEL,
+                                            0)
+        timestamp = struct.pack("<L", int(time.time()))
+        self.__write(b"\037\213\010\010" + timestamp + b"\002\377")
+        if self.name.endswith(".gz"):
+            self.name = self.name[:-3]
+        # RFC1952 says we must use ISO-8859-1 for the FNAME field.
+        self.__write(self.name.encode("iso-8859-1", "replace") + NUL)
+    def write(self, s):
+        """Write string s to the stream.
+        """
+        if self.comptype == "gz":
+            self.crc = self.zlib.crc32(s, self.crc)
+        self.pos += len(s)
+        if self.comptype != "tar":
+            s = self.cmp.compress(s)
+        self.__write(s)
+    def __write(self, s):
+        """Write string s to the stream if a whole new block
+           is ready to be written.
+        """
+        self.buf += s
+        while len(self.buf) > self.bufsize:
+            self.fileobj.write(self.buf[:self.bufsize])
+            self.buf = self.buf[self.bufsize:]
+    def close(self):
+        """Close the _Stream object. No operation should be
+           done on it afterwards.
+        """
+        if self.closed:
+            return
+        if self.mode == "w" and self.comptype != "tar":
+            self.buf += self.cmp.flush()
+        if self.mode == "w" and self.buf:
+            self.fileobj.write(self.buf)
+            self.buf = b""
+            if self.comptype == "gz":
+                # The native zlib crc is an unsigned 32-bit integer, but
+                # the Python wrapper implicitly casts that to a signed C
+                # long.  So, on a 32-bit box self.crc may "look negative",
+                # while the same crc on a 64-bit box may "look positive".
+                # To avoid irksome warnings from the `struct` module, force
+                # it to look positive on all boxes.
+                self.fileobj.write(struct.pack("<L", self.crc & 0xffffffff))
+                self.fileobj.write(struct.pack("<L", self.pos & 0xffffFFFF))
+        if not self._extfileobj:
+            self.fileobj.close()
+        self.closed = True
+    def _init_read_gz(self):
+        """Initialize for reading a gzip compressed fileobj.
+        """
+        self.cmp = self.zlib.decompressobj(-self.zlib.MAX_WBITS)
+        self.dbuf = b""
+        # taken from gzip.GzipFile with some alterations
+        if self.__read(2) != b"\037\213":
+            raise ReadError("not a gzip file")
+        if self.__read(1) != b"\010":
+            raise CompressionError("unsupported compression method")
+        flag = ord(self.__read(1))
+        self.__read(6)
+        if flag & 4:
+            xlen = ord(self.__read(1)) + 256 * ord(self.__read(1))
+            self.read(xlen)
+        if flag & 8:
+            while True:
+                s = self.__read(1)
+                if not s or s == NUL:
+                    break
+        if flag & 16:
+            while True:
+                s = self.__read(1)
+                if not s or s == NUL:
+                    break
+        if flag & 2:
+            self.__read(2)
+    def tell(self):
+        """Return the stream's file pointer position.
+        """
+        return self.pos
+    def seek(self, pos=0):
+        """Set the stream's file pointer to pos. Negative seeking
+           is forbidden.
+        """
+        if pos - self.pos >= 0:
+            blocks, remainder = divmod(pos - self.pos, self.bufsize)
+            for i in range(blocks):
+                self.read(self.bufsize)
+            self.read(remainder)
+        else:
+            raise StreamError("seeking backwards is not allowed")
+        return self.pos
+    def read(self, size=None):
+        """Return the next size number of bytes from the stream.
+           If size is not defined, return all bytes of the stream
+           up to EOF.
+        """
+        if size is None:
+            t = []
+            while True:
+                buf = self._read(self.bufsize)
+                if not buf:
+                    break
+                t.append(buf)
+            buf = "".join(t)
+        else:
+            buf = self._read(size)
+        self.pos += len(buf)
+        return buf
+    def _read(self, size):
+        """Return size bytes from the stream.
+        """
+        if self.comptype == "tar":
+            return self.__read(size)
+        c = len(self.dbuf)
+        while c < size:
+            buf = self.__read(self.bufsize)
+            if not buf:
+                break
+            try:
+                buf = self.cmp.decompress(buf)
+            except IOError:
+                raise ReadError("invalid compressed data")
+            self.dbuf += buf
+            c += len(buf)
+        buf = self.dbuf[:size]
+        self.dbuf = self.dbuf[size:]
+        return buf
+    def __read(self, size):
+        """Return size bytes from stream. If internal buffer is empty,
+           read another block from the stream.
+        """
+        c = len(self.buf)
+        while c < size:
+            buf = self.fileobj.read(self.bufsize)
+            if not buf:
+                break
+            self.buf += buf
+            c += len(buf)
+        buf = self.buf[:size]
+        self.buf = self.buf[size:]
+        return buf
+# class _Stream
+class _StreamProxy(object):
+    """Small proxy class that enables transparent compression
+       detection for the Stream interface (mode 'r|*').
+    """
+    def __init__(self, fileobj):
+        self.fileobj = fileobj
+        self.buf = self.fileobj.read(BLOCKSIZE)
+    def read(self, size):
+        self.read = self.fileobj.read
+        return self.buf
+    def getcomptype(self):
+        if self.buf.startswith(b"\037\213\010"):
+            return "gz"
+        if self.buf.startswith(b"BZh91"):
+            return "bz2"
+        return "tar"
+    def close(self):
+        self.fileobj.close()
+# class StreamProxy
+class _BZ2Proxy(object):
+    """Small proxy class that enables external file object
+       support for "r:bz2" and "w:bz2" modes. This is actually
+       a workaround for a limitation in bz2 module's BZ2File
+       class which (unlike gzip.GzipFile) has no support for
+       a file object argument.
+    """
+    blocksize = 16 * 1024
+    def __init__(self, fileobj, mode):
+        self.fileobj = fileobj
+        self.mode = mode
+        self.name = getattr(self.fileobj, "name", None)
+        self.init()
+    def init(self):
+        import bz2
+        self.pos = 0
+        if self.mode == "r":
+            self.bz2obj = bz2.BZ2Decompressor()
+            self.fileobj.seek(0)
+            self.buf = b""
+        else:
+            self.bz2obj = bz2.BZ2Compressor()
+    def read(self, size):
+        x = len(self.buf)
+        while x < size:
+            raw = self.fileobj.read(self.blocksize)
+            if not raw:
+                break
+            data = self.bz2obj.decompress(raw)
+            self.buf += data
+            x += len(data)
+        buf = self.buf[:size]
+        self.buf = self.buf[size:]
+        self.pos += len(buf)
+        return buf
+    def seek(self, pos):
+        if pos < self.pos:
+            self.init()
+        self.read(pos - self.pos)
+    def tell(self):
+        return self.pos
+    def write(self, data):
+        self.pos += len(data)
+        raw = self.bz2obj.compress(data)
+        self.fileobj.write(raw)
+    def close(self):
+        if self.mode == "w":
+            raw = self.bz2obj.flush()
+            self.fileobj.write(raw)
+# class _BZ2Proxy
+#------------------------
+# Extraction file object
+#------------------------
+class _FileInFile(object):
+    """A thin wrapper around an existing file object that
+       provides a part of its data as an individual file
+       object.
+    """
+    def __init__(self, fileobj, offset, size, blockinfo=None):
+        self.fileobj = fileobj
+        self.offset = offset
+        self.size = size
+        self.position = 0
+        if blockinfo is None:
+            blockinfo = [(0, size)]
+        # Construct a map with data and zero blocks.
+        self.map_index = 0
+        self.map = []
+        lastpos = 0
+        realpos = self.offset
+        for offset, size in blockinfo:
+            if offset > lastpos:
+                self.map.append((False, lastpos, offset, None))
+            self.map.append((True, offset, offset + size, realpos))
+            realpos += size
+            lastpos = offset + size
+        if lastpos < self.size:
+            self.map.append((False, lastpos, self.size, None))
+    def seekable(self):
+        if not hasattr(self.fileobj, "seekable"):
+            # XXX gzip.GzipFile and bz2.BZ2File
+            return True
+        return self.fileobj.seekable()
+    def tell(self):
+        """Return the current file position.
+        """
+        return self.position
+    def seek(self, position):
+        """Seek to a position in the file.
+        """
+        self.position = position
+    def read(self, size=None):
+        """Read data from the file.
+        """
+        if size is None:
+            size = self.size - self.position
+        else:
+            size = min(size, self.size - self.position)
+        buf = b""
+        while size > 0:
+            while True:
+                data, start, stop, offset = self.map[self.map_index]
+                if start <= self.position < stop:
+                    break
+                else:
+                    self.map_index += 1
+                    if self.map_index == len(self.map):
+                        self.map_index = 0
+            length = min(size, stop - self.position)
+            if data:
+                self.fileobj.seek(offset + (self.position - start))
+                buf += self.fileobj.read(length)
+            else:
+                buf += NUL * length
+            size -= length
+            self.position += length
+        return buf
+#class _FileInFile
+class ExFileObject(object):
+    """File-like object for reading an archive member.
+       Is returned by TarFile.extractfile().
+    """
+    blocksize = 1024
+    def __init__(self, tarfile, tarinfo):
+        self.fileobj = _FileInFile(tarfile.fileobj,
+                                   tarinfo.offset_data,
+                                   tarinfo.size,
+                                   tarinfo.sparse)
+        self.name = tarinfo.name
+        self.mode = "r"
+        self.closed = False
+        self.size = tarinfo.size
+        self.position = 0
+        self.buffer = b""
+    def readable(self):
+        return True
+    def writable(self):
+        return False
+    def seekable(self):
+        return self.fileobj.seekable()
+    def read(self, size=None):
+        """Read at most size bytes from the file. If size is not
+           present or None, read all data until EOF is reached.
+        """
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        buf = b""
+        if self.buffer:
+            if size is None:
+                buf = self.buffer
+                self.buffer = b""
+            else:
+                buf = self.buffer[:size]
+                self.buffer = self.buffer[size:]
+        if size is None:
+            buf += self.fileobj.read()
+        else:
+            buf += self.fileobj.read(size - len(buf))
+        self.position += len(buf)
+        return buf
+    # XXX TextIOWrapper uses the read1() method.
+    read1 = read
+    def readline(self, size=-1):
+        """Read one entire line from the file. If size is present
+           and non-negative, return a string with at most that
+           size, which may be an incomplete line.
+        """
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        pos = self.buffer.find(b"\n") + 1
+        if pos == 0:
+            # no newline found.
+            while True:
+                buf = self.fileobj.read(self.blocksize)
+                self.buffer += buf
+                if not buf or b"\n" in buf:
+                    pos = self.buffer.find(b"\n") + 1
+                    if pos == 0:
+                        # no newline found.
+                        pos = len(self.buffer)
+                    break
+        if size != -1:
+            pos = min(size, pos)
+        buf = self.buffer[:pos]
+        self.buffer = self.buffer[pos:]
+        self.position += len(buf)
+        return buf
+    def readlines(self):
+        """Return a list with all remaining lines.
+        """
+        result = []
+        while True:
+            line = self.readline()
+            if not line: break
+            result.append(line)
+        return result
+    def tell(self):
+        """Return the current file position.
+        """
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        return self.position
+    def seek(self, pos, whence=os.SEEK_SET):
+        """Seek to a position in the file.
+        """
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        if whence == os.SEEK_SET:
+            self.position = min(max(pos, 0), self.size)
+        elif whence == os.SEEK_CUR:
+            if pos < 0:
+                self.position = max(self.position + pos, 0)
+            else:
+                self.position = min(self.position + pos, self.size)
+        elif whence == os.SEEK_END:
+            self.position = max(min(self.size + pos, self.size), 0)
+        else:
+            raise ValueError("Invalid argument")
+        self.buffer = b""
+        self.fileobj.seek(self.position)
+    def close(self):
+        """Close the file object.
+        """
+        self.closed = True
+    def __iter__(self):
+        """Get an iterator over the file's lines.
+        """
+        while True:
+            line = self.readline()
+            if not line:
+                break
+            yield line
+#class ExFileObject
+#------------------
+# Exported Classes
+#------------------
+class TarInfo(object):
+    """Informational class which holds the details about an
+       archive member given by a tar header block.
+       TarInfo objects are returned by TarFile.getmember(),
+       TarFile.getmembers() and TarFile.gettarinfo() and are
+       usually created internally.
+    """
+    __slots__ = ("name", "mode", "uid", "gid", "size", "mtime",
+                 "chksum", "type", "linkname", "uname", "gname",
+                 "devmajor", "devminor",
+                 "offset", "offset_data", "pax_headers", "sparse",
+                 "tarfile", "_sparse_structs", "_link_target")
+    def __init__(self, name=""):
+        """Construct a TarInfo object. name is the optional name
+           of the member.
+        """
+        self.name = name        # member name
+        self.mode = 0o644       # file permissions
+        self.uid = 0            # user id
+        self.gid = 0            # group id
+        self.size = 0           # file size
+        self.mtime = 0          # modification time
+        self.chksum = 0         # header checksum
+        self.type = REGTYPE     # member type
+        self.linkname = ""      # link name
+        self.uname = ""         # user name
+        self.gname = ""         # group name
+        self.devmajor = 0       # device major number
+        self.devminor = 0       # device minor number
+        self.offset = 0         # the tar header starts here
+        self.offset_data = 0    # the file's data starts here
+        self.sparse = None      # sparse member information
+        self.pax_headers = {}   # pax header information
+    # In pax headers the "name" and "linkname" field are called
+    # "path" and "linkpath".
+    def _getpath(self):
+        return self.name
+    def _setpath(self, name):
+        self.name = name
+    path = property(_getpath, _setpath)
+    def _getlinkpath(self):
+        return self.linkname
+    def _setlinkpath(self, linkname):
+        self.linkname = linkname
+    linkpath = property(_getlinkpath, _setlinkpath)
+    def __repr__(self):
+        return "<%s %r at %#x>" % (self.__class__.__name__,self.name,id(self))
+    def get_info(self):
+        """Return the TarInfo's attributes as a dictionary.
+        """
+        info = {
+            "name":     self.name,
+            "mode":     self.mode & 0o7777,
+            "uid":      self.uid,
+            "gid":      self.gid,
+            "size":     self.size,
+            "mtime":    self.mtime,
+            "chksum":   self.chksum,
+            "type":     self.type,
+            "linkname": self.linkname,
+            "uname":    self.uname,
+            "gname":    self.gname,
+            "devmajor": self.devmajor,
+            "devminor": self.devminor
+        }
+        if info["type"] == DIRTYPE and not info["name"].endswith("/"):
+            info["name"] += "/"
+        return info
+    def tobuf(self, format=DEFAULT_FORMAT, encoding=ENCODING, errors="surrogateescape"):
+        """Return a tar header as a string of 512 byte blocks.
+        """
+        info = self.get_info()
+        if format == USTAR_FORMAT:
+            return self.create_ustar_header(info, encoding, errors)
+        elif format == GNU_FORMAT:
+            return self.create_gnu_header(info, encoding, errors)
+        elif format == PAX_FORMAT:
+            return self.create_pax_header(info, encoding)
+        else:
+            raise ValueError("invalid format")
+    def create_ustar_header(self, info, encoding, errors):
+        """Return the object as a ustar header block.
+        """
+        info["magic"] = POSIX_MAGIC
+        if len(info["linkname"]) > LENGTH_LINK:
+            raise ValueError("linkname is too long")
+        if len(info["name"]) > LENGTH_NAME:
+            info["prefix"], info["name"] = self._posix_split_name(info["name"])
+        return self._create_header(info, USTAR_FORMAT, encoding, errors)
+    def create_gnu_header(self, info, encoding, errors):
+        """Return the object as a GNU header block sequence.
+        """
+        info["magic"] = GNU_MAGIC
+        buf = b""
+        if len(info["linkname"]) > LENGTH_LINK:
+            buf += self._create_gnu_long_header(info["linkname"], GNUTYPE_LONGLINK, encoding, errors)
+        if len(info["name"]) > LENGTH_NAME:
+            buf += self._create_gnu_long_header(info["name"], GNUTYPE_LONGNAME, encoding, errors)
+        return buf + self._create_header(info, GNU_FORMAT, encoding, errors)
+    def create_pax_header(self, info, encoding):
+        """Return the object as a ustar header block. If it cannot be
+           represented this way, prepend a pax extended header sequence
+           with supplement information.
+        """
+        info["magic"] = POSIX_MAGIC
+        pax_headers = self.pax_headers.copy()
+        # Test string fields for values that exceed the field length or cannot
+        # be represented in ASCII encoding.
+        for name, hname, length in (
+                ("name", "path", LENGTH_NAME), ("linkname", "linkpath", LENGTH_LINK),
+                ("uname", "uname", 32), ("gname", "gname", 32)):
+            if hname in pax_headers:
+                # The pax header has priority.
+                continue
+            # Try to encode the string as ASCII.
+            try:
+                info[name].encode("ascii", "strict")
+            except UnicodeEncodeError:
+                pax_headers[hname] = info[name]
+                continue
+            if len(info[name]) > length:
+                pax_headers[hname] = info[name]
+        # Test number fields for values that exceed the field limit or values
+        # that like to be stored as float.
+        for name, digits in (("uid", 8), ("gid", 8), ("size", 12), ("mtime", 12)):
+            if name in pax_headers:
+                # The pax header has priority. Avoid overflow.
+                info[name] = 0
+                continue
+            val = info[name]
+            if not 0 <= val < 8 ** (digits - 1) or isinstance(val, float):
+                pax_headers[name] = str(val)
+                info[name] = 0
+        # Create a pax extended header if necessary.
+        if pax_headers:
+            buf = self._create_pax_generic_header(pax_headers, XHDTYPE, encoding)
+        else:
+            buf = b""
+        return buf + self._create_header(info, USTAR_FORMAT, "ascii", "replace")
+    @classmethod
+    def create_pax_global_header(cls, pax_headers):
+        """Return the object as a pax global header block sequence.
+        """
+        return cls._create_pax_generic_header(pax_headers, XGLTYPE, "utf8")
+    def _posix_split_name(self, name):
+        """Split a name longer than 100 chars into a prefix
+           and a name part.
+        """
+        prefix = name[:LENGTH_PREFIX + 1]
+        while prefix and prefix[-1] != "/":
+            prefix = prefix[:-1]
+        name = name[len(prefix):]
+        prefix = prefix[:-1]
+        if not prefix or len(name) > LENGTH_NAME:
+            raise ValueError("name is too long")
+        return prefix, name
+    @staticmethod
+    def _create_header(info, format, encoding, errors):
+        """Return a header block. info is a dictionary with file
+           information, format must be one of the *_FORMAT constants.
+        """
+        parts = [
+            stn(info.get("name", ""), 100, encoding, errors),
+            itn(info.get("mode", 0) & 0o7777, 8, format),
+            itn(info.get("uid", 0), 8, format),
+            itn(info.get("gid", 0), 8, format),
+            itn(info.get("size", 0), 12, format),
+            itn(info.get("mtime", 0), 12, format),
+            b"        ", # checksum field
+            info.get("type", REGTYPE),
+            stn(info.get("linkname", ""), 100, encoding, errors),
+            info.get("magic", POSIX_MAGIC),
+            stn(info.get("uname", ""), 32, encoding, errors),
+            stn(info.get("gname", ""), 32, encoding, errors),
+            itn(info.get("devmajor", 0), 8, format),
+            itn(info.get("devminor", 0), 8, format),
+            stn(info.get("prefix", ""), 155, encoding, errors)
+        ]
+        buf = struct.pack("%ds" % BLOCKSIZE, b"".join(parts))
+        chksum = calc_chksums(buf[-BLOCKSIZE:])[0]
+        buf = buf[:-364] + ("%06o\0" % chksum).encode("ascii") + buf[-357:]
+        return buf
+    @staticmethod
+    def _create_payload(payload):
+        """Return the string payload filled with zero bytes
+           up to the next 512 byte border.
+        """
+        blocks, remainder = divmod(len(payload), BLOCKSIZE)
+        if remainder > 0:
+            payload += (BLOCKSIZE - remainder) * NUL
+        return payload
+    @classmethod
+    def _create_gnu_long_header(cls, name, type, encoding, errors):
+        """Return a GNUTYPE_LONGNAME or GNUTYPE_LONGLINK sequence
+           for name.
+        """
+        name = name.encode(encoding, errors) + NUL
+        info = {}
+        info["name"] = "././@LongLink"
+        info["type"] = type
+        info["size"] = len(name)
+        info["magic"] = GNU_MAGIC
+        # create extended header + name blocks.
+        return cls._create_header(info, USTAR_FORMAT, encoding, errors) + \
+                cls._create_payload(name)
+    @classmethod
+    def _create_pax_generic_header(cls, pax_headers, type, encoding):
+        """Return a POSIX.1-2008 extended or global header sequence
+           that contains a list of keyword, value pairs. The values
+           must be strings.
+        """
+        # Check if one of the fields contains surrogate characters and thereby
+        # forces hdrcharset=BINARY, see _proc_pax() for more information.
+        binary = False
+        for keyword, value in pax_headers.items():
+            try:
+                value.encode("utf8", "strict")
+            except UnicodeEncodeError:
+                binary = True
+                break
+        records = b""
+        if binary:
+            # Put the hdrcharset field at the beginning of the header.
+            records += b"21 hdrcharset=BINARY\n"
+        for keyword, value in pax_headers.items():
+            keyword = keyword.encode("utf8")
+            if binary:
+                # Try to restore the original byte representation of `value'.
+                # Needless to say, that the encoding must match the string.
+                value = value.encode(encoding, "surrogateescape")
+            else:
+                value = value.encode("utf8")
+            l = len(keyword) + len(value) + 3   # ' ' + '=' + '\n'
+            n = p = 0
+            while True:
+                n = l + len(str(p))
+                if n == p:
+                    break
+                p = n
+            records += bytes(str(p), "ascii") + b" " + keyword + b"=" + value + b"\n"
+        # We use a hardcoded "././@PaxHeader" name like star does
+        # instead of the one that POSIX recommends.
+        info = {}
+        info["name"] = "././@PaxHeader"
+        info["type"] = type
+        info["size"] = len(records)
+        info["magic"] = POSIX_MAGIC
+        # Create pax header + record blocks.
+        return cls._create_header(info, USTAR_FORMAT, "ascii", "replace") + \
+                cls._create_payload(records)
+    @classmethod
+    def frombuf(cls, buf, encoding, errors):
+        """Construct a TarInfo object from a 512 byte bytes object.
+        """
+        if len(buf) == 0:
+            raise EmptyHeaderError("empty header")
+        if len(buf) != BLOCKSIZE:
+            raise TruncatedHeaderError("truncated header")
+        if buf.count(NUL) == BLOCKSIZE:
+            raise EOFHeaderError("end of file header")
+        chksum = nti(buf[148:156])
+        if chksum not in calc_chksums(buf):
+            raise InvalidHeaderError("bad checksum")
+        obj = cls()
+        obj.name = nts(buf[0:100], encoding, errors)
+        obj.mode = nti(buf[100:108])
+        obj.uid = nti(buf[108:116])
+        obj.gid = nti(buf[116:124])
+        obj.size = nti(buf[124:136])
+        obj.mtime = nti(buf[136:148])
+        obj.chksum = chksum
+        obj.type = buf[156:157]
+        obj.linkname = nts(buf[157:257], encoding, errors)
+        obj.uname = nts(buf[265:297], encoding, errors)
+        obj.gname = nts(buf[297:329], encoding, errors)
+        obj.devmajor = nti(buf[329:337])
+        obj.devminor = nti(buf[337:345])
+        prefix = nts(buf[345:500], encoding, errors)
+        # Old V7 tar format represents a directory as a regular
+        # file with a trailing slash.
+        if obj.type == AREGTYPE and obj.name.endswith("/"):
+            obj.type = DIRTYPE
+        # The old GNU sparse format occupies some of the unused
+        # space in the buffer for up to 4 sparse structures.
+        # Save the them for later processing in _proc_sparse().
+        if obj.type == GNUTYPE_SPARSE:
+            pos = 386
+            structs = []
+            for i in range(4):
+                try:
+                    offset = nti(buf[pos:pos + 12])
+                    numbytes = nti(buf[pos + 12:pos + 24])
+                except ValueError:
+                    break
+                structs.append((offset, numbytes))
+                pos += 24
+            isextended = bool(buf[482])
+            origsize = nti(buf[483:495])
+            obj._sparse_structs = (structs, isextended, origsize)
+        # Remove redundant slashes from directories.
+        if obj.isdir():
+            obj.name = obj.name.rstrip("/")
+        # Reconstruct a ustar longname.
+        if prefix and obj.type not in GNU_TYPES:
+            obj.name = prefix + "/" + obj.name
+        return obj
+    @classmethod
+    def fromtarfile(cls, tarfile):
+        """Return the next TarInfo object from TarFile object
+           tarfile.
+        """
+        buf = tarfile.fileobj.read(BLOCKSIZE)
+        obj = cls.frombuf(buf, tarfile.encoding, tarfile.errors)
+        obj.offset = tarfile.fileobj.tell() - BLOCKSIZE
+        return obj._proc_member(tarfile)
+    #--------------------------------------------------------------------------
+    # The following are methods that are called depending on the type of a
+    # member. The entry point is _proc_member() which can be overridden in a
+    # subclass to add custom _proc_*() methods. A _proc_*() method MUST
+    # implement the following
+    # operations:
+    # 1. Set self.offset_data to the position where the data blocks begin,
+    #    if there is data that follows.
+    # 2. Set tarfile.offset to the position where the next member's header will
+    #    begin.
+    # 3. Return self or another valid TarInfo object.
+    def _proc_member(self, tarfile):
+        """Choose the right processing method depending on
+           the type and call it.
+        """
+        if self.type in (GNUTYPE_LONGNAME, GNUTYPE_LONGLINK):
+            return self._proc_gnulong(tarfile)
+        elif self.type == GNUTYPE_SPARSE:
+            return self._proc_sparse(tarfile)
+        elif self.type in (XHDTYPE, XGLTYPE, SOLARIS_XHDTYPE):
+            return self._proc_pax(tarfile)
+        else:
+            return self._proc_builtin(tarfile)
+    def _proc_builtin(self, tarfile):
+        """Process a builtin type or an unknown type which
+           will be treated as a regular file.
+        """
+        self.offset_data = tarfile.fileobj.tell()
+        offset = self.offset_data
+        if self.isreg() or self.type not in SUPPORTED_TYPES:
+            # Skip the following data blocks.
+            offset += self._block(self.size)
+        tarfile.offset = offset
+        # Patch the TarInfo object with saved global
+        # header information.
+        self._apply_pax_info(tarfile.pax_headers, tarfile.encoding, tarfile.errors)
+        return self
+    def _proc_gnulong(self, tarfile):
+        """Process the blocks that hold a GNU longname
+           or longlink member.
+        """
+        buf = tarfile.fileobj.read(self._block(self.size))
+        # Fetch the next header and process it.
+        try:
+            next = self.fromtarfile(tarfile)
+        except HeaderError:
+            raise SubsequentHeaderError("missing or bad subsequent header")
+        # Patch the TarInfo object from the next header with
+        # the longname information.
+        next.offset = self.offset
+        if self.type == GNUTYPE_LONGNAME:
+            next.name = nts(buf, tarfile.encoding, tarfile.errors)
+        elif self.type == GNUTYPE_LONGLINK:
+            next.linkname = nts(buf, tarfile.encoding, tarfile.errors)
+        return next
+    def _proc_sparse(self, tarfile):
+        """Process a GNU sparse header plus extra headers.
+        """
+        # We already collected some sparse structures in frombuf().
+        structs, isextended, origsize = self._sparse_structs
+        del self._sparse_structs
+        # Collect sparse structures from extended header blocks.
+        while isextended:
+            buf = tarfile.fileobj.read(BLOCKSIZE)
+            pos = 0
+            for i in range(21):
+                try:
+                    offset = nti(buf[pos:pos + 12])
+                    numbytes = nti(buf[pos + 12:pos + 24])
+                except ValueError:
+                    break
+                if offset and numbytes:
+                    structs.append((offset, numbytes))
+                pos += 24
+            isextended = bool(buf[504])
+        self.sparse = structs
+        self.offset_data = tarfile.fileobj.tell()
+        tarfile.offset = self.offset_data + self._block(self.size)
+        self.size = origsize
+        return self
+    def _proc_pax(self, tarfile):
+        """Process an extended or global header as described in
+           POSIX.1-2008.
+        """
+        # Read the header information.
+        buf = tarfile.fileobj.read(self._block(self.size))
+        # A pax header stores supplemental information for either
+        # the following file (extended) or all following files
+        # (global).
+        if self.type == XGLTYPE:
+            pax_headers = tarfile.pax_headers
+        else:
+            pax_headers = tarfile.pax_headers.copy()
+        # Check if the pax header contains a hdrcharset field. This tells us
+        # the encoding of the path, linkpath, uname and gname fields. Normally,
+        # these fields are UTF-8 encoded but since POSIX.1-2008 tar
+        # implementations are allowed to store them as raw binary strings if
+        # the translation to UTF-8 fails.
+        match = re.search(br"\d+ hdrcharset=([^\n]+)\n", buf)
+        if match is not None:
+            pax_headers["hdrcharset"] = match.group(1).decode("utf8")
+        # For the time being, we don't care about anything other than "BINARY".
+        # The only other value that is currently allowed by the standard is
+        # "ISO-IR 10646 2000 UTF-8" in other words UTF-8.
+        hdrcharset = pax_headers.get("hdrcharset")
+        if hdrcharset == "BINARY":
+            encoding = tarfile.encoding
+        else:
+            encoding = "utf8"
+        # Parse pax header information. A record looks like that:
+        # "%d %s=%s\n" % (length, keyword, value). length is the size
+        # of the complete record including the length field itself and
+        # the newline. keyword and value are both UTF-8 encoded strings.
+        regex = re.compile(br"(\d+) ([^=]+)=")
+        pos = 0
+        while True:
+            match = regex.match(buf, pos)
+            if not match:
+                break
+            length, keyword = match.groups()
+            length = int(length)
+            value = buf[match.end(2) + 1:match.start(1) + length - 1]
+            # Normally, we could just use "utf8" as the encoding and "strict"
+            # as the error handler, but we better not take the risk. For
+            # example, GNU tar <= 1.23 is known to store filenames it cannot
+            # translate to UTF-8 as raw strings (unfortunately without a
+            # hdrcharset=BINARY header).
+            # We first try the strict standard encoding, and if that fails we
+            # fall back on the user's encoding and error handler.
+            keyword = self._decode_pax_field(keyword, "utf8", "utf8",
+                    tarfile.errors)
+            if keyword in PAX_NAME_FIELDS:
+                value = self._decode_pax_field(value, encoding, tarfile.encoding,
+                        tarfile.errors)
+            else:
+                value = self._decode_pax_field(value, "utf8", "utf8",
+                        tarfile.errors)
+            pax_headers[keyword] = value
+            pos += length
+        # Fetch the next header.
+        try:
+            next = self.fromtarfile(tarfile)
+        except HeaderError:
+            raise SubsequentHeaderError("missing or bad subsequent header")
+        # Process GNU sparse information.
+        if "GNU.sparse.map" in pax_headers:
+            # GNU extended sparse format version 0.1.
+            self._proc_gnusparse_01(next, pax_headers)
+        elif "GNU.sparse.size" in pax_headers:
+            # GNU extended sparse format version 0.0.
+            self._proc_gnusparse_00(next, pax_headers, buf)
+        elif pax_headers.get("GNU.sparse.major") == "1" and pax_headers.get("GNU.sparse.minor") == "0":
+            # GNU extended sparse format version 1.0.
+            self._proc_gnusparse_10(next, pax_headers, tarfile)
+        if self.type in (XHDTYPE, SOLARIS_XHDTYPE):
+            # Patch the TarInfo object with the extended header info.
+            next._apply_pax_info(pax_headers, tarfile.encoding, tarfile.errors)
+            next.offset = self.offset
+            if "size" in pax_headers:
+                # If the extended header replaces the size field,
+                # we need to recalculate the offset where the next
+                # header starts.
+                offset = next.offset_data
+                if next.isreg() or next.type not in SUPPORTED_TYPES:
+                    offset += next._block(next.size)
+                tarfile.offset = offset
+        return next
+    def _proc_gnusparse_00(self, next, pax_headers, buf):
+        """Process a GNU tar extended sparse header, version 0.0.
+        """
+        offsets = []
+        for match in re.finditer(br"\d+ GNU.sparse.offset=(\d+)\n", buf):
+            offsets.append(int(match.group(1)))
+        numbytes = []
+        for match in re.finditer(br"\d+ GNU.sparse.numbytes=(\d+)\n", buf):
+            numbytes.append(int(match.group(1)))
+        next.sparse = list(zip(offsets, numbytes))
+    def _proc_gnusparse_01(self, next, pax_headers):
+        """Process a GNU tar extended sparse header, version 0.1.
+        """
+        sparse = [int(x) for x in pax_headers["GNU.sparse.map"].split(",")]
+        next.sparse = list(zip(sparse[::2], sparse[1::2]))
+    def _proc_gnusparse_10(self, next, pax_headers, tarfile):
+        """Process a GNU tar extended sparse header, version 1.0.
+        """
+        fields = None
+        sparse = []
+        buf = tarfile.fileobj.read(BLOCKSIZE)
+        fields, buf = buf.split(b"\n", 1)
+        fields = int(fields)
+        while len(sparse) < fields * 2:
+            if b"\n" not in buf:
+                buf += tarfile.fileobj.read(BLOCKSIZE)
+            number, buf = buf.split(b"\n", 1)
+            sparse.append(int(number))
+        next.offset_data = tarfile.fileobj.tell()
+        next.sparse = list(zip(sparse[::2], sparse[1::2]))
+    def _apply_pax_info(self, pax_headers, encoding, errors):
+        """Replace fields with supplemental information from a previous
+           pax extended or global header.
+        """
+        for keyword, value in pax_headers.items():
+            if keyword == "GNU.sparse.name":
+                setattr(self, "path", value)
+            elif keyword == "GNU.sparse.size":
+                setattr(self, "size", int(value))
+            elif keyword == "GNU.sparse.realsize":
+                setattr(self, "size", int(value))
+            elif keyword in PAX_FIELDS:
+                if keyword in PAX_NUMBER_FIELDS:
+                    try:
+                        value = PAX_NUMBER_FIELDS[keyword](value)
+                    except ValueError:
+                        value = 0
+                if keyword == "path":
+                    value = value.rstrip("/")
+                setattr(self, keyword, value)
+        self.pax_headers = pax_headers.copy()
+    def _decode_pax_field(self, value, encoding, fallback_encoding, fallback_errors):
+        """Decode a single field from a pax record.
+        """
+        try:
+            return value.decode(encoding, "strict")
+        except UnicodeDecodeError:
+            return value.decode(fallback_encoding, fallback_errors)
+    def _block(self, count):
+        """Round up a byte count by BLOCKSIZE and return it,
+           e.g. _block(834) => 1024.
+        """
+        blocks, remainder = divmod(count, BLOCKSIZE)
+        if remainder:
+            blocks += 1
+        return blocks * BLOCKSIZE
+    def isreg(self):
+        return self.type in REGULAR_TYPES
+    def isfile(self):
+        return self.isreg()
+    def isdir(self):
+        return self.type == DIRTYPE
+    def issym(self):
+        return self.type == SYMTYPE
+    def islnk(self):
+        return self.type == LNKTYPE
+    def ischr(self):
+        return self.type == CHRTYPE
+    def isblk(self):
+        return self.type == BLKTYPE
+    def isfifo(self):
+        return self.type == FIFOTYPE
+    def issparse(self):
+        return self.sparse is not None
+    def isdev(self):
+        return self.type in (CHRTYPE, BLKTYPE, FIFOTYPE)
+# class TarInfo
+class TarFile(object):
+    """The TarFile Class provides an interface to tar archives.
+    """
+    debug = 0                   # May be set from 0 (no msgs) to 3 (all msgs)
+    dereference = False         # If true, add content of linked file to the
+                                # tar file, else the link.
+    ignore_zeros = False        # If true, skips empty or invalid blocks and
+                                # continues processing.
+    errorlevel = 1              # If 0, fatal errors only appear in debug
+                                # messages (if debug >= 0). If > 0, errors
+                                # are passed to the caller as exceptions.
+    format = DEFAULT_FORMAT     # The format to use when creating an archive.
+    encoding = ENCODING         # Encoding for 8-bit character strings.
+    errors = None               # Error handler for unicode conversion.
+    tarinfo = TarInfo           # The default TarInfo class to use.
+    fileobject = ExFileObject   # The default ExFileObject class to use.
+    def __init__(self, name=None, mode="r", fileobj=None, format=None,
+            tarinfo=None, dereference=None, ignore_zeros=None, encoding=None,
+            errors="surrogateescape", pax_headers=None, debug=None, errorlevel=None):
+        """Open an (uncompressed) tar archive `name'. `mode' is either 'r' to
+           read from an existing archive, 'a' to append data to an existing
+           file or 'w' to create a new file overwriting an existing one. `mode'
+           defaults to 'r'.
+           If `fileobj' is given, it is used for reading or writing data. If it
+           can be determined, `mode' is overridden by `fileobj's mode.
+           `fileobj' is not closed, when TarFile is closed.
+        """
+        if len(mode) > 1 or mode not in "raw":
+            raise ValueError("mode must be 'r', 'a' or 'w'")
+        self.mode = mode
+        self._mode = {"r": "rb", "a": "r+b", "w": "wb"}[mode]
+        if not fileobj:
+            if self.mode == "a" and not os.path.exists(name):
+                # Create nonexistent files in append mode.
+                self.mode = "w"
+                self._mode = "wb"
+            fileobj = bltn_open(name, self._mode)
+            self._extfileobj = False
+        else:
+            if name is None and hasattr(fileobj, "name"):
+                name = fileobj.name
+            if hasattr(fileobj, "mode"):
+                self._mode = fileobj.mode
+            self._extfileobj = True
+        self.name = os.path.abspath(name) if name else None
+        self.fileobj = fileobj
+        # Init attributes.
+        if format is not None:
+            self.format = format
+        if tarinfo is not None:
+            self.tarinfo = tarinfo
+        if dereference is not None:
+            self.dereference = dereference
+        if ignore_zeros is not None:
+            self.ignore_zeros = ignore_zeros
+        if encoding is not None:
+            self.encoding = encoding
+        self.errors = errors
+        if pax_headers is not None and self.format == PAX_FORMAT:
+            self.pax_headers = pax_headers
+        else:
+            self.pax_headers = {}
+        if debug is not None:
+            self.debug = debug
+        if errorlevel is not None:
+            self.errorlevel = errorlevel
+        # Init datastructures.
+        self.closed = False
+        self.members = []       # list of members as TarInfo objects
+        self._loaded = False    # flag if all members have been read
+        self.offset = self.fileobj.tell()
+                                # current position in the archive file
+        self.inodes = {}        # dictionary caching the inodes of
+                                # archive members already added
+        try:
+            if self.mode == "r":
+                self.firstmember = None
+                self.firstmember = self.next()
+            if self.mode == "a":
+                # Move to the end of the archive,
+                # before the first empty block.
+                while True:
+                    self.fileobj.seek(self.offset)
+                    try:
+                        tarinfo = self.tarinfo.fromtarfile(self)
+                        self.members.append(tarinfo)
+                    except EOFHeaderError:
+                        self.fileobj.seek(self.offset)
+                        break
+                    except HeaderError as e:
+                        raise ReadError(str(e))
+            if self.mode in "aw":
+                self._loaded = True
+                if self.pax_headers:
+                    buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy())
+                    self.fileobj.write(buf)
+                    self.offset += len(buf)
+        except:
+            if not self._extfileobj:
+                self.fileobj.close()
+            self.closed = True
+            raise
+    #--------------------------------------------------------------------------
+    # Below are the classmethods which act as alternate constructors to the
+    # TarFile class. The open() method is the only one that is needed for
+    # public use; it is the "super"-constructor and is able to select an
+    # adequate "sub"-constructor for a particular compression using the mapping
+    # from OPEN_METH.
+    #
+    # This concept allows one to subclass TarFile without losing the comfort of
+    # the super-constructor. A sub-constructor is registered and made available
+    # by adding it to the mapping in OPEN_METH.
+    @classmethod
+    def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs):
+        """Open a tar archive for reading, writing or appending. Return
+           an appropriate TarFile class.
+           mode:
+           'r' or 'r:*' open for reading with transparent compression
+           'r:'         open for reading exclusively uncompressed
+           'r:gz'       open for reading with gzip compression
+           'r:bz2'      open for reading with bzip2 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
+           '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
+           '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
+        """
+        if not name and not fileobj:
+            raise ValueError("nothing to open")
+        if mode in ("r", "r:*"):
+            # Find out which *open() is appropriate for opening the file.
+            for comptype in cls.OPEN_METH:
+                func = getattr(cls, cls.OPEN_METH[comptype])
+                if fileobj is not None:
+                    saved_pos = fileobj.tell()
+                try:
+                    return func(name, "r", fileobj, **kwargs)
+                except (ReadError, CompressionError) as e:
+                    if fileobj is not None:
+                        fileobj.seek(saved_pos)
+                    continue
+            raise ReadError("file could not be opened successfully")
+        elif ":" in mode:
+            filemode, comptype = mode.split(":", 1)
+            filemode = filemode or "r"
+            comptype = comptype or "tar"
+            # Select the *open() function according to
+            # given compression.
+            if comptype in cls.OPEN_METH:
+                func = getattr(cls, cls.OPEN_METH[comptype])
+            else:
+                raise CompressionError("unknown compression type %r" % comptype)
+            return func(name, filemode, fileobj, **kwargs)
+        elif "|" in mode:
+            filemode, comptype = mode.split("|", 1)
+            filemode = filemode or "r"
+            comptype = comptype or "tar"
+            if filemode not in "rw":
+                raise ValueError("mode must be 'r' or 'w'")
+            stream = _Stream(name, filemode, comptype, fileobj, bufsize)
+            try:
+                t = cls(name, filemode, stream, **kwargs)
+            except:
+                stream.close()
+                raise
+            t._extfileobj = False
+            return t
+        elif mode in "aw":
+            return cls.taropen(name, mode, fileobj, **kwargs)
+        raise ValueError("undiscernible mode")
+    @classmethod
+    def taropen(cls, name, mode="r", fileobj=None, **kwargs):
+        """Open uncompressed tar archive name for reading or writing.
+        """
+        if len(mode) > 1 or mode not in "raw":
+            raise ValueError("mode must be 'r', 'a' or 'w'")
+        return cls(name, mode, fileobj, **kwargs)
+    @classmethod
+    def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
+        """Open gzip compressed tar archive name for reading or writing.
+           Appending is not allowed.
+        """
+        if len(mode) > 1 or mode not in "rw":
+            raise ValueError("mode must be 'r' or 'w'")
+        try:
+            import gzip
+            gzip.GzipFile
+        except (ImportError, AttributeError):
+            raise CompressionError("gzip module is not available")
+        extfileobj = fileobj is not None
+        try:
+            fileobj = gzip.GzipFile(name, mode + "b", compresslevel, fileobj)
+            t = cls.taropen(name, mode, fileobj, **kwargs)
+        except IOError:
+            if not extfileobj and fileobj is not None:
+                fileobj.close()
+            if fileobj is None:
+                raise
+            raise ReadError("not a gzip file")
+        except:
+            if not extfileobj and fileobj is not None:
+                fileobj.close()
+            raise
+        t._extfileobj = extfileobj
+        return t
+    @classmethod
+    def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
+        """Open bzip2 compressed tar archive name for reading or writing.
+           Appending is not allowed.
+        """
+        if len(mode) > 1 or mode not in "rw":
+            raise ValueError("mode must be 'r' or 'w'.")
+        try:
+            import bz2
+        except ImportError:
+            raise CompressionError("bz2 module is not available")
+        if fileobj is not None:
+            fileobj = _BZ2Proxy(fileobj, mode)
+        else:
+            fileobj = bz2.BZ2File(name, mode, compresslevel=compresslevel)
+        try:
+            t = cls.taropen(name, mode, fileobj, **kwargs)
+        except (IOError, EOFError):
+            fileobj.close()
+            raise ReadError("not a bzip2 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
+    }
+    #--------------------------------------------------------------------------
+    # The public methods which TarFile provides:
+    def close(self):
+        """Close the TarFile. In write-mode, two finishing zero blocks are
+           appended to the archive.
+        """
+        if self.closed:
+            return
+        if self.mode in "aw":
+            self.fileobj.write(NUL * (BLOCKSIZE * 2))
+            self.offset += (BLOCKSIZE * 2)
+            # fill up the end with zero-blocks
+            # (like option -b20 for tar does)
+            blocks, remainder = divmod(self.offset, RECORDSIZE)
+            if remainder > 0:
+                self.fileobj.write(NUL * (RECORDSIZE - remainder))
+        if not self._extfileobj:
+            self.fileobj.close()
+        self.closed = True
+    def getmember(self, name):
+        """Return a TarInfo object for member `name'. If `name' can not be
+           found in the archive, KeyError is raised. If a member occurs more
+           than once in the archive, its last occurrence is assumed to be the
+           most up-to-date version.
+        """
+        tarinfo = self._getmember(name)
+        if tarinfo is None:
+            raise KeyError("filename %r not found" % name)
+        return tarinfo
+    def getmembers(self):
+        """Return the members of the archive as a list of TarInfo objects. The
+           list has the same order as the members in the archive.
+        """
+        self._check()
+        if not self._loaded:    # if we want to obtain a list of
+            self._load()        # all members, we first have to
+                                # scan the whole archive.
+        return self.members
+    def getnames(self):
+        """Return the members of the archive as a list of their names. It has
+           the same order as the list returned by getmembers().
+        """
+        return [tarinfo.name for tarinfo in self.getmembers()]
+    def gettarinfo(self, name=None, arcname=None, fileobj=None):
+        """Create a TarInfo object for either the file `name' or the file
+           object `fileobj' (using os.fstat on its file descriptor). You can
+           modify some of the TarInfo's attributes before you add it using
+           addfile(). If given, `arcname' specifies an alternative name for the
+           file in the archive.
+        """
+        self._check("aw")
+        # When fileobj is given, replace name by
+        # fileobj's real name.
+        if fileobj is not None:
+            name = fileobj.name
+        # Building the name of the member in the archive.
+        # Backward slashes are converted to forward slashes,
+        # Absolute paths are turned to relative paths.
+        if arcname is None:
+            arcname = name
+        drv, arcname = os.path.splitdrive(arcname)
+        arcname = arcname.replace(os.sep, "/")
+        arcname = arcname.lstrip("/")
+        # Now, fill the TarInfo object with
+        # information specific for the file.
+        tarinfo = self.tarinfo()
+        tarinfo.tarfile = self
+        # Use os.stat or os.lstat, depending on platform
+        # and if symlinks shall be resolved.
+        if fileobj is None:
+            if hasattr(os, "lstat") and not self.dereference:
+                statres = os.lstat(name)
+            else:
+                statres = os.stat(name)
+        else:
+            statres = os.fstat(fileobj.fileno())
+        linkname = ""
+        stmd = statres.st_mode
+        if stat.S_ISREG(stmd):
+            inode = (statres.st_ino, statres.st_dev)
+            if not self.dereference and statres.st_nlink > 1 and \
+                    inode in self.inodes and arcname != self.inodes[inode]:
+                # Is it a hardlink to an already
+                # archived file?
+                type = LNKTYPE
+                linkname = self.inodes[inode]
+            else:
+                # The inode is added only if its valid.
+                # For win32 it is always 0.
+                type = REGTYPE
+                if inode[0]:
+                    self.inodes[inode] = arcname
+        elif stat.S_ISDIR(stmd):
+            type = DIRTYPE
+        elif stat.S_ISFIFO(stmd):
+            type = FIFOTYPE
+        elif stat.S_ISLNK(stmd):
+            type = SYMTYPE
+            linkname = os.readlink(name)
+        elif stat.S_ISCHR(stmd):
+            type = CHRTYPE
+        elif stat.S_ISBLK(stmd):
+            type = BLKTYPE
+        else:
+            return None
+        # Fill the TarInfo object with all
+        # information we can get.
+        tarinfo.name = arcname
+        tarinfo.mode = stmd
+        tarinfo.uid = statres.st_uid
+        tarinfo.gid = statres.st_gid
+        if type == REGTYPE:
+            tarinfo.size = statres.st_size
+        else:
+            tarinfo.size = 0
+        tarinfo.mtime = statres.st_mtime
+        tarinfo.type = type
+        tarinfo.linkname = linkname
+        if pwd:
+            try:
+                tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0]
+            except KeyError:
+                pass
+        if grp:
+            try:
+                tarinfo.gname = grp.getgrgid(tarinfo.gid)[0]
+            except KeyError:
+                pass
+        if type in (CHRTYPE, BLKTYPE):
+            if hasattr(os, "major") and hasattr(os, "minor"):
+                tarinfo.devmajor = os.major(statres.st_rdev)
+                tarinfo.devminor = os.minor(statres.st_rdev)
+        return tarinfo
+    def list(self, verbose=True):
+        """Print a table of contents to sys.stdout. If `verbose' is False, only
+           the names of the members are printed. If it is True, an `ls -l'-like
+           output is produced.
+        """
+        self._check()
+        for tarinfo in self:
+            if verbose:
+                print(filemode(tarinfo.mode), end=' ')
+                print("%s/%s" % (tarinfo.uname or tarinfo.uid,
+                                 tarinfo.gname or tarinfo.gid), end=' ')
+                if tarinfo.ischr() or tarinfo.isblk():
+                    print("%10s" % ("%d,%d" \
+                                    % (tarinfo.devmajor, tarinfo.devminor)), end=' ')
+                else:
+                    print("%10d" % tarinfo.size, end=' ')
+                print("%d-%02d-%02d %02d:%02d:%02d" \
+                      % time.localtime(tarinfo.mtime)[:6], end=' ')
+            print(tarinfo.name + ("/" if tarinfo.isdir() else ""), end=' ')
+            if verbose:
+                if tarinfo.issym():
+                    print("->", tarinfo.linkname, end=' ')
+                if tarinfo.islnk():
+                    print("link to", tarinfo.linkname, end=' ')
+            print()
+    def add(self, name, arcname=None, recursive=True, exclude=None, filter=None):
+        """Add the file `name' to the archive. `name' may be any type of file
+           (directory, fifo, symbolic link, etc.). If given, `arcname'
+           specifies an alternative name for the file in the archive.
+           Directories are added recursively by default. This can be avoided by
+           setting `recursive' to False. `exclude' is a function that should
+           return True for each filename to be excluded. `filter' is a function
+           that expects a TarInfo object argument and returns the changed
+           TarInfo object, if it returns None the TarInfo object will be
+           excluded from the archive.
+        """
+        self._check("aw")
+        if arcname is None:
+            arcname = name
+        # Exclude pathnames.
+        if exclude is not None:
+            import warnings
+            warnings.warn("use the filter argument instead",
+                    DeprecationWarning, 2)
+            if exclude(name):
+                self._dbg(2, "tarfile: Excluded %r" % name)
+                return
+        # Skip if somebody tries to archive the archive...
+        if self.name is not None and os.path.abspath(name) == self.name:
+            self._dbg(2, "tarfile: Skipped %r" % name)
+            return
+        self._dbg(1, name)
+        # Create a TarInfo object from the file.
+        tarinfo = self.gettarinfo(name, arcname)
+        if tarinfo is None:
+            self._dbg(1, "tarfile: Unsupported type %r" % name)
+            return
+        # Change or exclude the TarInfo object.
+        if filter is not None:
+            tarinfo = filter(tarinfo)
+            if tarinfo is None:
+                self._dbg(2, "tarfile: Excluded %r" % name)
+                return
+        # Append the tar header and data to the archive.
+        if tarinfo.isreg():
+            f = bltn_open(name, "rb")
+            self.addfile(tarinfo, f)
+            f.close()
+        elif tarinfo.isdir():
+            self.addfile(tarinfo)
+            if recursive:
+                for f in os.listdir(name):
+                    self.add(os.path.join(name, f), os.path.join(arcname, f),
+                            recursive, exclude, filter=filter)
+        else:
+            self.addfile(tarinfo)
+    def addfile(self, tarinfo, fileobj=None):
+        """Add the TarInfo object `tarinfo' to the archive. If `fileobj' is
+           given, tarinfo.size bytes are read from it and added to the archive.
+           You can create TarInfo objects using gettarinfo().
+           On Windows platforms, `fileobj' should always be opened with mode
+           'rb' to avoid irritation about the file size.
+        """
+        self._check("aw")
+        tarinfo = copy.copy(tarinfo)
+        buf = tarinfo.tobuf(self.format, self.encoding, self.errors)
+        self.fileobj.write(buf)
+        self.offset += len(buf)
+        # If there's data to follow, append it.
+        if fileobj is not None:
+            copyfileobj(fileobj, self.fileobj, tarinfo.size)
+            blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
+            if remainder > 0:
+                self.fileobj.write(NUL * (BLOCKSIZE - remainder))
+                blocks += 1
+            self.offset += blocks * BLOCKSIZE
+        self.members.append(tarinfo)
+    def extractall(self, path=".", members=None):
+        """Extract all members from the archive to the current working
+           directory and set owner, modification time and permissions on
+           directories afterwards. `path' specifies a different directory
+           to extract to. `members' is optional and must be a subset of the
+           list returned by getmembers().
+        """
+        directories = []
+        if members is None:
+            members = self
+        for tarinfo in members:
+            if tarinfo.isdir():
+                # Extract directories with a safe mode.
+                directories.append(tarinfo)
+                tarinfo = copy.copy(tarinfo)
+                tarinfo.mode = 0o700
+            # Do not set_attrs directories, as we will do that further down
+            self.extract(tarinfo, path, set_attrs=not tarinfo.isdir())
+        # Reverse sort directories.
+        directories.sort(key=lambda a: a.name)
+        directories.reverse()
+        # Set correct owner, mtime and filemode on directories.
+        for tarinfo in directories:
+            dirpath = os.path.join(path, tarinfo.name)
+            try:
+                self.chown(tarinfo, dirpath)
+                self.utime(tarinfo, dirpath)
+                self.chmod(tarinfo, dirpath)
+            except ExtractError as e:
+                if self.errorlevel > 1:
+                    raise
+                else:
+                    self._dbg(1, "tarfile: %s" % e)
+    def extract(self, member, path="", set_attrs=True):
+        """Extract a member from the archive to the current working directory,
+           using its full name. Its file information is extracted as accurately
+           as possible. `member' may be a filename or a TarInfo object. You can
+           specify a different directory using `path'. File attributes (owner,
+           mtime, mode) are set unless `set_attrs' is False.
+        """
+        self._check("r")
+        if isinstance(member, str):
+            tarinfo = self.getmember(member)
+        else:
+            tarinfo = member
+        # Prepare the link target for makelink().
+        if tarinfo.islnk():
+            tarinfo._link_target = os.path.join(path, tarinfo.linkname)
+        try:
+            self._extract_member(tarinfo, os.path.join(path, tarinfo.name),
+                                 set_attrs=set_attrs)
+        except EnvironmentError as e:
+            if self.errorlevel > 0:
+                raise
+            else:
+                if e.filename is None:
+                    self._dbg(1, "tarfile: %s" % e.strerror)
+                else:
+                    self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename))
+        except ExtractError as e:
+            if self.errorlevel > 1:
+                raise
+            else:
+                self._dbg(1, "tarfile: %s" % e)
+    def extractfile(self, member):
+        """Extract a member from the archive as a file object. `member' may be
+           a filename or a TarInfo object. If `member' is a regular file, a
+           file-like object is returned. If `member' is a link, a file-like
+           object is constructed from the link's target. If `member' is none of
+           the above, None is returned.
+           The file-like object is read-only and provides the following
+           methods: read(), readline(), readlines(), seek() and tell()
+        """
+        self._check("r")
+        if isinstance(member, str):
+            tarinfo = self.getmember(member)
+        else:
+            tarinfo = member
+        if tarinfo.isreg():
+            return self.fileobject(self, tarinfo)
+        elif tarinfo.type not in SUPPORTED_TYPES:
+            # If a member's type is unknown, it is treated as a
+            # regular file.
+            return self.fileobject(self, tarinfo)
+        elif tarinfo.islnk() or tarinfo.issym():
+            if isinstance(self.fileobj, _Stream):
+                # A small but ugly workaround for the case that someone tries
+                # to extract a (sym)link as a file-object from a non-seekable
+                # stream of tar blocks.
+                raise StreamError("cannot extract (sym)link as file object")
+            else:
+                # A (sym)link's file object is its target's file object.
+                return self.extractfile(self._find_link_target(tarinfo))
+        else:
+            # If there's no data associated with the member (directory, chrdev,
+            # blkdev, etc.), return None instead of a file object.
+            return None
+    def _extract_member(self, tarinfo, targetpath, set_attrs=True):
+        """Extract the TarInfo object tarinfo to a physical
+           file called targetpath.
+        """
+        # Fetch the TarInfo object for the given name
+        # and build the destination pathname, replacing
+        # forward slashes to platform specific separators.
+        targetpath = targetpath.rstrip("/")
+        targetpath = targetpath.replace("/", os.sep)
+        # Create all upper directories.
+        upperdirs = os.path.dirname(targetpath)
+        if upperdirs and not os.path.exists(upperdirs):
+            # Create directories that are not part of the archive with
+            # default permissions.
+            os.makedirs(upperdirs)
+        if tarinfo.islnk() or tarinfo.issym():
+            self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname))
+        else:
+            self._dbg(1, tarinfo.name)
+        if tarinfo.isreg():
+            self.makefile(tarinfo, targetpath)
+        elif tarinfo.isdir():
+            self.makedir(tarinfo, targetpath)
+        elif tarinfo.isfifo():
+            self.makefifo(tarinfo, targetpath)
+        elif tarinfo.ischr() or tarinfo.isblk():
+            self.makedev(tarinfo, targetpath)
+        elif tarinfo.islnk() or tarinfo.issym():
+            self.makelink(tarinfo, targetpath)
+        elif tarinfo.type not in SUPPORTED_TYPES:
+            self.makeunknown(tarinfo, targetpath)
+        else:
+            self.makefile(tarinfo, targetpath)
+        if set_attrs:
+            self.chown(tarinfo, targetpath)
+            if not tarinfo.issym():
+                self.chmod(tarinfo, targetpath)
+                self.utime(tarinfo, targetpath)
+    #--------------------------------------------------------------------------
+    # Below are the different file methods. They are called via
+    # _extract_member() when extract() is called. They can be replaced in a
+    # subclass to implement other functionality.
+    def makedir(self, tarinfo, targetpath):
+        """Make a directory called targetpath.
+        """
+        try:
+            # Use a safe mode for the directory, the real mode is set
+            # later in _extract_member().
+            os.mkdir(targetpath, 0o700)
+        except EnvironmentError as e:
+            if e.errno != errno.EEXIST:
+                raise
+    def makefile(self, tarinfo, targetpath):
+        """Make a file called targetpath.
+        """
+        source = self.fileobj
+        source.seek(tarinfo.offset_data)
+        target = bltn_open(targetpath, "wb")
+        if tarinfo.sparse is not None:
+            for offset, size in tarinfo.sparse:
+                target.seek(offset)
+                copyfileobj(source, target, size)
+        else:
+            copyfileobj(source, target, tarinfo.size)
+        target.seek(tarinfo.size)
+        target.truncate()
+        target.close()
+    def makeunknown(self, tarinfo, targetpath):
+        """Make a file from a TarInfo object with an unknown type
+           at targetpath.
+        """
+        self.makefile(tarinfo, targetpath)
+        self._dbg(1, "tarfile: Unknown file type %r, " \
+                     "extracted as regular file." % tarinfo.type)
+    def makefifo(self, tarinfo, targetpath):
+        """Make a fifo called targetpath.
+        """
+        if hasattr(os, "mkfifo"):
+            os.mkfifo(targetpath)
+        else:
+            raise ExtractError("fifo not supported by system")
+    def makedev(self, tarinfo, targetpath):
+        """Make a character or block device called targetpath.
+        """
+        if not hasattr(os, "mknod") or not hasattr(os, "makedev"):
+            raise ExtractError("special devices not supported by system")
+        mode = tarinfo.mode
+        if tarinfo.isblk():
+            mode |= stat.S_IFBLK
+        else:
+            mode |= stat.S_IFCHR
+        os.mknod(targetpath, mode,
+                 os.makedev(tarinfo.devmajor, tarinfo.devminor))
+    def makelink(self, tarinfo, targetpath):
+        """Make a (symbolic) link called targetpath. If it cannot be created
+          (platform limitation), we try to make a copy of the referenced file
+          instead of a link.
+        """
+        try:
+            # For systems that support symbolic and hard links.
+            if tarinfo.issym():
+                os.symlink(tarinfo.linkname, targetpath)
+            else:
+                # See extract().
+                if os.path.exists(tarinfo._link_target):
+                    os.link(tarinfo._link_target, targetpath)
+                else:
+                    self._extract_member(self._find_link_target(tarinfo),
+                                         targetpath)
+        except symlink_exception:
+            if tarinfo.issym():
+                linkpath = os.path.join(os.path.dirname(tarinfo.name),
+                                        tarinfo.linkname)
+            else:
+                linkpath = tarinfo.linkname
+        else:
+            try:
+                self._extract_member(self._find_link_target(tarinfo),
+                                     targetpath)
+            except KeyError:
+                raise ExtractError("unable to resolve link inside archive")
+    def chown(self, tarinfo, targetpath):
+        """Set owner of targetpath according to tarinfo.
+        """
+        if pwd and hasattr(os, "geteuid") and os.geteuid() == 0:
+            # We have to be root to do so.
+            try:
+                g = grp.getgrnam(tarinfo.gname)[2]
+            except KeyError:
+                g = tarinfo.gid
+            try:
+                u = pwd.getpwnam(tarinfo.uname)[2]
+            except KeyError:
+                u = tarinfo.uid
+            try:
+                if tarinfo.issym() and hasattr(os, "lchown"):
+                    os.lchown(targetpath, u, g)
+                else:
+                    if sys.platform != "os2emx":
+                        os.chown(targetpath, u, g)
+            except EnvironmentError as e:
+                raise ExtractError("could not change owner")
+    def chmod(self, tarinfo, targetpath):
+        """Set file permissions of targetpath according to tarinfo.
+        """
+        if hasattr(os, 'chmod'):
+            try:
+                os.chmod(targetpath, tarinfo.mode)
+            except EnvironmentError as e:
+                raise ExtractError("could not change mode")
+    def utime(self, tarinfo, targetpath):
+        """Set modification time of targetpath according to tarinfo.
+        """
+        if not hasattr(os, 'utime'):
+            return
+        try:
+            os.utime(targetpath, (tarinfo.mtime, tarinfo.mtime))
+        except EnvironmentError as e:
+            raise ExtractError("could not change modification time")
+    #--------------------------------------------------------------------------
+    def next(self):
+        """Return the next member of the archive as a TarInfo object, when
+           TarFile is opened for reading. Return None if there is no more
+           available.
+        """
+        self._check("ra")
+        if self.firstmember is not None:
+            m = self.firstmember
+            self.firstmember = None
+            return m
+        # Read the next block.
+        self.fileobj.seek(self.offset)
+        tarinfo = None
+        while True:
+            try:
+                tarinfo = self.tarinfo.fromtarfile(self)
+            except EOFHeaderError as e:
+                if self.ignore_zeros:
+                    self._dbg(2, "0x%X: %s" % (self.offset, e))
+                    self.offset += BLOCKSIZE
+                    continue
+            except InvalidHeaderError as e:
+                if self.ignore_zeros:
+                    self._dbg(2, "0x%X: %s" % (self.offset, e))
+                    self.offset += BLOCKSIZE
+                    continue
+                elif self.offset == 0:
+                    raise ReadError(str(e))
+            except EmptyHeaderError:
+                if self.offset == 0:
+                    raise ReadError("empty file")
+            except TruncatedHeaderError as e:
+                if self.offset == 0:
+                    raise ReadError(str(e))
+            except SubsequentHeaderError as e:
+                raise ReadError(str(e))
+            break
+        if tarinfo is not None:
+            self.members.append(tarinfo)
+        else:
+            self._loaded = True
+        return tarinfo
+    #--------------------------------------------------------------------------
+    # Little helper methods:
+    def _getmember(self, name, tarinfo=None, normalize=False):
+        """Find an archive member by name from bottom to top.
+           If tarinfo is given, it is used as the starting point.
+        """
+        # Ensure that all members have been loaded.
+        members = self.getmembers()
+        # Limit the member search list up to tarinfo.
+        if tarinfo is not None:
+            members = members[:members.index(tarinfo)]
+        if normalize:
+            name = os.path.normpath(name)
+        for member in reversed(members):
+            if normalize:
+                member_name = os.path.normpath(member.name)
+            else:
+                member_name = member.name
+            if name == member_name:
+                return member
+    def _load(self):
+        """Read through the entire archive file and look for readable
+           members.
+        """
+        while True:
+            tarinfo = self.next()
+            if tarinfo is None:
+                break
+        self._loaded = True
+    def _check(self, mode=None):
+        """Check if TarFile is still open, and if the operation's mode
+           corresponds to TarFile's mode.
+        """
+        if self.closed:
+            raise IOError("%s is closed" % self.__class__.__name__)
+        if mode is not None and self.mode not in mode:
+            raise IOError("bad operation for mode %r" % self.mode)
+    def _find_link_target(self, tarinfo):
+        """Find the target member of a symlink or hardlink member in the
+           archive.
+        """
+        if tarinfo.issym():
+            # Always search the entire archive.
+            linkname = os.path.dirname(tarinfo.name) + "/" + tarinfo.linkname
+            limit = None
+        else:
+            # Search the archive before the link, because a hard link is
+            # just a reference to an already archived file.
+            linkname = tarinfo.linkname
+            limit = tarinfo
+        member = self._getmember(linkname, tarinfo=limit, normalize=True)
+        if member is None:
+            raise KeyError("linkname %r not found" % linkname)
+        return member
+    def __iter__(self):
+        """Provide an iterator object.
+        """
+        if self._loaded:
+            return iter(self.members)
+        else:
+            return TarIter(self)
+    def _dbg(self, level, msg):
+        """Write debugging output to sys.stderr.
+        """
+        if level <= self.debug:
+            print(msg, file=sys.stderr)
+    def __enter__(self):
+        self._check()
+        return self
+    def __exit__(self, type, value, traceback):
+        if type is None:
+            self.close()
+        else:
+            # An exception occurred. We must not call close() because
+            # it would try to write end-of-archive blocks and padding.
+            if not self._extfileobj:
+                self.fileobj.close()
+            self.closed = True
+# class TarFile
+class TarIter(object):
+    """Iterator Class.
+       for tarinfo in TarFile(...):
+           suite...
+    """
+    def __init__(self, tarfile):
+        """Construct a TarIter object.
+        """
+        self.tarfile = tarfile
+        self.index = 0
+    def __iter__(self):
+        """Return iterator object.
+        """
+        return self
+    def __next__(self):
+        """Return the next item using TarFile's next() method.
+           When all members have been read, set TarFile as _loaded.
+        """
+        # Fix for SF #1100429: Under rare circumstances it can
+        # happen that getmembers() is called during iteration,
+        # which will cause TarIter to stop prematurely.
+        if not self.tarfile._loaded:
+            tarinfo = self.tarfile.next()
+            if not tarinfo:
+                self.tarfile._loaded = True
+                raise StopIteration
+        else:
+            try:
+                tarinfo = self.tarfile.members[self.index]
+            except IndexError:
+                raise StopIteration
+        self.index += 1
+        return tarinfo
+    next = __next__ # for Python 2.x
+#--------------------
+# exported functions
+#--------------------
+def is_tarfile(name):
+    """Return True if name points to a tar archive that we
+       are able to handle, else return False.
+    """
+    try:
+        t = open(name)
+        t.close()
+        return True
+    except TarError:
+        return False
+bltn_open = open
+open = TarFile.open
author	Shubham Saini <shubham6405@gmail.com>	2018-12-11 10:01:23 +0000
committer	Shubham Saini <shubham6405@gmail.com>	2018-12-11 10:01:23 +0000
commit	68df54d6629ec019142eb149dd037774f2d11e7c (patch)
tree	345bc22d46b4e01a4ba8303b94278952a4ed2b9e /venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/distlib/_backport/tarfile.py