branch_updater.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 """An object that updates a bunch of branches based on data imported."""
  18
  19 from operator import itemgetter
  20
  21 from bzrlib import bzrdir, errors, osutils, transport
  22 from bzrlib.trace import error, note
  23
  24 import branch_mapper
  25 import helpers
  26
  27
  28 class BranchUpdater(object):
  29
  30     def __init__(self, repo, branch, cache_mgr, heads_by_ref, last_ref, tags):
  31         """Create an object responsible for updating branches.
  32
  33         :param heads_by_ref: a dictionary where
  34           names are git-style references like refs/heads/master;
  35           values are one item lists of commits marks.
  36         """
  37         self.repo = repo
  38         self.branch = branch
  39         self.cache_mgr = cache_mgr
  40         self.heads_by_ref = heads_by_ref
  41         self.last_ref = last_ref
  42         self.tags = tags
  43         self.name_mapper = branch_mapper.BranchMapper()
  44         self._branch_format = \
  45             helpers.best_format_for_objects_in_a_repository(repo)
  46
  47     def update(self):
  48         """Update the Bazaar branches and tips matching the heads.
  49
  50         If the repository is shared, this routine creates branches
  51         as required. If it isn't, warnings are produced about the
  52         lost of information.
  53
  54         :return: updated, lost_heads where
  55           updated = the list of branches updated ('trunk' is first)
  56           lost_heads = a list of (bazaar-name,revision) for branches that
  57             would have been created had the repository been shared
  58         """
  59         updated = []
  60         branch_tips, lost_heads = self._get_matching_branches()
  61         for br, tip in branch_tips:
  62             if self._update_branch(br, tip):
  63                 updated.append(br)
  64         return updated, lost_heads
  65
  66     def _get_matching_branches(self):
  67         """Get the Bazaar branches.
  68
  69         :return: branch_tips, lost_heads where
  70           branch_tips = a list of (branch,tip) tuples for branches. The
  71             first tip is the 'trunk'.
  72           lost_heads = a list of (bazaar-name,revision) for branches that
  73             would have been created had the repository been shared and
  74             everything succeeded
  75         """
  76         branch_tips = []
  77         lost_heads = []
  78         ref_names = self.heads_by_ref.keys()
  79         if self.branch is not None:
  80             trunk = self.select_trunk(ref_names)
  81             default_tip = self.heads_by_ref[trunk][0]
  82             branch_tips.append((self.branch, default_tip))
  83             ref_names.remove(trunk)
  84
  85         # Convert the reference names into Bazaar speak. If we haven't
  86         # already put the 'trunk' first, do it now.
  87         git_to_bzr_map = self.name_mapper.git_to_bzr(ref_names)
  88         if ref_names and self.branch is None:
  89             trunk = self.select_trunk(ref_names)
  90             git_bzr_items = [(trunk, git_to_bzr_map[trunk])]
  91             del git_to_bzr_map[trunk]
  92         else:
  93             git_bzr_items = []
  94         git_bzr_items.extend(sorted(git_to_bzr_map.items(), key=itemgetter(1)))
  95
  96         # Policy for locating branches
  97         def dir_under_current(name, ref_name):
  98             # Using the Bazaar name, get a directory under the current one
  99             repo_base = self.repo.bzrdir.transport.base
 100             return osutils.pathjoin(repo_base, "..", name)
 101         def dir_sister_branch(name, ref_name):
 102             # Using the Bazaar name, get a sister directory to the branch
 103             return osutils.pathjoin(self.branch.base, "..", name)
 104         if self.branch is not None:
 105             dir_policy = dir_sister_branch
 106         else:
 107             dir_policy = dir_under_current
 108
 109         # Create/track missing branches
 110         shared_repo = self.repo.is_shared()
 111         for ref_name, name in git_bzr_items:
 112             tip = self.heads_by_ref[ref_name][0]
 113             if shared_repo:
 114                 location = dir_policy(name, ref_name)
 115                 try:
 116                     br = self.make_branch(location)
 117                     branch_tips.append((br,tip))
 118                     continue
 119                 except errors.BzrError, ex:
 120                     error("ERROR: failed to create branch %s: %s",
 121                         location, ex)
 122             lost_head = self.cache_mgr.revision_ids[tip]
 123             lost_info = (name, lost_head)
 124             lost_heads.append(lost_info)
 125         return branch_tips, lost_heads
 126
 127     def select_trunk(self, ref_names):
 128         """Given a set of ref names, choose one as the trunk."""
 129         for candidate in ['refs/heads/master']:
 130             if candidate in ref_names:
 131                 return candidate
 132         # Use the last reference in the import stream
 133         return self.last_ref
 134
 135     def make_branch(self, location):
 136         """Make a branch in the repository if not already there."""
 137         to_transport = transport.get_transport(location)
 138         to_transport.create_prefix()
 139         try:
 140             return bzrdir.BzrDir.open(location).open_branch()
 141         except errors.NotBranchError, ex:
 142             return bzrdir.BzrDir.create_branch_convenience(location,
 143                 format=self._branch_format,
 144                 possible_transports=[to_transport])
 145
 146     def _update_branch(self, br, last_mark):
 147         """Update a branch with last revision and tag information.
 148
 149         :return: whether the branch was changed or not
 150         """
 151         last_rev_id = self.cache_mgr.revision_ids[last_mark]
 152         revs = list(self.repo.iter_reverse_revision_history(last_rev_id))
 153         revno = len(revs)
 154         existing_revno, existing_last_rev_id = br.last_revision_info()
 155         changed = False
 156         if revno != existing_revno or last_rev_id != existing_last_rev_id:
 157             br.set_last_revision_info(revno, last_rev_id)
 158             changed = True
 159         # apply tags known in this branch
 160         my_tags = {}
 161         if self.tags:
 162             ancestry = self.repo.get_ancestry(last_rev_id)
 163             for tag,rev in self.tags.items():
 164                 if rev in ancestry:
 165                     my_tags[tag] = rev
 166             if my_tags:
 167                 br.tags._set_tag_dict(my_tags)
 168                 changed = True
 169         if changed:
 170             tagno = len(my_tags)
 171             note("\t branch %s now has %d %s and %d %s", br.nick,
 172                 revno, helpers.single_plural(revno, "revision", "revisions"),
 173                 tagno, helpers.single_plural(tagno, "tag", "tags"))
 174         return changed