reftracker.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
  17 """Tracker of refs."""
  18
  19
  20 class RefTracker(object):
  21
  22     def __init__(self):
  23         # Head tracking: last ref, last id per ref & map of commit ids to ref*s*
  24         self.last_ref = None
  25         self.last_ids = {}
  26         self.heads = {}
  27
  28     def dump_stats(self, note):
  29         self._show_stats_for(self.last_ids, "last-ids", note=note)
  30         self._show_stats_for(self.heads, "heads", note=note)
  31
  32     def clear(self):
  33         self.last_ids.clear()
  34         self.heads.clear()
  35
  36     def track_heads(self, cmd):
  37         """Track the repository heads given a CommitCommand.
  38
  39         :param cmd: the CommitCommand
  40         :return: the list of parents in terms of commit-ids
  41         """
  42         # Get the true set of parents
  43         if cmd.from_ is not None:
  44             parents = [cmd.from_]
  45         else:
  46             last_id = self.last_ids.get(cmd.ref)
  47             if last_id is not None:
  48                 parents = [last_id]
  49             else:
  50                 parents = []
  51         parents.extend(cmd.merges)
  52
  53         # Track the heads
  54         self.track_heads_for_ref(cmd.ref, cmd.id, parents)
  55         return parents
  56
  57     def track_heads_for_ref(self, cmd_ref, cmd_id, parents=None):
  58         if parents is not None:
  59             for parent in parents:
  60                 if parent in self.heads:
  61                     del self.heads[parent]
  62         self.heads.setdefault(cmd_id, set()).add(cmd_ref)
  63         self.last_ids[cmd_ref] = cmd_id
  64         self.last_ref = cmd_ref
  65
  66