oops, guess this works better if I send it to the group ;) On Wed, Oct 12, 2016 at 1:09 PM Steve Ebersole <steve(a)hibernate.org&gt; wrote: Since this is gaining some traction, I think we need to start deciding: 1. whether to have Byte Buddy *replace* Javassist, or to have it as an alternative impl 2. IIUC some of our issues could be alleviated by generating a Javassist shaded jar. Should we consider that for Byte Buddy out the gate? On Tue, Oct 4, 2016 at 9:18 AM Steve Ebersole <steve(a)hibernate.org&gt; wrote: I created https://hibernate.atlassian.net/browse/HHH-11152 to track this On Mon, Oct 3, 2016 at 6:55 AM Steve Ebersole <steve(a)hibernate.org&gt; wrote: I'd also like to revisit the BytecodeProvider contracts. I wrote those really to fit CGLIB and Javassist and our legacy code around CGLIB specifically. But I'd like to revamp that to be more logical. So feel free to suggest any edits to the SPI that you feel make sense. We should also decide if we want to support both, or just move to ByteBuddy. If we support both, we will not be able to leverage things that ByteBuddy can do that Javassist cant (like you mention annotation retention). Personally I think we should just pick one and go with it. I can't imagine users generally care. However I do think the SPI still has merit as it makes it easier to experiment with alternatives/replacements later (as it made it easier for you here). On Mon, Oct 3, 2016, 6:43 AM Rafael Winterhalter <rafael.wth(a)gmail.com&gt; wrote: Hi Steve, it is great to hear you are interested! By "proof of concept" I mean that I have not yet put much effort into it as I did not know if this was an option at all. I only wrote a very general implementation without testing it to see if there is anything missing in Byte Buddy that Javassist is offering and that you relied upon. Byte Buddy makes a few things different when it comes to manipulating existing code but this is not in the scope of what Hibernate is currently using Javassist for. I am more than happy to write a real BytecodeProvider using Byte Buddy. In a first step, I would simply mimic the current Javassist provider. In a later step, I would then try to apply a few optimizations to make the interceptor a bit more lean; this would benefit performance due to on inlining size and make it easier to debug. At this stage, we can also look into a few features that Javassist does not offer as for example annotation retention. I try to find some time in the next two or three weeks and get back with a prototype. Best regards, Rafael 2016-10-02 2:23 GMT+02:00 Steve Ebersole <steve(a)hibernate.org&gt;: That's awesome that you were able to code something up Rafael. I will set aside some time next week to look this over. When you say "proof of concept" I am curious how complete you feel this is. You mentioned not dealing with the fast-class stuff, which is ok by me - as you say, this is not so much an issue anymore as it was back in JDK 1.4 :) More I mean in terms of both proxy generation support and bytecode enhancement. In regards to those 2, how complete do you feel this work is? And again, thanks for taking this on. This is something I have wanted to look at, but just could never find the time. Glad someone took this on. On Sat, Oct 1, 2016 at 10:25 AM Rafael Winterhalter <rafael.wth(a)gmail.com&gt; wrote: Hello everybody, I was wondering how big the chances are to get a Byte Buddy bytecode provider into Hibernate? Byte Buddy has matured a lot over the last two years and it aims a lot on performance what is something Hibernate could benefit of. There are comparion charts posted on the Byte Buddy webpage. As a bonus, Byte Buddy is already ready for Java 9 and gives a lot of features for free, for example generic meta data retention and a possibility to retain annotations on subclassed types and overridden methods. I have written a simple proof of concept here: https://github.com/raphw/hibernate-bb without having tested it - I did not implement the fast class providers as I have learned after a lot of benchmarking that those do not improve performance on Java 8+ VMs anymore. Using such fast-classing rather pollutes the code cache than bring any benefit. The only advantage with code generation in this field comes when avoiding boxing what is not the case. But of course, I can implement something in Byte Buddy to apply such a fast-class mechanism. Let me know what you think. I am more then happy to help you with implementing such a provider. Other frameworks such as Mockito already use Byte Buddy on a large scale and made good experiences with it. Best regards, Rafael _______________________________________________ hibernate-dev mailing list hibernate-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev