Examples with Edge org.openkilda.pce.model.Edge used on opensource projects

Example 11 with Edge

use of org.openkilda.pce.model.Edge in project open-kilda by telstra.

the class BestWeightAndShortestPathFinder method findNPathsBetweenSwitches.

/**
 * Find N (or less) best paths. To find N paths Yen's algorithm is used.
 *
 * @return an list of N (or less) best paths.
 */
private List<List<Edge>> findNPathsBetweenSwitches(AvailableNetwork network, SwitchId startSwitchId, SwitchId endSwitchId, int count, WeightFunction weightFunction, Function<Node, FindOneDirectionPathResult> getPath) throws UnroutableFlowException {
    Node start = network.getSwitch(startSwitchId);
    Node end = network.getSwitch(endSwitchId);
    if (start == null || end == null) {
        throw new UnroutableFlowException(format("Switch %s doesn't have links with enough bandwidth", start == null ? startSwitchId : endSwitchId));
    }
    // Determine the shortest path from the start to the end.
    List<List<Edge>> bestPaths = new ArrayList<>();
    List<Edge> firstPath = getPath.apply(start).getFoundPath();
    if (firstPath.isEmpty()) {
        return new ArrayList<>();
    }
    bestPaths.add(getPath.apply(start).getFoundPath());
    // Initialize the set to store the potential kth shortest path.
    // Use LinkedHashSet to have deterministic results.
    Set<List<Edge>> potentialKthShortestPaths = new LinkedHashSet<>();
    for (int k = 1; k < count; k++) {
        List<Edge> bestPath = bestPaths.get(k - 1);
        for (int i = 0; i < bestPath.size(); i++) {
            // Spur node is retrieved from the previous k-shortest path.
            Node spurNode = bestPath.get(i).getSrcSwitch();
            // The sequence of edges from the start to the spur node (without spur node).
            List<Edge> rootPath = new ArrayList<>(bestPath.subList(0, i));
            Set<Edge> removedEdges = new HashSet<>();
            // Remove the links that are part of the previous shortest paths which share the same root path.
            for (List<Edge> path : bestPaths) {
                if (path.size() > i && rootPath.equals(path.subList(0, i)) && spurNode.equals(path.get(i).getSrcSwitch())) {
                    removedEdges.add(path.get(i));
                    removeEdge(path.get(i));
                }
            }
            for (Edge edge : rootPath) {
                edge.getSrcSwitch().remove();
            }
            // Calculate the spur path from the spur node to the end.
            List<Edge> pathFromSpurNode = getPath.apply(spurNode).getFoundPath();
            if (!pathFromSpurNode.isEmpty()) {
                List<Edge> totalPath = new ArrayList<>(rootPath);
                // Entire path is made up of the root path and spur path.
                totalPath.addAll(pathFromSpurNode);
                // Add the potential k-shortest path to the heap.
                potentialKthShortestPaths.add(totalPath);
            }
            // Add back the edges and nodes that were removed from the graph.
            for (Edge edge : removedEdges) {
                restoreEdge(edge);
            }
            for (Edge edge : rootPath) {
                edge.getSrcSwitch().restore();
            }
        }
        if (potentialKthShortestPaths.isEmpty()) {
            break;
        }
        // Add the lowest weight path becomes the k-shortest path.
        List<Edge> newBestPath = getBestPotentialKthShortestPath(potentialKthShortestPaths, bestPaths, weightFunction);
        bestPaths.add(newBestPath);
    }
    return bestPaths;
}

Example 12 with Edge

use of org.openkilda.pce.model.Edge in project open-kilda by telstra.

the class BestWeightAndShortestPathFinderTest method shouldReturnTheShortestPath.

@Test
public void shouldReturnTheShortestPath() throws UnroutableFlowException {
    AvailableNetwork network = buildTestNetwork();
    BestWeightAndShortestPathFinder pathFinder = new BestWeightAndShortestPathFinder(ALLOWED_DEPTH);
    Pair<List<Edge>, List<Edge>> pairPath = pathFinder.findPathWithMinWeight(network, SWITCH_ID_E, SWITCH_ID_F, WEIGHT_FUNCTION).getFoundPath();
    List<Edge> fpath = pairPath.getLeft();
    assertThat(fpath, Matchers.hasSize(2));
    assertEquals(SWITCH_ID_E, fpath.get(0).getSrcSwitch().getSwitchId());
    assertEquals(SWITCH_ID_F, fpath.get(1).getDestSwitch().getSwitchId());
    List<Edge> rpath = pairPath.getRight();
    assertThat(rpath, Matchers.hasSize(2));
    assertEquals(SWITCH_ID_F, rpath.get(0).getSrcSwitch().getSwitchId());
    assertEquals(SWITCH_ID_E, rpath.get(1).getDestSwitch().getSwitchId());
}

Example 13 with Edge

use of org.openkilda.pce.model.Edge in project open-kilda by telstra.

the class BestWeightAndShortestPathFinderTest method shouldFindSymmetricPath.

@Test
public void shouldFindSymmetricPath() throws UnroutableFlowException {
    AvailableNetwork network = buildLinearNetworkWithPairLinks();
    BestWeightAndShortestPathFinder pathFinder = new BestWeightAndShortestPathFinder(2);
    Pair<List<Edge>, List<Edge>> pathPair = pathFinder.findPathWithMinWeight(network, SWITCH_ID_1, SWITCH_ID_3, WEIGHT_FUNCTION).getFoundPath();
    List<Edge> forward = pathPair.getLeft();
    List<Edge> reverse = Lists.reverse(pathPair.getRight());
    List<Boolean> validation = IntStream.range(0, forward.size()).mapToObj(i -> Objects.equals(forward.get(i).getSrcPort(), reverse.get(i).getDestPort())).collect(Collectors.toList());
    assertFalse(validation.contains(false));
}

Example 14 with Edge

use of org.openkilda.pce.model.Edge in project open-kilda by telstra.

the class AvailableNetworkFactory method addIslAsEdge.

private void addIslAsEdge(IslImmutableView isl, AvailableNetwork network) {
    Node srcSwitch = network.getOrAddNode(isl.getSrcSwitchId(), isl.getSrcPop());
    Node dstSwitch = network.getOrAddNode(isl.getDestSwitchId(), isl.getDestPop());
    Edge edge = Edge.builder().srcSwitch(srcSwitch).srcPort(isl.getSrcPort()).destSwitch(dstSwitch).destPort(isl.getDestPort()).cost(isl.getCost()).latency(isl.getLatency()).underMaintenance(isl.isUnderMaintenance()).unstable(isl.isUnstable()).availableBandwidth(isl.getAvailableBandwidth()).build();
    network.addEdge(edge);
}

Example 15 with Edge

use of org.openkilda.pce.model.Edge in project open-kilda by telstra.

the class BestWeightAndShortestPathFinder method removeEdge.

private void removeEdge(Edge edge) {
    edge.getSrcSwitch().getOutgoingLinks().remove(edge);
    edge.getDestSwitch().getIncomingLinks().remove(edge);
    Edge reverseEdge = edge.swap();
    reverseEdge.getSrcSwitch().getOutgoingLinks().remove(reverseEdge);
    reverseEdge.getDestSwitch().getIncomingLinks().remove(reverseEdge);
}