qpdfview team mailing list archive

[Adam Reichold <adam.reichold@xxxxxxxxxxx>]

Hello again,

and trunk revision 1993 should do the lazy loading. I am not sure if I
like the links popping up after the page is rendered, but overall
responsiveness is improved. What do you think?

Best regards, Adam.

Am 20.03.2016 um 13:43 schrieb Adam Reichold:
> Hello again,
> 
> could you give trunk revision 1992 a try? It moves loading of
> interactive elements out of the main event loop so that one can begin to
> work with the document even though it will take quite some time to check
> every page for annotations and form fields.
> 
> I am not completely happy with the result yet because...
> * ...it takes quite some time just to load all pages just enqueuing
> those tasks. Have to find out where most of the time is spent.
> * ...it will now take even longer to load all interactive elements which
> will for example block closing the document since these tasks are not
> cancellable. But at least it does not impede reading the document.
> 
> There a probably various way to improve upon this:
> * Use a single task over all pages instead of a task per page which
> could remove some load from the task queuing mechanism. But it also
> implies a more complicated collaboration between the document view and
> the page items.
> * Really load interactive elements lazily, i.e. only when the page in
> question is shown at least once. This should speed opening the document
> and also reduce memory consumption. But I have to see whether this makes
> it problematic if the elements pop up during reading. Maybe it will work
> well combined with prefetching.
> 
> I am grateful for any feedback on these changes and I think I will look
> into lazy loading next...
> 
> Best regards, Adam.
> 
> Am 20.03.2016 um 12:43 schrieb Adam Reichold:
>> Hello Arnaud,
>>
>> trying the document, the problem seems to be that while we do load the
>> interactive elements (links, annotations, form fields) asynchronously,
>> we do so using the main event loop. With the more than one thousand
>> pages of that document, this keeps the event loop rather busy which
>> makes the program unresponsive during that time. (Loading all pages at
>> the beginning still does take some time, but not that much more than the
>> two seconds it seems.)
>>
>> Probably the next best solution would be to load the interactive
>> elements on separate threads, e.g. using QtConcurrent, and only insert
>> them using the main event loop. I'll have a look of how that works out...
>>
>> Best regards, Adam.
>>
>> Am 20.03.2016 um 10:00 schrieb Arnaud Schmittbuhl:
>>> Hi,
>>>
>>> Is there any possibility to accelerate huge file opening?
>>>
>>> More precisely, I take a long time (43 seconds) to open the tikz
>>> manual (a latex user will know what I am talking about
>>> https://www.ctan.org/pkg/pgf, 11.2 Mo pdf) with my computer whereas it
>>> is almost immediate (2 s) with evince.
>>>
>>> Thanks in advance,
>>>
>>
>>
>>
> 
> 
>

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