[Thunar-dev] Thumblerd and large files collections

[Grigory Tuboltsev]

On 11/19/2010 07:43 PM, Jannis Pohlmann wrote:

> 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.

I alsways use a list view to work with collections. So, opening a 
directory with pdf files makes over 100 of them visible. More than 
enough to make thumbler eat 90% of my CPU and i/o.

>> 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.

Thats what i am trying to explain: there SHOULD be a way to quickly 
configure it. Otherwise one cannot work with really large file archives. 
Is it SO difficuilt to make a simple hotkey to switch thumbnailing on 
and off ? Sorry i am no progammer so i can not judge if it's an easy 
task or not.

> 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.

It does become slow and\or unresponsive. Not sure if its has to do with 
CPU or disk i/o.

> 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.

That would be a greate feature.

> 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.

He-he :) You have probably never seen Really Large PDF Files. All pdf 
files i am working with are scanned books with hundreds of 
high-resolution TIFFs inside. First pages in such PDF files are 5-8 Mb 
TIFFs :)

30 000 of small jpeg files make Thunar (+thumblerd) just as slow as 100 
of large PDFs. I think that thumblerd gets so much requests because I 
always scroll in such folders. So, when i open the directory, thumblerd 
gets first 300 requests (list view!), than i start to scroll and it gets 
other 15 000 requestst and eats 90 % of my CPU.

>> 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.

Well i thought thunar sends thumbnailing requests to thumbnailerd. So it 
could send this requests just for selected files, not for all files in 
the directory (or just for selected files after pressing some hotkey).


> Again, creating thumbnails for all files is a standard feature in
> modern file managers.
Yes, eating 90 % of CPU and i/o badwidth seem to be a feature of modern 
file managers. I just thought Thunar is kinda lightweight file manager 
and shouldn't have this feature. No offence, just asking...


> 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.

Viewing 100+ files at once does not slow UI down if thumbnailing is 
switched off.



Anyway, thank you for your answers.


Grigory