[Emu] Disjoint Path Utils Exposed (to DefaultTopology)

Change-Id: I1d59d7a5a89618bd7419f00a0da674e87fe9bdb3

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.net;
+
+import org.onosproject.net.provider.ProviderId;
+
+import java.util.List;
+import java.util.Objects;
+import static com.google.common.collect.ImmutableSet.of;
+
+/**
+ * Default implementation of a network disjoint path pair.
+ */
+public class DefaultDisjointPath extends DefaultPath implements DisjointPath {
+
+    private final DefaultPath path1;
+    private final DefaultPath path2;
+
+    boolean usingPath1 = true;
+
+    /**
+     * Creates a disjoint path pair from two default paths.
+     *
+     * @param providerId provider identity
+     * @param path1      primary path
+     * @param path2      backup path
+     */
+    public DefaultDisjointPath(ProviderId providerId, DefaultPath path1, DefaultPath path2) {
+        super(providerId, path1.links(), path1.cost() + path2.cost());
+        this.path1 = path1;
+        this.path2 = path2;
+    }
+
+    @Override
+    public List<Link> links() {
+        if (usingPath1) {
+            return path1.links();
+        } else {
+            return path2.links();
+        }
+    }
+
+    @Override
+    public double cost() {
+        if (usingPath1) {
+            return path1.cost();
+        }
+        return path2.cost();
+    }
+
+    @Override
+    public Path primary() {
+        return path1;
+    }
+
+    @Override
+    public Path backup() {
+        return path2;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(of(path1, path2), src(), dst());
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof DefaultDisjointPath) {
+            final DefaultDisjointPath other = (DefaultDisjointPath) obj;
+            return Objects.equals(this.path1, other.path1) && Objects.equals(this.path2, other.path2);
+        }
+        return false;
+    }
+
+    @Override
+    public boolean useBackup() {
+        if (path2 == null || path2.links() == null) {
+            return false;
+        }
+        usingPath1 = !usingPath1;
+        return true;
+    }
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.net;
+
+
+/**
+ * Representation of a contiguous directed path in a network. Path comprises
+ * of a sequence of links, where adjacent links must share the same device,
+ * meaning that destination of the source of one link must coincide with the
+ * destination of the previous link.
+ */
+public interface DisjointPath extends Path {
+
+    /**
+     * Uses backup path.
+     *
+     * @return boolean corresponding to whether request to use
+     *          backup was successful.
+     */
+    boolean useBackup();
+
+    /**
+     * Gets primary path.
+     *
+     * @return primary path
+     */
+    Path primary();
+
+    /**
+     * Gets secondary path.
+     *
+     * @return secondary path
+     */
+    Path backup();
+}

@@ -25,12 +25,16 @@ import com.google.common.collect.ImmutableSetMultimap.Builder;
 import org.onlab.graph.DijkstraGraphSearch;
 import org.onlab.graph.GraphPathSearch;
 import org.onlab.graph.GraphPathSearch.Result;
+import org.onlab.graph.SRLGGraphSearch;
+import org.onlab.graph.SuurballeGraphSearch;
 import org.onlab.graph.TarjanGraphSearch;
 import org.onlab.graph.TarjanGraphSearch.SCCResult;
 import org.onosproject.net.AbstractModel;
 import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DefaultDisjointPath;
 import org.onosproject.net.DefaultPath;
 import org.onosproject.net.DeviceId;
+import org.onosproject.net.DisjointPath;
 import org.onosproject.net.Link;
 import org.onosproject.net.Path;
 import org.onosproject.net.provider.ProviderId;
@@ -46,6 +50,7 @@ import org.onosproject.net.topology.TopologyGraph;
 import org.onosproject.net.topology.TopologyVertex;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -67,6 +72,9 @@ public class DefaultTopology extends AbstractModel implements Topology {
 
     private static final DijkstraGraphSearch<TopologyVertex, TopologyEdge> DIJKSTRA = new DijkstraGraphSearch<>();
     private static final TarjanGraphSearch<TopologyVertex, TopologyEdge> TARJAN = new TarjanGraphSearch<>();
+    private static final SuurballeGraphSearch<TopologyVertex, TopologyEdge> SUURBALLE =
+            new SuurballeGraphSearch<>();
+
 
     private final long time;
     private final long creationTime;
@@ -314,6 +322,142 @@ public class DefaultTopology extends AbstractModel implements Topology {
         }
         return builder.build();
     }
+    /**
+     /**
+     * Returns the set of pre-computed shortest disjoint path pairs between source and
+     * destination devices.
+     *
+     * @param src source device
+     * @param dst destination device
+     * @return set of shortest disjoint path pairs
+     */
+    Set<DisjointPath> getDisjointPaths(DeviceId src, DeviceId dst) {
+        return getDisjointPaths(src, dst, null);
+    }
+
+    /**
+     * Computes on-demand the set of shortest disjoint path pairs between source and
+     * destination devices.
+     *
+     * @param src    source device
+     * @param dst    destination device
+     * @param weight link weight function
+     * @return set of disjoint shortest path pairs
+     */
+    Set<DisjointPath> getDisjointPaths(DeviceId src, DeviceId dst, LinkWeight weight) {
+        final DefaultTopologyVertex srcV = new DefaultTopologyVertex(src);
+        final DefaultTopologyVertex dstV = new DefaultTopologyVertex(dst);
+        Set<TopologyVertex> vertices = graph.getVertexes();
+        if (!vertices.contains(srcV) || !vertices.contains(dstV)) {
+            // src or dst not part of the current graph
+            return ImmutableSet.of();
+        }
+
+        GraphPathSearch.Result<TopologyVertex, TopologyEdge> result =
+                SUURBALLE.search(graph, srcV, dstV, weight, ALL_PATHS);
+        ImmutableSet.Builder<DisjointPath> builder = ImmutableSet.builder();
+        for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+            builder.add(networkDisjointPath((org.onlab.graph.DisjointPathPair<TopologyVertex, TopologyEdge>) path));
+        }
+        return builder.build();
+    }
+
+    /**
+     * Computes on-demand the set of shortest disjoint risk groups path pairs between source and
+     * destination devices.
+     *
+     * @param src           source device
+     * @param dst           destination device
+     * @param riskProfile   map representing risk groups for each edge
+     * @return  set of shortest disjoint paths
+     */
+    Set<DisjointPath> getSRLGDisjointPathsD(DeviceId src, DeviceId dst, Map<TopologyEdge, Object> riskProfile) {
+        return getSRLGDisjointPathsD(src, dst, null, riskProfile);
+    }
+
+    /**
+     * Computes on-demand the set of shortest disjoint risk groups path pairs between source and
+     * destination devices.
+     *
+     * @param src       source device
+     * @param dst       destination device
+     * @param weight    edge weight object
+     * @param riskProfile   map representing risk groups for each edge
+     * @return set of shortest disjoint paths
+     */
+    Set<DisjointPath> getSRLGDisjointPathsD(DeviceId src, DeviceId dst, LinkWeight weight, Map<TopologyEdge,
+            Object> riskProfile) {
+        final DefaultTopologyVertex srcV = new DefaultTopologyVertex(src);
+        final DefaultTopologyVertex dstV = new DefaultTopologyVertex(dst);
+        Set<TopologyVertex> vertices = graph.getVertexes();
+        if (!vertices.contains(srcV) || !vertices.contains(dstV)) {
+            // src or dst not part of the current graph
+            return ImmutableSet.of();
+        }
+
+        SRLGGraphSearch<TopologyVertex, TopologyEdge> srlg = new SRLGGraphSearch<>(riskProfile);
+        GraphPathSearch.Result<TopologyVertex, TopologyEdge> result =
+                srlg.search(graph, srcV, dstV, weight, ALL_PATHS);
+        ImmutableSet.Builder<DisjointPath> builder = ImmutableSet.builder();
+        for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+            builder.add(networkDisjointPath((org.onlab.graph.DisjointPathPair<TopologyVertex, TopologyEdge>) path));
+        }
+        return builder.build();
+    }
+
+    /**
+     * Computes on-demand the set of shortest disjoint risk groups path pairs between source and
+     * destination devices.
+     *
+     * @param src       source device
+     * @param dst       destination device
+     * @param weight    edge weight object
+     * @param riskProfile   map representing risk groups for each link
+     * @return set of shortest disjoint paths
+     */
+    Set<DisjointPath> getSRLGDisjointPaths(DeviceId src, DeviceId dst, LinkWeight weight,
+                                           Map<Link, Object> riskProfile) {
+        Map<TopologyEdge, Object> riskProfile2 = new HashMap<>();
+        for (Link l : riskProfile.keySet()) {
+            riskProfile2.put(new TopologyEdge() {
+                final Link cur = l;
+
+                public Link link() {
+                    return cur;
+                }
+
+                public TopologyVertex src() {
+                    return new TopologyVertex() {
+                        public DeviceId deviceId() {
+                            return src;
+                        }
+                    };
+                }
+
+                public TopologyVertex dst() {
+                    return new TopologyVertex() {
+                        public DeviceId deviceId() {
+                            return dst;
+                        }
+                    };
+                }
+            }, riskProfile.get(l));
+        }
+        return getSRLGDisjointPathsD(src, dst, weight, riskProfile2);
+    }
+
+    /**
+     * Computes on-demand the set of shortest disjoint risk groups path pairs between source and
+     * destination devices.
+     *
+     * @param src       source device
+     * @param dst       destination device
+     * @param riskProfile   map representing risk groups for each link
+     * @return set of shortest disjoint paths
+     */
+    Set<DisjointPath> getSRLGDisjointPaths(DeviceId src, DeviceId dst, Map<Link, Object> riskProfile) {
+        return getSRLGDisjointPaths(src, dst, null, riskProfile);
+    }
 
     // Converts graph path to a network path with the same cost.
     private Path networkPath(org.onlab.graph.Path<TopologyVertex, TopologyEdge> path) {
@@ -324,6 +468,11 @@ public class DefaultTopology extends AbstractModel implements Topology {
         return new DefaultPath(CORE_PROVIDER_ID, links, path.cost());
     }
 
+    private DisjointPath networkDisjointPath(org.onlab.graph.DisjointPathPair<TopologyVertex, TopologyEdge> path) {
+        return new DefaultDisjointPath(CORE_PROVIDER_ID,
+                                       (DefaultPath) networkPath(path.path1), (DefaultPath) networkPath(path.path2));
+    }
+
     // Searches for SCC clusters in the network topology graph using Tarjan
     // algorithm.
     private SCCResult<TopologyVertex, TopologyEdge> searchForClusters() {