helpers.py

   1 # Copyright (C) 2008 Canonical Ltd
   2 #
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 2 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program; if not, write to the Free Software
  15 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16
  17 """Miscellaneous useful stuff."""
  18
  19 from fastimport.helpers import (
  20     common_path,
  21     )
  22
  23
  24 def common_directory(paths):
  25     """Find the deepest common directory of a list of paths.
  26
  27     :return: if no paths are provided, None is returned;
  28       if there is no common directory, '' is returned;
  29       otherwise the common directory with a trailing / is returned.
  30     """
  31     from bzrlib import osutils
  32     def get_dir_with_slash(path):
  33         if path == '' or path.endswith('/'):
  34             return path
  35         else:
  36             dirname, basename = osutils.split(path)
  37             if dirname == '':
  38                 return dirname
  39             else:
  40                 return dirname + '/'
  41
  42     if not paths:
  43         return None
  44     elif len(paths) == 1:
  45         return get_dir_with_slash(paths[0])
  46     else:
  47         common = common_path(paths[0], paths[1])
  48         for path in paths[2:]:
  49             common = common_path(common, path)
  50         return get_dir_with_slash(common)
  51
  52
  53 def escape_commit_message(message):
  54     """Replace xml-incompatible control characters."""
  55     # This really ought to be provided by bzrlib.
  56     # Code copied from bzrlib.commit.
  57
  58     # Python strings can include characters that can't be
  59     # represented in well-formed XML; escape characters that
  60     # aren't listed in the XML specification
  61     # (http://www.w3.org/TR/REC-xml/#NT-Char).
  62     import re
  63     message, _ = re.subn(
  64         u'[^\x09\x0A\x0D\u0020-\uD7FF\uE000-\uFFFD]+',
  65         lambda match: match.group(0).encode('unicode_escape'),
  66         message)
  67     return message
  68
  69
  70 def best_format_for_objects_in_a_repository(repo):
  71     """Find the high-level format for branches and trees given a repository.
  72
  73     When creating branches and working trees within a repository, Bazaar
  74     defaults to using the default format which may not be the best choice.
  75     This routine does a reverse lookup of the high-level format registry
  76     to find the high-level format that a shared repository was most likely
  77     created via.
  78
  79     :return: the BzrDirFormat or None if no matches were found.
  80     """
  81     # Based on code from bzrlib/info.py ...
  82     from bzrlib import bzrdir
  83     repo_format = repo._format
  84     candidates  = []
  85     non_aliases = set(bzrdir.format_registry.keys())
  86     non_aliases.difference_update(bzrdir.format_registry.aliases())
  87     for key in non_aliases:
  88         format = bzrdir.format_registry.make_bzrdir(key)
  89         # LocalGitBzrDirFormat has no repository_format
  90         if hasattr(format, "repository_format"):
  91             if format.repository_format == repo_format:
  92                 candidates.append((key, format))
  93     if len(candidates):
  94         # Assume the first one. Is there any reason not to do that?
  95         name, format = candidates[0]
  96         return format
  97     else:
  98         return None
  99
 100
 101 def open_destination_directory(location, format=None, verbose=True):
 102     """Open a destination directory and return the BzrDir.
 103
 104     If destination has a control directory, it will be returned.
 105     Otherwise, the destination should be empty or non-existent and
 106     a shared repository will be created there.
 107
 108     :param location: the destination directory
 109     :param format: the format to use or None for the default
 110     :param verbose: display the format used if a repository is created.
 111     :return: BzrDir for the destination
 112     """
 113     import os
 114     from bzrlib import bzrdir, errors, trace, transport
 115     try:
 116         control, relpath = bzrdir.BzrDir.open_containing(location)
 117         # XXX: Check the relpath is None here?
 118         return control
 119     except errors.NotBranchError:
 120         pass
 121
 122     # If the directory exists, check it is empty. Otherwise create it.
 123     if os.path.exists(location):
 124         contents = os.listdir(location)
 125         if contents:
 126             errors.BzrCommandError("Destination must have a .bzr directory, "
 127                 " not yet exist or be empty - files found in %s" % (location,))
 128     else:
 129         try:
 130             os.mkdir(location)
 131         except IOError, ex:
 132             errors.BzrCommandError("Unable to create %s: %s" %
 133                 (location, ex))
 134
 135     # Create a repository for the nominated format.
 136     trace.note("Creating destination repository ...")
 137     if format is None:
 138         format = bzrdir.format_registry.make_bzrdir('default')
 139     to_transport = transport.get_transport(location)
 140     to_transport.ensure_base()
 141     control = format.initialize_on_transport(to_transport)
 142     repo = control.create_repository(shared=True)
 143     if verbose:
 144         from bzrlib.info import show_bzrdir_info
 145         show_bzrdir_info(repo.bzrdir, verbose=0)
 146     return control