Re: Scanning for annotated classes in MyFaces 2
On Sat, 2009-01-10 at 19:56 -0700, Matthias Wessendorf wrote: On Sat, Jan 10, 2009 at 11:21 AM, Jan-Kees van Andel jankeesvanan...@gmail.com wrote: I don't think Scannotation itself is an issue, but it has a required dependency on Javassist, which has an LGPL license. Isn't that a problem? hrm, I think not really, b/c it's not a direct dependency. I'm pretty sure that scannotation's dependency on an LGLP project is a showstopper. There is some brief info here: http://www.apache.org/legal/resolved.html I'm not sure this approach is a good one anyway. Javasisst's jar is 560kb. That's a fairly heavy dependency for such a simple task as scanning for annotations. Regards, Simon
RE: Scanning for annotated classes in MyFaces 2
Hi! -Original Message- From: Jan-Kees van Andel [mailto:jankeesvanan...@gmail.com] Mario, I've been looking at the Shale code that handles the annotation scanning, but I saw it uses Reflection and standard Java ClassLoaders for scanning the classpath for JSF artifacts. What's your experience with the performance of this? Does Shale heavily rely on specifying a base package to be efficient? Hmmm, it is a long time back we used it at least during development times it was very annoying not having specified the packages. If I remember correctly, with defining it, scanning-time drop down from something aroung 30 seconds to under 1 second. Wouldn't it be sufficient to do it that way for a first version of MyFaces 2.0? Do you think Mojarra will come up with a more sophisticated solution which bypasses the standard reflection stuff and uses something like Javasisst? I doubt. Ciao, Mario
Re: Scanning for annotated classes in MyFaces 2
Fwik Javassist uses a Mozilla Public License 1.1 not a pure LGPL (though I've not checked explicitly for the javassist version we use). MPL 1.1 is explicitly listed as appropriate license at least. Maybe we can kick scannotation, and do the scanning ourself (in a later phase). But Javassist is imho a big deal, because we don't need to class-load all classes. Otoh I have to admit that I've never did any performance/memory tests comparing them both. LieGrue, strub --- Simon Kitching skitch...@apache.org schrieb am So, 11.1.2009: Von: Simon Kitching skitch...@apache.org Betreff: Re: Scanning for annotated classes in MyFaces 2 An: MyFaces Development dev@myfaces.apache.org Datum: Sonntag, 11. Januar 2009, 12:06 On Sat, 2009-01-10 at 19:56 -0700, Matthias Wessendorf wrote: On Sat, Jan 10, 2009 at 11:21 AM, Jan-Kees van Andel jankeesvanan...@gmail.com wrote: I don't think Scannotation itself is an issue, but it has a required dependency on Javassist, which has an LGPL license. Isn't that a problem? hrm, I think not really, b/c it's not a direct dependency. I'm pretty sure that scannotation's dependency on an LGLP project is a showstopper. There is some brief info here: http://www.apache.org/legal/resolved.html I'm not sure this approach is a good one anyway. Javasisst's jar is 560kb. That's a fairly heavy dependency for such a simple task as scanning for annotations. Regards, Simon
RE: Scanning for annotated classes in MyFaces 2
Hi! not sure on the PERF, but if it is really (proven) the case, I am with you. Well... startup time isn't really a big problem, right? :-) Is that ironic? In projects with 3000 classes and 60 jar files you are up to 30 seconds, or even more, scanning time. Under load, with shale, I saw scanning times of 60 seconds. This _will_ drive you crazy! Ciao, Mario
Re: Scanning for annotated classes in MyFaces 2
Yep, I should have checked the original statement. The javassist website here: http://www.jboss.org/javassist/ states clearly that: quote License: You can choose either MPL or LGPL. /quote Surprising for a jboss project, but the website clearly says so. The MPL is no problem. So using Scannotation is also fine. I'm still not convinced that adding a 560kb dependency for such a simple task is optimal, but simply getting *any* solution in place for myfaces is better than doing multiple scans. It can always be further improved later.. Regards, Simon On Sun, 2009-01-11 at 11:45 +, Mark Struberg wrote: Fwik Javassist uses a Mozilla Public License 1.1 not a pure LGPL (though I've not checked explicitly for the javassist version we use). MPL 1.1 is explicitly listed as appropriate license at least. Maybe we can kick scannotation, and do the scanning ourself (in a later phase). But Javassist is imho a big deal, because we don't need to class-load all classes. Otoh I have to admit that I've never did any performance/memory tests comparing them both. LieGrue, strub --- Simon Kitching skitch...@apache.org schrieb am So, 11.1.2009: Von: Simon Kitching skitch...@apache.org Betreff: Re: Scanning for annotated classes in MyFaces 2 An: MyFaces Development dev@myfaces.apache.org Datum: Sonntag, 11. Januar 2009, 12:06 On Sat, 2009-01-10 at 19:56 -0700, Matthias Wessendorf wrote: On Sat, Jan 10, 2009 at 11:21 AM, Jan-Kees van Andel jankeesvanan...@gmail.com wrote: I don't think Scannotation itself is an issue, but it has a required dependency on Javassist, which has an LGPL license. Isn't that a problem? hrm, I think not really, b/c it's not a direct dependency. I'm pretty sure that scannotation's dependency on an LGLP project is a showstopper. There is some brief info here: http://www.apache.org/legal/resolved.html I'm not sure this approach is a good one anyway. Javasisst's jar is 560kb. That's a fairly heavy dependency for such a simple task as scanning for annotations. Regards, Simon
Re: Scanning for annotated classes in MyFaces 2
I've checked mojarra 2.0 some time ago to see how do they implemented this, well they're using reflection/class way. Spring's scanning mechanism also gives out of memory if you dont specify a sub package name to scan. So, my thought is to implement this in myfaces, it's not a complicated task as we all discussed. And if we do implement it, we get the advantage of tuning it for better performance in a web environment. C.C. On Sun, Jan 11, 2009 at 11:46 AM, Mario Ivankovits ma...@ops.co.at wrote: Hi! not sure on the PERF, but if it is really (proven) the case, I am with you. Well... startup time isn't really a big problem, right? :-) Is that ironic? In projects with 3000 classes and 60 jar files you are up to 30 seconds, or even more, scanning time. Under load, with shale, I saw scanning times of 60 seconds. This _will_ drive you crazy! Ciao, Mario
Re: Scanning for annotated classes in MyFaces 2
My 2 cents: Don't load classes to use java.lang.reflect on it:
- What if a class does something bad (or just about anything) in a static
initializer?
For example try to run the code below. It will EXIT THE VM
- Can you be sure that those classes are unloaded again?
- Performance: It is _faster_ to use a library (like javassist), because the
class loader must effectively parse the byte code, too, plus then do a lot
more (like validation).
package com.acme.foo;
class Exit {
static {
System.exit(-1);
}
}
public class Main {
public static void main(String[] args) throws InterruptedException,
ClassNotFoundException {
Class? clazz = Class.forName(com.acme.foo.Exit);
while(true) {
Thread.sleep(1000);
System.out.println(System.currentTimeMillis() / 1000);
}
}
}
Cagatay Civici wrote:
I've checked mojarra 2.0 some time ago to see how do they implemented
this, well they're using reflection/class way.
Spring's scanning mechanism also gives out of memory if you dont specify
a sub package name to scan.
So, my thought is to implement this in myfaces, it's not a complicated
task as we all discussed. And if we do implement it, we get the
advantage of tuning it
for better performance in a web environment.
C.C.
On Sun, Jan 11, 2009 at 11:46 AM, Mario Ivankovits ma...@ops.co.at
mailto:ma...@ops.co.at wrote:
Hi!
not sure on the PERF, but if it is really (proven) the case, I am
with
you.
Well... startup time isn't really a big problem, right? :-)
Is that ironic?
In projects with 3000 classes and 60 jar files you are up to 30
seconds, or even more, scanning time.
Under load, with shale, I saw scanning times of 60 seconds.
This _will_ drive you crazy!
Ciao,
Mario
Re: Scanning for annotated classes in MyFaces 2
On Sun, Jan 11, 2009 at 4:46 AM, Mario Ivankovits ma...@ops.co.at wrote: Hi! not sure on the PERF, but if it is really (proven) the case, I am with you. Well... startup time isn't really a big problem, right? :-) Is that ironic? ;-) I really hate to wait on the boot-up. :-) In projects with 3000 classes and 60 jar files you are up to 30 seconds, or even more, scanning time. Under load, with shale, I saw scanning times of 60 seconds. This _will_ drive you crazy! Ciao, Mario -- Matthias Wessendorf blog: http://matthiaswessendorf.wordpress.com/ sessions: http://www.slideshare.net/mwessendorf twitter: http://twitter.com/mwessendorf
