> I've had a report from a user that Plex runs about half
> as fast in 2.5 as it did in 2.4. In particular, the
> NFA-to-DFA conversion phase, which does a lot of
> messing about with dicts representing mappings between
> sets of states.
>
> Does anyone in the Ministry for Making Python Blazingly
> fast happen to know of some change that might have
> pessimised things in this area?
Hello, I investigated. On my environment, consumed time is
E:\Plex-1.1.5>py24 plex_test2.py
0.710999965668
E:\Plex-1.1.5>py25 plex_test2.py
0.921999931335
And after I applied this patch to Plex/Machines, (make `Node' new style
class)
62c62
< class Node:
---
> class Node(object):
E:\Plex-1.1.5>py24 plex_test2.py
0.401000022888
E:\Plex-1.1.5>py25 plex_test2.py
0.350999832153
So, probably hash, comparation mechanizm of old/new style class has changed.
# improved for new style class, worse for old style class. Maybe optimized
for new style class?
Try this for minimum test.
import timeit
init = """
class Class:
pass
c1 = Class()
c2 = Class()
"""
t1 = timeit.Timer("""
c1 < c2
""", init)
t2 = timeit.Timer("""
hash(c1)
hash(c2)
""", init)
print t1.timeit(1000)
print t2.timeit(1000)
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