Bug 490197 is a wishlist bug requesting progress information for large files. The example SVG file, re-attached here, is 2.2 MB and takes 53 minutes of Python time to optimise.
I am a fan of trying to find the root cause of problems in most cases, not masking them. So I'm reporting this bug to first try to get Scour faster than it is right now, before adding progress information.
Initial notes: There are 18426 polygons in that file, and each of them has 3 points. This means that, if the polygons take up most of the optimisation time, each took 0.17 second (442 million CPU cycles) to process. That's a long time for a 3-point polygon!
-- versions --
Scour 0.25
Python 2.6.5
Psyco not installed
-- specs --
2.6 GHz AMD processor
DDR2 800 MHz
32-bit Linux
-- command-line and output --
$ time ./scour.py --create-groups --enable-id-stripping --enable-comment-stripping --shorten-ids --remove-metadata -i example.svg -o example.opt.svg
[...]
real 55m54.557s
user 53m19.344s
sys 0m19.781s
Bad analysis on my part. I've determined with a fair bit of debug information that it's really the --create-groups option giving slowdowns. I'll debug this further and attach a patch.