[poppler] Re: [PATCH] poppler-qt links

[Wilfried Huss]

Am Wednesday, 20. September 2006 23:14 schrieb Albert Astals Cid:
> A Dijous 07 Setembre 2006 23:10, Wilfried Huss va escriure:
> > Am Thursday, 7. September 2006 11:48 schrieb Brad Hards:
> > > On Thursday 07 September 2006 19:07, Wilfried Huss wrote:
> > > > Hi,
> > > >
> > > > attached are two patches (for the qt3 and qt4 bindings) which change
> > > > Page::links() in a way to make it work correctly even if the render
> > > > function was not called with doLinks=true previously. The current code
> > > > results in a crash in such a situation.
> > >
> > > I'm not sure I fully understand this code, but it looks like you are
> > > recalculating the links every time.
> > >
> > > Have you timed this?
> >
> > No I havn't. With the current code, if you want to access link information,
> > you also need to call renderToImage() first, which is definitely not a
> > cheap operation.
> 
> It is if you want to show the page ;-)
> 
> >
> > > Is it worth trying to cache it?
> >
> > One could try to remember if the last time renderToImage() had been called
> > with doLinks=true, and then use the cached version of the link data
> > structure. But I'm not sure if it is really worth it.
> 
> Could you please time the diferences in
> render + getlinks that are there already
> and
> render + getlinks using your code
> .
> 
> I agree that making the library more functional using your patch may be a good 
> thing, but there is no necessity in making it slower for the rest, no?

> BTW if you don't have time for it, tellme and i'll test it next week at 
> aKademy.

Probably the easiest thing, would be to just use a flag in Poppler::Page to
remember if the last call to render had doLinks=true. If yes use the cached
Links like we do now, and if not create a link structure like in the new code.

Greetings,
Wilfried.