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Viewing changes to bzrlib/revision.py

  • Committer: Aaron Bentley
  • Date: 2005-08-26 12:38:57 UTC
  • mfrom: (974.1.45)
  • mto: (1185.3.4)
  • mto: This revision was merged to the branch mainline in revision 1178.
  • Revision ID: abentley@panoramicfeedback.com-20050826123857-06b8856e0fa2d374
Fixed ancestor-picking when -r is specified

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bzrlib/revision.py
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    behaves like Branch's.
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    """
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    for ancestor_id, distance in iter_ancestors(revision_id, revision_source):
 
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        if ancestor_id == candidate_id:
 
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            return True
 
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    return False
 
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def iter_ancestors(revision_id, revision_source, only_present=False):
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    ancestors = (revision_id,)
 
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    distance = 0
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    while len(ancestors) > 0:
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        new_ancestors = []
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        for ancestor in ancestors:
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            if ancestor == candidate_id:
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                return True
 
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            if not only_present:
 
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                yield ancestor, distance
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            try:
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                revision = revision_source.get_revision(ancestor)
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            except bzrlib.errors.NoSuchRevision, e:
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                    raise 
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                else:
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                    continue
 
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            if only_present:
 
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                yield ancestor, distance
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            new_ancestors.extend([p.revision_id for p in revision.parents])
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        ancestors = new_ancestors
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        distance += 1
 
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def find_present_ancestors(revision_id, revision_source):
 
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    found_ancestors = {}
 
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    count = 0
 
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    anc_iter = enumerate(iter_ancestors(revision_id, revision_source,
 
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                         only_present=True))
 
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    for anc_order, (anc_id, anc_distance) in anc_iter:
 
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        if not found_ancestors.has_key(anc_id):
 
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            found_ancestors[anc_id] = (anc_order, anc_distance)
 
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    return found_ancestors
 
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class AmbiguousBase(bzrlib.errors.BzrError):
 
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    def __init__(self, bases):
 
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        msg = "The correct base is unclear, becase %s are all equally close" %\
 
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            ", ".join(bases)
 
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        bzrlib.errors.BzrError.__init__(self, msg)
 
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        self.bases = bases
 
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def common_ancestor(revision_a, revision_b, revision_source):
 
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    """Find the ancestor common to both revisions that is closest to both.
 
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    """
 
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    from bzrlib.trace import mutter
 
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    a_ancestors = find_present_ancestors(revision_a, revision_source)
 
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    b_ancestors = find_present_ancestors(revision_b, revision_source)
 
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    a_intersection = []
 
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    b_intersection = []
 
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    # a_order is used as a tie-breaker when two equally-good bases are found
 
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    for revision, (a_order, a_distance) in a_ancestors.iteritems():
 
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        if b_ancestors.has_key(revision):
 
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            a_intersection.append((a_distance, a_order, revision))
 
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            b_intersection.append((b_ancestors[revision][1], a_order, revision))
 
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    mutter("a intersection: %r" % a_intersection)
 
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    mutter("b intersection: %r" % b_intersection)
 
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    def get_closest(intersection):
 
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        intersection.sort()
 
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        matches = [] 
 
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        for entry in intersection:
 
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            if entry[0] == intersection[0][0]:
 
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                matches.append(entry[2])
 
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        return matches
 
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    a_closest = get_closest(a_intersection)
 
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    if len(a_closest) == 0:
 
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        return None
 
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    b_closest = get_closest(b_intersection)
 
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    assert len(b_closest) != 0
 
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    mutter ("a_closest %r" % a_closest)
 
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    mutter ("b_closest %r" % b_closest)
 
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    if a_closest[0] in b_closest:
 
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        return a_closest[0]
 
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    elif b_closest[0] in a_closest:
 
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        return b_closest[0]
 
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    else:
 
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        raise AmbiguousBase((a_closest[0], b_closest[0]))
 
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    return a_closest[0]
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class MultipleRevisionSources(object):
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    def __init__(self, *args):
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            except bzrlib.errors.NoSuchRevision, e:
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                pass
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        raise e
 
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def get_intervening_revisions(ancestor_id, rev_id, rev_source, 
 
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                              revision_history=None):
 
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    """Find the longest line of descent from maybe_ancestor to revision.
 
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    Revision history is followed where possible.
 
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    If ancestor_id == rev_id, list will be empty.
 
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    Otherwise, rev_id will be the last entry.  ancestor_id will never appear.
 
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    If ancestor_id is not an ancestor, NotAncestor will be thrown
 
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    """
 
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    [rev_source.get_revision(r) for r in (ancestor_id, rev_id)]
 
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    if ancestor_id == rev_id:
 
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        return []
 
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    def historical_lines(line):
 
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        """Return a tuple of historical/non_historical lines, for sorting.
 
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        The non_historical count is negative, since non_historical lines are
 
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        a bad thing.
 
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        """
 
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        good_count = 0
 
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        bad_count = 0
 
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        for revision in line:
 
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            if revision in revision_history:
 
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                good_count += 1
 
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            else:
 
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                bad_count -= 1
 
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        return good_count, bad_count
 
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    active = [[rev_id]]
 
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    successful_lines = []
 
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    while len(active) > 0:
 
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        new_active = []
 
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        for line in active:
 
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            parent_ids = [p.revision_id for p in 
 
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                          rev_source.get_revision(line[-1]).parents]
 
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            for parent in parent_ids:
 
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                line_copy = line[:]
 
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                if parent == ancestor_id:
 
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                    successful_lines.append(line_copy)
 
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                else:
 
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                    line_copy.append(parent)
 
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                    new_active.append(line_copy)
 
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        active = new_active
 
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    if len(successful_lines) == 0:
 
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        raise bzrlib.errors.NotAncestor(rev_id, ancestor_id)
 
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    for line in successful_lines:
 
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        line.reverse()
 
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    if revision_history is not None:
 
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        by_historical_lines = []
 
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        for line in successful_lines:
 
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            count = historical_lines(line)
 
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            by_historical_lines.append((count, line))
 
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        by_historical_lines.sort()
 
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        if by_historical_lines[-1][0][0] > 0:
 
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            return by_historical_lines[-1][1]
 
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    assert len(successful_lines)
 
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    successful_lines.sort(cmp, len)
 
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    return successful_lines[-1]