| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.tinkerpop.gremlin.process.traversal.step.filter; |
| |
| import org.apache.tinkerpop.gremlin.process.traversal.P; |
| import org.apache.tinkerpop.gremlin.process.traversal.Pop; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.ByModulating; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.PathProcessor; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.Scoping; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.TraversalParent; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.ConnectiveP; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalRing; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalUtil; |
| import org.apache.tinkerpop.gremlin.structure.util.StringFactory; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Optional; |
| import java.util.Set; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class WherePredicateStep<S> extends FilterStep<S> implements Scoping, PathProcessor, ByModulating, TraversalParent { |
| |
| protected String startKey; |
| protected List<String> selectKeys; |
| protected P<Object> predicate; |
| protected final Set<String> scopeKeys = new HashSet<>(); |
| protected Set<String> keepLabels; |
| |
| protected TraversalRing<S, ?> traversalRing = new TraversalRing<>(); |
| |
| public WherePredicateStep(final Traversal.Admin traversal, final Optional<String> startKey, final P<String> predicate) { |
| super(traversal); |
| this.startKey = startKey.orElse(null); |
| if (null != this.startKey) |
| this.scopeKeys.add(this.startKey); |
| this.predicate = (P) predicate; |
| this.selectKeys = new ArrayList<>(); |
| this.configurePredicates(this.predicate); |
| } |
| |
| private void configurePredicates(final P<Object> predicate) { |
| if (predicate instanceof ConnectiveP) |
| ((ConnectiveP<Object>) predicate).getPredicates().forEach(this::configurePredicates); |
| else { |
| final String selectKey = getSelectKey(predicate); |
| this.selectKeys.add(selectKey); |
| this.scopeKeys.add(selectKey); |
| } |
| } |
| |
| private void setPredicateValues(final P<Object> predicate, final Traverser.Admin<S> traverser, final Iterator<String> selectKeysIterator) { |
| if (predicate instanceof ConnectiveP) |
| ((ConnectiveP<Object>) predicate).getPredicates().forEach(p -> this.setPredicateValues(p, traverser, selectKeysIterator)); |
| else |
| predicate.setValue(TraversalUtil.applyNullable((S) this.getSafeScopeValue(Pop.last, selectKeysIterator.next(), traverser), this.traversalRing.next())); |
| } |
| |
| public Optional<P<?>> getPredicate() { |
| return Optional.ofNullable(this.predicate); |
| } |
| |
| public Optional<String> getStartKey() { |
| return Optional.ofNullable(this.startKey); |
| } |
| |
| public String getSelectKey(final P<Object> predicate) { |
| return (String) (predicate.getValue() instanceof Collection ? ((Collection) predicate.getValue()).iterator().next() |
| : predicate.getValue()); // hack for within("x")) |
| } |
| |
| public void removeStartKey() { |
| this.selectKeys.remove(this.startKey); |
| this.startKey = null; |
| } |
| |
| @Override |
| protected boolean filter(final Traverser.Admin<S> traverser) { |
| final Object value = null == this.startKey ? |
| TraversalUtil.applyNullable(traverser, this.traversalRing.next()) : |
| TraversalUtil.applyNullable((S) this.getSafeScopeValue(Pop.last, this.startKey, traverser), this.traversalRing.next()); |
| this.setPredicateValues(this.predicate, traverser, this.selectKeys.iterator()); |
| this.traversalRing.reset(); |
| return this.predicate.test(value); |
| } |
| |
| @Override |
| public String toString() { |
| // TODO: revert the predicates to their string form? |
| return StringFactory.stepString(this, this.startKey, this.predicate, this.traversalRing); |
| } |
| |
| @Override |
| public Set<String> getScopeKeys() { |
| return Collections.unmodifiableSet(this.scopeKeys); |
| } |
| |
| @Override |
| public WherePredicateStep<S> clone() { |
| final WherePredicateStep<S> clone = (WherePredicateStep<S>) super.clone(); |
| clone.predicate = this.predicate.clone(); |
| clone.traversalRing = this.traversalRing.clone(); |
| return clone; |
| } |
| |
| @Override |
| public void setTraversal(final Traversal.Admin<?, ?> parentTraversal) { |
| super.setTraversal(parentTraversal); |
| this.traversalRing.getTraversals().forEach(this::integrateChild); |
| } |
| |
| @Override |
| public int hashCode() { |
| return super.hashCode() ^ this.traversalRing.hashCode() ^ (null == this.startKey ? "null".hashCode() : this.startKey.hashCode()) ^ this.predicate.hashCode(); |
| } |
| |
| @Override |
| public Set<TraverserRequirement> getRequirements() { |
| return this.getSelfAndChildRequirements(TraverserRequirement.OBJECT, TraverserRequirement.SIDE_EFFECTS); |
| } |
| |
| @Override |
| public List<Traversal.Admin<S, ?>> getLocalChildren() { |
| return (List) this.traversalRing.getTraversals(); |
| } |
| |
| @Override |
| protected Traverser.Admin<S> processNextStart() { |
| return PathProcessor.processTraverserPathLabels(super.processNextStart(), this.keepLabels); |
| } |
| |
| @Override |
| public void setKeepLabels(final Set<String> keepLabels) { |
| this.keepLabels = new HashSet<>(keepLabels); |
| } |
| |
| @Override |
| public Set<String> getKeepLabels() { |
| return this.keepLabels; |
| } |
| |
| @Override |
| public void modulateBy(final Traversal.Admin<?, ?> traversal) throws UnsupportedOperationException { |
| this.traversalRing.addTraversal(this.integrateChild(traversal)); |
| } |
| |
| @Override |
| public void replaceLocalChild(final Traversal.Admin<?, ?> oldTraversal, final Traversal.Admin<?, ?> newTraversal) { |
| this.traversalRing.replaceTraversal( |
| (Traversal.Admin) oldTraversal, |
| (Traversal.Admin) newTraversal); |
| } |
| } |