On Tue, 2012-04-24 at 20:30 +0100, sebb wrote:
> On 24 April 2012 19:33, Oleg Kalnichevski <[email protected]> wrote:
> > On Tue, 2012-04-24 at 19:03 +0100, sebb wrote:
> >> On 24 April 2012 18:28, Oleg Kalnichevski <[email protected]> wrote:
> >> > On Tue, 2012-04-24 at 18:07 +0100, sebb wrote:
> >> >> On 24 April 2012 17:18, Oleg Kalnichevski <[email protected]> wrote:
> >> >> > On Tue, 2012-04-24 at 16:59 +0100, sebb wrote:
> >> >> >> On 24 April 2012 16:03, Oleg Kalnichevski <[email protected]> wrote:
> >> >> >> > On Tue, 2012-04-24 at 15:18 +0100, sebb wrote:
> >> >> >> >> On 24 April 2012 12:13, Oleg Kalnichevski <[email protected]> 
> >> >> >> >> wrote:
> >> >> >> >> > On Tue, 2012-04-24 at 02:48 +0100, sebb wrote:
> >> >> >> >> >> On 23 April 2012 14:33, sebb <[email protected]> wrote:
> >> >> >> >> >> > On 21 April 2012 12:21, Oleg Kalnichevski <[email protected]> 
> >> >> >> >> >> > wrote:
> >> >> >> >> >> >> Please vote on releasing these packages as HttpComponents 
> >> >> >> >> >> >> Core 4.2. The
> >> >> >> >> >> >> vote is open for the at least 72 hours, and only votes from
> >> >> >> >> >> >> HttpComponents PMC members are binding. The vote passes if 
> >> >> >> >> >> >> at least
> >> >> >> >> >> >> three binding +1 votes are cast and there are more +1 than 
> >> >> >> >> >> >> -1 votes.
> >> >> >> >> >> >>
> >> >> >> >> >> >> Packages:
> >> >> >> >> >> >> http://people.apache.org/~olegk/httpcore-4.2-RC1/
> >> >> >> >> >> >>
> >> >> >> >> >> >> Release notes:
> >> >> >> >> >> >> http://people.apache.org/~olegk/httpcore-4.2-RC1/RELEASE_NOTES.txt
> >> >> >> >> >> >>
> >> >> >> >> >> >> Maven artefacts:
> >> >> >> >> >> >> https://repository.apache.org/content/repositories/orgapachehttpcomponents-078/org/apache/httpcomponents/
> >> >> >> >> >> >>
> >> >> >> >> >> >> SVN tag:
> >> >> >> >> >> >> https://svn.apache.org/repos/asf/httpcomponents/httpcore/tags/4.2-RC1/
> >> >> >> >> >> >>
> >> >> >> >> >> >> --------------------------------------------------------------------------
> >> >> >> >> >> >>  Vote:  HttpComponents Core 4.2 release
> >> >> >> >> >> >>  [ ] +1 Release the packages as HttpComponents Core 4.2.
> >> >> >> >> >>
> >> >> >> >> >> Sorry, I'm changing my vote:
> >> >> >> >> >>
> >> >> >> >> >> >>  [X] -1 I am against releasing the packages (must include a 
> >> >> >> >> >> >> reason).
> >> >> >> >> >>
> >> >> >> >> >> I've just noticed that Clirr reports several compatibility 
> >> >> >> >> >> issues against 4.1.
> >> >> >> >> >>
> >> >> >> >> >> I've not investigated in any detail, but it looks as though at 
> >> >> >> >> >> least
> >> >> >> >> >> some of these are binary compatibility issues, and they appear 
> >> >> >> >> >> to be
> >> >> >> >> >> in public APIs.
> >> >> >> >> >>
> >> >> >> >> >> It may be that these are not actually a problem, but I think 
> >> >> >> >> >> they need
> >> >> >> >> >> to be investigated further.
> >> >> >> >> >> If the errors are harmless - or perhaps only affect source 
> >> >> >> >> >> builds - it
> >> >> >> >> >> would be helpful to update the site (and ideally release notes)
> >> >> >> >> >> accordingly.
> >> >> >> >> >>
> >> >> >> >> >> [No need to cancel the vote just yet, in case I'm wrong.]
> >> >> >> >> >>
> >> >> >> >> >> BTW, we recently added test jars to the Commons Maven output.
> >> >> >> >> >> This should make it easier to run old tests against new 
> >> >> >> >> >> releases.
> >> >> >> >> >>
> >> >> >> >> >
> >> >> >> >> > Sebastian
> >> >> >> >> >
> >> >> >> >> > The reported differences in public APIs reported by Clirr are 
> >> >> >> >> > due to two
> >> >> >> >> > things (1) upgrade from Java 1.3 to Java 1.5 (2) removal of code
> >> >> >> >> > deprecated between 4.0-beta1 and 4.0 (that is, before 4.0 GA, 
> >> >> >> >> > more than
> >> >> >> >> > two years ago)
> >> >> >> >> >
> >> >> >> >> > We had a discussion about pros and cons of upgrading to Java 
> >> >> >> >> > 1.5 and if
> >> >> >> >> > I remember it correctly you were in favor of that idea [1]. The 
> >> >> >> >> > changes
> >> >> >> >> > have also been announced early enough (several releases in 
> >> >> >> >> > advance) [2].
> >> >> >> >> > They do make 4.1 and 4.2 not fully binary compatible but I 
> >> >> >> >> > seriously
> >> >> >> >> > doubt there will be a single user affected by incompatibility.
> >> >> >> >> >
> >> >> >> >> > I hope you will change your mind.
> >> >> >> >>
> >> >> >> >> I've been looking further at the changes.
> >> >> >> >> The changes to NIO are all removals of deprecated methods, so not 
> >> >> >> >> a
> >> >> >> >> problem (or at least, not our problem).
> >> >> >> >>
> >> >> >> >> The removed methods in HttpCore are also deprecated methods, so 
> >> >> >> >> not a problem.
> >> >> >> >>
> >> >> >> >
> >> >> >> > Not only were they deprecated, they are deprecated two release 
> >> >> >> > cycles
> >> >> >> > back (before 4.0 official release).
> >> >> >> >
> >> >> >> >> Not sure why the value definitions of 
> >> >> >> >> HTTP.DEFAULT_CONTENT_CHARSET and
> >> >> >> >> DEFAULT_PROTOCOL_CHARSET were changed.
> >> >> >> >> Given that they are now deprecated, I would have thought the 
> >> >> >> >> values
> >> >> >> >> could have been left untouched.
> >> >> >> >
> >> >> >> > I think the case changed (by mistake). I'll fix it right away.
> >> >> >> >
> >> >> >> >> However AFAICT that does not affect compatibility.
> >> >> >> >>
> >> >> >> >> [BTW, in future we ought to document in which release items are 
> >> >> >> >> deprecated]
> >> >> >> >>
> >> >> >> >> That just leaves the changed method signatures, which are due to
> >> >> >> >> adding generics to Iterator in o.a.h.message.Basic*Iterator and to
> >> >> >> >> AbstractMessageParser.
> >> >> >> >> In the case of the MessageParser subclasses, these were also 
> >> >> >> >> changed
> >> >> >> >> to use more specific subclasses:
> >> >> >> >> HttpRequest and HttpResponse instead of their common 
> >> >> >> >> super-interface HttpMessage
> >> >> >> >>
> >> >> >> >> It's not obvious to me if these methods are likely to be called 
> >> >> >> >> by 3rd
> >> >> >> >> party code or whether they are only likely to be used internally.
> >> >> >> >>
> >> >> >> >
> >> >> >> > You see, in any sane use case scenarios, especially as far as 
> >> >> >> > iterators
> >> >> >> > are concerned, the type returned from those methods would always 
> >> >> >> > be cast
> >> >> >> > to the expected subtype. In almost all cases regardless of how 
> >> >> >> > those
> >> >> >> > methods are being used the changes will have no effect at the 
> >> >> >> > runtime
> >> >> >> > behavior.
> >> >> >>
> >> >> >> The problem is that the return type of a method is part of the 
> >> >> >> signature.
> >> >> >> Java won't find the method at runtime if the signature changes 
> >> >> >> between
> >> >> >> compilation and run-time.
> >> >> >>
> >> >> >> This generally does not affect source compatibility, but it does
> >> >> >> affect binary compat.
> >> >> >>
> >> >> >> We had this exact problem in Commons IO
> >> >> >> We wanted to change a method return from void to something else;
> >> >> >> however testing against pre-existing binaries showed that this broke
> >> >> >> binary compat.
> >> >> >>
> >> >> >
> >> >> > All right. I'll revert those changes.
> >> >>
> >> >> We are already making the assumption breaking the API is OK for
> >> >> long-deprecated methods, i.e. that user applications have migrated
> >> >> away from the deprecated methods.
> >> >>
> >> >> So if the methods in question are not likely to be used by 3rd party
> >> >> applications - are they effectively internal ? - we could consider
> >> >> releasing with such breaks in compat, provided that such changes are
> >> >> clearly documented.
> >> >>
> >> >
> >> > It is almost as easy just to deprecate the affected classes.
> >>
> >> Which classes need to be deprecated?
> >>
> >> > What is done is done.
> >>
> >> Not sure I follow what you mean here.
> >>
> >
> > I already reverted the changes that made 4.2 binary incompatible with
> > 4.1 with exception of removal of deprecated code.
> >
> >> >> > I always thought the return type did not matter for binary method 
> >> >> > calls. Obviously I was wrong.
> >> >>
> >> >> I originally thought the same. It was one of the long-time Commons
> >> >> devs who pointed out the problem.
> >> >>
> >> >> It's particularly strange that changing void to non-void matters, but 
> >> >> it does.
> >> >> [Perhaps it was easier than making an exception for that particular 
> >> >> case]
> >> >>
> >> >
> >> > I am not sure I understand the point of including the return type in the
> >> > method signature since there will always be ambiguity in case there is
> >> > no assignment of the method return to a variable.
> >>
> >> Not possible, see below.
> >>
> >> > int i = obj.dostuff(); // returns int
> >> > double d = obj.dostuff(); // returns double
> >>
> >> That's not possible; obj.dostuff() can only have a single return type (or 
> >> void).
> >>
> >> Compiler complains about a "duplicate method" otherwise.
> >>
> >
> > Precisely. So, what is the point of including the return type in the
> > method signature?
> 
> [I'm guessing here]
> 
> The compiler checks that the caller of an API method is using the
> correct return type.
> It's obviously important that the same type is provided at run-time.
> 
> If the return type were ignored by the loader when resolving method
> references, the JVM would have to do additional run-time checks on the
> return types.
> This allows the error to be detected earlier (and it's cheaper).
> 

That sounds plausible. Performance does seem to be a factor here. 

> >> > obj.dostuff(); // trouble
> >> >
> >> > That begs the question: what is the point of making things more complex
> >> > than necessary.
> >>
> >> I don't think they did make things more complex.
> >>
> >
> > See above.
> >
> >> > Anyway, as soon as you are happy with the content of the release notes,
> >> > I'll cut another RC and call a vote.
> >>
> >> I've made some fixes to the parent pom, because unfortunately the
> >> buildNumber plugin with javasvn implementation does not work with SVN
> >> 1.7+ clients.
> >>
> >
> > Yes, I am still on version 1.6.x
> >
> >> I assume you have not yet upgraded, because the "Implementation-Build"
> >> headers are OK in the Manifests, so that can be fixed later.
> >>
> >
> > Shall I go ahead and cut a new RC?
> 
> OK.
> 
> The remaining Clirr errors are for deprecated methods only, so I no
> longer have objections on that score.
> 
> I see you have created new versions of the AbstractMessageParser
> sub-classes, so the old ones can be kept and deprecated.
> Solves the compat. problem without losing the type improvements. Excellent.
> 
> It would be great if there were a similar solution for the Iterator
> classes that were reverted, but unfortunately that does not look
> possible, and the classes might well have been used/extended by 3rd
> parties. At least there are type-safe nextEntry() methods available
> for use.
> 

I think similar approach could easily be used for iterator classes.
However, given there is a type-safe method I just felt it was not worth
the trouble.

If no other objections are raised, I'll start cutting RC2 tomorrow.

Cheers

Oleg

> > Oleg
> >
> >
> >
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