[webbeans-dev] Re: CreationalContext
On Jan 9, 2009, at 2:49 AM, Gavin King wrote:
Hrm, after further thought I'm not sure this is necessary.
* for objects with normal scope types, you can just inject proxies, no
need to recurse
* dependent objects are unshared, so they don't get added to
CreationalContext
So what cases, precisely, were you having problems with, Scott?
Even the most trivial case requires the capability:
@ApplicationScoped
class Foo {
@Current Bar _bar;
}
@ApplicationScoped
class Bar {
@Current Foo _bar;
}
Requiring proxies for all beans is a performance hit which is entirely
unnecessary with the proper SPI.
If the tradeoff is a performance hit on every method call (proxy) for
every bean, vs a slight added complexity in the _SPI_, i.e. an
interface that 98% of developers _never even see_, it should be
obvious that the SPI change is the right one.
I guess I can that it might be useful for pseudo-scopes other than
@Dependent, or possibly as a performance optimization...
It's not an "optimization", it's the basic overhead of the basic
method call.
-- Scott
On Fri, Jan 9, 2009 at 5:03 AM, Gavin King <gavin(a)hibernate.org>
wrote:
> Folks, I would like to go ahead and write up this change, unless
> anyone objects.
>
> It's a hole that needs fixing.
>
> On Fri, Jan 2, 2009 at 4:19 PM, Gavin King <gavin(a)hibernate.org>
> wrote:
>
>> The alternate solution is something like:
>>
>> interface CreationalContext {
>> <X> void add(Bean<X> bean, X instance); //registers an
>> "incomplete" instance
>> }
>>
>> interface Contextual<T> {
>> public abstract T create(CreationalContext ctx);
>> ...
>> }
>>
>> interface Context {
>> public <T> T get(Contextual<T> bean); //get any existing
>> instance
>> public <T> T get(Contextual<T> bean, CreationalContext ctx);
>> //get
>> or create an instance
>>
>> public Class<? extends Annotation> getScopeType();
>> boolean isActive();
>> }
>>
>> interface Manager {
>> Object getInstanceToInject(CreationalContext ctx,
>> InjectionPoint ij, Type type,
>> Annotation... bindings);
>> ...
>> }
>>
>> And getInstanceToInject() would be smart enough to return any object
>> that had already been registered with the CreationalContext.
>>
>> Note that this solution addresses the problem of circular
>> references,
>> and also fixes a hole in how the Manager knows about the
>> InjectionPoint.
>
>
> --
> Gavin King
> gavin.king(a)gmail.com
> http://in.relation.to/Bloggers/Gavin
> http://hibernate.org
> http://seamframework.org
>
--
Gavin King
gavin.king(a)gmail.com
http://in.relation.to/Bloggers/Gavin
http://hibernate.org
http://seamframework.org