Re: [classad-users] What is the future of the ClassAd C++ library ?

[Alain Aslag Roy <roy@xxxxxxxxxxx>]

>I've seen a message in classad-dev mailing list about this mail title, 
>where there's this sentence : "I'm interested in how ClassAds are being 
>used now, particularly outside of Condor.  I'd also like to know what 
>ClassAd users want from ClassAds. "
>
>So well, as a user of ClassAds, here's my input.

Laurent, thank you for your input! We are always delighted to have more 
examples of where people are using ClassAds.

>The first one is AliEn (http://alien.cern.ch) which could be summarized as 
>a mini data grid for the CERN Experiment ALICE 
>(http://alice.web.cern.ch/Alice/). There ClassAds are used to make 
>matchmaking between jobs and machines, i.e. their natural way I would say 
>(only "originality" is that as AliEn is written in PERL, I wrote a PERL 
>module for wrapping C++ ClassAd  library). So far we are very happy with 
>what ClassAds provide.

Is there any relation to the resource broker used in the EDG, or is this 
totally independent work.

Also, how did you write the Perl wrapper? I've been meaning to make that 
easier for people, but I haven't had a chance to do it. I was thinking 
about using SWIG and extending the c interfacein cclassad.c.

>The idea is to use ClassAds to make generic object factories.

I'm not sure I completely understand, but this sounds very interesting!

>I would really like to see the C++ ClassAd library being developped for 
>more portability. Our PHENIX code strives to run on as many compilers 
>pairs as possible. One of such is Sun Workshop Pro 6. I tried to use 
>ClassAd 0.9.4 and got a hard time to get it working (I had to clutter the 
>code with stuff like :
>
>#ifdef _DO_NOT_HAVE_HASHMAP
>typedef std::map<std::string, ExprTree*, CaseIgnLTStr> AttrList;
>#else
>typedef std::hash_map<std::string, ExprTree*, StringCaseIgnHash, 
>CaseIgnEqStr> AttrList;
>#endif

Yes, I am happy to try to make everything more portable. We are happy to 
see ClassAds being more widely used, and would like to encourage it.

Given other things in my schedule, it's not likely to happen for a month or 
two. If you wish to make some nice modifications to the code to make it 
more portable in a pretty way, I would be happy to take your submissions 
and add them to the ClassAd library. Otherwise, it will be on my 
medium-term to do list.

Are there any other issues you have had with the SunPro compiler, or is it 
just the hash_map? We also use another non-standard STL container class (I 
forget which one off the top of my head, and I'm writing this without 
Internet access.

>Also, as I already requested in a previous mail, it would be very 
>convenient to prefix all the ClassAd source code (at least the .h that get 
>installed), so naming clashes won't happen (which is currently very likely 
>in a big project that would use the library as it is now, due e.g. to 
>common.h ;-))

Yes, I'll try to do this. It's a bit of a hassle, because I have to deal 
with CVS, but it's clearly important to do, so I will do it.

>OK, that's it. Thank you for your attention and sorry for the long mail.

No need to apologize--your input is important and useful.

-alain