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# -*- coding: UTF-8 -*-
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"""Directed graph production.
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This module contains the code to produce an ordered directed graph of a
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bzr branch, such as we display in the tree view at the top of the bzrk
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__copyright__ = "Copyright © 2005 Canonical Ltd."
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__author__ = "Scott James Remnant <scott@ubuntu.com>"
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from bzrlib.revision import Revision
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from bzrlib.tsort import merge_sort
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class DummyRevision(Revision):
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"""Dummy bzr revision.
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Sometimes, especially in older bzr branches, a revision is referenced
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as the parent of another but not actually present in the branch's store.
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When this happens we use an instance of this class instead of the real
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Revision object (which we can't get).
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def __init__(self, revid):
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super(DummyRevision, self).__init__(revid)
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class RevisionProxy(object):
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"""A revision proxy object.
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This will demand load the revision it represents when the committer or
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message attributes are accessed in order to populate them. It is
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constructed with the revision id and parent_ids list and a repository
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object to request the revision from when needed.
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def __init__(self, revid, parent_ids, repository):
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self.revision_id = revid
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self.parent_ids = parent_ids
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self._repository = repository
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def _get_attribute_getter(attr):
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def get_attribute(self):
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if self._revision is None:
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return getattr(self._revision, attr)
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committer = property(_get_attribute_getter('committer'))
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message = property(_get_attribute_getter('message'))
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properties = property(_get_attribute_getter('properties'))
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timestamp = property(_get_attribute_getter('timestamp'))
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timezone = property(_get_attribute_getter('timezone'))
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"""Load the revision object."""
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self._revision = self._repository.get_revision(self.revision_id)
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class DistanceMethod(object):
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def __init__(self, branch, start):
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self.children_of_id = {start: set()}
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self.parent_ids_of = {}
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self.colours = { start: 0 }
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self.direct_parent_of = {}
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def fill_caches(self):
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graph = self.branch.repository.get_revision_graph_with_ghosts([self.start])
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for revid in graph.ghosts:
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self.cache_revision(DummyRevision(revid))
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for revid, parents in graph.get_ancestors().items():
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self.cache_revision(RevisionProxy(revid, parents, self.branch.repository))
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def cache_revision(self, revision):
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"Set the caches for a newly retrieved revision."""
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revid = revision.revision_id
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# Build a revision cache
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self.revisions[revid] = revision
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# Build a children dictionary
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for parent_id in revision.parent_ids:
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self.children_of_id.setdefault(parent_id, set()).add(revision)
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# Build a parents dictionnary, where redundant parents will be removed,
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# and that will be passed along tothe rest of program.
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if len(revision.parent_ids) != len(set(revision.parent_ids)):
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# fix the parent_ids list.
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parent_ids_set = set()
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for parent_id in revision.parent_ids:
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if parent_id in parent_ids_set:
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parent_ids.append(parent_id)
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parent_ids_set.add(parent_id)
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revision.parent_ids = parent_ids
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self.parent_ids_of[revision] = list(revision.parent_ids)
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self.graph[revid] = revision.parent_ids
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def make_children_map(self):
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revisions = self.revisions
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return dict((revisions[revid], c)
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for (revid, c) in self.children_of_id.iteritems())
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def sort_revisions(self, sorted_revids, maxnum):
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revisions = self.revisions
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parent_ids_of = self.parent_ids_of
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children_of_id = self.children_of_id
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# Try to compact sequences of revisions on the same branch.
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expected_id = sorted_revids[0]
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revid = sorted_revids.pop(0)
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if revid != expected_id:
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skipped_revids.append(revid)
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revision = revisions[revid]
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for child in children_of_id[revid]:
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# postpone if any child is missing
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if child.revision_id not in distances:
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if expected_id not in pending_ids:
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pending_ids.append(expected_id)
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expected_id = pending_ids.pop(0)
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skipped_revids.append(revid)
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sorted_revids[:0] = skipped_revids
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del skipped_revids[:]
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# all children are here, push!
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distances[revid] = len(distances)
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if maxnum is not None and len(distances) > maxnum:
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# bail out early if a limit was specified
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sorted_revids[:0] = skipped_revids
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for revid in sorted_revids:
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distances[revid] = len(distances)
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# all parents will need to be pushed as soon as possible
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for parent in parent_ids_of[revision]:
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if parent not in pending_ids:
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pending_ids.insert(0, parent)
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expected_id = pending_ids.pop(0)
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# if the next expected revid has already been skipped, requeue
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# the skipped ids, except those that would go right back to the
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if expected_id in skipped_revids:
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pos = skipped_revids.index(expected_id)
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sorted_revids[:0] = skipped_revids[pos:]
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del skipped_revids[pos:]
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self.distances = distances
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return sorted(distances, key=distances.get)
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def choose_colour(self, revid):
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revision = self.revisions[revid]
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children_of_id = self.children_of_id
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parent_ids_of = self.parent_ids_of
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colours = self.colours
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the_children = children_of_id[revid]
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if len(the_children) == 1:
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[child] = the_children
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if len(parent_ids_of[child]) == 1:
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# one-one relationship between parent and child, same
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colours[revid] = colours[child.revision_id]
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self.choose_colour_one_child(revision, child)
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self.choose_colour_many_children(revision, the_children)
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def choose_colour_one_child(self, revision, child):
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revid = revision.revision_id
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direct_parent_of = self.direct_parent_of
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revisions = self.revisions
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# one child with multiple parents, the first parent with
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# the same committer gets the colour
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direct_parent = direct_parent_of.get(child)
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if direct_parent is None:
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# if it has not been found yet, find it now and remember
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for parent_id in self.parent_ids_of[child]:
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parent_revision = revisions[parent_id]
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if parent_revision.committer == child.committer:
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# found the first parent with the same committer
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direct_parent = parent_revision
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direct_parent_of[child] = direct_parent
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if direct_parent == revision:
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self.colours[revid] = self.colours[child.revision_id]
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self.colours[revid] = self.last_colour = self.last_colour + 1
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def choose_colour_many_children(self, revision, the_children):
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"""Colour revision revision."""
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revid = revision.revision_id
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direct_parent_of = self.direct_parent_of
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# multiple children, get the colour of the last displayed child
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# with the same committer which does not already have its colour
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for child in the_children:
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if child.committer != revision.committer:
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direct_parent = direct_parent_of.get(child)
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if direct_parent == revision:
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self.colours[revid] = self.colours[child.revision_id]
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# FIXME: Colouring based on whats been displayed MUST be done with
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# knowledge of the revisions being output.
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# until the refactoring to fold graph() into this more compactly is
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# done, I've disabled this reuse. RBC 20060403
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# if direct_parent is None:
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# available[child] = distances[child.revision_id]
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# .. it will be something like available[child] = \
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# revs[child.revision_id][0] - which is the sequence number
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sorted_children = sorted(available, key=available.get)
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child = sorted_children[-1]
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direct_parent_of[child] = revision
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self.colours[revid] = self.colours[child.revision_id]
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# no candidate children is available, pick the next
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self.colours[revid] = self.last_colour = self.last_colour + 1
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def distances(branch, start):
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"""Sort the revisions.
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Traverses the branch revision tree starting at start and produces an
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ordered list of revisions such that a revision always comes after
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any revision it is the parent of.
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Returns a tuple of (revids, revisions, colours, children)
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distance = DistanceMethod(branch, start)
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distance.fill_caches()
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distance.merge_sorted = merge_sort(distance.graph, distance.start)
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children = distance.make_children_map()
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for seq, revid, merge_depth, end_of_merge in distance.merge_sorted:
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distance.choose_colour(revid)
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revisions = distance.revisions
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colours = distance.colours
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parent_ids_of = distance.parent_ids_of
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return (revisions, colours, children, parent_ids_of, distance.merge_sorted)
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def graph(revisions, colours, merge_sorted):
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"""Produce a directed graph of a bzr branch.
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For each revision it then yields a tuple of (revision, node, lines).
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If the revision is only referenced in the branch and not present in the
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store, revision will be a DummyRevision object, otherwise it is the bzr
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Revision object with the meta-data for the revision.
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Node is a tuple of (column, colour) with column being a zero-indexed
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column number of the graph that this revision represents and colour
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being a zero-indexed colour (which doesn't specify any actual colour
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in particular) to draw the node in.
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Lines is a list of tuples which represent lines you should draw away
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from the revision, if you also need to draw lines into the revision
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you should use the lines list from the previous iteration. Each
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typle in the list is in the form (start, end, colour) with start and
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end being zero-indexed column numbers and colour as in node.
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It's up to you how to actually draw the nodes and lines (straight,
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curved, kinked, etc.) and to pick the actual colours for each index.
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if not len(merge_sorted):
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# split merge_sorted into a map:
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# FIXME: get a hint on this from the merge_sorted data rather than
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# calculating it ourselves
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# mapping from rev_id to the sequence number of the next lowest rev
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# mapping from rev_id to next-in-branch-revid - may be None for end
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next_branch_revid = {}
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# the stack we are in in the sorted data for determining which
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# next_lower_rev to set. It is a stack which has one list at each
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# depth - the ids at that depth that need the same id allocated.
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for seq, revid, indent, end_merge in merge_sorted:
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revs[revid] = (seq, indent, end_merge)
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if indent == len(current_stack):
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# new merge group starts
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current_stack.append([revid])
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elif indent == len(current_stack) - 1:
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# part of the current merge group
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current_stack[-1].append(revid)
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# end of a merge group
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while current_stack[-1]:
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stack_rev_id = current_stack[-1].pop()
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# record the next lower rev for this rev:
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next_lower_rev[stack_rev_id] = seq
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# if this followed a non-end-merge rev in this group note that
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if len(current_stack[-1]):
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if not revs[current_stack[-1][-1]][2]:
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next_branch_revid[current_stack[-1][-1]] = stack_rev_id
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# append to the now-current merge group
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current_stack[-1].append(revid)
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# assign a value to all the depth 0 revisions
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while current_stack[-1]:
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stack_rev_id = current_stack[-1].pop()
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# record the next lower rev for this rev:
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next_lower_rev[stack_rev_id] = len(merge_sorted)
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# if this followed a non-end-merge rev in this group note that
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if len(current_stack[-1]):
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if not revs[current_stack[-1][-1]][2]:
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next_branch_revid[current_stack[-1][-1]] = stack_rev_id
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# a list of the current revisions we are drawing lines TO indicating
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# the sequence of their lines on the screen.
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# i.e. [A, B, C] means that the line to A, to B, and to C are in
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# (respectively), 0, 1, 2 on the screen.
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hanging = [merge_sorted[0][1]]
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for seq, revid, indent, end_merge in merge_sorted:
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# a list of the lines to draw: their position in the
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# previous row, their position in this row, and the colour
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# (which is the colour they are routing to).
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for h_idx, hang in enumerate(hanging):
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# one of these will be the current lines node:
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# we are drawing a line. h_idx
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# we have found the current lines node
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node = (h_idx, colours[revid])
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# note that we might have done the main parent
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drawn_parents = set()
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def draw_line(from_idx, to_idx, revision_id):
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n_idx = new_hanging.index(revision_id)
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# force this to be vertical at the place this rev was
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new_hanging.insert(to_idx, revision_id)
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lines.append((from_idx, n_idx, colours[revision_id]))
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# we want to draw a line to the next commit on 'this' branch
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# drop this line first.
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parent_id = next_branch_revid[revid]
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draw_line(h_idx, h_idx, parent_id)
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# we have drawn this parent
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drawn_parents.add(parent_id)
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# this is the last revision in a 'merge', show where it came from
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if len(revisions[revid].parent_ids) > 1:
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# parents means this commit was a merge, and being
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# the end point of a merge group means that all
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# the parent revisions were merged into branches
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# to the left of this before this was committed
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# - so we want to show this as a new branch from
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# to do this, we show the parent with the lowest
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# sequence number, which is the one that this
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# branch 'spawned from', and no others.
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# If this sounds like a problem, remember that:
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# if the parent was not already in our mainline
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# it would show up as a merge into this making
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# this not the end of a merge-line.
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lowest = len(merge_sorted)
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for parent_id in revisions[revid].parent_ids:
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if revs[parent_id][0] < lowest:
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lowest = revs[parent_id][0]
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assert lowest != len(merge_sorted)
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draw_line(h_idx, len(new_hanging), merge_sorted[lowest][1])
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drawn_parents.add(merge_sorted[lowest][1])
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elif len(revisions[revid].parent_ids) == 1:
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# only one parent, must show this link to be useful.
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parent_id = revisions[revid].parent_ids[0]
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draw_line(h_idx, len(new_hanging), parent_id)
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drawn_parents.add(parent_id)
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# what do we want to draw lines to from here:
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# each parent IF its relevant.
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# Now we need to hang its parents, we put them at the point
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# the old column was so anything to the right of this has
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# to move outwards to make room. We also try and collapse
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# hangs to keep the graph small.
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# RBC: we do not draw lines to parents that were already merged
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# unless its the last revision in a merge group.
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for parent_id in revisions[revid].parent_ids:
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if parent_id in drawn_parents:
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parent_seq = revs[parent_id][0]
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parent_depth = revs[parent_id][1]
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if parent_depth == indent + 1:
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# The parent was a merge into this branch determine if
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# it was already merged into the mainline via a
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# different merge: if all revisions between us and
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# parent_seq have a indent greater than there are no
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# revisions with a lower indent than us.
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# We do not use 'parent_depth < indent' because that
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# would allow un-uniqueified merges to show up, and
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# merge_sorted should take care of that for us (but
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# does not trim the values)
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if parent_seq < next_lower_rev[revid]:
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draw_line(h_idx, len(new_hanging), parent_id)
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elif parent_depth == indent and parent_seq == seq + 1:
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# part of this branch
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draw_line(h_idx, len(new_hanging), parent_id)
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# draw a line from the previous position of this line to the
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# h_idx is the old position.
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# new_indent is the new position.
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draw_line(h_idx, len(new_hanging), hang)
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# we've calculated the row, assign new_hanging to hanging to setup for
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hanging = new_hanging
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yield (revisions[revid], node, lines)
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def same_branch(a, b):
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"""Return whether we think revisions a and b are on the same branch."""
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if len(a.parent_ids) == 1:
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# Defacto same branch if only parent
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elif a.committer == b.committer:
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# Same committer so may as well be