[keycloak-dev] caching custom per-user objects

I've run into a few places where I need to cache custom things per-user that are evicted along with the user. I also need some fine grain control of things that get cached with a user. Here are the scenarios * UserStorageProvider SPI needs to cache something that doesn't fit with the current UserModel metadata * Certain credential types like HOTP need to be updated per login. We don't want to cache these things, and we do not want to evict users in the cache that use these credential types * It should be possible to cache credentials that are validated by an external provider. For example, password and LDAP. JBoss has supported caching successfully validated credentials since forever. I'm going to expose a new interface via KeycloakSession: UserCache interface UserCache extends UserProvider { boolean isCached(UserModel user); void cacheWith(UserMode userl, Object key, Object value); } I'm also going to add a callback interface interface OnUserCache { void cacheUser(RealmModel realm, UserModel user, Map cache); } I originally thought about having a ProviderEvent for OnUserCache, but this callback needs to be targeted to specific objects rather than everything. i.e. a specific User Storage Provider rather than being sent to every storage provider. Bill