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
  20 def single_plural(n, single, plural):
  21     """Return a single or plural form of a noun based on number."""
  22     if n == 1:
  23         return single
  24     else:
  25         return plural
  26
  27
  28 def defines_to_dict(defines):
  29     """Convert a list of definition strings to a dictionary."""
  30     if defines is None:
  31         return None
  32     result = {}
  33     for define in defines:
  34         kv = define.split('=', 1)
  35         if len(kv) == 1:
  36             result[define.strip()] = 1
  37         else:
  38             result[kv[0].strip()] = kv[1].strip()
  39     return result
  40
  41
  42 def invert_dict(d):
  43     """Invert a dictionary with keys matching each value turned into a list."""
  44     # Based on recipe from ASPN
  45     result = {}
  46     for k, v in d.iteritems():
  47         keys = result.setdefault(v, [])
  48         keys.append(k)
  49     return result
  50
  51
  52 def invert_dictset(d):
  53     """Invert a dictionary with keys matching a set of values, turned into lists."""
  54     # Based on recipe from ASPN
  55     result = {}
  56     for k, c in d.iteritems():
  57         for v in c:
  58             keys = result.setdefault(v, [])
  59             keys.append(k)
  60     return result
  61
  62
  63 def _common_path_and_rest(l1, l2, common=[]):
  64     # From http://code.activestate.com/recipes/208993/
  65     if len(l1) < 1: return (common, l1, l2)
  66     if len(l2) < 1: return (common, l1, l2)
  67     if l1[0] != l2[0]: return (common, l1, l2)
  68     return _common_path_and_rest(l1[1:], l2[1:], common+[l1[0]])
  69
  70
  71 def common_path(path1, path2):
  72     """Find the common bit of 2 paths."""
  73     return ''.join(_common_path_and_rest(path1, path2)[0])
  74
  75
  76 def common_directory(paths):
  77     """Find the deepest common directory of a list of paths.
  78
  79     :return: if no paths are provided, None is returned;
  80       if there is no common directory, '' is returned;
  81       otherwise the common directory with a trailing / is returned.
  82     """
  83     from bzrlib import osutils
  84     def get_dir_with_slash(path):
  85         if path == '' or path.endswith('/'):
  86             return path
  87         else:
  88             dirname, basename = osutils.split(path)
  89             if dirname == '':
  90                 return dirname
  91             else:
  92                 return dirname + '/'
  93
  94     if not paths:
  95         return None
  96     elif len(paths) == 1:
  97         return get_dir_with_slash(paths[0])
  98     else:
  99         common = common_path(paths[0], paths[1])
 100         for path in paths[2:]:
 101             common = common_path(common, path)
 102         return get_dir_with_slash(common)
 103
 104
 105 def escape_commit_message(message):
 106     """Replace xml-incompatible control characters."""
 107     # This really ought to be provided by bzrlib.
 108     # Code copied from bzrlib.commit.
 109
 110     # Python strings can include characters that can't be
 111     # represented in well-formed XML; escape characters that
 112     # aren't listed in the XML specification
 113     # (http://www.w3.org/TR/REC-xml/#NT-Char).
 114     import re
 115     message, _ = re.subn(
 116         u'[^\x09\x0A\x0D\u0020-\uD7FF\uE000-\uFFFD]+',
 117         lambda match: match.group(0).encode('unicode_escape'),
 118         message)
 119     return message
 120
 121
 122 def binary_stream(stream):
 123     """Ensure a stream is binary on Windows.
 124
 125     :return: the stream
 126     """
 127     try:
 128         import os
 129         if os.name == 'nt':
 130             fileno = getattr(stream, 'fileno', None)
 131             if fileno:
 132                 no = fileno()
 133                 if no >= 0:     # -1 means we're working as subprocess
 134                     import msvcrt
 135                     msvcrt.setmode(no, os.O_BINARY)
 136     except ImportError:
 137         pass
 138     return stream
 139
 140
 141 def best_format_for_objects_in_a_repository(repo):
 142     """Find the high-level format for branches and trees given a repository.
 143
 144     When creating branches and working trees within a repository, Bazaar
 145     defaults to using the default format which may not be the best choice.
 146     This routine does a reverse lookup of the high-level format registry
 147     to find the high-level format that a shared repository was most likely
 148     created via.
 149
 150     :return: the BzrDirFormat or None if no matches were found.
 151     """
 152     # Based on code from bzrlib/info.py ...
 153     from bzrlib import bzrdir
 154     repo_format = repo._format
 155     candidates  = []
 156     non_aliases = set(bzrdir.format_registry.keys())
 157     non_aliases.difference_update(bzrdir.format_registry.aliases())
 158     for key in non_aliases:
 159         format = bzrdir.format_registry.make_bzrdir(key)
 160         # LocalGitBzrDirFormat has no repository_format
 161         if hasattr(format, "repository_format"):
 162             if format.repository_format == repo_format:
 163                 candidates.append((key, format))
 164     if len(candidates):
 165         # Assume the first one. Is there any reason not to do that?
 166         name, format = candidates[0]
 167         return format
 168     else:
 169         return None
 170
 171
 172 def open_destination_directory(location, format=None, verbose=True):
 173     """Open a destination directory and return the BzrDir.
 174
 175     If destination has a control directory, it will be returned.
 176     Otherwise, the destination should be empty or non-existent and
 177     a shared repository will be created there.
 178
 179     :param location: the destination directory
 180     :param format: the format to use or None for the default
 181     :param verbose: display the format used if a repository is created.
 182     :return: BzrDir for the destination
 183     """
 184     import os
 185     from bzrlib import bzrdir, errors, trace, transport
 186     try:
 187         control, relpath = bzrdir.BzrDir.open_containing(location)
 188         # XXX: Check the relpath is None here?
 189         return control
 190     except errors.NotBranchError:
 191         pass
 192
 193     # If the directory exists, check it is empty. Otherwise create it.
 194     if os.path.exists(location):
 195         contents = os.listdir(location)
 196         if contents:
 197             errors.BzrCommandError("Destination must have a .bzr directory, "
 198                 " not yet exist or be empty - files found in %s" % (location,))
 199     else:
 200         try:
 201             os.mkdir(location)
 202         except IOError, ex:
 203             errors.BzrCommandError("Unable to create %s: %s" %
 204                 (location, ex))
 205
 206     # Create a repository for the nominated format.
 207     trace.note("Creating destination repository ...")
 208     if format is None:
 209         format = bzrdir.format_registry.make_bzrdir('default')
 210     to_transport = transport.get_transport(location)
 211     to_transport.ensure_base()
 212     control = format.initialize_on_transport(to_transport)
 213     repo = control.create_repository(shared=True)
 214     if verbose:
 215         from bzrlib.info import show_bzrdir_info
 216         show_bzrdir_info(repo.bzrdir, verbose=0)
 217     return control