org.apache.flink.streaming.examples.statemachine.dfa.State Java Examples

/**
 * Creates an event for an illegal state transition of one of the internal
 * state machines. If the generator has not yet started any state machines
 * (for example, because no call to {@link #next(int, int)} was made, yet), this
 * will return null.
 *
 * @return An event for a illegal state transition, or null, if not possible.
 */
@Nullable
public Event nextInvalid() {
	final Iterator<Entry<Integer, State>> iter = states.entrySet().iterator();
	if (iter.hasNext()) {
		final Entry<Integer, State> entry = iter.next();

		State currentState = entry.getValue();
		int address = entry.getKey();
		iter.remove();

		EventType event = currentState.randomInvalidTransition(rnd);
		return new Event(event, address);
	}
	else {
		return null;
	}
}
 

@Override
public void flatMap(Event evt, Collector<Alert> out) throws Exception {
	// get the current state for the key (source address)
	// if no state exists, yet, the state must be the state machine's initial state
	State state = currentState.value();
	if (state == null) {
		state = State.Initial;
	}

	// ask the state machine what state we should go to based on the given event
	State nextState = state.transition(evt.type());

	if (nextState == State.InvalidTransition) {
		// the current event resulted in an invalid transition
		// raise an alert!
		out.collect(new Alert(evt.sourceAddress(), state, evt.type()));
	}
	else if (nextState.isTerminal()) {
		// we reached a terminal state, clean up the current state
		currentState.clear();
	}
	else {
		// remember the new state
		currentState.update(nextState);
	}
}
 

/**
 * Creates an event for an illegal state transition of one of the internal
 * state machines. If the generator has not yet started any state machines
 * (for example, because no call to {@link #next(int, int)} was made, yet), this
 * will return null.
 *
 * @return An event for a illegal state transition, or null, if not possible.
 */
@Nullable
public Event nextInvalid() {
	final Iterator<Entry<Integer, State>> iter = states.entrySet().iterator();
	if (iter.hasNext()) {
		final Entry<Integer, State> entry = iter.next();

		State currentState = entry.getValue();
		int address = entry.getKey();
		iter.remove();

		EventType event = currentState.randomInvalidTransition(rnd);
		return new Event(event, address);
	}
	else {
		return null;
	}
}
 

@Override
public void flatMap(Event evt, Collector<Alert> out) throws Exception {
	// get the current state for the key (source address)
	// if no state exists, yet, the state must be the state machine's initial state
	State state = currentState.value();
	if (state == null) {
		state = State.Initial;
	}

	// ask the state machine what state we should go to based on the given event
	State nextState = state.transition(evt.type());

	if (nextState == State.InvalidTransition) {
		// the current event resulted in an invalid transition
		// raise an alert!
		out.collect(new Alert(evt.sourceAddress(), state, evt.type()));
	}
	else if (nextState.isTerminal()) {
		// we reached a terminal state, clean up the current state
		currentState.clear();
	}
	else {
		// remember the new state
		currentState.update(nextState);
	}
}
 

/**
 * Creates an event for an illegal state transition of one of the internal
 * state machines. If the generator has not yet started any state machines
 * (for example, because no call to {@link #next(int, int)} was made, yet), this
 * will return null.
 *
 * @return An event for a illegal state transition, or null, if not possible.
 */
@Nullable
public Event nextInvalid() {
	final Iterator<Entry<Integer, State>> iter = states.entrySet().iterator();
	if (iter.hasNext()) {
		final Entry<Integer, State> entry = iter.next();

		State currentState = entry.getValue();
		int address = entry.getKey();
		iter.remove();

		EventType event = currentState.randomInvalidTransition(rnd);
		return new Event(event, address);
	}
	else {
		return null;
	}
}
 

@Override
public void flatMap(Event evt, Collector<Alert> out) throws Exception {
	// get the current state for the key (source address)
	// if no state exists, yet, the state must be the state machine's initial state
	State state = currentState.value();
	if (state == null) {
		state = State.Initial;
	}

	// ask the state machine what state we should go to based on the given event
	State nextState = state.transition(evt.type());

	if (nextState == State.InvalidTransition) {
		// the current event resulted in an invalid transition
		// raise an alert!
		out.collect(new Alert(evt.sourceAddress(), state, evt.type()));
	}
	else if (nextState.isTerminal()) {
		// we reached a terminal state, clean up the current state
		currentState.clear();
	}
	else {
		// remember the new state
		currentState.update(nextState);
	}
}
 

public State state() {
	return state;
}
 

@Override
public void open(Configuration conf) {
	// get access to the state object
	currentState = getRuntimeContext().getState(
				new ValueStateDescriptor<>("state", State.class));
}
 

public State state() {
	return state;
}
 

@Override
public void open(Configuration conf) {
	// get access to the state object
	currentState = getRuntimeContext().getState(
				new ValueStateDescriptor<>("state", State.class));
}
 

public State state() {
	return state;
}
 

@Override
public void open(Configuration conf) {
	// get access to the state object
	currentState = getRuntimeContext().getState(
				new ValueStateDescriptor<>("state", State.class));
}
 

/**
 * Creates a new alert.
 *
 * @param address The originating address (think 32 bit IPv4 address).
 * @param state The state that the event state machine found.
 * @param transition The transition that was considered invalid.
 */
public Alert(int address, State state, EventType transition) {
	this.address = address;
	this.state = checkNotNull(state);
	this.transition = checkNotNull(transition);
}
 

/**
 * Creates a new alert.
 *
 * @param address The originating address (think 32 bit IPv4 address).
 * @param state The state that the event state machine found.
 * @param transition The transition that was considered invalid.
 */
public Alert(int address, State state, EventType transition) {
	this.address = address;
	this.state = checkNotNull(state);
	this.transition = checkNotNull(transition);
}
 

/**
 * Creates a new alert.
 *
 * @param address The originating address (think 32 bit IPv4 address).
 * @param state The state that the event state machine found.
 * @param transition The transition that was considered invalid.
 */
public Alert(int address, State state, EventType transition) {
	this.address = address;
	this.state = checkNotNull(state);
	this.transition = checkNotNull(transition);
}