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authorTim Peters <tim.peters@gmail.com>2001-05-13 06:43:53 (GMT)
committerTim Peters <tim.peters@gmail.com>2001-05-13 06:43:53 (GMT)
commit342c65e19ac0cc47bf2b21026c76e63440b23748 (patch)
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Aggressive reordering of dict comparisons. In case of collision, it stands
to reason that me_key is much more likely to match the key we're looking for than to match dummy, and if the key is absent me_key is much more likely to be NULL than dummy: most dicts don't even have a dummy entry. Running instrumented dict code over the test suite and some apps confirmed that matching dummy was 200-300x less frequent than matching key in practice. So this reorders the tests to try the common case first. It can lose if a large dict with many collisions is mostly deleted, not resized, and then frequently searched, but that's hardly a case we should be favoring.
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