Added getTopology() helpers to the GlobalOracle

src/de/tud/kom/p2psim/impl/util/oracle/GlobalOracle.java

@@ -22,16 +22,26 @@ package de.tud.kom.p2psim.impl.util.oracle;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Set;
 
 import de.tud.kom.p2psim.api.common.SimHost;
+import de.tudarmstadt.maki.simonstrator.api.Graphs;
 import de.tudarmstadt.maki.simonstrator.api.Host;
 import de.tudarmstadt.maki.simonstrator.api.Randoms;
+import de.tudarmstadt.maki.simonstrator.api.common.graph.DirectedEdge;
+import de.tudarmstadt.maki.simonstrator.api.common.graph.Graph;
+import de.tudarmstadt.maki.simonstrator.api.common.graph.Node;
+import de.tudarmstadt.maki.simonstrator.api.component.ComponentNotAvailableException;
 import de.tudarmstadt.maki.simonstrator.api.component.core.OracleComponent;
 import de.tudarmstadt.maki.simonstrator.api.component.network.NetID;
 import de.tudarmstadt.maki.simonstrator.api.component.network.NetInterface;
+import de.tudarmstadt.maki.simonstrator.api.component.topology.TopologyID;
+import de.tudarmstadt.maki.simonstrator.api.component.topology.TopologyProvider;
 
 /**
  * This class gives access to the hosts of the scenario. To work, it has to be
@@ -172,6 +182,92 @@ public class GlobalOracle implements OracleComponent {
 	public boolean isSimulation() {
 		return true;
 	}
+	
+	/**
+	 * Returns a global view of the topology for the specified mechanism. The
+	 * mechanism must be a HostComponent that is registered at the local host.
+	 * Otherwise, this method will not be able to find the local mechanism
+	 * objects.
+	 * 
+	 * @param component
+	 * @param identifier
+	 * @return
+	 */
+	public static <T extends TopologyProvider> Graph getTopology(
+			Class<T> component, TopologyID identifier) {
+
+		HashSet<DirectedEdge> edges = new LinkedHashSet<>();
+		HashSet<Node> nodes = new LinkedHashSet<Node>();
+
+		LinkedList<TopologyProvider> allProviders = new LinkedList<>();
+
+		for (SimHost host : getHosts()) {
+			try {
+				TopologyProvider topologyProvider = host
+						.getComponent(component);
+
+				Node providerNode = topologyProvider.getNode(identifier);
+
+				nodes.add(providerNode);
+
+				allProviders.add(topologyProvider);
+
+			} catch (ComponentNotAvailableException e) {
+				// if the component is not available on the host, we can't do
+				// anything about it
+				// no reason to crash the simulation as this might be the case
+				// in various scenarios
+			}
+		}
+
+		for (TopologyProvider topologyProvider : allProviders) {
+			Set<de.tudarmstadt.maki.simonstrator.api.common.graph.DirectedEdge> neighbors = topologyProvider
+					.getNeighbors(identifier);
+			edges.addAll(neighbors);
+		}
+
+		Graph graph = Graphs.createGraph();
+		for(Node node : nodes){
+			graph.add(node);
+		}
+		for(DirectedEdge edge : edges) {
+			graph.add(edge);
+		}
+		
+		return graph;
+	}
+	
+	/**
+	 * Returns available topology identifiers for the given component. Throws an
+	 * {@link ComponentNotAvailableException} if the component is not available
+	 * on any node in the network. Assumes that all instances of a given
+	 * component class provide the same topology identifiers.
+	 * 
+	 * @throws ComponentNotAvailableException 
+	 */
+	public static <T extends TopologyProvider> Iterable<TopologyID> getTopologyIdentifiers(
+			Class<T> component) throws ComponentNotAvailableException {
+
+		// iterate over all the hosts, find one host that contains the given
+		// component class and ask this component about available topologies
+		for (SimHost host : getHosts()) {
+			try {
+				TopologyProvider topologyProvider = host
+						.getComponent(component);
+				return topologyProvider.getTopologyIdentifiers();
+
+			} catch (ComponentNotAvailableException e) {
+				// if the component is not available on the host, we can't do
+				// anything about it
+				// no reason to crash the simulation as this might be the case
+				// in various scenarios
+			}
+		}
+		
+		throw new ComponentNotAvailableException();
+	}
+
+	
 
 	/**
 	 * Checks whether the host with the given NetID is online using a global