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, see <http://www.gnu.org/licenses/>.
  15
  16 """Routines for reading/writing a marks file."""
  17
  18
  19 from bzrlib.trace import warning
  20
  21
  22 def import_marks(filename):
  23     """Read the mapping of marks to revision-ids from a file.
  24
  25     :param filename: the file to read from
  26     :return: None if an error is encountered or a dictionary with marks
  27         as keys and revision-ids as values
  28     """
  29     # Check that the file is readable and in the right format
  30     try:
  31         f = file(filename)
  32     except IOError:
  33         warning("Could not import marks file %s - not importing marks",
  34             filename)
  35         return None
  36
  37     # Read the revision info
  38     revision_ids = {}
  39
  40     line = f.readline()
  41     if line == 'format=1\n':
  42         # Cope with old-style marks files
  43         # Read the branch info
  44         branch_names = {}
  45         for string in f.readline().rstrip('\n').split('\0'):
  46             if not string:
  47                 continue
  48             name, integer = string.rsplit('.', 1)
  49             branch_names[name] = int(integer)
  50         line = f.readline()
  51
  52     while line:
  53         line = line.rstrip('\n')
  54         mark, revid = line.split(' ', 1)
  55         mark = mark.lstrip(':')
  56         revision_ids[mark] = revid
  57         line = f.readline()
  58     f.close()
  59     return revision_ids
  60
  61
  62 def export_marks(filename, revision_ids):
  63     """Save marks to a file.
  64
  65     :param filename: filename to save data to
  66     :param revision_ids: dictionary mapping marks -> bzr revision-ids
  67     """
  68     try:
  69         f = file(filename, 'w')
  70     except IOError:
  71         warning("Could not open export-marks file %s - not exporting marks",
  72             filename)
  73         return
  74
  75     # Write the revision info
  76     for mark, revid in revision_ids.iteritems():
  77         f.write(':%s %s\n' % (str(mark).lstrip(':'), revid))
  78     f.close()