Hi Steve, this could be a case for a marker interface? We could introduce an "ImmutableAttributeConverter", to be implemented by the safe ones, so that it doesn't break any existing converter.
On 24 September 2015 at 22:54, Steve Ebersole <st...@hibernate.org> wrote: > I went ahead and resolved HHH-10111 to be correct in the mutable cases as > well. I created a new Jira[1] to continue the discussion related to > allowing the user to indicate that the type is immutable (as an > optimization), so let's move discussion of those follow-on steps to that > Jira. > > > [1] - https://hibernate.atlassian.net/browse/HHH-10127 > > On Thu, Sep 24, 2015 at 2:08 PM Steve Ebersole <st...@hibernate.org> wrote: > >> Reference https://hibernate.atlassian.net/browse/HHH-10111 >> >> This comes down to the idea of a Type's mutability : can the thing's >> internal state be changed? We use this for all kinds of optimizations. If >> the internal state is not mutable, we know that "making a deep copy", for >> example, is a simple matter of just returning the original. It also >> affects how we dirty check it, how we (2nd level) cache it, etc. >> >> So far we have assumed that types mapped using AttributeConverters are >> immutable. However, this Jira is an example of where that breaks down. >> >> I think for now we will have to assume that the AttributeConverter entity >> type is mutable and build an appropriate MutabilityPlan. Moving forward I >> think we should consider a means to allow developers >> using AttributeConverter along with immutable state (which seems to be the >> majority case) the option to somehow indicate that the converted-to type is >> immutable which allows us to apply the more efficient plan. Thoughts on >> the best way to achieve this latter part? I am initially thinking an >> optional contract for the AttributeConverter impl itself to implement: >> >> @Converter >> class MyAttributeConverter >> implements AttributeConverter<Name,String>, >> HibernateAttributeConverter { >> // normal AttributeConverter methods >> >> /** >> * HibernateAttributeConverter >> */ >> @Override >> public boolean isMutable() { >> return true; >> } >> } >> >> Another option is to develop some annotations that are applied to the >> AttributeConverter impl (much like the javax.persistence.Converter itself): >> >> @Converter >> @org.hibernate.annotations.MutableConvertedState(true|false) >> class MyAttributeConverter implements AttributeConverter<Name,String> { >> // normal AttributeConverter methods >> } >> >> > _______________________________________________ > 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
