Re: [Libreoffice] An Improvement for libreoffice to access a file in disk

Hi Shantong,

        First - sorry for the delay in replying; we've been busy finishing
merging the Oracle contributions to LibreOffice from OO.o.

On Sat, 2011-03-12 at 12:58 +0800, shantong kang wrote:
> hi,i modified the code of libreoffice to access the file in
> disk,mainly in sot module and the speed for libreoffice  to open a ppt
> file from disk is 25% faster.

        Wow - this is brilliant :-) 

>    I found that when libreoffice  reads a byte from the file,it will
> traverse the list  of sectors and it is slow. So i use an array to
> save the list.when reading a byte,we can use the array to obtain the
> address of this byte in disk directly.This change wil accelerate  the
> process of opening a ppt file from disk.

        Okay - sounds interesting; so each time we read a byte we re-scan that
list of sectors ?

        So - I'll try to test out the patch, and more importantly createa a
unit test & verify the speedup if not tomorrow, then next week - it
shouldn't miss the 3.4 feature freeze anyhow.

        Thanks so much ! what else are you working on ? also what profiling
tools are you using to locate performance hot-spots & how are you
verifying the speedup: is it wall-clock time or ?

        Thanks !

                Michael.

-- 
 michael.meeks@novell.com  <><, Pseudo Engineer, itinerant idiot