[GSOC] ODS Styles Import Performance Work Update

[Daniel Bankston]

On 08/17/2012 07:20 PM, Kohei Yoshida wrote:
> Interesting thing is, we used to have similar performance problem with 
> styles import with Excel files. And I did take a very similar approach 
> to what you just tried. The difference is that, I set the styles 
> directly to ScDocument using the same data structure that's used in 
> ScAttrArray to store the styles attributes, to avoid unnecessary 
> conversation of data, and also unnecessary broadcasting etc that it 
> would normally do when modifying its internal content. That resulted 
> in a pretty big performance improvement. You can take a look at 
> ScDocument::SetAttrEntries and its call chain all the way down to 
> ScAttrArray. So, the approach I would aim for is to change the XML 
> import code to use ScDocument::SetAttrEntries to set the styles 
> directly, then see if that would improve the performance. I'm pretty 
> sure that, as long as we keep using the UNO layer to set properties 
> there isn't much we can do to improve performance further. We need to 
> break that layer first. I wonder if the biggest problem now for a file
I'm not sure if it would apply as much to this particular file, but I 
could be wrong.  Even so, your words give me hope.

My ultimate goal was to remove the UNO and ScDocFunc layers, but I first 
wanted to try my concept without removing them in order to make sure it 
would work and to minimize the amount of code I was initially changing.  
I think I got lost in the forest during the process and forgot about the 
possibility that complete removal of the UNO/ScDocFunc layer here in 
addition to what I had already done would have a much more significant 
effect on performance (as you said, because of avoiding the data 
conversion and broadcasts.)  I feel kind of silly now but hopeful.  I'll 
take a look at the suggested code and reevaluate.

Thanks, Kohei!

--Daniel