com.lambdazen.bitsy.gremlin.BitsyTraversalStrategy Maven / Gradle / Ivy
package com.lambdazen.bitsy.gremlin;
import org.apache.tinkerpop.gremlin.process.traversal.Step;
import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
import org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategy;
import org.apache.tinkerpop.gremlin.process.traversal.step.HasContainerHolder;
import org.apache.tinkerpop.gremlin.process.traversal.step.filter.HasStep;
import org.apache.tinkerpop.gremlin.process.traversal.step.map.GraphStep;
import org.apache.tinkerpop.gremlin.process.traversal.step.map.NoOpBarrierStep;
import org.apache.tinkerpop.gremlin.process.traversal.step.util.HasContainer;
import org.apache.tinkerpop.gremlin.process.traversal.strategy.AbstractTraversalStrategy;
import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalHelper;
//Bitsy traversal strategy based Tinkerpop's Neo4j implementation
public class BitsyTraversalStrategy extends AbstractTraversalStrategy implements TraversalStrategy.ProviderOptimizationStrategy {
private static final long serialVersionUID = 6405194525894707932L;
private static final BitsyTraversalStrategy INSTANCE = new BitsyTraversalStrategy();
private BitsyTraversalStrategy() {
}
@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();
}
}
}
public static BitsyTraversalStrategy instance() {
return INSTANCE;
}
}