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from bzrlib import graph
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from bzrlib.revision import NULL_REVISION
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class GraphWalker(object):
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"""Provide incremental access to revision graphs"""
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def __init__(self, graph):
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def distance_from_origin(self, revisions):
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ancestors = self._graph.get_ancestors()
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descendants = self._graph.get_descendants()
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descendants[NULL_REVISION] = {}
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ancestors[NULL_REVISION] = []
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for root in self._graph.roots:
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descendants[NULL_REVISION][root] = 1
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ancestors[root].append(NULL_REVISION)
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for ghost in self._graph.ghosts:
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# ghosts act as roots for the purpose of finding
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# the longest paths from the root: any ghost *might*
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# be directly attached to the root, so we treat them
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# ghost now descends from NULL
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descendants[NULL_REVISION][ghost] = 1
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# that is it has an ancestor of NULL
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ancestors[ghost] = [NULL_REVISION]
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distances = graph.node_distances(descendants, ancestors,
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return [distances.get(r) for r in revisions]
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bzrlib/graph_walker.py
