/brz/remove-bazaar

To get this branch, use:
bzr branch http://gegoxaren.bato24.eu/bzr/brz/remove-bazaar

« back to all changes in this revision

Viewing changes to bzrlib/serializer.py

  • Committer: John Arbash Meinel
  • Date: 2009-10-12 15:55:26 UTC
  • mto: (4679.5.3 2.1-static-tuple-no-use)
  • mto: This revision was merged to the branch mainline in revision 4735.
  • Revision ID: john@arbash-meinel.com-20091012155526-b46tuz5cibebbnct
Change the _lookup function to use Quadratic Probing.

The main strength is that we get a bit of locality (collision resolution
looks quickly close to the location.)
The main weakness is that we don't use the upper bits of the hash to
induce divergence. So while we nicely handle collisions in neighboring
buckets (Quadratic means their resolution chains will diverge), if
two objects hash to the same bucket, their resolution chains are identical.

Show diffs side-by-side

added added

removed removed

Lines of Context:
bzrlib/serializer.py
1
 
# Copyright (C) 2009, 2010 Canonical Ltd
 
1
# Copyright (C) 2005, 2006, 2009 Canonical Ltd
2
2
#
3
3
# This program is free software; you can redistribute it and/or modify
4
4
# it under the terms of the GNU General Public License as published by
50
50
        raise NotImplementedError(self.write_inventory_to_string)
51
51
 
52
52
    def read_inventory_from_string(self, string, revision_id=None,
53
 
                                   entry_cache=None, return_from_cache=False):
 
53
                                   entry_cache=None):
54
54
        """Read string into an inventory object.
55
55
 
56
56
        :param string: The serialized inventory to read.
64
64
        :param entry_cache: An optional cache of InventoryEntry objects. If
65
65
            supplied we will look up entries via (file_id, revision_id) which
66
66
            should map to a valid InventoryEntry (File/Directory/etc) object.
67
 
        :param return_from_cache: Return entries directly from the cache,
68
 
            rather than copying them first. This is only safe if the caller
69
 
            promises not to mutate the returned inventory entries, but it can
70
 
            make some operations significantly faster.
71
67
        """
72
68
        raise NotImplementedError(self.read_inventory_from_string)
73
69