[poppler] [PATCH] no big deal

[Rafael Rodríguez]

El Viernes, 1 de Septiembre de 2006 03:20, escribió:
> The only way to really know if your changes make any difference is to
> profile the code. When I tried my hands at improving poppler speed, I
> was rather surprised at which part were expensive
> (http://blog.kowalczyk.info/archives/2006/08/14/performance-optimization-st
>ory/).
Have those changes been backported to poppler?

> Even more importantly, profiler will tell you  which parts of the code
> take the biggest amount of time and hence are most worth optimizing.

Last course in University I had a full subject on profiling :) I can handle 
Oprofile and gprof. The first one is veery powerful!

> I haven't profiled on Unix but I've heard good things about valgrind
> (http://valgrind.org/).

Yeah, i've been using it along with kcachegrind to get a taste of poppler code 
(call trees).

> For measuring speed gains I use a small program that I wrote called
> pdftest. You can get it as part of my poppler copy in sumatra
> (http://blog.kowalczyk.info/software/sumatrapdf/develop.html), in
> directory poppler\test. It compiles under Unix but you'll have to
> write a makefile and add a file that implements  3 functions:
> extern void PreviewBitmap_Init(void);
> extern void PreviewBitmap(SplashBitmap *);
> extern void PreviewBitmap_Destroy(void);
> (can be dummies, only used if you want visual preview, you can see
> PdftestWinPreview.cc for example of implementation).
>
> Test program can measure loading time of the whole PDF and rendering
> of each page. I run it to verify that I've actually made some speedups
> (I usually run it 10 times on the same PDF and use an average time,
> after rejecting times that differ too much from average).

Thanks a lot, it was what i was looking for :)
-- 
Rafael Rodríguez

http://unrincon.blogspot.com
http://cornerofcode.blogspot.com