public String post()

in hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/KoutAPI.java [123:216]
85 lines of code
16 McCabe index (conditional complexity)

    public String post(@Context GraphManager manager,
                       @PathParam("graph") String graph,
                       Request request) {
        E.checkArgumentNotNull(request, "The request body can't be null");
        E.checkArgumentNotNull(request.source,
                               "The source of request can't be null");
        E.checkArgument(request.steps != null,
                        "The steps of request can't be null");
        if (request.countOnly) {
            E.checkArgument(!request.withVertex && !request.withPath && !request.withEdge,
                            "Can't return vertex, edge or path when count only");
        }
        HugeTraverser.checkTraverseMode(request.traverseMode);

        LOG.debug("Graph [{}] get customized kout from source vertex '{}', " +
                  "with steps '{}', max_depth '{}', nearest '{}', " +
                  "count_only '{}', capacity '{}', limit '{}', " +
                  "with_vertex '{}', with_path '{}' and with_edge '{}'",
                  graph, request.source, request.steps, request.maxDepth,
                  request.nearest, request.countOnly, request.capacity,
                  request.limit, request.withVertex, request.withPath,
                  request.withEdge);

        ApiMeasurer measure = new ApiMeasurer();

        HugeGraph g = graph(manager, graph);
        Id sourceId = HugeVertex.getIdValue(request.source);

        Steps steps = steps(g, request.steps);
        KoutRecords results;
        try (KoutTraverser traverser = new KoutTraverser(g)) {
            if (HugeTraverser.isTraverseModeDFS(request.traverseMode)) {
                results = traverser.dfsKout(sourceId, steps,
                                            request.maxDepth,
                                            request.nearest,
                                            request.capacity,
                                            request.limit);
            } else {
                results = traverser.customizedKout(sourceId, steps,
                                                   request.maxDepth,
                                                   request.nearest,
                                                   request.capacity,
                                                   request.limit);
            }
            measure.addIterCount(traverser.vertexIterCounter.get(),
                                 traverser.edgeIterCounter.get());
        }
        long size = results.size();
        if (request.limit != NO_LIMIT && size > request.limit) {
            size = request.limit;
        }
        List<Id> neighbors = request.countOnly ?
                             ImmutableList.of() : results.ids(request.limit);

        HugeTraverser.PathSet paths = new HugeTraverser.PathSet();
        if (request.withPath) {
            paths.addAll(results.paths(request.limit));
        }

        if (request.countOnly) {
            return manager.serializer(g, measure.measures())
                          .writeNodesWithPath("kout", neighbors, size, paths,
                                              QueryResults.emptyIterator(),
                                              QueryResults.emptyIterator());
        }

        Iterator<?> iterVertex;
        Set<Id> vertexIds = new HashSet<>(neighbors);
        if (request.withPath) {
            for (HugeTraverser.Path p : results.paths(request.limit)) {
                vertexIds.addAll(p.vertices());
            }
        }
        if (request.withVertex && !vertexIds.isEmpty()) {
            iterVertex = g.vertices(vertexIds.toArray());
            measure.addIterCount(vertexIds.size(), 0L);
        } else {
            iterVertex = vertexIds.iterator();
        }

        Iterator<?> iterEdge = Collections.emptyIterator();
        if (request.withPath) {
            Set<Edge> edges = results.edgeResults().getEdges(paths);
            if (request.withEdge) {
                iterEdge = edges.iterator();
            } else {
                iterEdge = HugeTraverser.EdgeRecord.getEdgeIds(edges).iterator();
            }
        }

        return manager.serializer(g, measure.measures())
                      .writeNodesWithPath("kout", neighbors, size, paths,
                                          iterVertex, iterEdge);
    }