1import os.path
2import gzip
3import tarfile
4
5TARGZ_DEFAULT_COMPRESSION_LEVEL = 9
6
7def make_tarball(tarball_path, sources, base_dir, prefix_dir=''):
8    """Parameters:
9    tarball_path: output path of the .tar.gz file
10    sources: list of sources to include in the tarball, relative to the current directory
11    base_dir: if a source file is in a sub-directory of base_dir, then base_dir is stripped
12        from path in the tarball.
13    prefix_dir: all files stored in the tarball be sub-directory of prefix_dir. Set to ''
14        to make them child of root.
15    """
16    base_dir = os.path.normpath( os.path.abspath( base_dir ) )
17    def archive_name( path ):
18        """Makes path relative to base_dir."""
19        path = os.path.normpath( os.path.abspath( path ) )
20        common_path = os.path.commonprefix( (base_dir, path) )
21        archive_name = path[len(common_path):]
22        if os.path.isabs( archive_name ):
23            archive_name = archive_name[1:]
24        return os.path.join( prefix_dir, archive_name )
25    def visit(tar, dirname, names):
26        for name in names:
27            path = os.path.join(dirname, name)
28            if os.path.isfile(path):
29                path_in_tar = archive_name(path)
30                tar.add(path, path_in_tar )
31    compression = TARGZ_DEFAULT_COMPRESSION_LEVEL
32    tar = tarfile.TarFile.gzopen( tarball_path, 'w', compresslevel=compression )
33    try:
34        for source in sources:
35            source_path = source
36            if os.path.isdir( source ):
37                os.path.walk(source_path, visit, tar)
38            else:
39                path_in_tar = archive_name(source_path)
40                tar.add(source_path, path_in_tar )      # filename, arcname
41    finally:
42        tar.close()
43
44def decompress( tarball_path, base_dir ):
45    """Decompress the gzipped tarball into directory base_dir.
46    """
47    # !!! This class method is not documented in the online doc
48    # nor is bz2open!
49    tar = tarfile.TarFile.gzopen(tarball_path, mode='r')
50    try:
51        tar.extractall( base_dir )
52    finally:
53        tar.close()
54