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

@Override
@SuppressWarnings({ "rawtypes", "unchecked" })
public void apply(final Traversal.Admin<?, ?> traversal) {
    TraversalUtil.convAllHasSteps(traversal);

    List<VertexStep> steps = TraversalHelper.getStepsOfClass(
                             VertexStep.class, traversal);
    for (VertexStep originStep : steps) {
        HugeVertexStep<?> newStep = new HugeVertexStep<>(originStep);
        TraversalHelper.replaceStep(originStep, newStep, traversal);

        TraversalUtil.extractHasContainer(newStep, traversal);

        // TODO: support order-by optimize
        // TraversalUtil.extractOrder(newStep, traversal);

        TraversalUtil.extractRange(newStep, traversal, true);

        TraversalUtil.extractCount(newStep, traversal);
    }
}
 

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

    for (final GraphStep originalGraphStep : TraversalHelper.getStepsOfClass(GraphStep.class, traversal)) {
        final TinkerGraphStep<?, ?> tinkerGraphStep = new TinkerGraphStep<>(originalGraphStep);
        TraversalHelper.replaceStep(originalGraphStep, tinkerGraphStep, traversal);
        Step<?, ?> currentStep = tinkerGraphStep.getNextStep();
        while (currentStep instanceof HasStep || currentStep instanceof NoOpBarrierStep) {
            if (currentStep instanceof HasStep) {
                for (final HasContainer hasContainer : ((HasContainerHolder) currentStep).getHasContainers()) {
                    if (!GraphStep.processHasContainerIds(tinkerGraphStep, hasContainer))
                        tinkerGraphStep.addHasContainer(hasContainer);
                }
                TraversalHelper.copyLabels(currentStep, currentStep.getPreviousStep(), false);
                traversal.removeStep(currentStep);
            }
            currentStep = currentStep.getNextStep();
        }
    }
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
	for (final GraphStep originalGraphStep : TraversalHelper.getStepsOfClass(GraphStep.class, traversal)) {
		final BitsyGraphStep<?, ?> bitsyGraphStep = new BitsyGraphStep<>(originalGraphStep);
		TraversalHelper.replaceStep(originalGraphStep, bitsyGraphStep, traversal);
		Step<?, ?> currentStep = bitsyGraphStep.getNextStep();
		while (currentStep instanceof HasStep || currentStep instanceof NoOpBarrierStep) {
			if (currentStep instanceof HasStep) {
				for (final HasContainer hasContainer : ((HasContainerHolder) currentStep).getHasContainers()) {
					if (!GraphStep.processHasContainerIds(bitsyGraphStep, hasContainer))
						bitsyGraphStep.addHasContainer(hasContainer);
				}
				TraversalHelper.copyLabels(currentStep, currentStep.getPreviousStep(), false);
				traversal.removeStep(currentStep);
			}
			currentStep = currentStep.getNextStep();
		}
	}
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    for (final GraphStep originalGraphStep : TraversalHelper.getStepsOfClass(GraphStep.class, traversal)) {
        final Neo4jGraphStep<?, ?> neo4jGraphStep = new Neo4jGraphStep<>(originalGraphStep);
        TraversalHelper.replaceStep(originalGraphStep, neo4jGraphStep, traversal);
        Step<?, ?> currentStep = neo4jGraphStep.getNextStep();
        while (currentStep instanceof HasStep || currentStep instanceof NoOpBarrierStep) {
            if (currentStep instanceof HasStep) {
                for (final HasContainer hasContainer : ((HasContainerHolder) currentStep).getHasContainers()) {
                    if (!GraphStep.processHasContainerIds(neo4jGraphStep, hasContainer))
                        neo4jGraphStep.addHasContainer(hasContainer);
                }
                TraversalHelper.copyLabels(currentStep, currentStep.getPreviousStep(), false);
                traversal.removeStep(currentStep);
            }
            currentStep = currentStep.getNextStep();
        }
    }
}
 

@SuppressWarnings("unchecked")
@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    for (final VertexStep originalVertexStep : TraversalHelper.getStepsOfClass(VertexStep.class, traversal)) {
        final HBaseVertexStep<?> hbaseVertexStep = new HBaseVertexStep<>(originalVertexStep);
        TraversalHelper.replaceStep(originalVertexStep, hbaseVertexStep, traversal);
        Step<?, ?> currentStep = hbaseVertexStep.getNextStep();
        while (currentStep instanceof HasStep || currentStep instanceof NoOpBarrierStep) {
            if (currentStep instanceof HasStep) {
                for (final HasContainer hasContainer : ((HasContainerHolder) currentStep).getHasContainers()) {
                    hbaseVertexStep.addHasContainer(hasContainer);
                }
                TraversalHelper.copyLabels(currentStep, currentStep.getPreviousStep(), false);
                traversal.removeStep(currentStep);
            }
            currentStep = currentStep.getNextStep();
        }
    }
}
 

@SuppressWarnings("unchecked")
@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    for (final GraphStep originalGraphStep : TraversalHelper.getStepsOfClass(GraphStep.class, traversal)) {
        final HBaseGraphStep<?, ?> hbaseGraphStep = new HBaseGraphStep<>(originalGraphStep);
        TraversalHelper.replaceStep(originalGraphStep, hbaseGraphStep, traversal);
        Step<?, ?> currentStep = hbaseGraphStep.getNextStep();
        while (currentStep instanceof HasStep || currentStep instanceof NoOpBarrierStep) {
            if (currentStep instanceof HasStep) {
                for (final HasContainer hasContainer : ((HasContainerHolder) currentStep).getHasContainers()) {
                    if (!GraphStep.processHasContainerIds(hbaseGraphStep, hasContainer))
                        hbaseGraphStep.addHasContainer(hasContainer);
                }
                TraversalHelper.copyLabels(currentStep, currentStep.getPreviousStep(), false);
                traversal.removeStep(currentStep);
            }
            currentStep = currentStep.getNextStep();
        }
    }
}
 

@Override
@SuppressWarnings({ "rawtypes", "unchecked" })
public void apply(Traversal.Admin<?, ?> traversal) {
    TraversalUtil.convAllHasSteps(traversal);

    // Extract conditions in GraphStep
    List<GraphStep> steps = TraversalHelper.getStepsOfClass(
                            GraphStep.class, traversal);
    for (GraphStep originStep : steps) {
        HugeGraphStep<?, ?> newStep = new HugeGraphStep<>(originStep);
        TraversalHelper.replaceStep(originStep, newStep, traversal);

        TraversalUtil.extractHasContainer(newStep, traversal);

        // TODO: support order-by optimize
        // TraversalUtil.extractOrder(newStep, traversal);

        TraversalUtil.extractRange(newStep, traversal, false);

        TraversalUtil.extractCount(newStep, traversal);
    }
}
 

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

    for (final GraphStep originalGraphStep : TraversalHelper.getStepsOfClass(GraphStep.class, traversal)) {
        final TinkerGraphStep<?, ?> tinkerGraphStep = new TinkerGraphStep<>(originalGraphStep);
        TraversalHelper.replaceStep(originalGraphStep, tinkerGraphStep, traversal);
        Step<?, ?> currentStep = tinkerGraphStep.getNextStep();
        while (currentStep instanceof HasStep || currentStep instanceof NoOpBarrierStep) {
            if (currentStep instanceof HasStep) {
                for (final HasContainer hasContainer : ((HasContainerHolder) currentStep).getHasContainers()) {
                    if (!GraphStep.processHasContainerIds(tinkerGraphStep, hasContainer))
                        tinkerGraphStep.addHasContainer(hasContainer);
                }
                TraversalHelper.copyLabels(currentStep, currentStep.getPreviousStep(), false);
                traversal.removeStep(currentStep);
            }
            currentStep = currentStep.getNextStep();
        }
    }
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    //Only optimize SqlgGraph. StarGraph also passes through here.
    if (!(traversal.getGraph().orElseThrow(IllegalStateException::new) instanceof SqlgGraph)) {
        return;
    }
    if (!SqlgTraversalUtil.mayOptimize(traversal)) {
        return;
    }
    List<TraversalFilterStep> traversalFilterSteps = TraversalHelper.getStepsOfAssignableClass(TraversalFilterStep.class, traversal);
    for (@SuppressWarnings("unchecked") TraversalFilterStep<S> traversalFilterStep : traversalFilterSteps) {

        List<Traversal.Admin<S, ?>> filterTraversals = traversalFilterStep.getLocalChildren();
        Preconditions.checkState(filterTraversals.size() == 1);
        Traversal.Admin<S, ?> filterTraversal = filterTraversals.get(0);

        //reducing barrier steps like count does not work with Sqlg's barrier optimizations
        List<ReducingBarrierStep> reducingBarrierSteps = TraversalHelper.getStepsOfAssignableClassRecursively(ReducingBarrierStep.class, filterTraversal);
        if (!reducingBarrierSteps.isEmpty()) {
            continue;
        }

        SqlgTraversalFilterStepBarrier sqlgTraversalFilterStepBarrier = new SqlgTraversalFilterStepBarrier<>(
                traversal,
                filterTraversal
        );
        for (String label : traversalFilterStep.getLabels()) {
            sqlgTraversalFilterStepBarrier.addLabel(label);
        }
        //noinspection unchecked
        TraversalHelper.replaceStep(
                traversalFilterStep,
                sqlgTraversalFilterStepBarrier,
                traversalFilterStep.getTraversal()
        );
    }
}
 

@SuppressWarnings("unchecked")
@Override
protected void replaceStepInTraversal(Step stepToReplace, SqlgStep sqlgStep) {
    if (this.traversal.getSteps().contains(stepToReplace)) {
        TraversalHelper.replaceStep(stepToReplace, sqlgStep, this.traversal);
    } else {
        TraversalHelper.insertAfterStep(sqlgStep, stepToReplace.getPreviousStep(), this.traversal);
    }
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    //Only optimize SqlgGraph. StarGraph also passes through here.
    if (!(traversal.getGraph().orElseThrow(IllegalStateException::new) instanceof SqlgGraph)) {
        return;
    }
    if (!SqlgTraversalUtil.mayOptimize(traversal)) {
        return;
    }
    List<HasStep> hasSteps = TraversalHelper.getStepsOfAssignableClass(HasStep.class, traversal);
    for (HasStep<?> hasStep : hasSteps) {
        List<HasContainer> hasContainers = new ArrayList<>(hasStep.getHasContainers());
        SqlgHasStep sqlgHasStep = new SqlgHasStep(
                hasStep.getTraversal(),
                hasContainers.toArray(new HasContainer[]{})
        );
        for (String label : hasStep.getLabels()) {
            sqlgHasStep.addLabel(label);
        }
        //noinspection unchecked
        TraversalHelper.replaceStep(
                hasStep,
                sqlgHasStep,
                hasStep.getTraversal()
        );
    }
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    //Only optimize SqlgGraph. StarGraph also passes through here.
    if (!(traversal.getGraph().orElseThrow(IllegalStateException::new) instanceof SqlgGraph)) {
        return;
    }
    if (!SqlgTraversalUtil.mayOptimize(traversal)) {
        return;
    }
    List<AddVertexStartStep> addVertexStartSteps = TraversalHelper.getStepsOfAssignableClassRecursively(AddVertexStartStep.class, traversal);
    for (AddVertexStartStep addVertexStartStep : addVertexStartSteps) {
        SqlgAddVertexStartStep sqlgAddVertexStartStep = new SqlgAddVertexStartStep(
                addVertexStartStep.getTraversal(),
                addVertexStartStep.getParameters()
        );
        for (EventCallback<Event.VertexAddedEvent> callback : addVertexStartStep.getMutatingCallbackRegistry().getCallbacks()) {
            sqlgAddVertexStartStep.getMutatingCallbackRegistry().addCallback(callback);
        }
        for (String label : addVertexStartStep.getLabels()) {
            sqlgAddVertexStartStep.addLabel(label);
        }
        //noinspection unchecked
        TraversalHelper.replaceStep(
                addVertexStartStep,
                sqlgAddVertexStartStep,
                addVertexStartStep.getTraversal()
        );
    }
}
 

@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    //Only optimize SqlgGraph. StarGraph also passes through here.
    if (!(traversal.getGraph().orElseThrow(IllegalStateException::new) instanceof SqlgGraph)) {
        return;
    }
    if (!SqlgTraversalUtil.mayOptimize(traversal)) {
        return;
    }
    List<WhereTraversalStep> whereTraversalSteps = TraversalHelper.getStepsOfAssignableClass(WhereTraversalStep.class, traversal);
    for (@SuppressWarnings("unchecked") WhereTraversalStep<S> whereTraversalStep : whereTraversalSteps) {

        List<Traversal.Admin<?, ?>> whereTraversals = whereTraversalStep.getLocalChildren();
        Preconditions.checkState(whereTraversals.size() == 1);
        Traversal.Admin<?, ?> whereTraversal = whereTraversals.get(0);

        //reducing barrier steps like count does not work with Sqlg's barrier optimizations
        List<ReducingBarrierStep> reducingBarrierSteps = TraversalHelper.getStepsOfAssignableClassRecursively(ReducingBarrierStep.class, whereTraversal);
        if (!reducingBarrierSteps.isEmpty()) {
            continue;
        }

        SqlgWhereTraversalStepBarrier sqlgTraversalFilterStepBarrier = new SqlgWhereTraversalStepBarrier<>(
                traversal,
                whereTraversalStep
        );
        for (String label : whereTraversalStep.getLabels()) {
            sqlgTraversalFilterStepBarrier.addLabel(label);
        }
        //noinspection unchecked
        TraversalHelper.replaceStep(
                whereTraversalStep,
                sqlgTraversalFilterStepBarrier,
                whereTraversalStep.getTraversal()
        );
    }
}
 

@Test
public void shouldSetPreviousStepToEmptyStep() {
    final Traversal.Admin<?, ?> traversal = __.V().out().asAdmin();
    //transform the traversal to __.V().not(out())
    //the VertexStep's previousStep should be the EmptyStep
    Optional<VertexStep> vertexStepOpt = TraversalHelper.getFirstStepOfAssignableClass(VertexStep.class, traversal);
    assertTrue(vertexStepOpt.isPresent());
    Traversal.Admin<?,?> inner = __.start().asAdmin();
    inner.addStep(0, vertexStepOpt.get());
    TraversalHelper.replaceStep(vertexStepOpt.get(), new NotStep<>(__.identity().asAdmin(), inner), traversal);
    List<VertexStep> vertexSteps = TraversalHelper.getStepsOfAssignableClassRecursively(VertexStep.class, traversal);
    assertEquals(1, vertexSteps.size());
    VertexStep vertexStep = vertexSteps.get(0);
    assertTrue("Expected the previousStep to be an EmptyStep, found instead " + vertexStep.getPreviousStep().toString(),vertexStep.getPreviousStep() == EmptyStep.instance());
}
 

@Override
public void apply(Traversal.Admin<?, ?> traversal) {
    if (!(traversal.getGraph().orElseThrow(IllegalStateException::new) instanceof SqlgGraph)) {
        return;
    }
    if (!SqlgTraversalUtil.mayOptimize(traversal)) {
        return;
    }
    Optional<DropStep> dropStepOptional = TraversalHelper.getLastStepOfAssignableClass(DropStep.class, traversal);
    if (dropStepOptional.isPresent()) {
        DropStep<?> dropStep = dropStepOptional.get();
        TraversalHelper.replaceStep(dropStep, new SqlgDropStepBarrier<>(traversal, dropStep.getMutatingCallbackRegistry()), traversal);
    }
}
 

/**
 * If this step is followed by a subsequent has step then the properties will need to be
 * known when that has step is executed. The batch property pre-fetching optimisation
 * loads those properties into the vertex cache with a multiQuery preventing the need to
 * go back to the storage back-end for each vertex to fetch the properties.
 *
 * @param traversal         The traversal containing the step
 * @param vertexStep        The step to potentially apply the optimisation to
 * @param nextStep          The next step in the traversal
 * @param txVertexCacheSize The size of the vertex cache
 */
private void applyBatchPropertyPrefetching(Admin<?, ?> traversal, JanusGraphVertexStep vertexStep, Step nextStep, int txVertexCacheSize) {
    if (Vertex.class.isAssignableFrom(vertexStep.getReturnClass())) {
        if (HasStepFolder.foldableHasContainerNoLimit(vertexStep)) {
            vertexStep.setBatchPropertyPrefetching(true);
            vertexStep.setTxVertexCacheSize(txVertexCacheSize);
        }
    } else if (nextStep instanceof EdgeVertexStep) {
        EdgeVertexStep edgeVertexStep = (EdgeVertexStep) nextStep;
        if (HasStepFolder.foldableHasContainerNoLimit(edgeVertexStep)) {
            JanusGraphEdgeVertexStep estep = new JanusGraphEdgeVertexStep(edgeVertexStep, txVertexCacheSize);
            TraversalHelper.replaceStep(nextStep, estep, traversal);
        }
    }
}
 

/**
 * Replace the {@code graphStep} and {@code filterStep} with a new JanusPreviousPropertyStep in the given
 * {@code traversal}.
 */
private void executeStrategy(
        Traversal.Admin<?, ?> traversal, GraphStep<?, ?> graphStep, TraversalFilterStep<Vertex> filterStep,
        String propertyKey, String label) {

    JanusPreviousPropertyStep newStep = new JanusPreviousPropertyStep(traversal, propertyKey, label);
    traversal.removeStep(filterStep);
    TraversalHelper.replaceStep(graphStep, newStep, traversal);
}
 

public static void extractRange(Step<?, ?> newStep,
                                Traversal.Admin<?, ?> traversal,
                                boolean extractOnlyLimit) {
    QueryHolder holder = (QueryHolder) newStep;
    Step<?, ?> step = newStep;
    do {
        step = step.getNextStep();
        if (step instanceof RangeGlobalStep) {
            @SuppressWarnings("unchecked")
            RangeGlobalStep<Object> range = (RangeGlobalStep<Object>) step;
            /*
             * NOTE: keep the step to limit results after query from DB
             * due to `limit`(in DB) may not be implemented accurately.
             * but the backend driver should ensure `offset` accurately.
             */
            // TraversalHelper.copyLabels(step, newStep, false);
            // traversal.removeStep(step);
            if (extractOnlyLimit) {
                // May need to retain offset for multiple sub-queries
                holder.setRange(0, range.getHighRange());
            } else {
                long limit = holder.setRange(range.getLowRange(),
                                             range.getHighRange());
                RangeGlobalStep<Object> newRange = new RangeGlobalStep<>(
                                                   traversal, 0, limit);
                TraversalHelper.replaceStep(range, newRange, traversal);
            }
        }
    } while (step instanceof RangeGlobalStep ||
             step instanceof IdentityStep ||
             step instanceof NoOpBarrierStep);
}
 

private static final boolean processOrStep(final OrStep<?> step, final Traversal.Admin<?, ?> traversal) {
    boolean process = true;
    String key = null;
    P predicate = null;
    final List<String> labels = new ArrayList<>();
    for (final Traversal.Admin<?, ?> childTraversal : step.getLocalChildren()) {
        InlineFilterStrategy.instance().apply(childTraversal); // todo: this may be a bad idea, but I can't seem to find a test case to break it
        for (final Step<?, ?> childStep : childTraversal.getSteps()) {
            if (childStep instanceof HasStep) {
                P p = null;
                for (final HasContainer hasContainer : ((HasStep<?>) childStep).getHasContainers()) {
                    if (null == key)
                        key = hasContainer.getKey();
                    else if (!hasContainer.getKey().equals(key)) {
                        process = false;
                        break;
                    }
                    p = null == p ?
                            hasContainer.getPredicate() :
                            p.and(hasContainer.getPredicate());
                }
                if (process) {
                    predicate = null == predicate ? p : predicate.or(p);
                }
                labels.addAll(childStep.getLabels());
            } else {
                process = false;
                break;
            }
        }
        if (!process)
            break;
    }
    if (process) {
        final HasStep hasStep = new HasStep<>(traversal, new HasContainer(key, predicate));
        TraversalHelper.replaceStep(step, hasStep, traversal);
        TraversalHelper.copyLabels(step, hasStep, false);
        for (final String label : labels) {
            hasStep.addLabel(label);
        }
        return true;
    }
    return false;
}
 

@SuppressWarnings("unchecked")
@Override
public void apply(final Traversal.Admin<?, ?> traversal) {
    //Only optimize SqlgGraph. StarGraph also passes through here.
    //noinspection OptionalGetWithoutIsPresent
    if (!(traversal.getGraph().orElseThrow(IllegalStateException::new) instanceof SqlgGraph)) {
        return;
    }
    if (!SqlgTraversalUtil.mayOptimize(traversal)) {
        return;
    }
    List<ChooseStep> chooseSteps = TraversalHelper.getStepsOfAssignableClass(ChooseStep.class, traversal);
    for (ChooseStep<S, E, M> chooseStep : chooseSteps) {
        Traversal.Admin<S, M> predicateTraversal = chooseStep.getLocalChildren().get(0);

        //The predicate branch step is a local traversal.
        //As such if it contains a ReducingBarrierStep the SqlgBranchStepBarrier will not work.
        List<ReducingBarrierStep> reducingBarrierSteps = TraversalHelper.getStepsOfAssignableClass(ReducingBarrierStep.class, predicateTraversal);
        if (!reducingBarrierSteps.isEmpty()) {
            continue;
        }

        if (predicateTraversal.getSteps().get(predicateTraversal.getSteps().size() - 1) instanceof HasNextStep) {
            predicateTraversal.removeStep(predicateTraversal.getSteps().get(predicateTraversal.getSteps().size() - 1));
        }

        SqlgBranchStepBarrier sqlgBranchStepBarrier = new SqlgChooseStepBarrier<>(
                traversal,
                predicateTraversal
        );
        for (String label : chooseStep.getLabels()) {
            sqlgBranchStepBarrier.addLabel(label);
        }
        try {
            Field traversalOptionsField = chooseStep.getClass().getSuperclass().getDeclaredField("traversalOptions");
            traversalOptionsField.setAccessible(true);
            Map<M, List<Traversal.Admin<S, E>>> traversalOptions = (Map<M, List<Traversal.Admin<S, E>>>) traversalOptionsField.get(chooseStep);
            for (Map.Entry<M, List<Traversal.Admin<S, E>>> entry : traversalOptions.entrySet()) {
                for (Traversal.Admin<S, E> admin : entry.getValue()) {
                    sqlgBranchStepBarrier.addGlobalChildOption(entry.getKey(), admin);
                }
            }
        } catch (NoSuchFieldException | IllegalAccessException e) {
            throw new RuntimeException(e);
        }

        TraversalHelper.replaceStep(
                chooseStep,
                sqlgBranchStepBarrier,
                chooseStep.getTraversal()
        );
    }
}