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Viewing changes to bzrlib/tests/test_groupcompress.py

  • Committer: John Arbash Meinel
  • Date: 2010-08-05 16:27:35 UTC
  • mto: This revision was merged to the branch mainline in revision 5374.
  • Revision ID: john@arbash-meinel.com-20100805162735-172opvx34sr5gpbl
Find a case where we are wasting a bit of memory.

Specifically the 'build_details' tuple contains a lot of wasted references,
and we hold on to one of these for each record we are fetching.
And for something like 'bzr pack', that is all keys.

For just loading all text build details on my bzr+ repository, With:
locations = b.repository.texts._index.get_build_details(b.repository.texts.keys())
This drops the memory consumption from:
WorkingSize   77604KiB
 to
WorkingSize   64640KiB

Or around 10.6MB. I worked it out to a savings of about 80 bytes/record
on data that can have hundreds of thousands of records (in 32-bit).

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Lines of Context:
bzrlib/tests/test_groupcompress.py
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        # consumption
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        self.add_key_to_manager(('key4',), locations, block, manager)
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        self.assertTrue(manager.check_is_well_utilized())
 
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class Test_GCBuildDetails(tests.TestCase):
 
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    def test_acts_like_tuple(self):
 
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        # _GCBuildDetails inlines some of the data that used to be spread out
 
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        # across a bunch of tuples
 
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        bd = groupcompress._GCBuildDetails((('parent1',), ('parent2',)),
 
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            ('INDEX', 10, 20, 0, 5))
 
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        self.assertEqual(4, len(bd))
 
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        self.assertEqual(('INDEX', 10, 20, 0, 5), bd[0])
 
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        self.assertEqual(None, bd[1]) # Compression Parent is always None
 
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        self.assertEqual((('parent1',), ('parent2',)), bd[2])
 
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        self.assertEqual(('group', None), bd[3]) # Record details
 
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    def test__repr__(self):
 
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        bd = groupcompress._GCBuildDetails((('parent1',), ('parent2',)),
 
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            ('INDEX', 10, 20, 0, 5))
 
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        self.assertEqual("_GCBuildDetails(('INDEX', 10, 20, 0, 5),"
 
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                         " (('parent1',), ('parent2',)))",
 
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                         repr(bd))
 
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