Examples with PathExpander org.neo4j.graphdb.PathExpander used on opensource projects

Example 11 with PathExpander

use of org.neo4j.graphdb.PathExpander in project neo4j by neo4j.

the class TestShortestPath method makeSureAMaxResultCountIsObeyed.

@Test
void makeSureAMaxResultCountIsObeyed() {
    // 
    try (Transaction transaction = graphDb.beginTx()) {
        graph.makeEdgeChain(transaction, "a,b,c,d,e");
        graph.makeEdgeChain(transaction, "a,f,g,h,e");
        graph.makeEdgeChain(transaction, "f,i,j,e");
        graph.makeEdgeChain(transaction, "i,k,e");
        final Node a = graph.getNode(transaction, "a");
        final Node e = graph.getNode(transaction, "e");
        final PathExpander expander = forTypeAndDirection(R1, OUTGOING);
        var context = new BasicEvaluationContext(transaction, graphDb);
        testShortestPathFinder(context, finder -> assertEquals(4, count(finder.findAllPaths(a, e))), expander, 10, 10);
        for (int i = 4; i >= 1; i--) {
            final int count = i;
            testShortestPathFinder(context, finder -> assertEquals(count, count(finder.findAllPaths(a, e))), expander, 10, count);
        }
        transaction.commit();
    }
}

Example 12 with PathExpander

use of org.neo4j.graphdb.PathExpander in project neo4j by neo4j.

the class TestShortestPath method filtersTouchesAllIntermediateNodes.

@Test
void filtersTouchesAllIntermediateNodes() {
    // 
    try (Transaction transaction = graphDb.beginTx()) {
        graph.makeEdgeChain(transaction, "a,b,c,d");
        final Node a = graph.getNode(transaction, "a");
        final Node d = graph.getNode(transaction, "d");
        Collection<Node> touchedByFilter = new HashSet<>();
        final Predicate<Node> filter = item -> {
            touchedByFilter.add(item);
            return true;
        };
        final PathExpander expander = PathExpanderBuilder.empty().add(R1, OUTGOING).addNodeFilter(filter).build();
        // final PathExpander expander = ((StandardExpander) PathExpanders.forTypeAndDirection(R1, OUTGOING)).addNodeFilter( filter );
        var context = new BasicEvaluationContext(transaction, graphDb);
        Path path = Iterables.single(shortestPath(context, expander, 10).findAllPaths(a, d));
        assertEquals(3, path.length());
        List<Node> nodes = Iterables.asList(path.nodes());
        List<Node> intermediateNodes = nodes.subList(1, nodes.size() - 1);
        assertTrue(touchedByFilter.containsAll(intermediateNodes), "touchedByFilter: " + touchedByFilter);
        assertFalse(touchedByFilter.contains(a));
        assertFalse(touchedByFilter.contains(d));
        transaction.commit();
    }
}

Example 13 with PathExpander

use of org.neo4j.graphdb.PathExpander in project neo4j by neo4j.

the class TraversalBranchImplTest method shouldExpandOnFirstAccess.

@SuppressWarnings("unchecked")
@Test
void shouldExpandOnFirstAccess() {
    // GIVEN
    TraversalBranch parent = mock(TraversalBranch.class);
    Node source = mock(Node.class);
    TraversalBranchImpl branch = new TraversalBranchImpl(parent, source);
    @SuppressWarnings("rawtypes") PathExpander expander = mock(PathExpander.class);
    when(expander.expand(eq(branch), any(BranchState.class))).thenReturn(Iterables.emptyResourceIterable());
    TraversalContext context = mock(TraversalContext.class);
    when(context.evaluate(eq(branch), isNull())).thenReturn(INCLUDE_AND_CONTINUE);
    // WHEN initializing
    branch.initialize(expander, context);
    // THEN the branch should not be expanded
    verifyNoInteractions(source);
    // and WHEN actually traversing from it
    branch.next(expander, context);
    // THEN we should expand it
    verify(expander).expand(any(Path.class), any(BranchState.class));
}