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b13a7c8e36
Previously when checking ancestors, we would walk all the way up the ancestry chain checking each parent for a matching class or module. I believe this was especially unfriendly to CPU cache since for each step we need to check two cache lines (the class and class ext). This check is used quite often in: * case statements * rescue statements * Calling protected methods * Class#is_a? * Module#=== * Module#<=> I believe it's most common to check a class against a parent class, to this commit aims to improve that (unfortunately does not help checking for an included Module). This is done by storing on each class the number and an array of all parent classes, in order (BasicObject is at index 0). Using this we can check whether a class is a subclass of another in constant time since we know the location to expect it in the hierarchy.
27 lines
676 B
YAML
27 lines
676 B
YAML
prelude: |
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class SimpleClass; end
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class MediumClass
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10.times { include Module.new }
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end
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class LargeClass
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100.times { include Module.new }
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end
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class HugeClass
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300.times { include Module.new }
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end
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SimpleObj = SimpleClass.new
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MediumObj = MediumClass.new
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LargeObj = LargeClass.new
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HugeObj = HugeClass.new
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benchmark:
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simple_class_eqq_simple_obj: |
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SimpleClass === SimpleObj
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medium_class_eqq_simple_obj: |
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MediumClass === SimpleObj
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simple_class_eqq_medium_obj: |
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SimpleClass === MediumObj
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simple_class_eqq_large_obj: |
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SimpleClass === LargeObj
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simple_class_eqq_huge_obj: |
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SimpleClass === HugeObj
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loop_count: 20000000
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