[keycloak-dev] caching changes

I'm still working on stuff, but here is a summary of things so far: * ConcurrenyTest is passing * Caching implementation is now a pessimistic locking style based on versions. Locking never happens on reads, only writes. There are two caches. One cache holds the actual data, and is pretty much a vanilla invalidation cache. The other cache olds versioning information and is a local-only cache and just is an id->version map. Given an id, what is the current version of it. Hopefully, the implementation makes sure that you never are able to add or obtain a stale version of an object from the cache. Locking happens for updates. At the end of a transaction, all registered invalidations are iterated on, and a version cache lock on that id is obtain. The db is updated, and after that the locks are released. A lock is also obtained whever something is added to the cache. Again a lock is only obtained on the version cache, so any reads will never block. * KeycloakTransactionManager now has an enlistPrepare method. * There is a new RealmProvider.getClientByClientId() method. Clients now have a clientId "index" in the cache. * There is a new RealmProvider.removeClient() method. This was needed to support getClientByClientId() Some other things that were done: * Unnecessary @JoinTables were removed for certain @OneToMany relationships. * getId() will no longer cause a DB query if you are invoking on a reference to a JPA adapter * RealmModel.getClients() and getClientNameMap() is no longer used to implement getClientByClientId() :) * CachedRealm now stores PrivateKey, PublicKey, and Certificate in a transient variable. We were actually unmarshalling from the cached pem format every time these things were access, which is like few times per login. Next steps: * Create a client list cache for each realm. Currently, if you add/remove a client, this invalidates the realm cache and its doing a big query for each client. * Do some profiling to see if there's other things we can do. -- Bill Burke JBoss, a division of Red Hat http://bill.burkecentral.com