targzstream 1.1

Summary

This module provides an extension to the standard tarfile.TarFile class which provides the ability to add files to a TarFile that are compressed on-the-fly. It will only work on an uncompressed output tarfile, since after the data is written it will overwrite the header for the file with the correct size data.

Limitations

• The object to which the tarfile is being written must support “seek()”, so this cannot work over a socket, nor presumably with a compressed tarfile. Note: re-compressing contents is not very useful.

• The “close_gz_file” method will be called when calling “close” on the file stream. Note: close_gz_file() and close_file() are interchangeable.

• The constructor does not support reading, use the open() class method or use the base class tarfile.TarFile constructor.

Example Usage

#!/usr/bin/env python3
import os, sys, shutil

import targzstream

# USAGE:  ./foo.py TARFILE INPUT [ INPUT2 ... ]
#  Eg: ./foo.py myoutput.tar *.cpp *.h

with targzstream.TarFile(sys.argv[1], mode='w') as tarball:
    for fname in sys.argv[2:]:
        st = os.stat(fname)
        with tarball.add_gz_file(name=fname + '.gz', mtime=st.st_mtime,
                                 uid=st.st_uid, gid=st.st_gid, mode=st.st_mode) as fout:
            # Copy the data.
            with open(fname, 'rb') as fin:
                shutil.copyfileobj(fin, fout)
# The end.

TODO

• Have add_gz_file handle the result of an os.stat. Eg:

  with tarball.gz_file(name=fname + '.gz', stat=os.stat(fname)) as obj:
      with open(fname, 'rb') as fin:
          shutil.copyfileobj(fin, obj)

• Wrap add_gz_file and close_gz_file as a context manager.

  Done.

• Allow streaming uncompressed files, too.

  Done.