Пример #1
0
    inline void RelaxOutgoingEdges(const DataFacadeT &facade,
                                   const NodeID node,
                                   const EdgeWeight weight,
                                   QueryHeap &query_heap) const
    {
        for (auto edge : facade.GetAdjacentEdgeRange(node))
        {
            const auto &data = facade.GetEdgeData(edge);
            const bool direction_flag = (forward_direction ? data.forward : data.backward);
            if (direction_flag)
            {
                const NodeID to = facade.GetTarget(edge);
                const int edge_weight = data.weight;

                BOOST_ASSERT_MSG(edge_weight > 0, "edge_weight invalid");
                const int to_weight = weight + edge_weight;

                // New Node discovered -> Add to Heap + Node Info Storage
                if (!query_heap.WasInserted(to))
                {
                    query_heap.Insert(to, to_weight, node);
                }
                // Found a shorter Path -> Update weight
                else if (to_weight < query_heap.GetKey(to))
                {
                    // new parent
                    query_heap.GetData(to).parent = node;
                    query_heap.DecreaseKey(to, to_weight);
                }
            }
        }
    }
Пример #2
0
 inline bool StallAtNode(const DataFacadeT &facade,
                         const NodeID node,
                         const EdgeWeight weight,
                         QueryHeap &query_heap) const
 {
     for (auto edge : facade.GetAdjacentEdgeRange(node))
     {
         const auto &data = facade.GetEdgeData(edge);
         const bool reverse_flag = ((!forward_direction) ? data.forward : data.backward);
         if (reverse_flag)
         {
             const NodeID to = facade.GetTarget(edge);
             const int edge_weight = data.weight;
             BOOST_ASSERT_MSG(edge_weight > 0, "edge_weight invalid");
             if (query_heap.WasInserted(to))
             {
                 if (query_heap.GetKey(to) + edge_weight < weight)
                 {
                     return true;
                 }
             }
         }
     }
     return false;
 }
Пример #3
0
    void AlternativeRoutingStep(QueryHeap &heap1,
                                QueryHeap &heap2,
                                NodeID *middle_node,
                                int *upper_bound_to_shortest_path_distance,
                                std::vector<NodeID> &search_space_intersection,
                                std::vector<SearchSpaceEdge> &search_space,
                                const EdgeWeight min_edge_offset) const
    {
        QueryHeap &forward_heap = (is_forward_directed ? heap1 : heap2);
        QueryHeap &reverse_heap = (is_forward_directed ? heap2 : heap1);

        const NodeID node = forward_heap.DeleteMin();
        const int distance = forward_heap.GetKey(node);
        // const NodeID parentnode = forward_heap.GetData(node).parent;
        // SimpleLogger().Write() << (is_forward_directed ? "[fwd] " : "[rev] ") << "settled edge ("
        // << parentnode << "," << node << "), dist: " << distance;

        const int scaled_distance =
            static_cast<int>((distance + min_edge_offset) / (1. + VIAPATH_EPSILON));
        if ((INVALID_EDGE_WEIGHT != *upper_bound_to_shortest_path_distance) &&
                (scaled_distance > *upper_bound_to_shortest_path_distance))
        {
            forward_heap.DeleteAll();
            return;
        }

        search_space.emplace_back(forward_heap.GetData(node).parent, node);

        if (reverse_heap.WasInserted(node))
        {
            search_space_intersection.emplace_back(node);
            const int new_distance = reverse_heap.GetKey(node) + distance;
            if (new_distance < *upper_bound_to_shortest_path_distance)
            {
                if (new_distance >= 0)
                {
                    *middle_node = node;
                    *upper_bound_to_shortest_path_distance = new_distance;
                    //     SimpleLogger().Write() << "accepted middle_node " << *middle_node << " at
                    //     distance " << new_distance;
                    // } else {
                    //     SimpleLogger().Write() << "discarded middle_node " << *middle_node << "
                    //     at distance " << new_distance;
                }
            }
        }

        for (auto edge : facade->GetAdjacentEdgeRange(node))
        {
            const EdgeData &data = facade->GetEdgeData(edge);
            const bool edge_is_forward_directed =
                (is_forward_directed ? data.forward : data.backward);
            if (edge_is_forward_directed)
            {

                const NodeID to = facade->GetTarget(edge);
                const int edge_weight = data.distance;

                BOOST_ASSERT(edge_weight > 0);
                const int to_distance = distance + edge_weight;

                // New Node discovered -> Add to Heap + Node Info Storage
                if (!forward_heap.WasInserted(to))
                {
                    forward_heap.Insert(to, to_distance, node);
                }
                // Found a shorter Path -> Update distance
                else if (to_distance < forward_heap.GetKey(to))
                {
                    // new parent
                    forward_heap.GetData(to).parent = node;
                    // decreased distance
                    forward_heap.DecreaseKey(to, to_distance);
                }
            }
        }
    }