Re: [Python-Dev] New regex module for 3.2?

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. Stefan