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.
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.
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
19
from bzrlib.graph import node_distances, select_farthest, all_descendants
23
class Revision(object):
24
"""Single revision on a branch.
26
Revisions may know their revision_hash, but only once they've been
27
written out. This is not stored because you cannot write the hash
28
into the file it describes.
30
After bzr 0.0.5 revisions are allowed to have multiple parents.
33
List of parent revision_ids
36
def __init__(self, revision_id, properties=None, **args):
37
self.revision_id = revision_id
38
self.properties = properties or {}
39
self.__dict__.update(args)
41
self.parent_sha1s = []
44
return "<Revision id %s>" % self.revision_id
46
def __eq__(self, other):
47
if not isinstance(other, Revision):
49
# FIXME: rbc 20050930 parent_ids are not being compared
51
self.inventory_sha1 == other.inventory_sha1
52
and self.revision_id == other.revision_id
53
and self.timestamp == other.timestamp
54
and self.message == other.message
55
and self.timezone == other.timezone
56
and self.committer == other.committer
57
and self.properties == other.properties)
59
def __ne__(self, other):
60
return not self.__eq__(other)
63
def is_ancestor(revision_id, candidate_id, branch):
64
"""Return true if candidate_id is an ancestor of revision_id.
66
A false negative will be returned if any intermediate descendent of
67
candidate_id is not present in any of the revision_sources.
69
revisions_source is an object supporting a get_revision operation that
70
behaves like Branch's.
72
return candidate_id in branch.get_ancestry(revision_id)
75
def iter_ancestors(revision_id, revision_source, only_present=False):
76
ancestors = (revision_id,)
78
while len(ancestors) > 0:
80
for ancestor in ancestors:
82
yield ancestor, distance
84
revision = revision_source.get_revision(ancestor)
85
except bzrlib.errors.NoSuchRevision, e:
86
if e.revision == revision_id:
91
yield ancestor, distance
92
new_ancestors.extend(revision.parent_ids)
93
ancestors = new_ancestors
97
def find_present_ancestors(revision_id, revision_source):
98
"""Return the ancestors of a revision present in a branch.
100
It's possible that a branch won't have the complete ancestry of
101
one of its revisions.
105
anc_iter = enumerate(iter_ancestors(revision_id, revision_source,
107
for anc_order, (anc_id, anc_distance) in anc_iter:
108
if not found_ancestors.has_key(anc_id):
109
found_ancestors[anc_id] = (anc_order, anc_distance)
110
return found_ancestors
113
def __get_closest(intersection):
116
for entry in intersection:
117
if entry[0] == intersection[0][0]:
118
matches.append(entry[2])
122
def old_common_ancestor(revision_a, revision_b, revision_source):
123
"""Find the ancestor common to both revisions that is closest to both.
125
from bzrlib.trace import mutter
126
a_ancestors = find_present_ancestors(revision_a, revision_source)
127
b_ancestors = find_present_ancestors(revision_b, revision_source)
130
# a_order is used as a tie-breaker when two equally-good bases are found
131
for revision, (a_order, a_distance) in a_ancestors.iteritems():
132
if b_ancestors.has_key(revision):
133
a_intersection.append((a_distance, a_order, revision))
134
b_intersection.append((b_ancestors[revision][1], a_order, revision))
135
mutter("a intersection: %r" % a_intersection)
136
mutter("b intersection: %r" % b_intersection)
138
a_closest = __get_closest(a_intersection)
139
if len(a_closest) == 0:
141
b_closest = __get_closest(b_intersection)
142
assert len(b_closest) != 0
143
mutter ("a_closest %r" % a_closest)
144
mutter ("b_closest %r" % b_closest)
145
if a_closest[0] in b_closest:
147
elif b_closest[0] in a_closest:
150
raise bzrlib.errors.AmbiguousBase((a_closest[0], b_closest[0]))
153
def revision_graph(revision, revision_source):
154
"""Produce a graph of the ancestry of the specified revision.
155
Return root, ancestors map, descendants map
157
TODO: Produce graphs with the NULL revision as root, so that we can find
158
a common even when trees are not branches don't represent a single line
165
descendants[revision] = {}
166
while len(lines) > 0:
169
if line == NULL_REVISION:
174
rev = revision_source.get_revision(line)
175
parents = list(rev.parent_ids)
176
if len(parents) == 0:
177
parents = [NULL_REVISION]
178
except bzrlib.errors.NoSuchRevision:
182
if parents is not None:
183
for parent in parents:
184
if parent not in ancestors:
185
new_lines.add(parent)
186
if parent not in descendants:
187
descendants[parent] = {}
188
descendants[parent][line] = 1
189
if parents is not None:
190
ancestors[line] = set(parents)
192
assert root not in descendants[root]
193
assert root not in ancestors[root]
194
return root, ancestors, descendants
197
def combined_graph(revision_a, revision_b, revision_source):
198
"""Produce a combined ancestry graph.
199
Return graph root, ancestors map, descendants map, set of common nodes"""
200
root, ancestors, descendants = revision_graph(revision_a, revision_source)
201
root_b, ancestors_b, descendants_b = revision_graph(revision_b,
204
raise bzrlib.errors.NoCommonRoot(revision_a, revision_b)
206
for node, node_anc in ancestors_b.iteritems():
207
if node in ancestors:
210
ancestors[node] = set()
211
ancestors[node].update(node_anc)
212
for node, node_dec in descendants_b.iteritems():
213
if node not in descendants:
214
descendants[node] = {}
215
descendants[node].update(node_dec)
216
return root, ancestors, descendants, common
219
def common_ancestor(revision_a, revision_b, revision_source):
221
root, ancestors, descendants, common = \
222
combined_graph(revision_a, revision_b, revision_source)
223
except bzrlib.errors.NoCommonRoot:
224
raise bzrlib.errors.NoCommonAncestor(revision_a, revision_b)
226
distances = node_distances (descendants, ancestors, root)
227
farthest = select_farthest(distances, common)
228
if farthest is None or farthest == NULL_REVISION:
229
raise bzrlib.errors.NoCommonAncestor(revision_a, revision_b)
233
class MultipleRevisionSources(object):
234
"""Proxy that looks in multiple branches for revisions."""
235
def __init__(self, *args):
236
object.__init__(self)
237
assert len(args) != 0
238
self._revision_sources = args
240
def get_revision(self, revision_id):
241
for source in self._revision_sources:
243
return source.get_revision(revision_id)
244
except bzrlib.errors.NoSuchRevision, e:
248
def get_intervening_revisions(ancestor_id, rev_id, rev_source,
249
revision_history=None):
250
"""Find the longest line of descent from maybe_ancestor to revision.
251
Revision history is followed where possible.
253
If ancestor_id == rev_id, list will be empty.
254
Otherwise, rev_id will be the last entry. ancestor_id will never appear.
255
If ancestor_id is not an ancestor, NotAncestor will be thrown
257
root, ancestors, descendants = revision_graph(rev_id, rev_source)
258
if len(descendants) == 0:
259
raise NoSuchRevision(rev_source, rev_id)
260
if ancestor_id not in descendants:
261
rev_source.get_revision(ancestor_id)
262
raise bzrlib.errors.NotAncestor(rev_id, ancestor_id)
263
root_descendants = all_descendants(descendants, ancestor_id)
264
root_descendants.add(ancestor_id)
265
if rev_id not in root_descendants:
266
raise bzrlib.errors.NotAncestor(rev_id, ancestor_id)
267
distances = node_distances(descendants, ancestors, ancestor_id,
268
root_descendants=root_descendants)
270
def best_ancestor(rev_id):
272
for anc_id in ancestors[rev_id]:
274
distance = distances[anc_id]
277
if revision_history is not None and anc_id in revision_history:
279
elif best is None or distance > best[1]:
280
best = (anc_id, distance)
285
while next != ancestor_id:
287
next = best_ancestor(next)
added
removed
bzrlib/revision.py
