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, see <http://www.gnu.org/licenses/>.
  15
  16 """Miscellaneous useful stuff."""
  17
  18 import stat
  19
  20
  21 def escape_commit_message(message):
  22     """Replace xml-incompatible control characters."""
  23     # This really ought to be provided by bzrlib.
  24     # Code copied from bzrlib.commit.
  25
  26     # Python strings can include characters that can't be
  27     # represented in well-formed XML; escape characters that
  28     # aren't listed in the XML specification
  29     # (http://www.w3.org/TR/REC-xml/#NT-Char).
  30     import re
  31     message, _ = re.subn(
  32         u'[^\x09\x0A\x0D\u0020-\uD7FF\uE000-\uFFFD]+',
  33         lambda match: match.group(0).encode('unicode_escape'),
  34         message)
  35     return message
  36
  37
  38 def best_format_for_objects_in_a_repository(repo):
  39     """Find the high-level format for branches and trees given a repository.
  40
  41     When creating branches and working trees within a repository, Bazaar
  42     defaults to using the default format which may not be the best choice.
  43     This routine does a reverse lookup of the high-level format registry
  44     to find the high-level format that a shared repository was most likely
  45     created via.
  46
  47     :return: the BzrDirFormat or None if no matches were found.
  48     """
  49     # Based on code from bzrlib/info.py ...
  50     from bzrlib import bzrdir
  51     repo_format = repo._format
  52     candidates  = []
  53     non_aliases = set(bzrdir.format_registry.keys())
  54     non_aliases.difference_update(bzrdir.format_registry.aliases())
  55     for key in non_aliases:
  56         format = bzrdir.format_registry.make_bzrdir(key)
  57         # LocalGitBzrDirFormat has no repository_format
  58         if hasattr(format, "repository_format"):
  59             if format.repository_format == repo_format:
  60                 candidates.append((key, format))
  61     if len(candidates):
  62         # Assume the first one. Is there any reason not to do that?
  63         name, format = candidates[0]
  64         return format
  65     else:
  66         return None
  67
  68
  69 def open_destination_directory(location, format=None, verbose=True):
  70     """Open a destination directory and return the BzrDir.
  71
  72     If destination has a control directory, it will be returned.
  73     Otherwise, the destination should be empty or non-existent and
  74     a shared repository will be created there.
  75
  76     :param location: the destination directory
  77     :param format: the format to use or None for the default
  78     :param verbose: display the format used if a repository is created.
  79     :return: BzrDir for the destination
  80     """
  81     import os
  82     from bzrlib import bzrdir, errors, trace, transport
  83     try:
  84         control, relpath = bzrdir.BzrDir.open_containing(location)
  85         # XXX: Check the relpath is None here?
  86         return control
  87     except errors.NotBranchError:
  88         pass
  89
  90     # If the directory exists, check it is empty. Otherwise create it.
  91     if os.path.exists(location):
  92         contents = os.listdir(location)
  93         if contents:
  94             errors.BzrCommandError("Destination must have a .bzr directory, "
  95                 " not yet exist or be empty - files found in %s" % (location,))
  96     else:
  97         try:
  98             os.mkdir(location)
  99         except IOError, ex:
 100             errors.BzrCommandError("Unable to create %s: %s" %
 101                 (location, ex))
 102
 103     # Create a repository for the nominated format.
 104     trace.note("Creating destination repository ...")
 105     if format is None:
 106         format = bzrdir.format_registry.make_bzrdir('default')
 107     to_transport = transport.get_transport(location)
 108     to_transport.ensure_base()
 109     control = format.initialize_on_transport(to_transport)
 110     repo = control.create_repository(shared=True)
 111     if verbose:
 112         from bzrlib.info import show_bzrdir_info
 113         show_bzrdir_info(repo.bzrdir, verbose=0)
 114     return control
 115
 116
 117 def kind_to_mode(kind, executable):
 118     if kind == "file":
 119         if executable == True:
 120             return stat.S_IFREG | 0755
 121         elif executable == False:
 122             return stat.S_IFREG | 0644
 123         else:
 124             raise AssertionError("Executable %r invalid" % executable)
 125     elif kind == "symlink":
 126         return stat.S_IFLNK
 127     elif kind == "directory":
 128         return stat.S_IFDIR
 129     elif kind == "tree-reference":
 130         return 0160000
 131     else:
 132         raise AssertionError("Unknown file kind '%s'" % kind)
 133
 134
 135 def mode_to_kind(mode):
 136     # Note: Output from git-fast-export slightly different to spec
 137     if mode in (0644, 0100644):
 138         return 'file', False
 139     elif mode in (0755, 0100755):
 140         return 'file', True
 141     elif mode == 0040000:
 142         return 'directory', False
 143     elif mode == 0120000:
 144         return 'symlink', False
 145     elif mode == 0160000:
 146         return 'tree-reference', False
 147     else:
 148         raise AssertionError("invalid mode %o" % mode)
 149
 150
 151 def binary_stream(stream):
 152     """Ensure a stream is binary on Windows.
 153
 154     :return: the stream
 155     """
 156     try:
 157         import os
 158         if os.name == 'nt':
 159             fileno = getattr(stream, 'fileno', None)
 160             if fileno:
 161                 no = fileno()
 162                 if no >= 0:     # -1 means we're working as subprocess
 163                     import msvcrt
 164                     msvcrt.setmode(no, os.O_BINARY)
 165     except ImportError:
 166         pass
 167     return stream
 168
 169
 170 def single_plural(n, single, plural):
 171     """Return a single or plural form of a noun based on number."""
 172     if n == 1:
 173         return single
 174     else:
 175         return plural
 176
 177
 178 def invert_dictset(d):
 179     """Invert a dictionary with keys matching a set of values, turned into lists."""
 180     # Based on recipe from ASPN
 181     result = {}
 182     for k, c in d.iteritems():
 183         for v in c:
 184             keys = result.setdefault(v, [])
 185             keys.append(k)
 186     return result
 187
 188
 189 def invert_dict(d):
 190     """Invert a dictionary with keys matching each value turned into a list."""
 191     # Based on recipe from ASPN
 192     result = {}
 193     for k, v in d.iteritems():
 194         keys = result.setdefault(v, [])
 195         keys.append(k)
 196     return result
 197
 198