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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.errors import NoSuchRevision
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class DummyRevision(object):
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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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self.revision_id = revid
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self.message = self.revision_id
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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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revisions = { start: branch.get_revision(start) }
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children = { revisions[start]: set() }
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distances = { start: 0 }
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colours = { start: 0 }
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# Sort the revisions; the fastest way to do this is to visit each node
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# as few times as possible (by keeping the todo list in a set) and record
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# the largest distance to it before queuing up the children if we
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# increased the distance. This produces the sort order we desire
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revision = revisions[revid]
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distance = distances[revid] + 1
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colour = colours[revid]
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for parent_id in revision.parent_ids:
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# Check whether there's any point re-processing this
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if parent_id in distances and distances[parent_id] >= distance:
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# Get the parent from the cache, or put it in the cache
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parent = revisions[parent_id]
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children[parent].add(revision)
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parent = revisions[parent_id] \
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= branch.get_revision(parent_id)
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except NoSuchRevision:
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parent = revisions[parent_id] = DummyRevision(parent_id)
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children[parent] = set([ revision ])
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# Penalise revisions a little at a fork if we think they're on
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# the same branch -- this makes the few few (at least) revisions
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# of a branch appear straight after the fork
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if same_branch(revision, parent):
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colours[parent_id] = colour
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if len(revision.parent_ids) > 1:
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distances[parent_id] = distance + 10
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distances[parent_id] = distance
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colours[parent_id] = last_colour = last_colour + 1
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distances[parent_id] = distance
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return ( sorted(distances, key=distances.get), revisions, colours,
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def graph(revids, revisions, colours):
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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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for h_idx, hang in enumerate(hanging):
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# We've matched a hanging revision, so need to output a node
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node = (h_idx, colours[revid])
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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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for parent_id in revisions[revid].parent_ids:
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n_idx = new_hanging.index(parent_id)
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n_idx = len(new_hanging)
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new_hanging.append(parent_id)
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lines.append((h_idx, n_idx, colours[parent_id]))
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# Revision keeps on hanging, adjust for any change in the
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# graph shape and try to collapse hangs to keep the graph
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n_idx = new_hanging.index(hang)
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n_idx = len(new_hanging)
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new_hanging.append(hang)
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lines.append((h_idx, n_idx, colours[hang]))
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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
added
removed
graph.py
