R. David Murray, 28.07.2010 03:43:
On Tue, 27 Jul 2010 08:27:35 +0200, Stefan Behnel wrote:
Gregory P. Smith, 27.07.2010 07:40:
A max cache size of 100 was too small. I just increased it to 500 in the py3k branch along with implementing a random replacement cache overflow policy. It now randomly drops 20% of the compiled regular expression cache instead of simply dropping the entire cache on overflow.
With the regex_v8 benchmark, the better cache replacement policy sped it up ~7% while raising the cache size on top of that (likely meaning the cache was never overflowing) sped it up ~25%.
Random replacement without dropping everything at least means apps thrashing the cache degrade much more gracefully.
The same algorithm should be helpful in ElementTree's ElementPath module.
We recently added the old re cache-clearing strategy to fnmatch, because previously its cache would grow indefinitely. It sounds like this should be applied there as well.
That's three...time to figure out how to share the code?
What about actually putting it visibly into the stdlib? Except for files, I didn't see much about caching there, which seems like a missing battery to me. Why not do it as with the collections module and add stuff as it comes in? Stefan