public void forward()

in hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/SingleSourceShortestPathTraverser.java [135:195]
49 lines of code
14 McCabe index (conditional complexity)

        public void forward() {
            long degree = this.skipDegree > 0L ? this.skipDegree : this.degree;
            for (NodeWithWeight node : this.sources) {
                Iterator<Edge> edges = edgesOfVertex(node.node().id(),
                                                     this.direction,
                                                     this.label, degree);
                edges = this.skipSuperNodeIfNeeded(edges);
                while (edges.hasNext()) {
                    HugeEdge edge = (HugeEdge) edges.next();
                    Id target = edge.id().otherVertexId();

                    if (this.foundNodes.containsKey(target) ||
                        this.source.equals(target)) {
                        // Already find shortest path for target, skip
                        continue;
                    }

                    double currentWeight = this.edgeWeight(edge);
                    double weight = currentWeight + node.weight();
                    NodeWithWeight nw = new NodeWithWeight(weight, target, node);
                    NodeWithWeight exist = this.findingNodes.get(target);
                    if (exist == null || weight < exist.weight()) {
                        /*
                         * There are 2 scenarios to update finding nodes:
                         * 1. The 'target' found first time, add current path
                         * 2. Already exist path for 'target' and current
                         *    path is shorter, update path for 'target'
                         */
                        this.findingNodes.put(target, nw);
                    }
                }
            }

            Map<Id, NodeWithWeight> sorted = CollectionUtil.sortByValue(
                                             this.findingNodes, true);
            double minWeight = 0;
            Set<NodeWithWeight> newSources = InsertionOrderUtil.newSet();
            for (Map.Entry<Id, NodeWithWeight> entry : sorted.entrySet()) {
                Id id = entry.getKey();
                NodeWithWeight wn = entry.getValue();
                if (minWeight == 0) {
                    minWeight = wn.weight();
                } else if (wn.weight() > minWeight) {
                    break;
                }
                // Move shortest paths from 'findingNodes' to 'foundNodes'
                this.foundNodes.put(id, wn);
                if (this.limit != NO_LIMIT &&
                    this.foundNodes.size() >= this.limit) {
                    this.done = true;
                    return;
                }
                this.findingNodes.remove(id);
                // Re-init 'sources'
                newSources.add(wn);
            }
            this.sources = newSources;
            if (this.sources.isEmpty()) {
                this.done = true;
            }
        }