Added default link description & model entities.

@@ -7,7 +7,7 @@ import java.util.Objects;
 import static com.google.common.base.Objects.toStringHelper;
 
 /**
- * Default device model implementation.
+ * Default infrastructure device model implementation.
  */
 public class DefaultDevice extends AbstractElement implements Device {
 

+package org.onlab.onos.net;
+
+import org.onlab.onos.net.link.LinkDescription;
+
+import java.util.Objects;
+
+import static com.google.common.base.Objects.toStringHelper;
+
+/**
+ * Default infrastructure link model implementation.
+ */
+public class DefaultLink implements LinkDescription {
+
+    private ConnectPoint src;
+    private ConnectPoint dst;
+
+    /**
+     * Creates a link description using the supplied information.
+     *
+     * @param src link source
+     * @param dst link destination
+     */
+    public DefaultLink(ConnectPoint src, ConnectPoint dst) {
+        this.src = src;
+        this.dst = dst;
+    }
+
+    @Override
+    public ConnectPoint src() {
+        return src;
+    }
+
+    @Override
+    public ConnectPoint dst() {
+        return dst;
+    }
+
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(src, dst);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof DefaultDevice) {
+            final DefaultLink other = (DefaultLink) obj;
+            return Objects.equals(this.src, other.src) &&
+                    Objects.equals(this.dst, other.dst);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("src", src)
+                .add("dst", dst)
+                .toString();
+    }
+
+}

@@ -4,7 +4,6 @@ package org.onlab.onos.net;
  * Abstraction of a network infrastructure link.
  */
 public interface Link extends Provided {
-// TODO: Consider extending graph Edge<Element> once the graph module is available
 
     /**
      * Coarse representation of the link type.

+package org.onlab.onos.net.link;
+
+import org.onlab.onos.net.ConnectPoint;
+
+/**
+ * Default implementation of immutable link description entity.
+ */
+public class DefaultLinkDescription implements LinkDescription {
+
+    private ConnectPoint src;
+    private ConnectPoint dst;
+
+    /**
+     * Creates a link description using the supplied information.
+     *
+     * @param src link source
+     * @param dst link destination
+     */
+    public DefaultLinkDescription(ConnectPoint src, ConnectPoint dst) {
+        this.src = src;
+        this.dst = dst;
+    }
+
+    @Override
+    public ConnectPoint src() {
+        return src;
+    }
+
+    @Override
+    public ConnectPoint dst() {
+        return dst;
+    }
+
+}

 package org.onlab.onos.net.link;
 
+import org.onlab.onos.net.ConnectPoint;
+
 /**
  * Describes an infrastructure link.
  */
 public interface LinkDescription {
 
-    // TODO: src, dst connection points, which are pairs of (DeviceId, PortNumber)
-
-//    On the north:
-//    Link = (ConnectPoint src, ConnectPoint dst);
-//    ConnectPoint = (DeviceId, PortNumber);
+    /**
+     * Returns the link source.
+     *
+     * @return links source
+     */
+    ConnectPoint src();
 
-//    On the south
-//    LinkDescription ~ Link
+    /**
+     * Returns the link destination.
+     *
+     * @return links destination
+     */
+    ConnectPoint dst();
 
+    // Add further link attributes
 }

@@ -34,6 +34,8 @@ public class SimpleLinkManager
     private final AbstractListenerRegistry<LinkEvent, LinkListener>
             listenerRegistry = new AbstractListenerRegistry<>();
 
+    private final SimpleLinkStore store = new SimpleLinkStore();
+
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     private EventDeliveryService eventDispatcher;
 

+package org.onlab.onos.net.trivial.impl;
+
+/**
+ * Manages inventory of infrastructure links using trivial in-memory link
+ * implementation.
+ */
+public class SimpleLinkStore {
+}