Limiting the number of books in a recently added shelf

[titorico56]

Hi
I was expecting some troubles this afternoon by creating a recently added grouped shelf who add inside it all my library (+5000) and freeze KoReader for a long time ... Is there a way to limit the number of books inside this kind of shelf ?
I get out read ones but that's not enough !
Thanks

[AndyHazz]

What group type did you use? It shouldn't be freezing even with 5k books, if you can give any more details there might be a bottleneck on that specific group/sort/view mode.

[AndyHazz]

That could be useful if possible, thanks

[titorico56]

crash.log
Here it is

[AndyHazz]

Thanks for the log. I couldn't get it to freeze here: the same shelf (Latest added, Added then unread first, Covers, Not opened + Reading) over 6,000 books opens in about 2 seconds on my test setup. The log shows KOReader going to sleep at 15:21 rather than hanging, so it can't tell me how long the freeze was.

A few things that would help me match your setup:

1. Your home folder, and whether you changed Bookshelf settings > Advanced > Performance tweaks > "Latest" walk depth (it sets how many folders deep Bookshelf looks for books on every shelf, not only Latest added).
2. What KOReader shows at Settings (the gear icon in the file browser's top menu) > Document > Book metadata location: "book folder" or a folder path.
3. Roughly how long it froze for, and whether it came back by itself.

I've also found the shelf does more work than it needs to with a filter on, so the next version speeds that up either way.

[titorico56]

So

1. my home folder is at the first level of my reader's HD and I didn't change the "Latest" walk depth, still defaut at 5
2. book folder
3. I had a first similar problem in the afternoon, maybe at 15:21, after renaming a shelf with a copy/paste of an Adobe Pi Std check (✔︎) who already works fine for my read collections : KOReader was frozen like, very very slow or inactive even after restarting the reader. After 20 mn I changed the check name of the shelf in settings.lua by standard letters, because I was thinking that this Adobe Pi Std check could be the problem. KOReader came back well after restarting, Bookshelf too, and the same frozen like issue came back when I create this Latest added shelf. I wait about 40 mn, trying to restart the reader several times, but KOReader only comes back when I changed its starting prefs from "bookshelf" to "last" in its settings.lua, with a manual reinstallation of bookshelf.
   Thanks

[AndyHazz]

Thanks, that helped a lot. With the home folder at the top of the storage, Bookshelf's book scan also goes through KOReader's own folder (/mnt/ext1/applications/koreader on a PocketBook), which is where KOReader keeps its settings. Every time the settings were saved, which Bookshelf does as you turn pages or switch shelves, it looked as if the library had changed, so Bookshelf scanned the whole device again. With a library your size that can take minutes, and it starts over at the next save, which matches the freezes you saw.

The next version leaves KOReader's folder out of the scan and does much less work per scan. Until then, setting your home folder to /mnt/ext1/Books should avoid it.

I couldn't get the ✔︎ in a shelf name to slow anything down here, so I think that part was a coincidence, but do let me know if it comes back.