How to use

getCondition

method

in

org.apache.flink.cep.nfa.StateTransition

/**
 * Tear-down method for the NFA.
 */
public void close() throws Exception {
  for (State<T> state : getStates()) {
    for (StateTransition<T> transition : state.getStateTransitions()) {
      IterativeCondition condition = transition.getCondition();
      FunctionUtils.closeFunction(condition);
    }
  }
}

/**
 * Initialization method for the NFA. It is called before any element is passed and thus suitable for one time setup
 * work.
 * @param cepRuntimeContext runtime context of the enclosing operator
 * @param conf The configuration containing the parameters attached to the contract.
 */
public void open(RuntimeContext cepRuntimeContext, Configuration conf) throws Exception {
  for (State<T> state : getStates()) {
    for (StateTransition<T> transition : state.getStateTransitions()) {
      IterativeCondition condition = transition.getCondition();
      FunctionUtils.setFunctionRuntimeContext(condition, cepRuntimeContext);
      FunctionUtils.openFunction(condition, conf);
    }
  }
}

private State<T> findFinalStateAfterProceed(
    ConditionContext context,
    State<T> state,
    T event) {
  final Stack<State<T>> statesToCheck = new Stack<>();
  statesToCheck.push(state);
  try {
    while (!statesToCheck.isEmpty()) {
      final State<T> currentState = statesToCheck.pop();
      for (StateTransition<T> transition : currentState.getStateTransitions()) {
        if (transition.getAction() == StateTransitionAction.PROCEED &&
            checkFilterCondition(context, transition.getCondition(), event)) {
          if (transition.getTargetState().isFinal()) {
            return transition.getTargetState();
          } else {
            statesToCheck.push(transition.getTargetState());
          }
        }
      }
    }
  } catch (Exception e) {
    throw new FlinkRuntimeException("Failure happened in filter function.", e);
  }
  return null;
}

  private void updateWithGreedyCondition(
    State<T> state,
    IterativeCondition<T> takeCondition) {
    for (StateTransition<T> stateTransition : state.getStateTransitions()) {
      stateTransition.setCondition(
        new RichAndCondition<>(stateTransition.getCondition(), new RichNotCondition<>(takeCondition)));
    }
  }
}

if (checkFilterCondition(context, stateTransition.getCondition(), event)) {

private State<T> copy(final State<T> state) {
  final State<T> copyOfState = createState(
    NFAStateNameHandler.getOriginalNameFromInternal(state.getName()),
    state.getStateType());
  for (StateTransition<T> tStateTransition : state.getStateTransitions()) {
    copyOfState.addStateTransition(
      tStateTransition.getAction(),
      tStateTransition.getTargetState().equals(tStateTransition.getSourceState())
          ? copyOfState
          : tStateTransition.getTargetState(),
      tStateTransition.getCondition());
  }
  return copyOfState;
}

  copyOfSink.addStateTransition(tStateTransition.getAction(), targetState, tStateTransition.getCondition());
        ? copyOfSink
        : tStateTransition.getTargetState(),
    tStateTransition.getCondition()
);

  private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
    ois.defaultReadObject();

    //Backward compatibility. Previous version of StateTransition did not have source state
    if (!stateTransitions.isEmpty() && stateTransitions.iterator().next().getSourceState() == null) {
      final List<StateTransition<T>> tmp = new ArrayList<>();
      tmp.addAll(this.stateTransitions);

      this.stateTransitions.clear();
      for (StateTransition<T> transition : tmp) {
        addStateTransition(transition.getAction(), transition.getTargetState(), transition.getCondition());
      }
    }
  }
}

private State<T> findFinalStateAfterProceed(State<T> state, T event, ComputationState<T> computationState) {
  final Stack<State<T>> statesToCheck = new Stack<>();
  statesToCheck.push(state);
  try {
    while (!statesToCheck.isEmpty()) {
      final State<T> currentState = statesToCheck.pop();
      for (StateTransition<T> transition : currentState.getStateTransitions()) {
        if (transition.getAction() == StateTransitionAction.PROCEED &&
            checkFilterCondition(computationState, transition.getCondition(), event)) {
          if (transition.getTargetState().isFinal()) {
            return transition.getTargetState();
          } else {
            statesToCheck.push(transition.getTargetState());
          }
        }
      }
    }
  } catch (Exception e) {
    throw new RuntimeException("Failure happened in filter function.", e);
  }
  return null;
}

private State<T> findFinalStateAfterProceed(
    ConditionContext<T> context,
    State<T> state,
    T event) {
  final Stack<State<T>> statesToCheck = new Stack<>();
  statesToCheck.push(state);
  try {
    while (!statesToCheck.isEmpty()) {
      final State<T> currentState = statesToCheck.pop();
      for (StateTransition<T> transition : currentState.getStateTransitions()) {
        if (transition.getAction() == StateTransitionAction.PROCEED &&
            checkFilterCondition(context, transition.getCondition(), event)) {
          if (transition.getTargetState().isFinal()) {
            return transition.getTargetState();
          } else {
            statesToCheck.push(transition.getTargetState());
          }
        }
      }
    }
  } catch (Exception e) {
    throw new FlinkRuntimeException("Failure happened in filter function.", e);
  }
  return null;
}

private State<T> findFinalStateAfterProceed(
    ConditionContext<T> context,
    State<T> state,
    T event) {
  final Stack<State<T>> statesToCheck = new Stack<>();
  statesToCheck.push(state);
  try {
    while (!statesToCheck.isEmpty()) {
      final State<T> currentState = statesToCheck.pop();
      for (StateTransition<T> transition : currentState.getStateTransitions()) {
        if (transition.getAction() == StateTransitionAction.PROCEED &&
            checkFilterCondition(context, transition.getCondition(), event)) {
          if (transition.getTargetState().isFinal()) {
            return transition.getTargetState();
          } else {
            statesToCheck.push(transition.getTargetState());
          }
        }
      }
    }
  } catch (Exception e) {
    throw new FlinkRuntimeException("Failure happened in filter function.", e);
  }
  return null;
}

if (checkFilterCondition(computationState, stateTransition.getCondition(), event)) {

  private void updateWithGreedyCondition(
    State<T> state,
    IterativeCondition<T> takeCondition) {
    for (StateTransition<T> stateTransition : state.getStateTransitions()) {
      stateTransition.setCondition(
        new AndCondition<>(stateTransition.getCondition(), new NotCondition<>(takeCondition)));
    }
  }
}

if (checkFilterCondition(context, stateTransition.getCondition(), event)) {

  private void updateWithGreedyCondition(
    State<T> state,
    IterativeCondition<T> takeCondition) {
    for (StateTransition<T> stateTransition : state.getStateTransitions()) {
      stateTransition.setCondition(
        new AndCondition<>(stateTransition.getCondition(), new NotCondition<>(takeCondition)));
    }
  }
}

if (checkFilterCondition(context, stateTransition.getCondition(), event)) {

private State<T> copy(final State<T> state) {
  final State<T> copyOfState = createState(
    NFAStateNameHandler.getOriginalNameFromInternal(state.getName()),
    state.getStateType());
  for (StateTransition<T> tStateTransition : state.getStateTransitions()) {
    copyOfState.addStateTransition(
      tStateTransition.getAction(),
      tStateTransition.getTargetState().equals(tStateTransition.getSourceState())
          ? copyOfState
          : tStateTransition.getTargetState(),
      tStateTransition.getCondition());
  }
  return copyOfState;
}

private State<T> copy(final State<T> state) {
  final State<T> copyOfState = createState(
    NFAStateNameHandler.getOriginalNameFromInternal(state.getName()),
    state.getStateType());
  for (StateTransition<T> tStateTransition : state.getStateTransitions()) {
    copyOfState.addStateTransition(
      tStateTransition.getAction(),
      tStateTransition.getTargetState().equals(tStateTransition.getSourceState())
          ? copyOfState
          : tStateTransition.getTargetState(),
      tStateTransition.getCondition());
  }
  return copyOfState;
}

  copyOfSink.addStateTransition(tStateTransition.getAction(), targetState, tStateTransition.getCondition());
        ? copyOfSink
        : tStateTransition.getTargetState(),
    tStateTransition.getCondition()
);

private void serializeStates(Set<State<T>> states, DataOutputView out) throws IOException {
  TypeSerializer<String> nameSerializer = StringSerializer.INSTANCE;
  TypeSerializer<State.StateType> stateTypeSerializer = new EnumSerializer<>(State.StateType.class);
  TypeSerializer<StateTransitionAction> actionSerializer = new EnumSerializer<>(StateTransitionAction.class);
  out.writeInt(states.size());
  for (State<T> state: states) {
    nameSerializer.serialize(state.getName(), out);
    stateTypeSerializer.serialize(state.getStateType(), out);
  }
  for (State<T> state: states) {
    nameSerializer.serialize(state.getName(), out);
    out.writeInt(state.getStateTransitions().size());
    for (StateTransition<T> transition : state.getStateTransitions()) {
      nameSerializer.serialize(transition.getSourceState().getName(), out);
      nameSerializer.serialize(transition.getTargetState().getName(), out);
      actionSerializer.serialize(transition.getAction(), out);
      serializeCondition(transition.getCondition(), out);
    }
  }
}