One way could be to start a promise, return the future representing the result of that promise, locally accumulate the results as they come and complete de promise ( thus resolving the future ) when orient db notifies you that the command has completed.
def executeAsync(osql: String, params: Map[String, String] = Map()): Future[List[ODocument]] = {
import scala.concurrent._
val p = promise[List[ODocument]]
val f =p.future
val req: OCommandRequest = database.command(
new OSQLAsynchQuery[ODocument]("select * from animal where name = 'Gipsy'",
new OCommandResultListener() {
var acc = List[ODocument]()
@Override
def result(iRecord:Any):Boolean= {
val doc = iRecord.asInstanceOf[ODocument]
acc=doc::acc
true
}
@Override
def end() {
p.success(acc)
}
}))
req.execute()
f
}
Be careful though, to enable graph navigation and field lazy loading, orientdb objects used to keep an internal reference to the database instance they were loaded from ( or to depend on a threadlocal database connected instance ) for lazily loading elements from the database. Manipulating these objects asynchronously may result in loading errors. I haven't checked changes from 1.6 but that seemed to be deeply embedded in the design.