/**
* Managing timeouts is trickier than putting all of them in a long list, like regular message
* delivery. Timeouts are ordered and can be cancelled, so they need special treatment. Hence a
* separate method for managing timeouts triggering.
*/
private Pair<ClusterAction, ClusterState> performNextTimeoutFrom(ClusterInstance instance)
throws Exception {
ClusterState newState = snapshot();
ClusterAction clusterAction = newState.instance(instance.uri().toASCIIString()).popTimeout();
clusterAction.perform(newState);
return Pair.of(clusterAction, newState);
}
/**
* Clone the state and perform the action with the provided index. Returns the new state and the
* action.
*/
ClusterState performAction(ClusterAction action) throws Exception {
ClusterState newState = snapshot();
// Remove the action from the list of things that can happen in the snapshot
newState.pendingActions.remove(action);
// Perform the action on the cloned state
Iterable<ClusterAction> newActions = action.perform(newState);
// Include any outcome actions into the new state snapshot
newState.pendingActions.addAll(asCollection(newActions));
return newState;
}