This is an early draft of enabling Reactor's Composable to provide asynchronous data access even if the underlying datastore access is fully-blocking.
This submodule provides an interface similar to Spring Data's CrudRepository but replaces references to domain objects with references to Composable<DomainObject>. This gives you a chainable, composable data API that doesn't block the caller while waiting on data (it uses a background IO thread instead).
Given a domain object called Person, and a Spring Data Repository to manage it, you just have to declare a subclass of ComposableCrudRepository and you will get a fluent composable API that lets you do map, filter, and other composable actions like the following silly example:
@Inject
ComposablePersonRepository people;
Composable<String> fullName = people.findOne(personId).map(new Function<Person, String>() {
public String apply(Person p) {
return p.getFirstName() + " " + p.getLastName();
}
});
You can block if you want by calling Composable's await(long timeout, TimeUnit unit) method. Or you can do a non-blocking call to get() (Composable<T>s are also Supplier<T>s).
String s = fullName.await(5, TimeUnit.SECONDS); // block caller for 5 seconds