/**
* Implements evaluate with additional context and destination group id operation. The
* implementation modifies a global object.
*
* @param destinationValueLoader value loader that corresponds to the destination group
* @param evaluateCommandHandler provides a particular request type
*/
public RelayOk evaluateAsync(
String expression,
Map<String, ? extends SerializableValue> additionalContext,
WipValueLoader destinationValueLoader,
EvaluateCommandHandler<?> evaluateCommandHandler,
final JsEvaluateContext.EvaluateCallback callback,
SyncCallback syncCallback) {
RelaySyncCallback relaySyncCallback = new RelaySyncCallback(syncCallback);
final EvaluateSession evaluateSession =
new EvaluateSession(
expression, additionalContext, destinationValueLoader, evaluateCommandHandler);
final RelaySyncCallback.Guard guard = relaySyncCallback.newGuard();
GenericCallback<Void> postEnsureCallback =
new GenericCallback<Void>() {
@Override
public void success(Void value) {
RelayOk relayOk = evaluateSession.run(callback, guard.getRelay());
guard.discharge(relayOk);
}
@Override
public void failure(Exception exception) {
if (callback != null) {
callback.failure(exception);
}
}
};
return ensureObjectInjected(postEnsureCallback, guard.asSyncCallback());
}
/**
* Makes sure that we injected a helper object inside a global object. This cannot be implemented
* as step in {@link WipRelayRunner}, because the method is synchronized and cannot undergo
* required control inversion.
*/
private synchronized RelayOk ensureObjectInjected(
GenericCallback<Void> callback, SyncCallback syncCallback) {
if (objectInjected) {
callback.success(null);
return RelaySyncCallback.finish(syncCallback);
} else {
objectInjected = true;
return injectObject(callback, syncCallback);
}
}