[GNC-dev] Performance regression loading account

[john]

> On Mar 12, 2023, at 1:28 PM, Maarten Bosmans <mkbosmans at gmail.com> wrote:
> 
> Hi all,
> 
> When testing the 4.902 flatpak, I noticed that loading an account
> takes several (~4.5) seconds. This account has about 24k transactions
> and loads in less than half a second on the GnuCash 4.8 from my
> distribution. Is this a regression because of a code change, or
> perhaps simply the result of a debug build in the flatpak?
> 
> From the attached flamegraph you can see that a lot of time is spent
> in `g_utf8_collate` for the quickfill insert. That function does not
> appear below `gnc_quickfill_insert` for the 4.8 run. I did a quick
> search in the git history to see that may be some caller was changed
> to the `QUICKFILL_ALPHA` sort method, but could not easily find such a
> thing.
> 
> Another difference with 4.8 is stat `gnc_table_realize_gui` (which
> takes 0.85s) does not appear below
> `gnc_plugin_page_register_create_widget` and that function only takes
> 0.03s in total. This time seems to be spent in Gtk.
> 
> I don't think this is a release blocking bug, but GnuCash feels quite
> sluggish to me, so it would be nice to fix this papercut before 5.0.
> Any pointers on how to proceed?


My first guess is that it's from creating a cache of quickfill entries to populate a drop-down list of possible entries similar to the way the transfer account field has worked for a couple of years.

An obvious optimization is to get a collation key with g_utf8_collate_key for each string and use that for doing the actual sorting/ordered inserting. It's still a char-by-char comparison but it saves having to validate and normalize the strings on every compare.

Regards,
John Ralls