535 lines
28 KiB
C++
535 lines
28 KiB
C++
/*
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open source routing machine
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Copyright (C) Dennis Luxen, others 2010
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU AFFERO General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU Affero General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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or see http://www.gnu.org/licenses/agpl.txt.
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*/
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#ifndef ALTERNATIVEROUTES_H_
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#define ALTERNATIVEROUTES_H_
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#include "BasicRoutingInterface.h"
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#include <boost/unordered_map.hpp>
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#include <cmath>
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#include <vector>
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const double VIAPATH_ALPHA = 0.15;
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const double VIAPATH_EPSILON = 0.10; //alternative at most 15% longer
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const double VIAPATH_GAMMA = 0.75; //alternative shares at most 75% with the shortest.
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template<class QueryDataT>
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class AlternativeRouting : private BasicRoutingInterface<QueryDataT> {
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typedef BasicRoutingInterface<QueryDataT> super;
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typedef typename QueryDataT::Graph SearchGraph;
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typedef typename QueryDataT::QueryHeap QueryHeap;
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typedef std::pair<NodeID, NodeID> SearchSpaceEdge;
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struct RankedCandidateNode {
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RankedCandidateNode(const NodeID n, const int l, const int s) : node(n), length(l), sharing(s) {}
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NodeID node;
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int length;
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int sharing;
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bool operator<(const RankedCandidateNode& other) const {
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return (2*length + sharing) < (2*other.length + other.sharing);
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}
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};
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const SearchGraph * search_graph;
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public:
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AlternativeRouting(QueryDataT & qd) : super(qd), search_graph(qd.graph) { }
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~AlternativeRouting() {}
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void operator()(const PhantomNodes & phantomNodePair, RawRouteData & rawRouteData) {
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if(!phantomNodePair.AtLeastOnePhantomNodeIsUINTMAX() || phantomNodePair.PhantomNodesHaveEqualLocation()) {
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rawRouteData.lengthOfShortestPath = rawRouteData.lengthOfAlternativePath = INT_MAX;
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return;
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}
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std::vector<NodeID> alternativePath;
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std::vector<NodeID> viaNodeCandidates;
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std::vector<SearchSpaceEdge> forward_search_space;
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std::vector<SearchSpaceEdge> reverse_search_space;
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//Initialize Queues, semi-expensive because access to TSS invokes a system call
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super::_queryData.InitializeOrClearFirstThreadLocalStorage();
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super::_queryData.InitializeOrClearSecondThreadLocalStorage();
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super::_queryData.InitializeOrClearThirdThreadLocalStorage();
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QueryHeap & forward_heap1 = *(super::_queryData.forwardHeap);
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QueryHeap & reverse_heap1 = *(super::_queryData.backwardHeap);
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QueryHeap & forward_heap2 = *(super::_queryData.forwardHeap2);
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QueryHeap & reverse_heap2 = *(super::_queryData.backwardHeap2);
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int upper_bound_to_shortest_path_distance = INT_MAX;
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NodeID middle_node = UINT_MAX;
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forward_heap1.Insert(phantomNodePair.startPhantom.edgeBasedNode, -phantomNodePair.startPhantom.weight1, phantomNodePair.startPhantom.edgeBasedNode);
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if(phantomNodePair.startPhantom.isBidirected() ) {
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forward_heap1.Insert(phantomNodePair.startPhantom.edgeBasedNode+1, -phantomNodePair.startPhantom.weight2, phantomNodePair.startPhantom.edgeBasedNode+1);
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}
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reverse_heap1.Insert(phantomNodePair.targetPhantom.edgeBasedNode, phantomNodePair.targetPhantom.weight1, phantomNodePair.targetPhantom.edgeBasedNode);
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if(phantomNodePair.targetPhantom.isBidirected() ) {
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reverse_heap1.Insert(phantomNodePair.targetPhantom.edgeBasedNode+1, phantomNodePair.targetPhantom.weight2, phantomNodePair.targetPhantom.edgeBasedNode+1);
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}
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const int forward_offset = phantomNodePair.startPhantom.weight1 + (phantomNodePair.startPhantom.isBidirected() ? phantomNodePair.startPhantom.weight2 : 0);
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const int reverse_offset = phantomNodePair.targetPhantom.weight1 + (phantomNodePair.targetPhantom.isBidirected() ? phantomNodePair.targetPhantom.weight2 : 0);
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//exploration dijkstra from nodes s and t until deletemin/(1+epsilon) > _lengthOfShortestPath
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while(0 < (forward_heap1.Size() + reverse_heap1.Size())){
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if(0 < forward_heap1.Size()){
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AlternativeRoutingStep<true >(forward_heap1, reverse_heap1, &middle_node, &upper_bound_to_shortest_path_distance, viaNodeCandidates, forward_search_space, forward_offset);
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}
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if(0 < reverse_heap1.Size()){
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AlternativeRoutingStep<false>(reverse_heap1, forward_heap1, &middle_node, &upper_bound_to_shortest_path_distance, viaNodeCandidates, reverse_search_space, reverse_offset);
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}
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}
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sort_unique_resize(viaNodeCandidates);
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std::vector<NodeID> packed_forward_path;
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std::vector<NodeID> packed_reverse_path;
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super::RetrievePackedPathFromSingleHeap(forward_heap1, middle_node, packed_forward_path);
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super::RetrievePackedPathFromSingleHeap(reverse_heap1, middle_node, packed_reverse_path);
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boost::unordered_map<NodeID, int> approximated_forward_sharing;
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boost::unordered_map<NodeID, int> approximated_reverse_sharing;
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unsigned index_into_forward_path = 0;
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//sweep over search space, compute forward sharing for each current edge (u,v)
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BOOST_FOREACH(const SearchSpaceEdge & current_edge, forward_search_space) {
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const NodeID u = current_edge.first;
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const NodeID v = current_edge.second;
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if(packed_forward_path.size() < index_into_forward_path && current_edge == forward_search_space[index_into_forward_path]) {
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//current_edge is on shortest path => sharing(u):=queue.GetKey(u);
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++index_into_forward_path;
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approximated_forward_sharing[v] = forward_heap1.GetKey(u);
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} else {
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//sharing (s) = sharing (t)
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approximated_forward_sharing[v] = approximated_forward_sharing[u];
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}
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}
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unsigned index_into_reverse_path = 0;
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//sweep over search space, compute backward sharing
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BOOST_FOREACH(const SearchSpaceEdge & current_edge, reverse_search_space) {
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const NodeID u = current_edge.first;
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const NodeID v = current_edge.second;
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if(packed_reverse_path.size() < index_into_reverse_path && current_edge == reverse_search_space[index_into_reverse_path]) {
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//current_edge is on shortest path => sharing(u):=queue.GetKey(u);
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++index_into_reverse_path;
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approximated_reverse_sharing[v] = reverse_heap1.GetKey(u);
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} else {
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//sharing (s) = sharing (t)
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approximated_reverse_sharing[v] = approximated_reverse_sharing[u];
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}
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}
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std::vector<NodeID> nodes_that_passed_preselection;
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BOOST_FOREACH(const NodeID node, viaNodeCandidates) {
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int approximated_sharing = approximated_forward_sharing[node] + approximated_reverse_sharing[node];
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int approximated_length = forward_heap1.GetKey(node)+reverse_heap1.GetKey(node);
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bool lengthPassed = (approximated_length < upper_bound_to_shortest_path_distance*(1+VIAPATH_EPSILON));
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bool sharingPassed = (approximated_sharing <= upper_bound_to_shortest_path_distance*VIAPATH_GAMMA);
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bool stretchPassed = approximated_length - approximated_sharing < (1.+VIAPATH_EPSILON)*(upper_bound_to_shortest_path_distance-approximated_sharing);
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if(lengthPassed && sharingPassed && stretchPassed) {
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nodes_that_passed_preselection.push_back(node);
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}
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}
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std::vector<NodeID> & packedShortestPath = packed_forward_path;
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std::reverse(packedShortestPath.begin(), packedShortestPath.end());
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packedShortestPath.push_back(middle_node);
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packedShortestPath.insert(packedShortestPath.end(),packed_reverse_path.begin(), packed_reverse_path.end());
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std::vector<RankedCandidateNode > rankedCandidates;
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//prioritizing via nodes for deep inspection
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BOOST_FOREACH(const NodeID node, nodes_that_passed_preselection) {
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int lengthOfViaPath = 0, sharingOfViaPath = 0;
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computeLengthAndSharingOfViaPath(node, &lengthOfViaPath, &sharingOfViaPath, forward_offset+reverse_offset, packedShortestPath);
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if(sharingOfViaPath <= upper_bound_to_shortest_path_distance*VIAPATH_GAMMA) {
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rankedCandidates.push_back(RankedCandidateNode(node, lengthOfViaPath, sharingOfViaPath));
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}
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}
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std::sort(rankedCandidates.begin(), rankedCandidates.end());
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NodeID selectedViaNode = UINT_MAX;
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int lengthOfViaPath = INT_MAX;
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NodeID s_v_middle = UINT_MAX, v_t_middle = UINT_MAX;
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BOOST_FOREACH(const RankedCandidateNode & candidate, rankedCandidates){
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if(viaNodeCandidatePasses_T_Test(forward_heap1, reverse_heap1, forward_heap2, reverse_heap2, candidate, forward_offset+reverse_offset, upper_bound_to_shortest_path_distance, &lengthOfViaPath, &s_v_middle, &v_t_middle)) {
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// select first admissable
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selectedViaNode = candidate.node;
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break;
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}
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}
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//Unpack shortest path and alternative, if they exist
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if(INT_MAX != upper_bound_to_shortest_path_distance) {
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super::UnpackPath(packedShortestPath, rawRouteData.computedShortestPath);
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rawRouteData.lengthOfShortestPath = upper_bound_to_shortest_path_distance;
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} else {
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rawRouteData.lengthOfShortestPath = INT_MAX;
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}
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if(selectedViaNode != UINT_MAX) {
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retrievePackedViaPath(forward_heap1, reverse_heap1, forward_heap2, reverse_heap2, s_v_middle, v_t_middle, rawRouteData.computedAlternativePath);
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rawRouteData.lengthOfAlternativePath = lengthOfViaPath;
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} else {
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rawRouteData.lengthOfAlternativePath = INT_MAX;
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}
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}
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private:
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//unpack <s,..,v,..,t> by exploring search spaces from v
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inline void retrievePackedViaPath(QueryHeap & _forwardHeap1, QueryHeap & _backwardHeap1, QueryHeap & _forwardHeap2, QueryHeap & _backwardHeap2,
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const NodeID s_v_middle, const NodeID v_t_middle, std::vector<_PathData> & unpackedPath) {
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//unpack [s,v)
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std::vector<NodeID> packed_s_v_path, packed_v_t_path;
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super::RetrievePackedPathFromHeap(_forwardHeap1, _backwardHeap2, s_v_middle, packed_s_v_path);
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packed_s_v_path.resize(packed_s_v_path.size()-1);
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//unpack [v,t]
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super::RetrievePackedPathFromHeap(_forwardHeap2, _backwardHeap1, v_t_middle, packed_v_t_path);
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packed_s_v_path.insert(packed_s_v_path.end(),packed_v_t_path.begin(), packed_v_t_path.end() );
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super::UnpackPath(packed_s_v_path, unpackedPath);
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}
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inline void computeLengthAndSharingOfViaPath(const NodeID via_node, int *real_length_of_via_path, int *sharing_of_via_path,
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const int offset, const std::vector<NodeID> & packed_shortest_path) {
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//compute and unpack <s,..,v> and <v,..,t> by exploring search spaces from v and intersecting against queues
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//only half-searches have to be done at this stage
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super::_queryData.InitializeOrClearSecondThreadLocalStorage();
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QueryHeap & existingForwardHeap = *super::_queryData.forwardHeap;
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QueryHeap & existingBackwardHeap = *super::_queryData.backwardHeap;
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QueryHeap & newForwardHeap = *super::_queryData.forwardHeap2;
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QueryHeap & newBackwardHeap = *super::_queryData.backwardHeap2;
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std::vector < NodeID > packed_s_v_path;
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std::vector < NodeID > packed_v_t_path;
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std::vector<NodeID> partiallyUnpackedShortestPath;
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std::vector<NodeID> partiallyUnpackedViaPath;
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NodeID s_v_middle = UINT_MAX;
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int upperBoundFor_s_v_Path = INT_MAX;//compute path <s,..,v> by reusing forward search from s
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newBackwardHeap.Insert(via_node, 0, via_node);
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while (0 < newBackwardHeap.Size()) {
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super::RoutingStep(newBackwardHeap, existingForwardHeap, &s_v_middle, &upperBoundFor_s_v_Path, 2 * offset, false);
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}
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//compute path <v,..,t> by reusing backward search from node t
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NodeID v_t_middle = UINT_MAX;
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int upperBoundFor_v_t_Path = INT_MAX;
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newForwardHeap.Insert(via_node, 0, via_node);
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while (0 < newForwardHeap.Size() ) {
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super::RoutingStep(newForwardHeap, existingBackwardHeap, &v_t_middle, &upperBoundFor_v_t_Path, 2 * offset, true);
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}
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*real_length_of_via_path = upperBoundFor_s_v_Path + upperBoundFor_v_t_Path;
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if(UINT_MAX == s_v_middle || UINT_MAX == v_t_middle)
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return;
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//retrieve packed paths
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super::RetrievePackedPathFromHeap(existingForwardHeap, newBackwardHeap, s_v_middle, packed_s_v_path);
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super::RetrievePackedPathFromHeap(newForwardHeap, existingBackwardHeap, v_t_middle, packed_v_t_path);
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//partial unpacking, compute sharing
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//First partially unpack s-->v until paths deviate, note length of common path.
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for (unsigned i = 0, lengthOfPackedPath = std::min( packed_s_v_path.size(), packed_shortest_path.size()) - 1; (i < lengthOfPackedPath); ++i) {
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if (packed_s_v_path[i] == packed_shortest_path[i] && packed_s_v_path[i + 1] == packed_shortest_path[i + 1]) {
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typename SearchGraph::EdgeIterator edgeID = search_graph->FindEdgeInEitherDirection(packed_s_v_path[i], packed_s_v_path[i + 1]);
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*sharing_of_via_path += search_graph->GetEdgeData(edgeID).distance;
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} else {
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if (packed_s_v_path[i] == packed_shortest_path[i]) {
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super::UnpackEdge(packed_s_v_path[i], packed_s_v_path[i+1], partiallyUnpackedViaPath);
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super::UnpackEdge(packed_shortest_path[i], packed_shortest_path[i+1], partiallyUnpackedShortestPath);
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break;
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}
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}
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}
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//traverse partially unpacked edge and note common prefix
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for (int i = 0, lengthOfPackedPath = std::min( partiallyUnpackedViaPath.size(), partiallyUnpackedShortestPath.size()) - 1; (i < lengthOfPackedPath) && (partiallyUnpackedViaPath[i] == partiallyUnpackedShortestPath[i] && partiallyUnpackedViaPath[i+1] == partiallyUnpackedShortestPath[i+1]); ++i) {
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typename SearchGraph::EdgeIterator edgeID = search_graph->FindEdgeInEitherDirection(partiallyUnpackedViaPath[i], partiallyUnpackedViaPath[i+1]);
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*sharing_of_via_path += search_graph->GetEdgeData(edgeID).distance;
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}
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//Second, partially unpack v-->t in reverse order until paths deviate and note lengths
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int viaPathIndex = packed_v_t_path.size() - 1;
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int shortestPathIndex = packed_shortest_path.size() - 1;
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for (; viaPathIndex > 0 && shortestPathIndex > 0; --viaPathIndex,--shortestPathIndex ) {
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if (packed_v_t_path[viaPathIndex - 1] == packed_shortest_path[shortestPathIndex - 1] && packed_v_t_path[viaPathIndex] == packed_shortest_path[shortestPathIndex]) {
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typename SearchGraph::EdgeIterator edgeID = search_graph->FindEdgeInEitherDirection( packed_v_t_path[viaPathIndex - 1], packed_v_t_path[viaPathIndex]);
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*sharing_of_via_path += search_graph->GetEdgeData(edgeID).distance;
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} else {
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if (packed_v_t_path[viaPathIndex] == packed_shortest_path[shortestPathIndex]) {
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super::UnpackEdge(packed_v_t_path[viaPathIndex-1], packed_v_t_path[viaPathIndex], partiallyUnpackedViaPath);
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super::UnpackEdge(packed_shortest_path[shortestPathIndex-1] , packed_shortest_path[shortestPathIndex], partiallyUnpackedShortestPath);
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break;
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}
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}
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}
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viaPathIndex = partiallyUnpackedViaPath.size() - 1;
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shortestPathIndex = partiallyUnpackedShortestPath.size() - 1;
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for (; viaPathIndex > 0 && shortestPathIndex > 0; --viaPathIndex,--shortestPathIndex) {
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if (partiallyUnpackedViaPath[viaPathIndex - 1] == partiallyUnpackedShortestPath[shortestPathIndex - 1] && partiallyUnpackedViaPath[viaPathIndex] == partiallyUnpackedShortestPath[shortestPathIndex]) {
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typename SearchGraph::EdgeIterator edgeID = search_graph->FindEdgeInEitherDirection( partiallyUnpackedViaPath[viaPathIndex - 1], partiallyUnpackedViaPath[viaPathIndex]);
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*sharing_of_via_path += search_graph->GetEdgeData(edgeID).distance;
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} else {
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break;
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}
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}
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//finished partial unpacking spree! Amount of sharing is stored to appropriate pointer variable
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}
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inline int approximateAmountOfSharing(const NodeID middleNodeIDOfAlternativePath, QueryHeap & _forwardHeap, QueryHeap & _backwardHeap, const std::vector<NodeID> & packedShortestPath) {
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std::vector<NodeID> packedAlternativePath;
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super::RetrievePackedPathFromHeap(_forwardHeap, _backwardHeap, middleNodeIDOfAlternativePath, packedAlternativePath);
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if(packedShortestPath.size() < 2 || packedAlternativePath.size() < 2)
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return 0;
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int sharing = 0;
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int aindex = 0;
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//compute forward sharing
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while( (packedAlternativePath[aindex] == packedShortestPath[aindex]) && (packedAlternativePath[aindex+1] == packedShortestPath[aindex+1]) ) {
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// SimpleLogger().Write() << "retrieving edge (" << packedAlternativePath[aindex] << "," << packedAlternativePath[aindex+1] << ")";
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typename SearchGraph::EdgeIterator edgeID = search_graph->FindEdgeInEitherDirection(packedAlternativePath[aindex], packedAlternativePath[aindex+1]);
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sharing += search_graph->GetEdgeData(edgeID).distance;
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++aindex;
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}
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aindex = packedAlternativePath.size()-1;
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int bindex = packedShortestPath.size()-1;
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//compute backward sharing
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while( aindex > 0 && bindex > 0 && (packedAlternativePath[aindex] == packedShortestPath[bindex]) && (packedAlternativePath[aindex-1] == packedShortestPath[bindex-1]) ) {
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typename SearchGraph::EdgeIterator edgeID = search_graph->FindEdgeInEitherDirection(packedAlternativePath[aindex], packedAlternativePath[aindex-1]);
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sharing += search_graph->GetEdgeData(edgeID).distance;
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--aindex; --bindex;
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}
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return sharing;
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}
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template<bool forwardDirection>
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inline void AlternativeRoutingStep(
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QueryHeap & _forward_heap,
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QueryHeap & _reverse_heap,
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NodeID *middle_node,
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int *upper_bound_to_shortest_path_distance,
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std::vector<NodeID>& searchSpaceIntersection,
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std::vector<SearchSpaceEdge> & search_space,
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const int edgeBasedOffset
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) const {
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const NodeID node = _forward_heap.DeleteMin();
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const int distance = _forward_heap.GetKey(node);
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int scaledDistance = (distance-edgeBasedOffset)/(1.+VIAPATH_EPSILON);
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if(scaledDistance > *upper_bound_to_shortest_path_distance){
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_forward_heap.DeleteAll();
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return;
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}
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search_space.push_back(std::make_pair(_forward_heap.GetData( node ).parent, node));
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if(_reverse_heap.WasInserted(node) ){
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searchSpaceIntersection.push_back(node);
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const int newDistance = _reverse_heap.GetKey(node) + distance;
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if(newDistance < *upper_bound_to_shortest_path_distance ){
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if(newDistance>=0 ) {
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*middle_node = node;
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*upper_bound_to_shortest_path_distance = newDistance;
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}
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}
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}
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for ( typename SearchGraph::EdgeIterator edge = search_graph->BeginEdges( node ); edge < search_graph->EndEdges(node); edge++ ) {
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const typename SearchGraph::EdgeData & data = search_graph->GetEdgeData(edge);
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bool forwardDirectionFlag = (forwardDirection ? data.forward : data.backward );
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if(forwardDirectionFlag) {
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const NodeID to = search_graph->GetTarget(edge);
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const int edgeWeight = data.distance;
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assert( edgeWeight > 0 );
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const int toDistance = distance + edgeWeight;
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//New Node discovered -> Add to Heap + Node Info Storage
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if ( !_forward_heap.WasInserted( to ) ) {
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_forward_heap.Insert( to, toDistance, node );
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|
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}
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//Found a shorter Path -> Update distance
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else if ( toDistance < _forward_heap.GetKey( to ) ) {
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_forward_heap.GetData( to ).parent = node;
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_forward_heap.DecreaseKey( to, toDistance );
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//new parent
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}
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}
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}
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}
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//conduct T-Test
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inline bool viaNodeCandidatePasses_T_Test( QueryHeap& existingForwardHeap, QueryHeap& existingBackwardHeap, QueryHeap& newForwardHeap, QueryHeap& newBackwardHeap, const RankedCandidateNode& candidate, const int offset, const int lengthOfShortestPath, int * lengthOfViaPath, NodeID * s_v_middle, NodeID * v_t_middle) {
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newForwardHeap.Clear();
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newBackwardHeap.Clear();
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std::vector < NodeID > packed_s_v_path;
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std::vector < NodeID > packed_v_t_path;
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|
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*s_v_middle = UINT_MAX;
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int upperBoundFor_s_v_Path = INT_MAX;
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//compute path <s,..,v> by reusing forward search from s
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newBackwardHeap.Insert(candidate.node, 0, candidate.node);
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while (newBackwardHeap.Size() > 0) {
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super::RoutingStep(newBackwardHeap, existingForwardHeap, s_v_middle, &upperBoundFor_s_v_Path, 2*offset, false);
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}
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|
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if(INT_MAX == upperBoundFor_s_v_Path)
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return false;
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|
|
|
//compute path <v,..,t> by reusing backward search from t
|
|
*v_t_middle = UINT_MAX;
|
|
int upperBoundFor_v_t_Path = INT_MAX;
|
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newForwardHeap.Insert(candidate.node, 0, candidate.node);
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while (newForwardHeap.Size() > 0) {
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super::RoutingStep(newForwardHeap, existingBackwardHeap, v_t_middle, &upperBoundFor_v_t_Path, 2*offset, true);
|
|
}
|
|
|
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if(INT_MAX == upperBoundFor_v_t_Path)
|
|
return false;
|
|
|
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*lengthOfViaPath = upperBoundFor_s_v_Path + upperBoundFor_v_t_Path;
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|
|
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//retrieve packed paths
|
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super::RetrievePackedPathFromHeap(existingForwardHeap, newBackwardHeap, *s_v_middle, packed_s_v_path);
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super::RetrievePackedPathFromHeap(newForwardHeap, existingBackwardHeap, *v_t_middle, packed_v_t_path);
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|
|
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NodeID s_P = *s_v_middle, t_P = *v_t_middle;
|
|
if(UINT_MAX == s_P) {
|
|
return false;
|
|
}
|
|
|
|
if(UINT_MAX == t_P) {
|
|
return false;
|
|
}
|
|
const int T_threshold = VIAPATH_EPSILON * lengthOfShortestPath;
|
|
int unpackedUntilDistance = 0;
|
|
|
|
std::stack<SearchSpaceEdge> unpackStack;
|
|
//Traverse path s-->v
|
|
for (unsigned i = packed_s_v_path.size() - 1; (i > 0) && unpackStack.empty(); --i) {
|
|
typename SearchGraph::EdgeIterator edgeID = search_graph->FindEdgeInEitherDirection( packed_s_v_path[i - 1], packed_s_v_path[i]);
|
|
int lengthOfCurrentEdge = search_graph->GetEdgeData(edgeID).distance;
|
|
if (lengthOfCurrentEdge + unpackedUntilDistance >= T_threshold) {
|
|
unpackStack.push(std::make_pair(packed_s_v_path[i - 1], packed_s_v_path[i]));
|
|
} else {
|
|
unpackedUntilDistance += lengthOfCurrentEdge;
|
|
s_P = packed_s_v_path[i - 1];
|
|
}
|
|
}
|
|
|
|
while (!unpackStack.empty()) {
|
|
const SearchSpaceEdge viaPathEdge = unpackStack.top();
|
|
unpackStack.pop();
|
|
typename SearchGraph::EdgeIterator edgeIDInViaPath = search_graph->FindEdgeInEitherDirection(viaPathEdge.first, viaPathEdge.second);
|
|
if(UINT_MAX == edgeIDInViaPath)
|
|
return false;
|
|
typename SearchGraph::EdgeData currentEdgeData = search_graph->GetEdgeData(edgeIDInViaPath);
|
|
bool IsViaEdgeShortCut = currentEdgeData.shortcut;
|
|
if (IsViaEdgeShortCut) {
|
|
const NodeID middleOfViaPath = currentEdgeData.id;
|
|
typename SearchGraph::EdgeIterator edgeIDOfSecondSegment = search_graph->FindEdgeInEitherDirection(middleOfViaPath, viaPathEdge.second);
|
|
int lengthOfSecondSegment = search_graph->GetEdgeData(edgeIDOfSecondSegment).distance;
|
|
//attention: !unpacking in reverse!
|
|
//Check if second segment is the one to go over treshold? if yes add second segment to stack, else push first segment to stack and add distance of second one.
|
|
if (unpackedUntilDistance + lengthOfSecondSegment >= T_threshold) {
|
|
unpackStack.push(std::make_pair(middleOfViaPath, viaPathEdge.second));
|
|
} else {
|
|
unpackedUntilDistance += lengthOfSecondSegment;
|
|
unpackStack.push(std::make_pair(viaPathEdge.first, middleOfViaPath));
|
|
}
|
|
} else {
|
|
// edge is not a shortcut, set the start node for T-Test to end of edge.
|
|
unpackedUntilDistance += currentEdgeData.distance;
|
|
s_P = viaPathEdge.first;
|
|
}
|
|
}
|
|
|
|
int lengthOfPathT_Test_Path = unpackedUntilDistance;
|
|
unpackedUntilDistance = 0;
|
|
//Traverse path s-->v
|
|
for (unsigned i = 0, lengthOfPackedPath = packed_v_t_path.size() - 1; (i < lengthOfPackedPath) && unpackStack.empty(); ++i) {
|
|
typename SearchGraph::EdgeIterator edgeID = search_graph->FindEdgeInEitherDirection( packed_v_t_path[i], packed_v_t_path[i + 1]);
|
|
int lengthOfCurrentEdge = search_graph->GetEdgeData(edgeID).distance;
|
|
if (lengthOfCurrentEdge + unpackedUntilDistance >= T_threshold) {
|
|
unpackStack.push( std::make_pair(packed_v_t_path[i], packed_v_t_path[i + 1]));
|
|
} else {
|
|
unpackedUntilDistance += lengthOfCurrentEdge;
|
|
t_P = packed_v_t_path[i + 1];
|
|
}
|
|
}
|
|
|
|
while (!unpackStack.empty()) {
|
|
const SearchSpaceEdge viaPathEdge = unpackStack.top();
|
|
unpackStack.pop();
|
|
typename SearchGraph::EdgeIterator edgeIDInViaPath = search_graph->FindEdgeInEitherDirection(viaPathEdge.first, viaPathEdge.second);
|
|
if(UINT_MAX == edgeIDInViaPath)
|
|
return false;
|
|
typename SearchGraph::EdgeData currentEdgeData = search_graph->GetEdgeData(edgeIDInViaPath);
|
|
const bool IsViaEdgeShortCut = currentEdgeData.shortcut;
|
|
if (IsViaEdgeShortCut) {
|
|
const NodeID middleOfViaPath = currentEdgeData.id;
|
|
typename SearchGraph::EdgeIterator edgeIDOfFirstSegment = search_graph->FindEdgeInEitherDirection(viaPathEdge.first, middleOfViaPath);
|
|
int lengthOfFirstSegment = search_graph->GetEdgeData( edgeIDOfFirstSegment).distance;
|
|
//Check if first segment is the one to go over treshold? if yes first segment to stack, else push second segment to stack and add distance of first one.
|
|
if (unpackedUntilDistance + lengthOfFirstSegment >= T_threshold) {
|
|
unpackStack.push( std::make_pair(viaPathEdge.first, middleOfViaPath));
|
|
} else {
|
|
unpackedUntilDistance += lengthOfFirstSegment;
|
|
unpackStack.push( std::make_pair(middleOfViaPath, viaPathEdge.second));
|
|
}
|
|
} else {
|
|
// edge is not a shortcut, set the start node for T-Test to end of edge.
|
|
unpackedUntilDistance += currentEdgeData.distance;
|
|
t_P = viaPathEdge.second;
|
|
}
|
|
}
|
|
|
|
lengthOfPathT_Test_Path += unpackedUntilDistance;
|
|
//Run actual T-Test query and compare if distances equal.
|
|
super::_queryData.InitializeOrClearThirdThreadLocalStorage();
|
|
|
|
QueryHeap& forward_heap3 = *super::_queryData.forwardHeap3;
|
|
QueryHeap& backward_heap3 = *super::_queryData.backwardHeap3;
|
|
int _upperBound = INT_MAX;
|
|
NodeID middle = UINT_MAX;
|
|
forward_heap3.Insert(s_P, 0, s_P);
|
|
backward_heap3.Insert(t_P, 0, t_P);
|
|
//exploration from s and t until deletemin/(1+epsilon) > _lengthOfShortestPath
|
|
while (forward_heap3.Size() + backward_heap3.Size() > 0) {
|
|
if (forward_heap3.Size() > 0) {
|
|
super::RoutingStep(forward_heap3, backward_heap3, &middle, &_upperBound, offset, true);
|
|
}
|
|
if (backward_heap3.Size() > 0) {
|
|
super::RoutingStep(backward_heap3, forward_heap3, &middle, &_upperBound, offset, false);
|
|
}
|
|
}
|
|
return (_upperBound <= lengthOfPathT_Test_Path);
|
|
}
|
|
};
|
|
|
|
#endif /* ALTERNATIVEROUTES_H_ */
|