Examples with BranchCollisionPolicy org.neo4j.graphdb.traversal.BranchCollisionPolicy used on opensource projects

Example 1 with BranchCollisionPolicy

use of org.neo4j.graphdb.traversal.BranchCollisionPolicy in project neo4j by neo4j.

the class DijkstraBidirectional method traverser.

private Traverser traverser(Node start, final Node end, PathInterest interest) {
    final MutableDouble shortestSoFar = new MutableDouble(Double.MAX_VALUE);
    final MutableDouble startSideShortest = new MutableDouble(0);
    final MutableDouble endSideShortest = new MutableDouble(0);
    PathExpander dijkstraExpander = new DijkstraBidirectionalPathExpander(expander, shortestSoFar, true, startSideShortest, endSideShortest, epsilon);
    GraphDatabaseService db = start.getGraphDatabase();
    TraversalDescription side = db.traversalDescription().expand(dijkstraExpander, stateFactory).order(new DijkstraSelectorFactory(interest, costEvaluator)).evaluator(new DijkstraBidirectionalEvaluator(costEvaluator)).uniqueness(Uniqueness.NODE_PATH);
    TraversalDescription startSide = side;
    TraversalDescription endSide = side.reverse();
    BidirectionalTraversalDescription traversal = db.bidirectionalTraversalDescription().startSide(startSide).endSide(endSide).collisionEvaluator(Evaluators.all()).collisionPolicy(new BranchCollisionPolicy() {

        @Override
        public BranchCollisionDetector create(Evaluator evaluator, Predicate<Path> pathPredicate) {
            return new DijkstraBranchCollisionDetector(evaluator, costEvaluator, shortestSoFar, epsilon, pathPredicate);
        }
    });
    lastTraverser = traversal.traverse(start, end);
    return lastTraverser;
}

Example 2 with BranchCollisionPolicy

use of org.neo4j.graphdb.traversal.BranchCollisionPolicy in project neo4j by neo4j.

the class TestBidirectionalTraversal method mirroredTraversalReversesInitialState.

@Test
void mirroredTraversalReversesInitialState() {
    /*
         * (a)-->(b)-->(c)-->(d)
         */
    createGraph("a TO b", "b TO c", "c TO d");
    try (Transaction transaction = getGraphDb().beginTx()) {
        BranchCollisionPolicy collisionPolicy = (evaluator, pathPredicate) -> new StandardBranchCollisionDetector(null, null) {

            @Override
            protected boolean includePath(Path path, TraversalBranch startPath, TraversalBranch endPath) {
                assertEquals(0, startPath.state());
                assertEquals(10, endPath.state());
                return true;
            }
        };
        Iterables.count(transaction.bidirectionalTraversalDescription().mirroredSides(transaction.traversalDescription().uniqueness(NODE_PATH).expand(PathExpanders.forType(to), new InitialBranchState.State<>(0, 10))).collisionPolicy(collisionPolicy).traverse(getNodeWithName(transaction, "a"), getNodeWithName(transaction, "d")));
    }
}