Thanks for all the information, I think I have a clearer idea now. I'll start to write some code and see what happens :)
Davide On Fri, May 3, 2013 at 2:13 PM, Emmanuel Bernard <emman...@hibernate.org>wrote: > Hello Davide, > > Technically most of the knowledge is in > https://hibernate.atlassian.net/browse/OGM-208 but it's definitely quite > blurry for a new comer ;) > > Let me try and summarize it for you. With that you'll be able to better > grasp the comments in OGM-208 > > ## Goals > > We want a metadata facility as a way to pass mapping and configuration > from the developer to the grid dialect / > datastore provider. I will call these options. The facility should: > - be expressible via annotations > - be expressible via a programmatic API > - be as type-safe as possible but not too hard to add configuration > options > > This project is essentially smart plumbing so the "clients" of this API > are the developers on one hand and the Datastore providers on the other > hand. > > ## What to reuse > > We will most likely use Jandex to read annotations to benefit from the > ORM and WildFly work esp wrt indexing. > > ## Scopes: overriding and refining options > > Each option might be: > - global, per entity, per property (with optional overridability from > one to the other) > - global, specific to a session, specific to an operation (e.g. query) > > On top of that options can be polled together by functional affinities > like key/value generic options, Infinispan specific options, document > store options etc. > > ## Programmatic API > > The programmatic API can be used to define mapping options as well as > session or even operation options. It should be type-safe and will > likely look like Hibernate Search's approach more or less. > > This is more or less what is in the branch. Check out the > package-info.java for some more information. > > ## Annotation > > We need a way to convert an annotation into calls to the programmatic > API (semantically speaking at least). Something like an (meta)annotation > based conversion: > > @ToInternalModel(UnsafeConverter.class) > @interface Unsafe { > boolean value() default true; > static class UnsafeConverter implements > Convert<Unsafe,MongoDBMappingInternalModelGenerator> { > void call(Unsafe annotation, > MongoDBMappingInternalModelGenerator generator) { > return generator.unsafe(annotation.value()); > } > } > } > > This is todo > > ## Reading API > > Datastore providers and GridDialect implementations should be able to > read back these options. > > This is more or less what you can see in the last few code lines of my > OGM-207 comment of 27/Jul/12 6:33 PM. > The seed of it is the MappingService API on the branch but it looks all > untypesafe and wrong :) Let's call it unfinished. > > ## Expressing options in a type-safe way > > If you look at OGM-207's comment of 27/Jul/12 6:33 PM, you will wee an > example of NamedQuery and Quorum options and the infrastructure needed. > > It shows how to uniquely identify an option and how to model options > like quorum that are identified by their name and options like named > queries that are identified by their name + a key (the query name in > this case). > > It's available in options.Iteration2's class. > > ## Tests > > Tests are available in org.hibernate.ogm.test.mapping. > > ## Examples of options > > You can imagine the following examples of options: > > - quorum: express the R/W quorum (globally, per entity, per collection, > per session) ; useful for dynamo based systems > - WriteConcern: express the write concern options for MongoDB (globally, > per entity, per collection) > - Whether or not store association information in the main document or > in a separate document (see MongoDB IN_ENTITY etc. We could have this > option on a per collection basis and not a global setting. > - all datastore specific options whether they are global or relate to > one entity or one property > > I hope I have been clearer, fire the questions away. > > Emmanuel > > PS: JIRA no longer has a way to link to comments? > > On Wed 2013-05-01 9:41, Davide D'Alto wrote: > > Hi, > > I've started to work on the metamodel. I've look at the branch that > > emmanuel created and I've rebased it to the latest master fixing all > > checkstyle violations: https://github.com/DavideD/hibernate-ogm/tree/208 > > > > The problem is that I don't have a clear idea how the metamodel is > supposed > > to work, what could be a good test case to start with? > > > > Thanks, > > Davide > > _______________________________________________ > > hibernate-dev mailing list > > hibernate-dev@lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/hibernate-dev > _______________________________________________ hibernate-dev mailing list hibernate-dev@lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev
