# (C) 2005 Canonical # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA import bzrlib.errors class RevisionReference(object): """ Reference to a stored revision. Includes the revision_id and revision_sha1. """ revision_id = None revision_sha1 = None def __init__(self, revision_id, revision_sha1=None): if revision_id == None \ or isinstance(revision_id, basestring): self.revision_id = revision_id else: raise ValueError('bad revision_id %r' % revision_id) if revision_sha1 != None: if isinstance(revision_sha1, basestring) \ and len(revision_sha1) == 40: self.revision_sha1 = revision_sha1 else: raise ValueError('bad revision_sha1 %r' % revision_sha1) class Revision(object): """Single revision on a branch. Revisions may know their revision_hash, but only once they've been written out. This is not stored because you cannot write the hash into the file it describes. After bzr 0.0.5 revisions are allowed to have multiple parents. parents List of parent revisions, each is a RevisionReference. """ inventory_id = None inventory_sha1 = None revision_id = None timestamp = None message = None timezone = None committer = None def __init__(self, **args): self.__dict__.update(args) self.parents = [] def __repr__(self): return "" % self.revision_id def __eq__(self, other): if not isinstance(other, Revision): return False return (self.inventory_id == other.inventory_id and self.inventory_sha1 == other.inventory_sha1 and self.revision_id == other.revision_id and self.timestamp == other.timestamp and self.message == other.message and self.timezone == other.timezone and self.committer == other.committer) def __ne__(self, other): return not self.__eq__(other) REVISION_ID_RE = None def validate_revision_id(rid): """Check rid is syntactically valid for a revision id.""" global REVISION_ID_RE if not REVISION_ID_RE: import re REVISION_ID_RE = re.compile('[\w.-]+@[\w.-]+--?\d+--?[0-9a-f]+\Z') if not REVISION_ID_RE.match(rid): raise ValueError("malformed revision-id %r" % rid) def is_ancestor(revision_id, candidate_id, revision_source): """Return true if candidate_id is an ancestor of revision_id. A false negative will be returned if any intermediate descendent of candidate_id is not present in any of the revision_sources. revisions_source is an object supporting a get_revision operation that behaves like Branch's. """ for ancestor_id, distance in iter_ancestors(revision_id, revision_source): if ancestor_id == candidate_id: return True return False def iter_ancestors(revision_id, revision_source, only_present=False): ancestors = (revision_id,) distance = 0 while len(ancestors) > 0: new_ancestors = [] for ancestor in ancestors: if not only_present: yield ancestor, distance try: revision = revision_source.get_revision(ancestor) except bzrlib.errors.NoSuchRevision, e: if e.revision == revision_id: raise else: continue if only_present: yield ancestor, distance new_ancestors.extend([p.revision_id for p in revision.parents]) ancestors = new_ancestors distance += 1 def find_present_ancestors(revision_id, revision_source): """Return the ancestors of a revision present in a branch. It's possible that a branch won't have the complete ancestry of one of its revisions. """ found_ancestors = {} anc_iter = enumerate(iter_ancestors(revision_id, revision_source, only_present=True)) for anc_order, (anc_id, anc_distance) in anc_iter: if not found_ancestors.has_key(anc_id): found_ancestors[anc_id] = (anc_order, anc_distance) return found_ancestors def __get_closest(intersection): intersection.sort() matches = [] for entry in intersection: if entry[0] == intersection[0][0]: matches.append(entry[2]) return matches def common_ancestor(revision_a, revision_b, revision_source): """Find the ancestor common to both revisions that is closest to both. """ from bzrlib.trace import mutter a_ancestors = find_present_ancestors(revision_a, revision_source) b_ancestors = find_present_ancestors(revision_b, revision_source) a_intersection = [] b_intersection = [] # a_order is used as a tie-breaker when two equally-good bases are found for revision, (a_order, a_distance) in a_ancestors.iteritems(): if b_ancestors.has_key(revision): a_intersection.append((a_distance, a_order, revision)) b_intersection.append((b_ancestors[revision][1], a_order, revision)) mutter("a intersection: %r" % a_intersection) mutter("b intersection: %r" % b_intersection) a_closest = __get_closest(a_intersection) if len(a_closest) == 0: return None b_closest = __get_closest(b_intersection) assert len(b_closest) != 0 mutter ("a_closest %r" % a_closest) mutter ("b_closest %r" % b_closest) if a_closest[0] in b_closest: return a_closest[0] elif b_closest[0] in a_closest: return b_closest[0] else: raise bzrlib.errors.AmbiguousBase((a_closest[0], b_closest[0])) return a_closest[0] class MultipleRevisionSources(object): """Proxy that looks in multiple branches for revisions.""" def __init__(self, *args): object.__init__(self) assert len(args) != 0 self._revision_sources = args def get_revision(self, revision_id): for source in self._revision_sources: try: return source.get_revision(revision_id) except bzrlib.errors.NoSuchRevision, e: pass raise e def get_intervening_revisions(ancestor_id, rev_id, rev_source, revision_history=None): """Find the longest line of descent from maybe_ancestor to revision. Revision history is followed where possible. If ancestor_id == rev_id, list will be empty. Otherwise, rev_id will be the last entry. ancestor_id will never appear. If ancestor_id is not an ancestor, NotAncestor will be thrown """ [rev_source.get_revision(r) for r in (ancestor_id, rev_id)] if ancestor_id == rev_id: return [] def historical_lines(line): """Return a tuple of historical/non_historical lines, for sorting. The non_historical count is negative, since non_historical lines are a bad thing. """ good_count = 0 bad_count = 0 for revision in line: if revision in revision_history: good_count += 1 else: bad_count -= 1 return good_count, bad_count active = [[rev_id]] successful_lines = [] while len(active) > 0: new_active = [] for line in active: parent_ids = [p.revision_id for p in rev_source.get_revision(line[-1]).parents] for parent in parent_ids: line_copy = line[:] if parent == ancestor_id: successful_lines.append(line_copy) else: line_copy.append(parent) new_active.append(line_copy) active = new_active if len(successful_lines) == 0: raise bzrlib.errors.NotAncestor(rev_id, ancestor_id) for line in successful_lines: line.reverse() if revision_history is not None: by_historical_lines = [] for line in successful_lines: count = historical_lines(line) by_historical_lines.append((count, line)) by_historical_lines.sort() if by_historical_lines[-1][0][0] > 0: return by_historical_lines[-1][1] assert len(successful_lines) successful_lines.sort(cmp, len) return successful_lines[-1]