Subject: Re: patch -- cache last searched frag
From: Paul Rohr (paul@abisource.com)
Date: Fri Jul 06 2001 - 18:18:11 CDT
At 02:49 PM 7/6/01 +0200, Joaquín Cuenca Abela wrote:
>I've been taking a look at our pf_Fragments, and after some UT_DEBUGMSG
>I've seen that the searches for pf_Frag's are very (*very*) local. So
>I've added a little cache (of only 1 element) to this class.
Yay! When Jeff and I originally designed the piece table, this is the exact
optimization we thought would be most promising, but we decided to wait
until we had enough real-world profile data to prove it was worth it.
For example, until you have profile data on the calling patterns of a
fully-functional word processor, it's very hard to compare the following
potential optimization strategies:
- no caches,
- a last lookup cache (Joaquin),
- a binary search (Martin),
- both of the above (like we have now), or even
- another variant which seeds the binary search using Joaquin's cache.
At the time (circa 0.1.1) we were still working to get on-screen editing
working *at all* inside paragraphs, and getting across block boundaries into
paragraph two or three was still a future TODO.
Boy we've come a long way since then, huh? ;-)
Paul
PS: If anyone wants to have even more fun with their profiler, it might be
interesting to experiment with various caching strategies and see how they
compare.
This archive was generated by hypermail 2b25 : Fri Jul 06 2001 - 18:12:32 CDT