/**
* Runs a relay defined by a chain of steps.
*
* @param <RES> return type of the entire relay
* @param firstStep a first step that defines the entire relay
* @param callback
* @param relaySyncCallback a {@link SyncCallback} wrapped as {@link RelaySyncCallback}
*/
public static <RES> RelayOk run(
final WipCommandProcessor commandProcessor,
Step<RES> firstStep,
final GenericCallback<RES> callback,
final RelaySyncCallback relaySyncCallback) {
return firstStep.accept(
new Step.Visitor<RelayOk, RES>() {
@Override
public RelayOk visitFinal(RES finalResult) {
if (callback != null) {
callback.success(finalResult);
}
return relaySyncCallback.finish();
}
@Override
public RelayOk visitSend(final SendStepSimple<RES> sendStep) {
final RelaySyncCallback.Guard guard = relaySyncCallback.newGuard();
WipCommandCallback sendCallback =
new WipCommandCallback() {
@Override
public void messageReceived(WipCommandResponse response) {
Step<RES> processResult;
try {
processResult = sendStep.processResponse();
} catch (ProcessException e) {
if (callback != null) {
callback.failure(e);
}
// Todo: consider throwing e.
return;
}
RelayOk relayOk =
run(commandProcessor, processResult, callback, guard.getRelay());
guard.discharge(relayOk);
}
@Override
public void failure(String message) {
if (callback != null) {
callback.failure(sendStep.processFailure(new Exception(message)));
}
}
};
return commandProcessor.send(
sendStep.getParams(), sendCallback, guard.asSyncCallback());
}
@Override
public <RESPONSE> RelayOk visitSend(final SendStepWithResponse<RESPONSE, RES> sendStep) {
final RelaySyncCallback.Guard guard = relaySyncCallback.newGuard();
GenericCallback<RESPONSE> sendCallback =
new GenericCallback<RESPONSE>() {
@Override
public void success(RESPONSE response) {
Step<RES> processResult;
try {
processResult = sendStep.processResponse(response);
} catch (ProcessException e) {
if (callback != null) {
callback.failure(e);
}
// Todo: consider throwing e.
return;
}
RelayOk relayOk =
run(commandProcessor, processResult, callback, guard.getRelay());
guard.discharge(relayOk);
}
@Override
public void failure(Exception exception) {
if (callback != null) {
callback.failure(sendStep.processFailure(exception));
}
}
};
return commandProcessor.send(
sendStep.getParams(), sendCallback, guard.asSyncCallback());
}
});
}
