On 24 April 2012 21:25, Oleg Kalnichevski <[email protected]> wrote: > On Tue, 2012-04-24 at 21:10 +0100, sebb wrote: >> On 24 April 2012 20:48, Oleg Kalnichevski <[email protected]> wrote: >> > 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. >> >> I had a look, and the problem is that at least some of the interfaces >> are used elsewhere as return types. >> I don't think it's possible to provide a parallel set of interfaces >> and still maintain binary compat. elsewhere. >> > > I can be wrong again, but as far as interfaces are concerned we would > not need to replace them as their generic types get erased anyway. We > would only have to avoid using old implementations that have Objects as > the return type embedded in their method signatures. In fact as long as > the old iterator classes were used through the Itertor<Stuff> interface > there would be no binary compatibility issues at all.
I've looked again at the Clirr report and it only complains about the concrete classes, for example: Class: org.apache.http.message.BasicHeaderElementIterator Return type of method 'public java.lang.Object next()' has been changed to org.apache.http.HeaderElement It would be possible to create an alternate version of BasicHeaderElementIterator that has a different return type for the next() method. Similarly for the other implementations. It's not possible to compile the old classes against anything but Iterator<Object>. This means that we would need to continue to use casts when using the Iterator. I don't know (yet) how this will affect 3rd party code. > Oleg > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
