Re: Caching merged diffs

[Kai Willadsen <kai willadsen gmail com>]

2009/7/20 Piotr Piastucki <leech miranda gmail com>:
> One thing I have just noticed about my patch - it is a bit more flexible
> when the highlighting code changes (remember
> http://bugzilla.gnome.org/show_bug.cgi?id=587410 ?) as caching does not rely
> on the sequence matching algorithm.

It's true that my method would need to be updated slightly for changes
to the highlighting code, but it wouldn't be difficult to do so. In
fact, a second cache for storing differences between word-level tokens
might be a huge benefit in some fairly common cases. (I'm thinking of
comparisons that consist of lots of common prefix changes, like log
files in which only dates or file paths differ.)

One downside to your method is that chunk position is part of the
cache. The most obvious issue with this is that any change that
inserts or deletes lines causes lots of rediffing. For example,
instead of typing a single character in your "meld filediff.py
meldapp.py" example, just hit enter.

I'm going to look at whether we can combine parts of your approach to
avoid rehighlighting at all with my simpler caching mechanism.

cheers,
Kai