Re: [GSWHackers] Future of GnusStep WebObject

[David Ayers]

Helge Hess wrote:
> On Mar 2, 2004, at 4:27 PM, NeXT wrote:
>
> > > It will be a significantly slower, but is going to provide all the 
> > > KVC features available in gstep-base.
> >
> >
> > Why should it be "significantly" slower? It could not be cached, or 
> > KVC itself is so slow?
>
>
> Well, KVC only works with objects, which has a significant speed hit if 
> you do a lot of KVC on base types, which is very common with WO. Of 
> course KVC itself is not inherently slow.
>
> For example a conditional used in a repetition on thousands of objects:
> Component.wod:
>   Condition: WOConditional {
>     condition = showImage;
>   }
> Component.m:
>   - (BOOL)showImage {
>     return YES;
>   }
> WOConditional.m:
> ...
>   if ([[self->condition valueInComponent:[context component]] boolValue])
>
> Since there is no -boolValueForKey:, the naive implementation of 
> WOKeyPathAssociation will lookup the method, turn the (char) result into 
> a NSNumber object, then in the dynamic element will in turn convert the 
> number into a char (/BOOL) for the actual check (notably this is also 
> hit by the fact that we can't detect BOOL here which allows for further 
> optimizations). This is about 2-10 times slower than directly accessing 
> the bool result, do this in loops and see ;-)
> One of the optimizations in WOKeyPathAssociation, but there are others.
>
> Some years of profiling already went into SOPE.

Interesting... I actually prefer the approach that gnustep took in 
solving the main issue within -base/NSNumber which returns cached 
versions common NSNumber instances.  This solves the root of this 
particular problem for a wider range of applications.  Yet optimization 
within GSWeb and GDL2 is needed.

> > PS)
> > I'm going to test more extensively (with some real load) SOPE and 
> > GSWeb, I'm searching for all default options and documentations on 
> > both of them. Does anybody know good source of information? (Yes, 
> > source is very good source of information, but you know :-)

Documentation is definitely a missing for both GSWeb and GDL2.  We are 
aware of this and I would argue it is one of the major issues that need 
to be addressed in some acceptable manor before we release any "user" 
packages of either project.  Until then, I don't have much choice but to 
point you to Apple's documentation on WO45.

http://developer.apple.com/documentation/LegacyTechnologies/WebObjects/WebObjects_4.5/webobjects.html

We're fully aware that this is serious issue.

Cheers,
David