Re: [Springframework-developer] Extending Spring AOP

[Rod J. <ro...@in...>]

1. Performance (marketing more than reality, but marketing can't be ignored)
2. Problems with the CGLIB implementation. Another approach may well deliver better results.
3. Potential to add additional features, if the approach works out well.

It should be largely transparent to the developer view. I introduced the AopProxyFactory interface 
for that reason.

Dmitriy Kopylenko wrote:
> Rob/Rod,
> 
> can you please summarize the reasons to create another proxy 
> implementation strategy?
> 
> Thanks,
> Dmitriy.
> 
> Rob Harrop wrote:
> 
>> I agree, I'll put together a quick prototype either today or next week 
>> to see how a specificically created proxy will perform.
>>
>> Rob
>>
>> Rod Johnson wrote:
>>
>>> Rob
>>>
>>> I would favour the Java code-based approach, using Velocity. I think 
>>> that should deliver extremely good performance, and would rather we 
>>> don't commit to maintaining a byte code approach.
>>>
>>> I don't believe there is any problem using code generation with our 
>>> API. Indeed, I always meant to implement it, but performance 
>>> optimization of the AOP framework has never been of any significance 
>>> in practice. Only for marketing, as has been apparent recently :-)
>>>
>>> A Java based approach should definitely allow significant 
>>> optimization, and would hopefully be simpler than the CGLIB approach 
>>> and more maintainable. So there would be a real advantage, besides 
>>> performance. There should be a particular optimization for methods 
>>> with only before or after advice, skipping the present use of an 
>>> interceptor to wrap them. The
>>>
>>> I would recommend hand-authoring a Java class, and benchmarking, to 
>>> see exactly what the gains are, before putting a lot of effort into 
>>> the approach. (But I'm sure they'll be large.) But I think this is 
>>> definitely good stuff!
>>>
>>> Rgds
>>> Rod
>>>
>>> Rob Harrop wrote:
>>>
>>>> All,
>>>>
>>>> I am planning to add to an additional proxy implementation to Spring 
>>>> to solve some of the problems we are experiencing with other 
>>>> approaches and to allow for additional optimizations and advice 
>>>> types to be added in the most efficient way.
>>>>
>>>> Currently, I'm looking at two separate approaches - Java-based using 
>>>> Janino and Bytecode-based using SERP. The Java-based approach should 
>>>> be quite simple to create and could be coupled with Velocity to 
>>>> externalize much of the boilerplate code needed for the creation of 
>>>> proxy classes. Alternatively we could add a simple abstraction layer 
>>>> on top of Janino, a la .NET CodeDOM (good idea James). The bytecode 
>>>> approach is much more complex and will be harder to debug but it 
>>>> would probably allow for absolute raw performance.
>>>>
>>>> I am comfortable with either approach although I think that Janino 
>>>> would be ideal for our purposes.
>>>>
>>>> Your thoughts?
>>>>
>>>> Rob
>>>>
>>>>
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>>>
>>
>>
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> 
> 
> 
> 
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-- 

____________________________________________________
Rod Johnson
CEO, Interface21 - Spring Services from the Source
http://www.springframework.com

Founder, Spring Framework:
http://www.springframework.org

Author, "Expert One-on-One J2EE Development Without EJB"
(May 2004, with Juergen Hoeller).
http://www.amazon.com/exec/obidos/ASIN/0764558315/

Author, "Expert One-on-One J2EE Design and Development"
(October 2002).
http://www.amazon.com/exec/obidos/tg/detail/-/0764543857/


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