Java Code Examples for org.apache.flink.cep.pattern.Pattern#getPrevious()

/**
 * Check pattern after match skip strategy.
 */
private void checkPatternSkipStrategy() {
	if (afterMatchSkipStrategy.getPatternName().isPresent()) {
		String patternName = afterMatchSkipStrategy.getPatternName().get();
		Pattern<T, ?> pattern = currentPattern;
		while (pattern.getPrevious() != null && !pattern.getName().equals(patternName)) {
			pattern = pattern.getPrevious();
		}

		// pattern name match check.
		if (!pattern.getName().equals(patternName)) {
			throw new MalformedPatternException("The pattern name specified in AfterMatchSkipStrategy " +
				"can not be found in the given Pattern");
		}
	}
}
 

/**
 * Retrieves list of conditions resulting in Stop state and names of the corresponding NOT patterns.
 *
 * <p>A current not condition can be produced in two cases:
 * <ol>
 *     <li>the previous pattern is a {@link Quantifier.ConsumingStrategy#NOT_FOLLOW}</li>
 *     <li>exists a backward path of {@link Quantifier.QuantifierProperty#OPTIONAL} patterns to
 *       {@link Quantifier.ConsumingStrategy#NOT_FOLLOW}</li>
 * </ol>
 *
 * <p><b>WARNING:</b> for more info on the second case see: {@link NFAFactoryCompiler#copyWithoutTransitiveNots(State)}
 *
 * @return list of not conditions with corresponding names
 */
private List<Tuple2<IterativeCondition<T>, String>> getCurrentNotCondition() {
	List<Tuple2<IterativeCondition<T>, String>> notConditions = new ArrayList<>();

	Pattern<T, ? extends T> previousPattern = currentPattern;
	while (previousPattern.getPrevious() != null && (
		previousPattern.getPrevious().getQuantifier().hasProperty(Quantifier.QuantifierProperty.OPTIONAL) ||
		previousPattern.getPrevious().getQuantifier().getConsumingStrategy() == Quantifier.ConsumingStrategy.NOT_FOLLOW)) {

		previousPattern = previousPattern.getPrevious();

		if (previousPattern.getQuantifier().getConsumingStrategy() == Quantifier.ConsumingStrategy.NOT_FOLLOW) {
			final IterativeCondition<T> notCondition = getTakeCondition(previousPattern);
			notConditions.add(Tuple2.of(notCondition, previousPattern.getName()));
		}
	}
	return notConditions;
}
 

/**
 * Check pattern after match skip strategy.
 */
private void checkPatternSkipStrategy() {
	if (afterMatchSkipStrategy.getPatternName().isPresent()) {
		String patternName = afterMatchSkipStrategy.getPatternName().get();
		Pattern<T, ?> pattern = currentPattern;
		while (pattern.getPrevious() != null && !pattern.getName().equals(patternName)) {
			pattern = pattern.getPrevious();
		}

		// pattern name match check.
		if (!pattern.getName().equals(patternName)) {
			throw new MalformedPatternException("The pattern name specified in AfterMatchSkipStrategy " +
				"can not be found in the given Pattern");
		}
	}
}
 

/**
 * Retrieves list of conditions resulting in Stop state and names of the corresponding NOT patterns.
 *
 * <p>A current not condition can be produced in two cases:
 * <ol>
 *     <li>the previous pattern is a {@link Quantifier.ConsumingStrategy#NOT_FOLLOW}</li>
 *     <li>exists a backward path of {@link Quantifier.QuantifierProperty#OPTIONAL} patterns to
 *       {@link Quantifier.ConsumingStrategy#NOT_FOLLOW}</li>
 * </ol>
 *
 * <p><b>WARNING:</b> for more info on the second case see: {@link NFAFactoryCompiler#copyWithoutTransitiveNots(State)}
 *
 * @return list of not conditions with corresponding names
 */
private List<Tuple2<IterativeCondition<T>, String>> getCurrentNotCondition() {
	List<Tuple2<IterativeCondition<T>, String>> notConditions = new ArrayList<>();

	Pattern<T, ? extends T> previousPattern = currentPattern;
	while (previousPattern.getPrevious() != null && (
		previousPattern.getPrevious().getQuantifier().hasProperty(Quantifier.QuantifierProperty.OPTIONAL) ||
		previousPattern.getPrevious().getQuantifier().getConsumingStrategy() == Quantifier.ConsumingStrategy.NOT_FOLLOW)) {

		previousPattern = previousPattern.getPrevious();

		if (previousPattern.getQuantifier().getConsumingStrategy() == Quantifier.ConsumingStrategy.NOT_FOLLOW) {
			final IterativeCondition<T> notCondition = getTakeCondition(previousPattern);
			notConditions.add(Tuple2.of(notCondition, previousPattern.getName()));
		}
	}
	return notConditions;
}
 

/**
 * Check pattern after match skip strategy.
 */
private void checkPatternSkipStrategy() {
	if (afterMatchSkipStrategy.getPatternName().isPresent()) {
		String patternName = afterMatchSkipStrategy.getPatternName().get();
		Pattern<T, ?> pattern = currentPattern;
		while (pattern.getPrevious() != null && !pattern.getName().equals(patternName)) {
			pattern = pattern.getPrevious();
		}

		// pattern name match check.
		if (!pattern.getName().equals(patternName)) {
			throw new MalformedPatternException("The pattern name specified in AfterMatchSkipStrategy " +
				"can not be found in the given Pattern");
		}
	}
}
 

/**
 * Retrieves list of conditions resulting in Stop state and names of the corresponding NOT patterns.
 *
 * <p>A current not condition can be produced in two cases:
 * <ol>
 *     <li>the previous pattern is a {@link Quantifier.ConsumingStrategy#NOT_FOLLOW}</li>
 *     <li>exists a backward path of {@link Quantifier.QuantifierProperty#OPTIONAL} patterns to
 *       {@link Quantifier.ConsumingStrategy#NOT_FOLLOW}</li>
 * </ol>
 *
 * <p><b>WARNING:</b> for more info on the second case see: {@link NFAFactoryCompiler#copyWithoutTransitiveNots(State)}
 *
 * @return list of not conditions with corresponding names
 */
private List<Tuple2<IterativeCondition<T>, String>> getCurrentNotCondition() {
	List<Tuple2<IterativeCondition<T>, String>> notConditions = new ArrayList<>();

	Pattern<T, ? extends T> previousPattern = currentPattern;
	while (previousPattern.getPrevious() != null && (
		previousPattern.getPrevious().getQuantifier().hasProperty(Quantifier.QuantifierProperty.OPTIONAL) ||
		previousPattern.getPrevious().getQuantifier().getConsumingStrategy() == Quantifier.ConsumingStrategy.NOT_FOLLOW)) {

		previousPattern = previousPattern.getPrevious();

		if (previousPattern.getQuantifier().getConsumingStrategy() == Quantifier.ConsumingStrategy.NOT_FOLLOW) {
			final IterativeCondition<T> notCondition = getTakeCondition(previousPattern);
			notConditions.add(Tuple2.of(notCondition, previousPattern.getName()));
		}
	}
	return notConditions;
}
 

/**
 * Check if there are duplicate pattern names. If yes, it
 * throws a {@link MalformedPatternException}.
 */
private void checkPatternNameUniqueness() {
	// make sure there is no pattern with name "$endState$"
	stateNameHandler.checkNameUniqueness(ENDING_STATE_NAME);
	Pattern patternToCheck = currentPattern;
	while (patternToCheck != null) {
		checkPatternNameUniqueness(patternToCheck);
		patternToCheck = patternToCheck.getPrevious();
	}
	stateNameHandler.clear();
}
 

/**
 * Check if the given pattern's name is already used or not. If yes, it
 * throws a {@link MalformedPatternException}.
 *
 * @param pattern The pattern to be checked
 */
private void checkPatternNameUniqueness(final Pattern pattern) {
	if (pattern instanceof GroupPattern) {
		Pattern patternToCheck = ((GroupPattern) pattern).getRawPattern();
		while (patternToCheck != null) {
			checkPatternNameUniqueness(patternToCheck);
			patternToCheck = patternToCheck.getPrevious();
		}
	} else {
		stateNameHandler.checkNameUniqueness(pattern.getName());
	}
}
 

/**
 * Check if there are duplicate pattern names. If yes, it
 * throws a {@link MalformedPatternException}.
 */
private void checkPatternNameUniqueness() {
	// make sure there is no pattern with name "$endState$"
	stateNameHandler.checkNameUniqueness(ENDING_STATE_NAME);
	Pattern patternToCheck = currentPattern;
	while (patternToCheck != null) {
		checkPatternNameUniqueness(patternToCheck);
		patternToCheck = patternToCheck.getPrevious();
	}
	stateNameHandler.clear();
}
 

/**
 * Check if the given pattern's name is already used or not. If yes, it
 * throws a {@link MalformedPatternException}.
 *
 * @param pattern The pattern to be checked
 */
private void checkPatternNameUniqueness(final Pattern pattern) {
	if (pattern instanceof GroupPattern) {
		Pattern patternToCheck = ((GroupPattern) pattern).getRawPattern();
		while (patternToCheck != null) {
			checkPatternNameUniqueness(patternToCheck);
			patternToCheck = patternToCheck.getPrevious();
		}
	} else {
		stateNameHandler.checkNameUniqueness(pattern.getName());
	}
}
 

/**
 * Check if there are duplicate pattern names. If yes, it
 * throws a {@link MalformedPatternException}.
 */
private void checkPatternNameUniqueness() {
	// make sure there is no pattern with name "$endState$"
	stateNameHandler.checkNameUniqueness(ENDING_STATE_NAME);
	Pattern patternToCheck = currentPattern;
	while (patternToCheck != null) {
		checkPatternNameUniqueness(patternToCheck);
		patternToCheck = patternToCheck.getPrevious();
	}
	stateNameHandler.clear();
}
 

/**
 * Check if the given pattern's name is already used or not. If yes, it
 * throws a {@link MalformedPatternException}.
 *
 * @param pattern The pattern to be checked
 */
private void checkPatternNameUniqueness(final Pattern pattern) {
	if (pattern instanceof GroupPattern) {
		Pattern patternToCheck = ((GroupPattern) pattern).getRawPattern();
		while (patternToCheck != null) {
			checkPatternNameUniqueness(patternToCheck);
			patternToCheck = patternToCheck.getPrevious();
		}
	} else {
		stateNameHandler.checkNameUniqueness(pattern.getName());
	}
}
 

/**
 * Checks if the given pattern is the head pattern of the current group pattern.
 *
 * @param pattern the pattern to be checked
 * @return {@code true} iff the given pattern is in a group pattern and it is the head pattern of the
 * group pattern, {@code false} otherwise
 */
private boolean headOfGroup(Pattern<T, ?> pattern) {
	return currentGroupPattern != null && pattern.getPrevious() == null;
}
 

/**
 * Checks if the given pattern is the head pattern of the current group pattern.
 *
 * @param pattern the pattern to be checked
 * @return {@code true} iff the given pattern is in a group pattern and it is the head pattern of the
 * group pattern, {@code false} otherwise
 */
private boolean headOfGroup(Pattern<T, ?> pattern) {
	return currentGroupPattern != null && pattern.getPrevious() == null;
}
 

/**
 * Checks if the given pattern is the head pattern of the current group pattern.
 *
 * @param pattern the pattern to be checked
 * @return {@code true} iff the given pattern is in a group pattern and it is the head pattern of the
 * group pattern, {@code false} otherwise
 */
private boolean headOfGroup(Pattern<T, ?> pattern) {
	return currentGroupPattern != null && pattern.getPrevious() == null;
}