Merge remote-tracking branch 'origin/master'
diff --git a/core/api/src/main/java/org/onlab/onos/net/path/PathService.java b/core/api/src/main/java/org/onlab/onos/net/path/PathService.java
new file mode 100644
index 0000000..c1d664b
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/path/PathService.java
@@ -0,0 +1,58 @@
+package org.onlab.onos.net.path;
+
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.topology.LinkWeight;
+
+import java.util.Set;
+
+/**
+ * Service for obtaining pre-computed paths or for requesting computation of
+ * paths using the current topology snapshot.
+ */
+public interface PathService {
+
+ /**
+ * Returns the set of all shortest paths, precomputed in terms of hop-count,
+ * between the specified source and destination devices.
+ *
+ * @param src source device
+ * @param dst destination device
+ * @return set of all shortest paths between the two devices
+ */
+ Set<Path> getPaths(DeviceId src, DeviceId dst);
+
+ /**
+ * Returns the set of all shortest paths, computed using the supplied
+ * edge-weight entity, between the specified source and destination devices.
+ *
+ * @param src source device
+ * @param dst destination device
+ * @return set of all shortest paths between the two devices
+ */
+ Set<Path> getPaths(DeviceId src, DeviceId dst,
+ LinkWeight weight);
+
+
+ /**
+ * Returns the set of all shortest paths, precomputed in terms of hop-count,
+ * between the specified source and destination end-stations.
+ *
+ * @param src source device
+ * @param dst destination device
+ * @return set of all shortest paths between the two end-stations hosts
+ */
+ Set<Path> getPaths(HostId src, HostId dst);
+
+ /**
+ * Returns the set of all shortest paths, computed using the supplied
+ * edge-weight entity, between the specified source and end-stations.
+ *
+ * @param src source host
+ * @param dst destination host
+ * @return set of all shortest paths between the two end-station hosts
+ */
+ Set<Path> getPaths(HostId src, HostId dst, LinkWeight weight);
+
+}
diff --git a/core/trivial/src/main/java/org/onlab/onos/net/trivial/path/PathManager.java b/core/trivial/src/main/java/org/onlab/onos/net/trivial/path/PathManager.java
new file mode 100644
index 0000000..6f763ac
--- /dev/null
+++ b/core/trivial/src/main/java/org/onlab/onos/net/trivial/path/PathManager.java
@@ -0,0 +1,164 @@
+package org.onlab.onos.net.trivial.path;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultEdgeLink;
+import org.onlab.onos.net.DefaultPath;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.EdgeLink;
+import org.onlab.onos.net.Host;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.host.HostService;
+import org.onlab.onos.net.path.PathService;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.topology.LinkWeight;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyService;
+import org.slf4j.Logger;
+
+import java.util.List;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Provides implementation of a path selection service atop the current
+ * topology and host services.
+ */
+@Component(immediate = true)
+@Service
+public class PathManager implements PathService {
+
+ private static final String DEVICE_ID_NULL = "Device ID cannot be null";
+ private static final String HOST_ID_NULL = "Host ID cannot be null";
+
+ private static final ProviderId PID = new ProviderId("org.onlab.onos.core");
+ private static final PortNumber P0 = PortNumber.portNumber(0);
+
+ private final Logger log = getLogger(getClass());
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected TopologyService topologyService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected HostService hostService;
+
+ @Activate
+ public void setUp() {
+ log.info("Started");
+ }
+
+ @Deactivate
+ public void tearDown() {
+ log.info("Stopped");
+ }
+
+ @Override
+ public Set<Path> getPaths(DeviceId src, DeviceId dst) {
+ checkNotNull(src, DEVICE_ID_NULL);
+ checkNotNull(dst, DEVICE_ID_NULL);
+ Topology topology = topologyService.currentTopology();
+ return topologyService.getPaths(topology, src, dst);
+ }
+
+ @Override
+ public Set<Path> getPaths(DeviceId src, DeviceId dst, LinkWeight weight) {
+ checkNotNull(src, DEVICE_ID_NULL);
+ checkNotNull(dst, DEVICE_ID_NULL);
+ Topology topology = topologyService.currentTopology();
+ return topologyService.getPaths(topology, src, dst, weight);
+ }
+
+ @Override
+ public Set<Path> getPaths(HostId src, HostId dst) {
+ return getPaths(src, dst, null);
+ }
+
+ @Override
+ public Set<Path> getPaths(HostId src, HostId dst, LinkWeight weight) {
+ checkNotNull(src, HOST_ID_NULL);
+ checkNotNull(dst, HOST_ID_NULL);
+
+ // Resolve the source host, bail if unable.
+ Host srcHost = hostService.getHost(src);
+ if (srcHost == null) {
+ return Sets.newHashSet();
+ }
+
+ // Resolve the destination host, bail if unable.
+ Host dstHost = hostService.getHost(dst);
+ if (dstHost == null) {
+ return Sets.newHashSet();
+ }
+
+ // Get the source and destination edge locations
+ EdgeLink srcEdge = new DefaultEdgeLink(PID, new ConnectPoint(src, P0),
+ srcHost.location(), true);
+ EdgeLink dstEdge = new DefaultEdgeLink(PID, new ConnectPoint(dst, P0),
+ dstHost.location(), false);
+
+ // If the source and destination are on the same edge device, there
+ // is just one path, so build it and return it.
+ if (srcEdge.dst().deviceId().equals(dstEdge.src().deviceId())) {
+ return edgeToEdgePaths(srcEdge, dstEdge);
+ }
+
+ // Otherwise get all paths between the source and destination edge
+ // devices.
+ Topology topology = topologyService.currentTopology();
+ Set<Path> paths = weight == null ?
+ topologyService.getPaths(topology, srcEdge.dst().deviceId(),
+ dstEdge.src().deviceId()) :
+ topologyService.getPaths(topology, srcEdge.dst().deviceId(),
+ dstEdge.src().deviceId(), weight);
+
+ return edgeToEdgePaths(srcEdge, dstEdge, paths);
+ }
+
+ // Produces a set of direct edge-to-edge paths.
+ private Set<Path> edgeToEdgePaths(EdgeLink srcLink, EdgeLink dstLink) {
+ Set<Path> endToEndPaths = Sets.newHashSetWithExpectedSize(1);
+ endToEndPaths.add(edgeToEdgePath(srcLink, dstLink));
+ return endToEndPaths;
+ }
+
+ // Produces a direct edge-to-edge path.
+ private Path edgeToEdgePath(EdgeLink srcLink, EdgeLink dstLink) {
+ List<Link> links = Lists.newArrayListWithCapacity(2);
+ links.add(srcLink);
+ links.add(dstLink);
+ return new DefaultPath(PID, links, 2);
+ }
+
+ // Produces a set of edge-to-edge paths using the set of infrastructure
+ // paths and the given edge links.
+ private Set<Path> edgeToEdgePaths(EdgeLink srcLink, EdgeLink dstLink, Set<Path> paths) {
+ Set<Path> endToEndPaths = Sets.newHashSetWithExpectedSize(paths.size());
+ for (Path path : paths) {
+ endToEndPaths.add(edgeToEdgePath(srcLink, dstLink, path));
+ }
+ return endToEndPaths;
+ }
+
+ // Produces an edge-to-edge path using the specified infrastructure path
+ // and edge links.
+ private Path edgeToEdgePath(EdgeLink srcLink, EdgeLink dstLink, Path path) {
+ List<Link> links = Lists.newArrayListWithCapacity(path.links().size() + 2);
+ links.add(srcLink);
+ links.addAll(path.links());
+ links.add(dstLink);
+ return new DefaultPath(path.providerId(), links, path.cost() + 2);
+ }
+
+}