Java StartStep类代码示例

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
private static void assertNumStep(int expectedResults, int expectedSteps, GraphTraversal traversal, Class<? extends Step>... expectedStepTypes) {
        int num = 0;
        while (traversal.hasNext()) {
            traversal.next();
            num++;
        }
//        System.out.println(traversal);
        assertEquals(expectedResults, num);

        //Verify that steps line up with what is expected after Titan's optimizations are applied
        List<Step> steps = traversal.asAdmin().getSteps();
        Set<Class<? extends Step>> expSteps = Sets.newHashSet(expectedStepTypes);
        int numSteps = 0;
        for (Step s : steps) {
//            System.out.println(s.getClass());
            if (s.getClass().equals(GraphStep.class) || s.getClass().equals(StartStep.class)) continue;

            assertTrue(s.getClass().getName(), expSteps.contains(s.getClass()));
            numSteps++;
        }
        assertEquals(expectedSteps, numSteps);
    }
 

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
public default GraphTraversal<S, E> as(final String stepLabel, final String... stepLabels) {
    if (this.asAdmin().getSteps().size() == 0) this.asAdmin().addStep(new StartStep<>(this.asAdmin()));
    final Step<?, E> endStep = this.asAdmin().getEndStep();
    endStep.addLabel(stepLabel);
    for (final String label : stepLabels) {
        endStep.addLabel(label);
    }
    return this;
}
 

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
private static Set<Scoping.Variable> getVariableLocations(final Set<Scoping.Variable> variables, final Traversal.Admin<?, ?> traversal) {
    if (variables.size() == 2) return variables;    // has both START and END so no need to compute further
    final Step<?, ?> startStep = traversal.getStartStep();
    if (StartStep.isVariableStartStep(startStep))
        variables.add(Scoping.Variable.START);
    else if (startStep instanceof WherePredicateStep) {
        if (((WherePredicateStep) startStep).getStartKey().isPresent())
            variables.add(Scoping.Variable.START);
    } else if (startStep instanceof WhereTraversalStep.WhereStartStep) {
        if (!((WhereTraversalStep.WhereStartStep) startStep).getScopeKeys().isEmpty())
            variables.add(Scoping.Variable.START);
    } else if (startStep instanceof MatchStep.MatchStartStep) {
        if (((MatchStep.MatchStartStep) startStep).getSelectKey().isPresent())
            variables.add(Scoping.Variable.START);
    } else if (startStep instanceof MatchStep) {
        ((MatchStep<?, ?>) startStep).getGlobalChildren().forEach(child -> TraversalHelper.getVariableLocations(variables, child));
    } else if (startStep instanceof ConnectiveStep || startStep instanceof NotStep || startStep instanceof WhereTraversalStep)
        ((TraversalParent) startStep).getLocalChildren().forEach(child -> TraversalHelper.getVariableLocations(variables, child));
    ///
    final Step<?, ?> endStep = traversal.getEndStep();
    if (endStep instanceof WherePredicateStep) {
        if (((WherePredicateStep) endStep).getStartKey().isPresent())
            variables.add(Scoping.Variable.END);
    } else if (endStep instanceof WhereTraversalStep.WhereEndStep) {
        if (!((WhereTraversalStep.WhereEndStep) endStep).getScopeKeys().isEmpty())
            variables.add(Scoping.Variable.END);
    } else if (endStep instanceof MatchStep.MatchEndStep) {
        if (((MatchStep.MatchEndStep) endStep).getMatchKey().isPresent())
            variables.add(Scoping.Variable.END);
    } else if (!endStep.getLabels().isEmpty())
        variables.add(Scoping.Variable.END);
    ///
    return variables;
}
 

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
private static void processConjunctionMarker(final Class<? extends ConnectiveStep> markerClass, final Traversal.Admin<?, ?> traversal) {

        TraversalHelper.getStepsOfClass(markerClass, traversal).stream()
                .filter(conjunctionStep -> conjunctionStep.getLocalChildren().isEmpty())
                .findFirst().ifPresent(connectiveStep -> {

            Step<?, ?> currentStep = connectiveStep.getNextStep();
            final Traversal.Admin<?, ?> rightTraversal = __.start().asAdmin();
            if (!connectiveStep.getLabels().isEmpty()) {
                final StartStep<?> startStep = new StartStep<>(rightTraversal);
                final Set<String> conjunctionLabels = ((Step<?, ?>) connectiveStep).getLabels();
                conjunctionLabels.forEach(startStep::addLabel);
                conjunctionLabels.forEach(label -> connectiveStep.removeLabel(label));
                rightTraversal.addStep(startStep);
            }
            while (legalCurrentStep(currentStep)) {
                final Step<?, ?> nextStep = currentStep.getNextStep();
                rightTraversal.addStep(currentStep);
                traversal.removeStep(currentStep);
                currentStep = nextStep;
            }
            processConnectiveMarker(rightTraversal);

            currentStep = connectiveStep.getPreviousStep();
            final Traversal.Admin<?, ?> leftTraversal = __.start().asAdmin();
            while (legalCurrentStep(currentStep)) {
                final Step<?, ?> previousStep = currentStep.getPreviousStep();
                leftTraversal.addStep(0, currentStep);
                traversal.removeStep(currentStep);
                currentStep = previousStep;
            }
            processConnectiveMarker(leftTraversal);

            TraversalHelper.replaceStep(connectiveStep,
                    connectiveStep instanceof AndStep ?
                            new AndStep(traversal, leftTraversal, rightTraversal) :
                            new OrStep(traversal, leftTraversal, rightTraversal), traversal);
        });
    }
 

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
private static <T extends Traversal.Admin<Vertex, Edge>> T setVertexStart(
    Traversal.Admin<Vertex, Edge> incidentTraversal, Vertex vertex) {
incidentTraversal.addStep(0, new StartStep<>(incidentTraversal, vertex));
@SuppressWarnings("unchecked")
T t = (T) incidentTraversal;
return t;
   }
 

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
/**
 * A step modulator that provides a lable to the step that can be accessed later in the traversal by other steps.
 *
 * @param stepLabel  the name of the step
 * @param stepLabels additional names for the label
 * @return the traversal with the modified end step
 * @see <a href="http://tinkerpop.apache.org/docs/${project.version}/reference/#as-step" target="_blank">Reference Documentation - As Step</a>
 * @since 3.0.0-incubating
 */
public default GraphTraversal<S, E> as(final String stepLabel, final String... stepLabels) {
    this.asAdmin().getBytecode().addStep(Symbols.as, stepLabel, stepLabels);
    if (this.asAdmin().getSteps().size() == 0) this.asAdmin().addStep(new StartStep<>(this.asAdmin()));
    final Step<?, E> endStep = this.asAdmin().getEndStep();
    endStep.addLabel(stepLabel);
    for (final String label : stepLabels) {
        endStep.addLabel(label);
    }
    return this;
}
 

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
private static Set<Scoping.Variable> getVariableLocations(final Set<Scoping.Variable> variables, final Traversal.Admin<?, ?> traversal) {
    if (variables.size() == 2) return variables;    // has both START and END so no need to compute further
    final Step<?, ?> startStep = traversal.getStartStep();
    if (StartStep.isVariableStartStep(startStep))
        variables.add(Scoping.Variable.START);
    else if (startStep instanceof WherePredicateStep) {
        if (((WherePredicateStep) startStep).getStartKey().isPresent())
            variables.add(Scoping.Variable.START);
    } else if (startStep instanceof WhereTraversalStep.WhereStartStep) {
        if (!((WhereTraversalStep.WhereStartStep) startStep).getScopeKeys().isEmpty())
            variables.add(Scoping.Variable.START);
    } else if (startStep instanceof MatchStep.MatchStartStep) {
        if (((MatchStep.MatchStartStep) startStep).getSelectKey().isPresent())
            variables.add(Scoping.Variable.START);
    } else if (startStep instanceof MatchStep) {
        for (final Traversal.Admin<?, ?> global : ((MatchStep<?, ?>) startStep).getGlobalChildren()) {
            TraversalHelper.getVariableLocations(variables, global);
        }
    } else if (startStep instanceof ConnectiveStep || startStep instanceof NotStep || startStep instanceof WhereTraversalStep) {
        for (final Traversal.Admin<?, ?> local : ((TraversalParent) startStep).getLocalChildren()) {
            TraversalHelper.getVariableLocations(variables, local);
        }
    }
    ///
    final Step<?, ?> endStep = traversal.getEndStep();
    if (endStep instanceof WherePredicateStep) {
        if (((WherePredicateStep) endStep).getStartKey().isPresent())
            variables.add(Scoping.Variable.END);
    } else if (endStep instanceof WhereTraversalStep.WhereEndStep) {
        if (!((WhereTraversalStep.WhereEndStep) endStep).getScopeKeys().isEmpty())
            variables.add(Scoping.Variable.END);
    } else if (endStep instanceof MatchStep.MatchEndStep) {
        if (((MatchStep.MatchEndStep) endStep).getMatchKey().isPresent())
            variables.add(Scoping.Variable.END);
    } else if (!endStep.getLabels().isEmpty())
        variables.add(Scoping.Variable.END);
    ///
    return variables;
}
 

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
private static void processConjunctionMarker(final Class<? extends ConnectiveStep> markerClass, final Traversal.Admin<?, ?> traversal) {

        TraversalHelper.getStepsOfClass(markerClass, traversal).stream()
                .filter(conjunctionStep -> conjunctionStep.getLocalChildren().isEmpty())
                .findFirst().ifPresent(connectiveStep -> {

            Step<?, ?> currentStep = connectiveStep.getNextStep();
            final Traversal.Admin<?, ?> rightTraversal = __.start().asAdmin();
            if (!connectiveStep.getLabels().isEmpty()) {
                final StartStep<?> startStep = new StartStep<>(rightTraversal);
                final Set<String> conjunctionLabels = ((Step<?, ?>) connectiveStep).getLabels();
                conjunctionLabels.forEach(startStep::addLabel);
                conjunctionLabels.forEach(label -> connectiveStep.removeLabel(label));
                rightTraversal.addStep(startStep);
            }
            while (legalCurrentStep(currentStep)) {
                final Step<?, ?> nextStep = currentStep.getNextStep();
                rightTraversal.addStep(currentStep);
                traversal.removeStep(currentStep);
                currentStep = nextStep;
            }
            processConnectiveMarker(rightTraversal);

            currentStep = connectiveStep.getPreviousStep();
            final Traversal.Admin<?, ?> leftTraversal = __.start().asAdmin();
            while (legalCurrentStep(currentStep)) {
                final Step<?, ?> previousStep = currentStep.getPreviousStep();
                leftTraversal.addStep(0, currentStep);
                traversal.removeStep(currentStep);
                currentStep = previousStep;
            }
            processConnectiveMarker(leftTraversal);

            if (connectiveStep instanceof AndStep)
                TraversalHelper.replaceStep((Step) connectiveStep, new AndStep(traversal, leftTraversal, rightTraversal), traversal);
            else
                TraversalHelper.replaceStep((Step) connectiveStep, new OrStep(traversal, leftTraversal, rightTraversal), traversal);
        });
    }
 

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
private static boolean legalCurrentStep(final Step<?, ?> step) {
    return !(step instanceof EmptyStep || step instanceof ProfileSideEffectStep || step instanceof ComputerAwareStep.EndStep || (step instanceof StartStep && !StartStep.isVariableStartStep(step)) || GraphStep.isStartStep(step));
}
 

import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.StartStep; //导入依赖的package包/类
private static boolean legalCurrentStep(final Step<?, ?> step) {
    return !(step instanceof EmptyStep || step instanceof ProfileSideEffectStep || step instanceof HasNextStep ||
            step instanceof ComputerAwareStep.EndStep || (step instanceof StartStep && !StartStep.isVariableStartStep(step)) ||
            GraphStep.isStartStep(step));
}