Hello,
I am implementing some POCs for parallel preloading of named producer
methods and think I have a working prototype.
I wanted to know if you are interested in including this into Deltaspike
and if so, how I should contribute it.
It is separated into two parts, one is the context capturing in one
thread and the possibility to start these contexts for a new thread.
The other part is a phase listener that scans the component tree for
UEL-Expressions that evaluate to a named producer method which is
annotated with a special interceptor annotation(@PreloadingSafe). These
producers are then invoked in the before render response phase in
parallel. This currently works by creating a proxy from the returned
interface. The invocation handler behind it, just delegates to the
result of the future that was received by submitting the producer method
to an ExecutorService.
It would be nice if this could also work with non-interface types but
that would require some bytecode library which I didn't want to
introduce yet.
Here some example code:
public class SomeProducerBean {
@PreloadingSafe
@Named
@Produces
@RequestScoped
public List<String> getSupplierNames() { /* Some DB call */ }
}
<html>
...
<ui:repeat value="#{supplierNames}" var="supplName">
#{supplName}
<ui:repeat>
...
</html>
So the rendering until it reaches the ui:repeat runs in parallel to the
preloading of the supplier names. When the JSF-Component tries the
evaluate the expression it might need to block. Also note that other
expressions will still be evaluated in parallel even if one blocks so
this can be a huge boost for performance.
It's not fully tested yet. The easy case works but I haven't tested more
complex scenarios or possible threading issues yet.
What do you say?
--
Mit freundlichen Grüßen,
------------------------------------------------------------------------
*Christian Beikov*
