in gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/verification/StandardVerificationStrategy.java [52:90]
public void apply(final Traversal.Admin<?, ?> traversal) {
if (!traversal.getStrategies().getStrategy(ComputerFinalizationStrategy.class).isPresent() &&
!traversal.getStrategies().getStrategy(ComputerVerificationStrategy.class).isPresent()) {
if (!TraversalHelper.getStepsOfAssignableClass(VertexComputing.class, traversal).isEmpty())
throw new VerificationException("VertexComputing steps must be executed with a GraphComputer: " + TraversalHelper.getStepsOfAssignableClass(VertexComputing.class, traversal), traversal);
}
for (final Step<?, ?> step : traversal.getSteps()) {
for (String label : new HashSet<>(step.getLabels())) {
if (Graph.Hidden.isHidden(label))
step.removeLabel(label);
}
if (step instanceof ReducingBarrierStep && step.getTraversal().getParent() instanceof RepeatStep && step.getTraversal().getParent().getGlobalChildren().get(0).getSteps().contains(step))
throw new VerificationException("The parent of a reducing barrier can not be repeat()-step: " + step, traversal);
// prevents silly stuff like g.V().emit()
if (step instanceof RepeatStep && null == ((RepeatStep) step).getRepeatTraversal())
throw new VerificationException("The repeat()-traversal was not defined:" + traversal, traversal);
}
// The ProfileSideEffectStep must be one of the following
// (1) the last step
// (2) 2nd last step when accompanied by the cap step or none step (i.e. iterate() to nothing)
// (3) 3rd to last when the traversal ends with a RequirementsStep.
final Step<?, ?> endStep = traversal.asAdmin().getEndStep();
if (TraversalHelper.hasStepOfClass(ProfileSideEffectStep.class, traversal) &&
!(endStep instanceof ProfileSideEffectStep ||
(endStep instanceof SideEffectCapStep && endStep.getPreviousStep() instanceof ProfileSideEffectStep) ||
(endStep instanceof DiscardStep && endStep.getPreviousStep() instanceof SideEffectCapStep && endStep.getPreviousStep().getPreviousStep() instanceof ProfileSideEffectStep) ||
(endStep instanceof RequirementsStep && endStep.getPreviousStep() instanceof SideEffectCapStep && endStep.getPreviousStep().getPreviousStep() instanceof ProfileSideEffectStep) ||
(endStep instanceof RequirementsStep && endStep.getPreviousStep() instanceof DiscardStep && endStep.getPreviousStep().getPreviousStep() instanceof SideEffectCapStep && endStep.getPreviousStep().getPreviousStep().getPreviousStep() instanceof ProfileSideEffectStep))) {
throw new VerificationException("When specified, the profile()-Step must be the last step or followed only by the cap()-step.", traversal);
}
if (TraversalHelper.getStepsOfClass(ProfileSideEffectStep.class, traversal).size() > 1) {
throw new VerificationException("The profile()-Step cannot be specified multiple times.", traversal);
}
}