tom

Re-assembled the topology subsystem.

Showing 23 changed files with 333 additions and 362 deletions
......@@ -16,7 +16,7 @@ public class DefaultLink extends AbstractModel implements Link {
private final Type type;
/**
* Creates a link description using the supplied information.
* Creates an infrastructure link using the supplied information.
*
* @param providerId provider identity
* @param src link source
......
package org.onlab.onos.net;
import com.google.common.collect.ImmutableList;
import org.onlab.onos.net.provider.ProviderId;
import java.util.List;
import java.util.Objects;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
/**
* Default implementation of a network path.
*/
public class DefaultPath extends DefaultLink implements Path {
private final List<Link> links;
private final double cost;
/**
* Creates a path from the specified source and destination using the
* supplied list of links.
*
* @param providerId provider identity
* @param links contiguous links that comprise the path
* @param cost unit-less path cost
*/
public DefaultPath(ProviderId providerId, List<Link> links, double cost) {
super(providerId, source(links), destination(links), Type.INDIRECT);
this.links = ImmutableList.copyOf(links);
this.cost = cost;
}
@Override
public List<Link> links() {
return links;
}
@Override
public double cost() {
return cost;
}
// Returns the source of the first link.
private static ConnectPoint source(List<Link> links) {
checkNotNull(links, "List of path links cannot be null");
checkArgument(!links.isEmpty(), "List of path links cannot be empty");
return links.get(0).src();
}
// Returns the destination of the last link.
private static ConnectPoint destination(List<Link> links) {
checkNotNull(links, "List of path links cannot be null");
checkArgument(!links.isEmpty(), "List of path links cannot be empty");
return links.get(links.size() - 1).dst();
}
@Override
public int hashCode() {
return 31 * super.hashCode() + Objects.hash(links);
}
@Override
public boolean equals(Object obj) {
if (obj instanceof DefaultPath) {
final DefaultPath other = (DefaultPath) obj;
return Objects.equals(this.links, other.links);
}
return false;
}
}
......@@ -17,4 +17,11 @@ public interface Path extends Link {
*/
List<Link> links();
/**
* Returns the path cost as a unit-less value.
*
* @return unit-less path cost
*/
double cost();
}
......
......@@ -27,6 +27,15 @@ public final class ClusterId {
return new ClusterId(id);
}
/**
* Returns the backing integer index.
*
* @return backing integer index
*/
public int index() {
return id;
}
@Override
public int hashCode() {
return Objects.hash(id);
......
package org.onlab.onos.net.topology;
import com.google.common.collect.ImmutableSet;
import org.onlab.onos.net.Description;
/**
* Describes attribute(s) of a network graph.
*/
public interface GraphDescription extends Description {
/**
* Returns the creation timestamp of the graph description. This is
* expressed in system nanos to allow proper sequencing.
*
* @return graph description creation timestamp
*/
long timestamp();
/**
* Returns the set of topology graph vertexes.
*
* @return set of graph vertexes
*/
ImmutableSet<TopologyVertex> vertexes();
/**
* Returns the set of topology graph edges.
*
* @return set of graph edges
*/
ImmutableSet<TopologyEdge> edges();
}
......@@ -6,5 +6,5 @@ import org.onlab.graph.EdgeWeight;
* Entity capable of determining cost or weight of a specified topology
* graph edge.
*/
public interface LinkWeight extends EdgeWeight<TopoVertex, TopoEdge> {
public interface LinkWeight extends EdgeWeight<TopologyVertex, TopologyEdge> {
}
......
package org.onlab.onos.net.topology;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ImmutableSetMultimap;
import org.onlab.graph.Graph;
import org.onlab.onos.net.Description;
import org.onlab.onos.net.DeviceId;
import org.onlab.onos.net.Link;
import static org.onlab.graph.GraphPathSearch.Result;
/**
* Describes attribute(s) of a network topology.
*/
public interface TopologyDescription extends Description {
/**
* Returns the creation timestamp of the topology description. This is
* expressed in system nanos to allow proper sequencing.
*
* @return topology description creation timestamp
*/
long timestamp();
/**
* Returns the topology graph in immutable form.
*
* @return network graph
*/
Graph<TopoVertex, TopoEdge> graph();
/**
* Returns an immutable map of path search results for each source device.
*
* @return map of path search result for each source node
*/
ImmutableMap<DeviceId, Result<TopoVertex, TopoEdge>> pathsBySource();
/**
* Returns the set of topology SCC clusters.
*
* @return set of SCC clusters
*/
ImmutableSet<TopologyCluster> clusters();
/**
* Returns an immutable set multi-map of devices for each cluster.
*
* @return set multi-map of devices that belong to each cluster
*/
ImmutableSetMultimap<TopologyCluster, DeviceId> devicesByCluster();
/**
* Returns an immutable set multi-map of links for each cluster.
*
* @return set multi-map of links that belong to each cluster
*/
ImmutableSetMultimap<TopologyCluster, Link> linksByCluster();
}
......@@ -6,7 +6,7 @@ import org.onlab.onos.net.Link;
/**
* Represents an edge in the topology graph.
*/
public interface TopoEdge extends Edge<TopoVertex> {
public interface TopologyEdge extends Edge<TopologyVertex> {
/**
* Returns the associated infrastructure link.
......
package org.onlab.onos.net.topology;
import org.onlab.graph.Graph;
/**
* Represents an immutable topology graph.
*/
public interface TopologyGraph extends Graph<TopologyVertex, TopologyEdge> {
}
......@@ -10,16 +10,13 @@ import java.util.List;
*/
public interface TopologyProviderService extends ProviderService<TopologyProvider> {
// What can be conveyed in a topology that isn't by individual
// providers?
/**
* Signals the core that some aspect of the topology has changed.
*
* @param topoDescription information about topology
* @param graphDescription information about the network graph
* @param reasons events that triggered topology change
*/
void topologyChanged(TopologyDescription topoDescription,
void topologyChanged(GraphDescription graphDescription,
List<Event> reasons);
}
......
package org.onlab.onos.net.topology;
import org.onlab.graph.Graph;
import org.onlab.onos.net.ConnectPoint;
import org.onlab.onos.net.DeviceId;
import org.onlab.onos.net.Path;
......@@ -41,7 +40,7 @@ public interface TopologyService {
* @param topology topology descriptor
* @return topology graph view
*/
Graph<TopoVertex, TopoEdge> getGraph(Topology topology);
TopologyGraph getGraph(Topology topology);
/**
* Returns the set of all shortest paths, precomputed in terms of hop-count,
......
......@@ -6,7 +6,7 @@ import org.onlab.onos.net.DeviceId;
/**
* Represents a vertex in the topology graph.
*/
public interface TopoVertex extends Vertex {
public interface TopologyVertex extends Vertex {
/**
* Returns the associated infrastructure device identification.
......
package org.onlab.onos.net.trivial.topology.impl;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Maps;
import org.onlab.onos.net.ConnectPoint;
import org.onlab.onos.net.Device;
import org.onlab.onos.net.DeviceId;
import org.onlab.onos.net.Link;
import org.onlab.onos.net.topology.GraphDescription;
import org.onlab.onos.net.topology.TopologyEdge;
import org.onlab.onos.net.topology.TopologyVertex;
import java.util.Map;
/**
* Default implementation of an immutable topology graph data carrier.
*/
class DefaultGraphDescription implements GraphDescription {
private final long nanos;
private final ImmutableSet<TopologyVertex> vertexes;
private final ImmutableSet<TopologyEdge> edges;
private final Map<DeviceId, TopologyVertex> vertexesById = Maps.newHashMap();
/**
* Creates a minimal topology graph description to allow core to construct
* and process the topology graph.
*
* @param nanos time in nanos of when the topology description was created
* @param devices collection of infrastructure devices
* @param links collection of infrastructure links
*/
DefaultGraphDescription(long nanos, Iterable<Device> devices, Iterable<Link> links) {
this.nanos = nanos;
this.vertexes = buildVertexes(devices);
this.edges = buildEdges(links);
vertexesById.clear();
}
@Override
public long timestamp() {
return nanos;
}
@Override
public ImmutableSet<TopologyVertex> vertexes() {
return vertexes;
}
@Override
public ImmutableSet<TopologyEdge> edges() {
return edges;
}
// Builds a set of topology vertexes from the specified list of devices
private ImmutableSet<TopologyVertex> buildVertexes(Iterable<Device> devices) {
ImmutableSet.Builder<TopologyVertex> vertexes = ImmutableSet.builder();
for (Device device : devices) {
TopologyVertex vertex = new DefaultTopologyVertex(device.id());
vertexes.add(vertex);
vertexesById.put(vertex.deviceId(), vertex);
}
return vertexes.build();
}
// Builds a set of topology vertexes from the specified list of links
private ImmutableSet<TopologyEdge> buildEdges(Iterable<Link> links) {
ImmutableSet.Builder<TopologyEdge> edges = ImmutableSet.builder();
for (Link link : links) {
edges.add(new DefaultTopologyEdge(vertexOf(link.src()),
vertexOf(link.dst()), link));
}
return edges.build();
}
// Fetches a vertex corresponding to the given connection point device.
private TopologyVertex vertexOf(ConnectPoint connectPoint) {
DeviceId id = connectPoint.deviceId();
TopologyVertex vertex = vertexesById.get(id);
if (vertex == null) {
// If vertex does not exist, create one and register it.
vertex = new DefaultTopologyVertex(id);
vertexesById.put(id, vertex);
}
return vertex;
}
}
package org.onlab.onos.net.trivial.topology.provider.impl;
package org.onlab.onos.net.trivial.topology.impl;
import org.onlab.onos.net.Link;
import org.onlab.onos.net.topology.TopoEdge;
import org.onlab.onos.net.topology.TopoVertex;
import org.onlab.onos.net.topology.TopologyEdge;
import org.onlab.onos.net.topology.TopologyVertex;
import java.util.Objects;
......@@ -11,11 +11,11 @@ import static com.google.common.base.MoreObjects.toStringHelper;
/**
* Implementation of the topology edge backed by a link.
*/
class DefaultTopoEdge implements TopoEdge {
class DefaultTopologyEdge implements TopologyEdge {
private final Link link;
private final TopoVertex src;
private final TopoVertex dst;
private final TopologyVertex src;
private final TopologyVertex dst;
/**
* Creates a new topology edge.
......@@ -24,7 +24,7 @@ class DefaultTopoEdge implements TopoEdge {
* @param dst destination vertex
* @param link infrastructure link
*/
DefaultTopoEdge(TopoVertex src, TopoVertex dst, Link link) {
DefaultTopologyEdge(TopologyVertex src, TopologyVertex dst, Link link) {
this.src = src;
this.dst = dst;
this.link = link;
......@@ -36,12 +36,12 @@ class DefaultTopoEdge implements TopoEdge {
}
@Override
public TopoVertex src() {
public TopologyVertex src() {
return src;
}
@Override
public TopoVertex dst() {
public TopologyVertex dst() {
return dst;
}
......@@ -52,8 +52,8 @@ class DefaultTopoEdge implements TopoEdge {
@Override
public boolean equals(Object obj) {
if (obj instanceof DefaultTopoEdge) {
final DefaultTopoEdge other = (DefaultTopoEdge) obj;
if (obj instanceof DefaultTopologyEdge) {
final DefaultTopologyEdge other = (DefaultTopologyEdge) obj;
return Objects.equals(this.link, other.link);
}
return false;
......
package org.onlab.onos.net.trivial.topology.impl;
import org.onlab.graph.AdjacencyListsGraph;
import org.onlab.onos.net.topology.TopologyEdge;
import org.onlab.onos.net.topology.TopologyGraph;
import org.onlab.onos.net.topology.TopologyVertex;
import java.util.Set;
/**
* Default implementation of an immutable topology graph based on a generic
* implementation of adjacency lists graph.
*/
public class DefaultTopologyGraph
extends AdjacencyListsGraph<TopologyVertex, TopologyEdge>
implements TopologyGraph {
/**
* Creates a topology graph comprising of the specified vertexes and edges.
*
* @param vertexes set of graph vertexes
* @param edges set of graph edges
*/
public DefaultTopologyGraph(Set<TopologyVertex> vertexes, Set<TopologyEdge> edges) {
super(vertexes, edges);
}
}
package org.onlab.onos.net.trivial.topology.provider.impl;
package org.onlab.onos.net.trivial.topology.impl;
import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
......@@ -16,7 +16,7 @@ import org.onlab.onos.net.link.LinkListener;
import org.onlab.onos.net.link.LinkService;
import org.onlab.onos.net.provider.AbstractProvider;
import org.onlab.onos.net.provider.ProviderId;
import org.onlab.onos.net.topology.TopologyDescription;
import org.onlab.onos.net.topology.GraphDescription;
import org.onlab.onos.net.topology.TopologyProvider;
import org.onlab.onos.net.topology.TopologyProviderRegistry;
import org.onlab.onos.net.topology.TopologyProviderService;
......@@ -35,7 +35,7 @@ import static org.slf4j.LoggerFactory.getLogger;
* Simple implementation of a network topology provider/computor.
*/
@Component(immediate = true)
public class SimpleTopologyProvider extends AbstractProvider
public class DefaultTopologyProvider extends AbstractProvider
implements TopologyProvider {
// TODO: make these configurable
......@@ -70,7 +70,7 @@ public class SimpleTopologyProvider extends AbstractProvider
/**
* Creates a provider with the supplier identifier.
*/
public SimpleTopologyProvider() {
public DefaultTopologyProvider() {
super(new ProviderId("org.onlab.onos.provider.topology"));
}
......@@ -110,15 +110,17 @@ public class SimpleTopologyProvider extends AbstractProvider
* @param reasons events which triggered the topology change
*/
private synchronized void triggerTopologyBuild(List<Event> reasons) {
if (executor != null) {
executor.execute(new TopologyBuilderTask(reasons));
}
}
// Builds the topology using the latest device and link information
// and citing the specified events as reasons for the change.
private void buildTopology(List<Event> reasons) {
if (isStarted) {
TopologyDescription desc =
new DefaultTopologyDescription(System.nanoTime(),
GraphDescription desc =
new DefaultGraphDescription(System.nanoTime(),
deviceService.getDevices(),
linkService.getLinks());
providerService.topologyChanged(desc, reasons);
......
package org.onlab.onos.net.trivial.topology.provider.impl;
package org.onlab.onos.net.trivial.topology.impl;
import org.onlab.onos.net.DeviceId;
import org.onlab.onos.net.topology.TopoVertex;
import org.onlab.onos.net.topology.TopologyVertex;
import java.util.Objects;
/**
* Implementation of the topology vertex backed by a device id.
*/
class DefaultTopoVertex implements TopoVertex {
class DefaultTopologyVertex implements TopologyVertex {
private final DeviceId deviceId;
......@@ -17,7 +17,7 @@ class DefaultTopoVertex implements TopoVertex {
*
* @param deviceId backing infrastructure device identifier
*/
DefaultTopoVertex(DeviceId deviceId) {
DefaultTopologyVertex(DeviceId deviceId) {
this.deviceId = deviceId;
}
......@@ -33,8 +33,8 @@ class DefaultTopoVertex implements TopoVertex {
@Override
public boolean equals(Object obj) {
if (obj instanceof DefaultTopoVertex) {
final DefaultTopoVertex other = (DefaultTopoVertex) obj;
if (obj instanceof DefaultTopologyVertex) {
final DefaultTopologyVertex other = (DefaultTopologyVertex) obj;
return Objects.equals(this.deviceId, other.deviceId);
}
return false;
......
package org.onlab.onos.net.trivial.topology.impl;
import org.onlab.onos.net.DeviceId;
import java.util.Objects;
/**
* Key for filing src/dst paths.
*/
class PathKey {
private final DeviceId src;
private final DeviceId dst;
/**
* Creates a path key from the given source/dest pair.
* @param src source device
* @param dst destination device
*/
PathKey(DeviceId src, DeviceId dst) {
this.src = src;
this.dst = dst;
}
@Override
public int hashCode() {
return Objects.hash(src, dst);
}
@Override
public boolean equals(Object obj) {
if (obj instanceof PathKey) {
final PathKey other = (PathKey) obj;
return Objects.equals(this.src, other.src) && Objects.equals(this.dst, other.dst);
}
return false;
}
}
......@@ -6,7 +6,6 @@ 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.graph.Graph;
import org.onlab.onos.event.AbstractListenerRegistry;
import org.onlab.onos.event.Event;
import org.onlab.onos.event.EventDeliveryService;
......@@ -15,13 +14,12 @@ import org.onlab.onos.net.DeviceId;
import org.onlab.onos.net.Path;
import org.onlab.onos.net.provider.AbstractProviderRegistry;
import org.onlab.onos.net.provider.AbstractProviderService;
import org.onlab.onos.net.topology.GraphDescription;
import org.onlab.onos.net.topology.LinkWeight;
import org.onlab.onos.net.topology.TopoEdge;
import org.onlab.onos.net.topology.TopoVertex;
import org.onlab.onos.net.topology.Topology;
import org.onlab.onos.net.topology.TopologyCluster;
import org.onlab.onos.net.topology.TopologyDescription;
import org.onlab.onos.net.topology.TopologyEvent;
import org.onlab.onos.net.topology.TopologyGraph;
import org.onlab.onos.net.topology.TopologyListener;
import org.onlab.onos.net.topology.TopologyProvider;
import org.onlab.onos.net.topology.TopologyProviderRegistry;
......@@ -98,7 +96,7 @@ public class SimpleTopologyManager
}
@Override
public Graph<TopoVertex, TopoEdge> getGraph(Topology topology) {
public TopologyGraph getGraph(Topology topology) {
checkNotNull(topology, TOPOLOGY_NULL);
return store.getGraph(defaultTopology(topology));
}
......@@ -159,16 +157,14 @@ public class SimpleTopologyManager
}
@Override
public void topologyChanged(TopologyDescription topoDescription,
public void topologyChanged(GraphDescription topoDescription,
List<Event> reasons) {
checkNotNull(topoDescription, "Topology description cannot be null");
log.info("Topology changed due to: {}", // to be removed soon
reasons == null ? "initial compute" : reasons);
TopologyEvent event = store.updateTopology(provider().id(),
topoDescription, reasons);
if (event != null) {
log.info("Topology changed due to: {}",
log.info("Topology {} changed due to: {}", event.subject(),
reasons == null ? "initial compute" : reasons);
eventDispatcher.post(event);
}
......
package org.onlab.onos.net.trivial.topology.impl;
import org.onlab.graph.Graph;
import org.onlab.onos.event.Event;
import org.onlab.onos.net.ConnectPoint;
import org.onlab.onos.net.DeviceId;
import org.onlab.onos.net.Path;
import org.onlab.onos.net.provider.ProviderId;
import org.onlab.onos.net.topology.GraphDescription;
import org.onlab.onos.net.topology.LinkWeight;
import org.onlab.onos.net.topology.TopoEdge;
import org.onlab.onos.net.topology.TopoVertex;
import org.onlab.onos.net.topology.Topology;
import org.onlab.onos.net.topology.TopologyCluster;
import org.onlab.onos.net.topology.TopologyDescription;
import org.onlab.onos.net.topology.TopologyEvent;
import org.onlab.onos.net.topology.TopologyGraph;
import java.util.List;
import java.util.Set;
......@@ -61,7 +59,7 @@ class SimpleTopologyStore {
* @param topology topology descriptor
* @return graph view
*/
Graph<TopoVertex, TopoEdge> getGraph(DefaultTopology topology) {
TopologyGraph getGraph(DefaultTopology topology) {
return topology.getGraph();
}
......@@ -88,7 +86,7 @@ class SimpleTopologyStore {
*/
Set<Path> getPaths(DefaultTopology topology, DeviceId src, DeviceId dst,
LinkWeight weight) {
return null;
return topology.getPaths(src, dst, weight);
}
/**
......@@ -117,26 +115,28 @@ class SimpleTopologyStore {
* Generates a new topology snapshot from the specified description.
*
* @param providerId provider identification
* @param topoDescription topology description
* @param graphDescription topology graph description
* @param reasons list of events that triggered the update
* @return topology update event or null if the description is old
*/
TopologyEvent updateTopology(ProviderId providerId,
TopologyDescription topoDescription,
GraphDescription graphDescription,
List<Event> reasons) {
// First off, make sure that what we're given is indeed newer than
// what we already have.
if (current != null && topoDescription.timestamp() < current.time()) {
if (current != null && graphDescription.timestamp() < current.time()) {
return null;
}
// Have the default topology construct self from the description data.
DefaultTopology newTopology =
new DefaultTopology(providerId, topoDescription);
new DefaultTopology(providerId, graphDescription);
// Promote the new topology to current and return a ready-to-send event.
synchronized (this) {
current = newTopology;
return new TopologyEvent(TopologyEvent.Type.TOPOLOGY_CHANGED, current);
}
}
}
......
package org.onlab.onos.net.trivial.topology.provider.impl;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ImmutableSetMultimap;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import org.onlab.graph.AdjacencyListsGraph;
import org.onlab.graph.DijkstraGraphSearch;
import org.onlab.graph.Graph;
import org.onlab.graph.GraphPathSearch;
import org.onlab.graph.TarjanGraphSearch;
import org.onlab.onos.net.ConnectPoint;
import org.onlab.onos.net.Device;
import org.onlab.onos.net.DeviceId;
import org.onlab.onos.net.Link;
import org.onlab.onos.net.topology.ClusterId;
import org.onlab.onos.net.topology.DefaultTopologyCluster;
import org.onlab.onos.net.topology.LinkWeight;
import org.onlab.onos.net.topology.TopoEdge;
import org.onlab.onos.net.topology.TopoVertex;
import org.onlab.onos.net.topology.TopologyCluster;
import org.onlab.onos.net.topology.TopologyDescription;
import java.util.List;
import java.util.Map;
import java.util.Set;
import static com.google.common.collect.ImmutableSetMultimap.Builder;
import static com.google.common.collect.ImmutableSetMultimap.builder;
import static org.onlab.graph.GraphPathSearch.Result;
import static org.onlab.graph.TarjanGraphSearch.SCCResult;
import static org.onlab.onos.net.Link.Type.INDIRECT;
/**
* Default implementation of an immutable topology data carrier.
*/
class DefaultTopologyDescription implements TopologyDescription {
private static final GraphPathSearch<TopoVertex, TopoEdge> DIJKSTRA =
new DijkstraGraphSearch<>();
private static final TarjanGraphSearch<TopoVertex, TopoEdge> TARJAN =
new TarjanGraphSearch<>();
private final long nanos;
private final Map<DeviceId, TopoVertex> vertexesById = Maps.newHashMap();
private final Graph<TopoVertex, TopoEdge> graph;
private final ImmutableMap<DeviceId, Result<TopoVertex, TopoEdge>> results;
// Cluster-related structures
private final ImmutableSet<TopologyCluster> clusters;
private ImmutableSetMultimap<TopologyCluster, DeviceId> devicesByCluster;
private ImmutableSetMultimap<TopologyCluster, Link> linksByCluster;
/**
* Creates a topology description to carry topology vitals to the core.
*
* @param nanos time in nanos of when the topology description was created
* @param devices collection of infrastructure devices
* @param links collection of infrastructure links
*/
DefaultTopologyDescription(long nanos, Iterable<Device> devices, Iterable<Link> links) {
this.nanos = nanos;
this.graph = buildGraph(devices, links);
this.results = computeDefaultPaths();
this.clusters = computeClusters();
}
@Override
public long timestamp() {
return nanos;
}
@Override
public Graph<TopoVertex, TopoEdge> graph() {
return graph;
}
@Override
public ImmutableMap<DeviceId, Result<TopoVertex, TopoEdge>> pathsBySource() {
return results;
}
@Override
public ImmutableSet<TopologyCluster> clusters() {
return clusters;
}
@Override
public ImmutableSetMultimap<TopologyCluster, DeviceId> devicesByCluster() {
return devicesByCluster;
}
@Override
public ImmutableSetMultimap<TopologyCluster, Link> linksByCluster() {
return linksByCluster;
}
// Link weight for measuring link cost as hop count with indirect links
// being as expensive as traversing the entire graph to assume the worst.
private static class HopCountLinkWeight implements LinkWeight {
private final int indirectLinkCost;
HopCountLinkWeight(int indirectLinkCost) {
this.indirectLinkCost = indirectLinkCost;
}
@Override
public double weight(TopoEdge edge) {
// To force preference to use direct paths first, make indirect
// links as expensive as the linear vertex traversal.
return edge.link().type() == INDIRECT ? indirectLinkCost : 1;
}
}
// Link weight for preventing traversal over indirect links.
private static class NoIndirectLinksWeight implements LinkWeight {
@Override
public double weight(TopoEdge edge) {
return edge.link().type() == INDIRECT ? -1 : 1;
}
}
// Constructs the topology graph using the supplied devices and links.
private Graph<TopoVertex, TopoEdge> buildGraph(Iterable<Device> devices,
Iterable<Link> links) {
return new AdjacencyListsGraph<>(buildVertexes(devices),
buildEdges(links));
}
// Builds a set of topology vertexes from the specified list of devices
private Set<TopoVertex> buildVertexes(Iterable<Device> devices) {
Set<TopoVertex> vertexes = Sets.newHashSet();
for (Device device : devices) {
TopoVertex vertex = new DefaultTopoVertex(device.id());
vertexes.add(vertex);
vertexesById.put(vertex.deviceId(), vertex);
}
return vertexes;
}
// Builds a set of topology vertexes from the specified list of links
private Set<TopoEdge> buildEdges(Iterable<Link> links) {
Set<TopoEdge> edges = Sets.newHashSet();
for (Link link : links) {
edges.add(new DefaultTopoEdge(vertexOf(link.src()),
vertexOf(link.dst()), link));
}
return edges;
}
// Computes the default shortest paths for all source/dest pairs using
// the multi-path Dijkstra and hop-count as path cost.
private ImmutableMap<DeviceId, Result<TopoVertex, TopoEdge>> computeDefaultPaths() {
LinkWeight weight = new HopCountLinkWeight(graph.getVertexes().size());
ImmutableMap.Builder<DeviceId, Result<TopoVertex, TopoEdge>> results =
ImmutableMap.builder();
// Search graph paths for each source to all destinations.
for (TopoVertex src : vertexesById.values()) {
results.put(src.deviceId(), DIJKSTRA.search(graph, src, null, weight));
}
return results.build();
}
// Computes topology SCC clusters using Tarjan algorithm.
private ImmutableSet<TopologyCluster> computeClusters() {
ImmutableSet.Builder<TopologyCluster> clusterBuilder = ImmutableSet.builder();
SCCResult<TopoVertex, TopoEdge> result =
TARJAN.search(graph, new NoIndirectLinksWeight());
// Extract both vertexes and edges from the results; the lists form
// pairs along the same index.
List<Set<TopoVertex>> clusterVertexes = result.clusterVertexes();
List<Set<TopoEdge>> clusterEdges = result.clusterEdges();
Builder<TopologyCluster, DeviceId> devicesBuilder = ImmutableSetMultimap.builder();
Builder<TopologyCluster, Link> linksBuilder = ImmutableSetMultimap.builder();
// Scan over the lists and create a cluster from the results.
for (int i = 0, n = result.clusterCount(); i < n; i++) {
Set<TopoVertex> vertexSet = clusterVertexes.get(i);
Set<TopoEdge> edgeSet = clusterEdges.get(i);
DefaultTopologyCluster cluster =
new DefaultTopologyCluster(ClusterId.clusterId(i),
vertexSet.size(), edgeSet.size(),
findRoot(vertexSet).deviceId());
clusterBuilder.add(cluster);
findClusterDevices(vertexSet, cluster, devicesBuilder);
findClusterLinks(edgeSet, cluster, linksBuilder);
}
return clusterBuilder.build();
}
// Scans through the set of cluster vertexes and puts their devices in a
// multi-map associated with the cluster. It also binds the devices to
// the cluster.
private void findClusterDevices(Set<TopoVertex> vertexSet,
DefaultTopologyCluster cluster,
Builder<TopologyCluster, DeviceId> builder) {
for (TopoVertex vertex : vertexSet) {
DeviceId deviceId = vertex.deviceId();
builder.put(cluster, deviceId);
}
}
// Scans through the set of cluster edges and puts their links in a
// multi-map associated with the cluster.
private void findClusterLinks(Set<TopoEdge> edgeSet,
DefaultTopologyCluster cluster,
Builder<TopologyCluster, Link> builder) {
for (TopoEdge edge : edgeSet) {
builder.put(cluster, edge.link());
}
}
// Finds the vertex whose device id is the lexicographical minimum in the
// specified set.
private TopoVertex findRoot(Set<TopoVertex> vertexSet) {
TopoVertex minVertex = null;
for (TopoVertex vertex : vertexSet) {
if (minVertex == null ||
minVertex.deviceId().toString()
.compareTo(minVertex.deviceId().toString()) < 0) {
minVertex = vertex;
}
}
return minVertex;
}
// Fetches a vertex corresponding to the given connection point device.
private TopoVertex vertexOf(ConnectPoint connectPoint) {
DeviceId id = connectPoint.deviceId();
TopoVertex vertex = vertexesById.get(id);
if (vertex == null) {
// If vertex does not exist, create one and register it.
vertex = new DefaultTopoVertex(id);
vertexesById.put(id, vertex);
}
return vertex;
}
}
<body>
Built-in protocol-agnostic topology builder &amp; provider.
</body>
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