marks_file.py

   1 # Copyright (C) 2009 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 """Routines for reading/writing a marks file."""
  18
  19
  20 import re
  21 from bzrlib.trace import warning
  22
  23
  24 def import_marks(filename):
  25     """Read the mapping of marks to revision-ids from a file.
  26
  27     :param filename: the file to read from
  28     :return: None if an error is encountered or (revision_ids, branch_names)
  29       where
  30       * revision_ids is a dictionary with marks as keys and revision-ids
  31         as values
  32       * branch_names is a dictionary mapping branch names to some magic #
  33     """
  34     # Check that the file is readable and in the right format
  35     try:
  36         f = file(filename)
  37     except IOError:
  38         warning("Could not import marks file %s - not importing marks",
  39             filename)
  40         return None
  41     firstline = f.readline()
  42     match = re.match(r'^format=(\d+)$', firstline)
  43     if not match:
  44         warning("%r doesn't look like a marks file - not importing marks",
  45             filename)
  46         return None
  47     elif match.group(1) != '1':
  48         warning('format version in marks file %s not supported - not importing'
  49             'marks', filename)
  50         return None
  51
  52     # Read the branch info
  53     branch_names = {}
  54     for string in f.readline().rstrip('\n').split('\0'):
  55         if not string:
  56             continue
  57         name, integer = string.rsplit('.', 1)
  58         branch_names[name] = int(integer)
  59
  60     # Read the revision info
  61     revision_ids = {}
  62     for line in f:
  63         line = line.rstrip('\n')
  64         mark, revid = line.split(' ', 1)
  65         revision_ids[mark] = revid
  66     f.close()
  67     return (revision_ids, branch_names)
  68
  69
  70 def export_marks(filename, revision_ids, branch_names=None):
  71     """Save marks to a file.
  72
  73     :param filename: filename to save data to
  74     :param revision_ids: dictionary mapping marks -> bzr revision-ids
  75     :param branch_names: dictionary mapping branch names to some magic #
  76     """
  77     try:
  78         f = file(filename, 'w')
  79     except IOError:
  80         warning("Could not open export-marks file %s - not exporting marks",
  81             filename)
  82         return
  83     f.write('format=1\n')
  84
  85     # Write the branch names line
  86     if branch_names:
  87         branch_names = [ '%s.%d' % x for x in branch_names.iteritems() ]
  88         f.write('\0'.join(branch_names) + '\n')
  89     else:
  90         f.write('\0tmp.0\n')
  91
  92     # Write the revision info
  93     for mark, revid in revision_ids.iteritems():
  94         f.write('%s %s\n' % (mark, revid))
  95     f.close()