implicit convert spymemcache (>= 2.10.0) OperationFuture to scala.concurrent.Future

CbFutureAsScala.scala

package sd.cb

import net.spy.memcached.internal.{OperationCompletionListener, OperationFuture}
import scala.concurrent.{Future, Promise}

/**
 * @see http://stackoverflow.com/questions/11529145/how-do-i-wrap-a-java-util-concurrent-future-in-an-akka-future?rq=1
 *      http://stackoverflow.com/questions/17215421/scala-concurrent-future-wrapper-for-java-util-concurrent-future
 */
object CbFutureAsScala{
  implicit def cbFutureAsScala[T](underlying: OperationFuture[T]): Future[T] = {
    val p = Promise[T]()
    underlying.addListener(new OperationCompletionListener{
      def onComplete(f: OperationFuture[_]) {
        val status = f.getStatus //f is underlying
        //@see http://www.couchbase.com/issues/browse/JCBC-343#comment-68524
        if(status.isSuccess)
          p.success(underlying.get())
        else
          p.failure(new Exception(status.getMessage))
      }
    })
    p.future
  }
}