public static TarjanState startState(int start) { return new TarjanState(start, null); }
/** * This method removes the access to edges available from the nodes contained in the components. * But only if a components' size is smaller then the specified min value. * <p> * * @return number of removed edges */ int removeEdges(final PrepEdgeFilter bothFilter, List<IntArrayList> components, int min) { // remove edges determined from nodes but only if less than minimum size FlagEncoder encoder = bothFilter.getEncoder(); EdgeExplorer explorer = ghStorage.createEdgeExplorer(bothFilter); int removedEdges = 0; for (IntArrayList component : components) { removedEdges += removeEdges(explorer, encoder, component, min); } return removedEdges; }
@Override public void close() { landmarkWeightDA.close(); subnetworkStorage.close(); }
@Test public void testRemoveDeadEndUnvisitedNetworks() { GraphHopperStorage g = createDeadEndUnvisitedNetworkStorage(em); assertEquals(11, g.getNodes()); PrepareRoutingSubnetworks instance = new PrepareRoutingSubnetworks(g, Collections.singletonList(carFlagEncoder)). setMinOneWayNetworkSize(3); int removed = instance.removeDeadEndUnvisitedNetworks(new PrepEdgeFilter(carFlagEncoder)); assertEquals(3, removed); instance.markNodesRemovedIfUnreachable(); g.optimize(); assertEquals(8, g.getNodes()); }
@Test public void testKeepLargestNetworks() { GraphHopperStorage g = createSubnetworkTestStorage(); PrepEdgeFilter filter = new PrepEdgeFilter(carFlagEncoder); PrepareRoutingSubnetworks instance = new PrepareRoutingSubnetworks(g, Collections.singletonList(carFlagEncoder)); List<IntArrayList> components = instance.findSubnetworks(filter); assertEquals(3, components.size()); int removedEdges = instance.keepLargeNetworks(filter, components); assertEquals(8, removedEdges); instance.markNodesRemovedIfUnreachable(); g.optimize(); assertEquals(8, g.getNodes()); assertEquals(Arrays.<String>asList(), GHUtility.getProblems(g)); components = instance.findSubnetworks(filter); assertEquals(1, components.size()); }
@Test public void testNodeOrderingRegression() { // 1 -> 2 -> 0 GraphHopperStorage g = createStorage(em); g.edge(1, 2, 1, false); g.edge(2, 0, 1, false); PrepareRoutingSubnetworks instance = new PrepareRoutingSubnetworks(g, Collections.singletonList(carFlagEncoder)). setMinOneWayNetworkSize(2); int removedEdges = instance.removeDeadEndUnvisitedNetworks(new PrepEdgeFilter(carFlagEncoder)); assertEquals(2, removedEdges); }
/** * This method removes networks that will be never be visited by this filter. See #235 for * example, small areas like parking lots are sometimes connected to the whole network through a * one-way road. This is clearly an error - but is causes the routing to fail when a point gets * connected to this small area. This routine removes all these networks from the graph. * <p> * * @return number of removed edges */ int removeDeadEndUnvisitedNetworks(final PrepEdgeFilter bothFilter) { StopWatch sw = new StopWatch(bothFilter.getEncoder() + " findComponents").start(); final EdgeFilter outFilter = DefaultEdgeFilter.outEdges(bothFilter.getEncoder()); // partition graph into strongly connected components using Tarjan's algorithm TarjansSCCAlgorithm tarjan = new TarjansSCCAlgorithm(ghStorage, outFilter, true); List<IntArrayList> components = tarjan.findComponents(); logger.info(sw.stop() + ", size:" + components.size()); return removeEdges(bothFilter, components, minOneWayNetworkSize); }
@Test public void testFindSubnetworks() { GraphHopperStorage g = createSubnetworkTestStorage(); PrepEdgeFilter filter = new PrepEdgeFilter(carFlagEncoder); PrepareRoutingSubnetworks instance = new PrepareRoutingSubnetworks(g, Collections.singletonList(carFlagEncoder)); List<IntArrayList> components = instance.findSubnetworks(filter); assertEquals(3, components.size()); // start is at 0 => large network assertEquals(IntArrayList.from(0, 7, 3, 13, 5), components.get(0)); // next smallest and unvisited node is 1 => big network assertEquals(IntArrayList.from(1, 8, 4, 2, 11, 12, 9, 15), components.get(1)); assertEquals(IntArrayList.from(6, 14, 10), components.get(2)); }
@Test public void testSimple() { SubnetworkStorage storage = new SubnetworkStorage(new RAMDirectory(), "fastest"); storage.create(2000); storage.setSubnetwork(1, 88); assertEquals(88, storage.getSubnetwork(1)); assertEquals(0, storage.getSubnetwork(0)); storage.close(); } }
@Test public void testTarjan() { GraphHopperStorage g = createSubnetworkTestStorage(); // Requires a single vehicle type, otherwise we throw. final EdgeFilter filter = DefaultEdgeFilter.outEdges(carFlagEncoder); TarjansSCCAlgorithm tarjan = new TarjansSCCAlgorithm(g, filter, false); List<IntArrayList> components = tarjan.findComponents(); assertEquals(4, components.size()); assertEquals(IntArrayList.from(13, 5, 3, 7, 0), components.get(0)); assertEquals(IntArrayList.from(2, 4, 12, 11, 8, 1), components.get(1)); assertEquals(IntArrayList.from(10, 14, 6), components.get(2)); assertEquals(IntArrayList.from(15, 9), components.get(3)); }
/** * Removes nodes if all edges are not accessible. I.e. removes zero degree nodes. */ void markNodesRemovedIfUnreachable() { EdgeExplorer edgeExplorer = ghStorage.createEdgeExplorer(); for (int nodeIndex = 0; nodeIndex < ghStorage.getNodes(); nodeIndex++) { if (detectNodeRemovedForAllEncoders(edgeExplorer, nodeIndex)) ghStorage.markNodeRemoved(nodeIndex); } }
@Override public void flush() { landmarkWeightDA.flush(); subnetworkStorage.flush(); }
@Override public long getCapacity() { return landmarkWeightDA.getCapacity() + subnetworkStorage.getCapacity(); }
/** * Find and return list of all strongly connected components in g. */ public List<IntArrayList> findComponents() { int nodes = graph.getNodes(); for (int start = 0; start < nodes; start++) { if (nodeIndex[start] == 0 && !ignoreSet.contains(start) && !graph.isNodeRemoved(start)) strongConnect(start); } return components; }
GraphHopperStorage createDeadEndUnvisitedNetworkStorage(EncodingManager em) { GraphHopperStorage g = createStorage(em); // 0 <-> 1 <-> 2 <-> 3 <-> 4 <- 5 <-> 6 g.edge(0, 1, 1, true); g.edge(1, 2, 1, true); g.edge(2, 3, 1, true); g.edge(3, 4, 1, true); g.edge(5, 4, 1, false); g.edge(5, 6, 1, true); // 7 -> 8 <-> 9 <-> 10 g.edge(7, 8, 1, false); g.edge(8, 9, 1, true); g.edge(9, 10, 1, true); return g; }
public static boolean isConsistent(GraphHopperStorage storage) { EdgeExplorer edgeExplorer = storage.createEdgeExplorer(); int nNodes = storage.getNodes(); for(int i=0; i<nNodes; i++) { if(!check(storage, edgeExplorer, i)) return false; } return true; }
@Test public void testAddEdgesAfterwards() { GraphHopperStorage g = createDeadEndUnvisitedNetworkStorage(em); assertEquals(11, g.getNodes()); PrepareRoutingSubnetworks instance = new PrepareRoutingSubnetworks(g, Collections.singletonList(carFlagEncoder)). setMinOneWayNetworkSize(3); int removed = instance.removeDeadEndUnvisitedNetworks(new PrepEdgeFilter(carFlagEncoder)); assertEquals(3, removed); instance.markNodesRemovedIfUnreachable(); g.optimize(); assertEquals(8, g.getNodes()); assertTrue(isConsistent(g)); g.edge(7,8); assertTrue(isConsistent(g)); }
public static TarjanState resumeState(int start, EdgeIterator iter) { return new TarjanState(start, iter); }
GraphHopperStorage createTarjanTestStorage() { GraphHopperStorage g = createStorage(em); g.edge(1, 2, 1, false); g.edge(2, 3, 1, false); g.edge(3, 1, 1, false); g.edge(4, 2, 1, false); g.edge(4, 3, 1, false); g.edge(4, 5, 1, true); g.edge(5, 6, 1, false); g.edge(6, 3, 1, false); g.edge(6, 7, 1, true); g.edge(8, 5, 1, false); g.edge(8, 7, 1, false); g.edge(8, 8, 1, false); return g; }
GraphHopperStorage createSubnetworkTestStorage() { GraphHopperStorage g = createStorage(em); // big network g.edge(1, 2, 1, true); g.edge(1, 4, 1, false); g.edge(1, 8, 1, true); g.edge(2, 4, 1, true); g.edge(8, 4, 1, false); g.edge(8, 11, 1, true); g.edge(12, 11, 1, true); g.edge(9, 12, 1, false); g.edge(9, 15, 1, true); // large network g.edge(0, 13, 1, true); g.edge(0, 3, 1, true); g.edge(0, 7, 1, true); g.edge(3, 7, 1, true); g.edge(3, 5, 1, true); g.edge(13, 5, 1, true); // small network g.edge(6, 14, 1, true); g.edge(10, 14, 1, true); return g; }