Carsten Ziegeler wrote:
Sylvain Wallez wrote:Why is it a hack ? Calling isSelectable() is only of real use if the probability for it to return false is important and if you can make some corrective actions in that case.
The performance problem is that among all implementations of Source that I know of (URLSource, FileSource, SlideSource, BlobSource, XMLDBSource, SitemapSource and CVSSource), only one actually needs to be disposed (SitemapSource).
So having a isSelectable()-select()-release() cycle to call a factory.release() that does nothing most of the time seems CPU waste to me.
Now I agree that theoretically releasing is the factory's job. So, in order to lower my performance fears, what about removing the isSelectable() call in SourceResolverImpl.release() ? It would remove an unnecessary search in the ServiceSelector HashMaps, considering also that the select() that follows this isSelectable() is surrounded by a try/catch.
Wow, entering twilight zone...believe it or not, I just thought of this yesterday evening when I tried to think about some general performance improvements. Actually, I wasn't sure about it, because if we are honest, it's a hack.
Twilight zone again ;-)And throwing/catching exceptions is also a little bit time consuming. But as a (better?) solution I would like to make a factory for the URLSource as well - so all sources are handled by a factory and the select() call will always return a factory - and this will avoid the isSelectable() call. What do you think about this?
I wanted to raise this issue just after we finished with that one, because it seemed to me unclean for URLSource to be managed directly by the SourceResolver and not through a factory.
Cool. But I'm still not that happy with these methods being on Source itself. What about TraversableSource or HierarchicalSource (I have this last one ready on my PC with collections) ?Ah, btw you're right that the Source object should return a Collection instead of an Iterator for the children - I will fix that, too, asap.
Sylvain
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