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  • Committer: John Arbash Meinel
  • Date: 2008-03-15 13:51:09 UTC
  • mfrom: (3280 +trunk)
  • mto: This revision was merged to the branch mainline in revision 3281.
  • Revision ID: john@arbash-meinel.com-20080315135109-7v9gimdidd1s7llr
[merge] bzr.dev 3280

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bzrlib/graph.py
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            return set(heads)
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class FrozenHeadsCache(object):
 
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    """Cache heads() calls, assuming the caller won't modify them."""
 
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    def __init__(self, graph):
 
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        self.graph = graph
 
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        self._heads = {}
 
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    def heads(self, keys):
 
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        """Return the heads of keys.
 
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        Similar to Graph.heads(). The main difference is that the return value
 
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        is a frozen set which cannot be mutated.
 
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        :see also: Graph.heads.
 
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        :param keys: The keys to calculate heads for.
 
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        :return: A frozenset containing the heads.
 
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        """
 
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        keys = frozenset(keys)
 
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        try:
 
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            return self._heads[keys]
 
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        except KeyError:
 
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            heads = frozenset(self.graph.heads(keys))
 
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            self._heads[keys] = heads
 
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            return heads
 
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    def cache(self, keys, heads):
 
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        """Store a known value."""
 
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        self._heads[frozenset(keys)] = frozenset(heads)
 
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class _BreadthFirstSearcher(object):
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    """Parallel search breadth-first the ancestry of revisions.
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