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12094.2.1
by Henning Eggers
Moved tarfile helper into services. |
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# Copyright 2010 Canonical Ltd. This software is licensed under the
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# GNU Affero General Public License version 3 (see the file LICENSE).
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"""Helpers to work with tar files more easily."""
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__metaclass__ = type |
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__all__ = [ |
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'LaunchpadWriteTarFile', |
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]
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import os |
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from StringIO import StringIO |
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import tarfile |
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import tempfile |
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import time |
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# A note about tarballs, StringIO and unicode. SQLObject returns unicode
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# values for columns which are declared as StringCol. We have to be careful
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# not to pass unicode instances to the tarfile module, because when the
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# tarfile's filehandle is a StringIO object, the StringIO object gets upset
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# later when we ask it for its value and it tries to join together its
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# buffers. This is why the tarball code is sprinkled with ".encode('ascii')".
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# If we get separate StringCol and UnicodeCol column types, we won't need this
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# any longer.
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# -- Dafydd Harries, 2005-04-07.
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class LaunchpadWriteTarFile: |
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"""Convenience wrapper around the tarfile module.
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This class makes it convenient to generate tar files in various ways.
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"""
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def __init__(self, stream): |
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self.tarfile = tarfile.open('', 'w:gz', stream) |
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self.closed = False |
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@classmethod
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def files_to_stream(cls, files): |
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"""Turn a dictionary of files into a data stream."""
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buffer = tempfile.TemporaryFile() |
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archive = cls(buffer) |
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archive.add_files(files) |
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archive.close() |
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buffer.seek(0) |
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return buffer |
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@classmethod
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def files_to_string(cls, files): |
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"""Turn a dictionary of files into a data string."""
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return cls.files_to_stream(files).read() |
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@classmethod
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def files_to_tarfile(cls, files): |
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"""Turn a dictionary of files into a tarfile object."""
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return tarfile.open('', 'r', cls.files_to_stream(files)) |
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def close(self): |
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"""Close the archive.
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After the archive is closed, the data written to the filehandle will
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be complete. The archive may not be appended to after it has been
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closed.
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"""
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self.tarfile.close() |
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self.closed = True |
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def add_file(self, path, contents): |
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"""Add a file to the archive."""
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assert not self.closed, "Can't add a file to a closed archive" |
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now = int(time.time()) |
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path_bits = path.split(os.path.sep) |
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# Ensure that all the directories in the path are present in the
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# archive.
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for i in range(1, len(path_bits)): |
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joined_path = os.path.join(*path_bits[:i]) |
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try: |
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self.tarfile.getmember(joined_path) |
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except KeyError: |
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tarinfo = tarfile.TarInfo(joined_path) |
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tarinfo.type = tarfile.DIRTYPE |
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tarinfo.mtime = now |
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tarinfo.mode = 0755 |
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tarinfo.uname = 'launchpad' |
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tarinfo.gname = 'launchpad' |
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self.tarfile.addfile(tarinfo) |
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tarinfo = tarfile.TarInfo(path) |
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tarinfo.time = now |
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tarinfo.mtime = now |
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tarinfo.mode = 0644 |
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tarinfo.size = len(contents) |
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tarinfo.uname = 'launchpad' |
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tarinfo.gname = 'launchpad' |
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self.tarfile.addfile(tarinfo, StringIO(contents)) |
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def add_files(self, files): |
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"""Add a number of files to the archive.
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:param files: A dictionary mapping file names to file contents.
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"""
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for filename in sorted(files.keys()): |
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self.add_file(filename, files[filename]) |