[Thunar-dev] Thumblerd and large files collections

[Jannis Pohlmann]

Hey,

On Fri, 19 Nov 2010 19:26:25 +0300
Grigory Tuboltsev <gtubolcev at newmail.ru> wrote:

> Hi,
> 
> Thank you all devs for developing Thunar. It is small, lightweight
> and easy to use.
> 
> I've got some problems with Thunar trying to work with very large
> photo or PDF collections though.
> 
> I've got problems starting with 30 PDF files in a directory, not to 
> speak about Really Large Collections: 3000 pdf files, 2000 raw
> photos, 5000 (15Mbite large) jpegs and so on. Sometimes I even have
> to work with photo or PDF collections consisting of 30 000 + files.
> 
> I have "show thumbnails" setting switched on by default for everyday 
> use. Every time i try to browse a directory full of photo or PDFs or 
> video files Thunar (thumblerd) starts thumbnailing them. It takes
> about 60-90 of CPU time and probably the same amount of disk I/O
> capacity so So my PC gets unresponsive, slow etc.

One note about that: Thunar sends thumbnail requests only for those
files that are currently visible or were visible while you scrolled
up/down in a folder. So not for all files thumbnails are created.

> So, i see following problems:
> 
> 1) There is NO way to quickly switch thumbnailing off and on again.
> No button on the toolbar, no hotkey, NOTHING. I need to open settings 
> window every time, than click on checkbox, than OK. FOUR clicks just
> to switch thumbnailing off or on.

Creating thumbnails is a standard feature that should to be configured
very often. That's why there is no simple way to switch it on and off.

BTW, this is in no way different to previous versions of Thunar. There
Thunar would have taken up to 60-90% of the CPU time. The UI should not
become less responsive as most of the stuff is performed in ways that
don't block the UI.

> 2) Even if i make all this clicks (after navigating to a directory
> with a large file collection) thumblerd does not stop working. It
> just continues to use 90% of CPU time. So I need to kill thumblerd
> manually every time i make this navigation error.

This is an issue inside Thunar. At the moment, thumbnail requests
already sent to tumbler are not canceled when turning off thumbnails
or when switching folders. But no new requests should be sent (if
everything works correctly). This definitely can be improved but it's
not easy.

> 3) Thumblerd does not have limits (or GUI-way to change them) like
> "Does not start thumbnailing in folders with over 150 objects" or
> "does not make thumbnails for files over 3Mb large" and so on.

I agree, a file size limit option would be a good idea. But it does
not make sense for all file types. A large PNG is different from a
large PDF where only the first page has to be loaded for the thumbnail.

> 4) (more a FR than a problem) There is no way to tell thumblerd make 
> thumbnails just for selected files. This would be a killer feature :)

Tumbler has no idea what "selected files" are. That's entirely handled
in Thunar. I'm sorry to say this a feature request I'd reject.
Again, creating thumbnails for all files is a standard feature in
modern file managers.

> Working with 3000 or 5000 jpeg files is a usual everyday usecase for
> all us photographers or photo editors. Thousands of PDF files are
> often used by ebook-readers users and so on. So Thunar (or thumblerd)
> should be ready for such usecases.

We can speed things up a little bit by validating existing thumbnails
to avoid requesting thumbnails through tumbler. But the initial
generation will take some time, that's kinda normal. If I zoom out so
that I see 100+ files at once my UI will slow down no matter if
thumbnails are created in the background or not. 

  - Jannis
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