• Jason Madden's avatar
    Make all classes new-style. (#160) · e714f515
    Jason Madden authored
    * Make all classes new-style.
    
    On PyPy, it's documented (http://pypy.org/performance.html#id3) that
    old-style classes are slow, and classes that derive from both old and
    new are especially slow. I checked with the PyPy devs on IRC today and
    they confirmed that's still true with the latest PyPy2 releases.
    
    Unfortunately, FileStorage was one such mixed class, as was Connection.
    
    Moving to new-style classes seems to have a positive impact in the
    benchmarks. Here's zodbshootout on PyPy2 5.7.1 against a
    FileStorage (running in --threads and with 5 reps to be sure we get
    warmed up). First, current ZODB:
    
    "Transaction",                fs
    "Add 1000 Objects",            31,738
    "Update 1000 Objects",         42,444
    "Read 1000 Cold Objects",      51,894
    "Read 1000 Hot Objects",       53,187
    "Read 1000 Steamin' Objects", 835,877
    
    And with this PR:
    
    "Transaction",                fs
    "Add 1000 Objects",             35,651
    "Update 1000 Objects",          54,906
    "Read 1000 Cold Objects",      103,484
    "Read 1000 Hot Objects",        84,721
    "Read 1000 Steamin' Objects", 2,112,095
    
    The tests that hit the storage extensively are notably faster, as are
    steamin and hot, Connection having been a mixed class.
    
    I ran all tests multiple times. The data files were removed between
    runs. There's some variation, but the new-style classes always seem
    better.
    
    For comparison, here's CPython 2.7.13:
    
    "Transaction",                fs
    "Add 1000 Objects",            19,531
    "Update 1000 Objects",         16,201
    "Read 1000 Cold Objects",      22,111
    "Read 1000 Hot Objects",       21,851
    "Read 1000 Steamin' Objects", 880,582
    
    Locally I've run the tests under 2.7 and they all passed.
    e714f515
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CHANGES.rst 13.4 KB