Java Code Examples for org.apache.tinkerpop.gremlin.process.traversal.util.TraversalHelper#hasStepOfAssignableClassRecursively()

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    if (!traversal.getEndStep().getLabels().contains(MARKER) &&
            (traversal.isRoot() || traversal.getParent() instanceof VertexProgramStep) &&
            TraversalHelper.hasStepOfAssignableClassRecursively(ProfileSideEffectStep.class, traversal))
        TraversalHelper.applyTraversalRecursively(t -> t.getEndStep().addLabel(MARKER), traversal);

    if (traversal.getEndStep().getLabels().contains(MARKER)) {
        traversal.getEndStep().removeLabel(MARKER);
        // Add .profile() step after every pre-existing step.
        final List<Step> steps = traversal.getSteps();
        final int numSteps = steps.size();
        for (int i = 0; i < numSteps; i++) {
            // Do not inject profiling after ProfileSideEffectStep as this will be the last step on the root traversal.
            if (steps.get(i * 2) instanceof ProfileSideEffectStep)
                break;
            // Create and inject ProfileStep
            final ProfileStep profileStepToAdd = new ProfileStep(traversal);
            traversal.addStep((i * 2) + 1, profileStepToAdd);

            final Step stepToBeProfiled = traversal.getSteps().get(i * 2);
            if (stepToBeProfiled instanceof ProfilingAware) {
                ((ProfilingAware) stepToBeProfiled).prepareForProfiling();
            }
        }
    }
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    // using a hidden label marker to denote whether the traversal should not be processed by this strategy
    if ((traversal.isRoot() || traversal.getParent() instanceof VertexProgramStep) &&
            TraversalHelper.hasStepOfAssignableClassRecursively(INVALIDATING_STEP_CLASSES, traversal))
        TraversalHelper.applyTraversalRecursively(t -> t.getStartStep().addLabel(MARKER), traversal);
    if (traversal.getStartStep().getLabels().contains(MARKER)) {
        traversal.getStartStep().removeLabel(MARKER);
        return;
    }
    ////////////////////////////////////////////////////////////////////////////
    final Collection<Pair<VertexStep, Step>> stepsToReplace = new ArrayList<>();
    Step prev = null;
    for (final Step curr : traversal.getSteps()) {
        if (curr instanceof TraversalParent) {
            ((TraversalParent) curr).getLocalChildren().forEach(this::apply);
            ((TraversalParent) curr).getGlobalChildren().forEach(this::apply);
        }
        if (isOptimizable(prev, curr)) {
            stepsToReplace.add(Pair.with((VertexStep) prev, curr));
        }
        prev = curr;
    }
    if (!stepsToReplace.isEmpty()) {
        for (final Pair<VertexStep, Step> pair : stepsToReplace) {
            optimizeSteps(traversal, pair.getValue0(), pair.getValue1());
        }
    }
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    if (TraversalHelper.onGraphComputer(traversal))
        return;

    for (int i = 0; i < traversal.getSteps().size(); i++) {
        if (traversal.getSteps().get(i) instanceof RepeatStep) {
            final RepeatStep<?> repeatStep = (RepeatStep) traversal.getSteps().get(i);
            if (null == repeatStep.getEmitTraversal() && null != repeatStep.getRepeatTraversal() &&
                    repeatStep.getUntilTraversal() instanceof LoopTraversal && ((LoopTraversal) repeatStep.getUntilTraversal()).getMaxLoops() > 0 &&
                    !TraversalHelper.hasStepOfAssignableClassRecursively(Scope.global, DedupGlobalStep.class, repeatStep.getRepeatTraversal()) &&
                    !TraversalHelper.hasStepOfAssignableClassRecursively(INVALIDATING_STEPS, repeatStep.getRepeatTraversal())) {
                final Traversal.Admin<?, ?> repeatTraversal = repeatStep.getGlobalChildren().get(0);
                repeatTraversal.removeStep(repeatTraversal.getSteps().size() - 1); // removes the RepeatEndStep
                TraversalHelper.applySingleLevelStrategies(traversal, repeatTraversal, RepeatUnrollStrategy.class);
                final int repeatLength = repeatTraversal.getSteps().size();
                int insertIndex = i;
                final int loops = (int) ((LoopTraversal) repeatStep.getUntilTraversal()).getMaxLoops();
                for (int j = 0; j < loops; j++) {
                    TraversalHelper.insertTraversal(insertIndex, repeatTraversal.clone(), traversal);
                    insertIndex = insertIndex + repeatLength;
                    if ((j != (loops - 1) || !(traversal.getSteps().get(insertIndex).getNextStep() instanceof Barrier)) // only add a final NoOpBarrier is subsequent step is not a barrier
                        && !(traversal.getSteps().get(insertIndex) instanceof NoOpBarrierStep) // Don't add a barrier if this step is a barrier (prevents nested repeat adding the barrier multiple times)
                       ) {
                        traversal.addStep(++insertIndex, new NoOpBarrierStep<>(traversal, MAX_BARRIER_SIZE));
                    }
                }
                // label last step if repeat() was labeled
                if (!repeatStep.getLabels().isEmpty())
                    TraversalHelper.copyLabels(repeatStep, traversal.getSteps().get(insertIndex), false);
                traversal.removeStep(i); // remove the RepeatStep
            }
        }
    }
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    if (!TraversalHelper.onGraphComputer(traversal))
        return;

    if (traversal.getParent() instanceof TraversalVertexProgramStep) {
        if (TraversalHelper.getStepsOfAssignableClassRecursively(GraphStep.class, traversal).size() > 1)
            throw new VerificationException("Mid-traversal V()/E() is currently not supported on GraphComputer", traversal);
        if (TraversalHelper.hasStepOfAssignableClassRecursively(ProfileStep.class, traversal) && TraversalHelper.getStepsOfAssignableClass(VertexProgramStep.class, TraversalHelper.getRootTraversal(traversal)).size() > 1)
            throw new VerificationException("Profiling a multi-VertexProgramStep traversal is currently not supported on GraphComputer", traversal);
    }

    // this is a problem because sideEffect.merge() is transient on the OLAP reduction
    if (TraversalHelper.getRootTraversal(traversal).getTraverserRequirements().contains(TraverserRequirement.ONE_BULK))
        throw new VerificationException("One bulk is currently not supported on GraphComputer: " + traversal, traversal);

    // you can not traverse past the local star graph with localChildren (e.g. by()-modulators).
    if (!TraversalHelper.isGlobalChild(traversal) && !TraversalHelper.isLocalStarGraph(traversal))
        throw new VerificationException("Local traversals may not traverse past the local star-graph on GraphComputer: " + traversal, traversal);

    for (final Step<?, ?> step : traversal.getSteps()) {
        if (step instanceof PathProcessor && ((PathProcessor) step).getMaxRequirement() != PathProcessor.ElementRequirement.ID)
            throw new VerificationException("It is not possible to access more than a path element's id on GraphComputer: " + step + " requires " + ((PathProcessor) step).getMaxRequirement(), traversal);

        if (UNSUPPORTED_STEPS.stream().filter(c -> c.isAssignableFrom(step.getClass())).findFirst().isPresent())
            throw new VerificationException("The following step is currently not supported on GraphComputer: " + step, traversal);
    }

    Step<?, ?> nextParentStep = traversal.getParent().asStep();
    while (!(nextParentStep instanceof EmptyStep)) {
        if (nextParentStep instanceof PathProcessor && ((PathProcessor) nextParentStep).getMaxRequirement() != PathProcessor.ElementRequirement.ID)
            throw new VerificationException("The following path processor step requires more than the element id on GraphComputer: " + nextParentStep + " requires " + ((PathProcessor) nextParentStep).getMaxRequirement(), traversal);
        nextParentStep = nextParentStep.getNextStep();
    }
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    final Graph graph = traversal.getGraph().orElse(EmptyGraph.instance()); // best guess at what the graph will be as its dynamically determined
    for (final TraversalVertexProgramStep step : TraversalHelper.getStepsOfClass(TraversalVertexProgramStep.class, traversal)) {
        final Traversal.Admin<?, ?> computerTraversal = step.generateProgram(graph, EmptyMemory.instance()).getTraversal().get().clone();
        if (!computerTraversal.isLocked())
            computerTraversal.applyStrategies();
        ///
        boolean doesMessagePass = TraversalHelper.hasStepOfAssignableClassRecursively(Scope.global, MULTI_ITERATION_CLASSES, computerTraversal);
        if (!doesMessagePass) {
            for (final VertexStep vertexStep : TraversalHelper.getStepsOfAssignableClassRecursively(Scope.global, VertexStep.class, computerTraversal)) {
                if (vertexStep.returnsVertex() || !vertexStep.getDirection().equals(Direction.OUT)) { // in-edges require message pass in OLAP
                    doesMessagePass = true;
                    break;
                }
            }
        }
        if (!doesMessagePass &&
                !MessagePassingReductionStrategy.endsWithElement(computerTraversal.getEndStep()) &&
                !(computerTraversal.getTraverserRequirements().contains(TraverserRequirement.LABELED_PATH) || // TODO: remove this when dynamic detachment is available in 3.3.0
                        computerTraversal.getTraverserRequirements().contains(TraverserRequirement.PATH))) {  // TODO: remove this when dynamic detachment is available in 3.3.0
            step.setComputer(step.getComputer()
                    // if no message passing, don't partition the loaded graph
                    .configure(Constants.GREMLIN_SPARK_SKIP_PARTITIONER, true)
                    // if no message passing, don't cache the loaded graph
                    .configure(Constants.GREMLIN_SPARK_SKIP_GRAPH_CACHE, true));
        }
    }
}