Added simple link manager implementation.
Added link admin stuff; unit tests to come.
diff --git a/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleLinkManager.java b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleLinkManager.java
index b5d8cc4..1c7306f 100644
--- a/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleLinkManager.java
+++ b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleLinkManager.java
@@ -1,5 +1,6 @@
 package org.onlab.onos.net.trivial.impl;
 
+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;
@@ -8,16 +9,24 @@
 import org.apache.felix.scr.annotations.Service;
 import org.onlab.onos.event.AbstractListenerRegistry;
 import org.onlab.onos.event.EventDeliveryService;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.link.LinkAdminService;
 import org.onlab.onos.net.link.LinkDescription;
 import org.onlab.onos.net.link.LinkEvent;
 import org.onlab.onos.net.link.LinkListener;
 import org.onlab.onos.net.link.LinkProvider;
 import org.onlab.onos.net.link.LinkProviderRegistry;
 import org.onlab.onos.net.link.LinkProviderService;
+import org.onlab.onos.net.link.LinkService;
 import org.onlab.onos.net.provider.AbstractProviderRegistry;
 import org.onlab.onos.net.provider.AbstractProviderService;
 import org.slf4j.Logger;
 
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkNotNull;
 import static org.slf4j.LoggerFactory.getLogger;
 
 /**
@@ -27,7 +36,11 @@
 @Service
 public class SimpleLinkManager
         extends AbstractProviderRegistry<LinkProvider, LinkProviderService>
-        implements LinkProviderRegistry {
+        implements LinkService, LinkAdminService, LinkProviderRegistry {
+
+    private static final String DEVICE_ID_NULL = "Device ID cannot be null";
+    private static final String LINK_DESC_NULL = "Link description cannot be null";
+    private static final String CONNECT_POINT_NULL = "Connection point cannot be null";
 
     private final Logger log = getLogger(getClass());
 
@@ -56,6 +69,82 @@
         return new InternalLinkProviderService(provider);
     }
 
+    @Override
+    public int getLinkCount() {
+        return store.getLinkCount();
+    }
+
+    @Override
+    public Iterable<Link> getLinks() {
+        return store.getLinks();
+    }
+
+    @Override
+    public Set<Link> getDeviceLinks(DeviceId deviceId) {
+        checkNotNull(deviceId, DEVICE_ID_NULL);
+        return Sets.union(store.getDeviceEgressLinks(deviceId),
+                          store.getDeviceIngressLinks(deviceId));
+    }
+
+    @Override
+    public Set<Link> getDeviceEgressLinks(DeviceId deviceId) {
+        checkNotNull(deviceId, DEVICE_ID_NULL);
+        return store.getDeviceEgressLinks(deviceId);
+    }
+
+    @Override
+    public Set<Link> getDeviceInressLinks(DeviceId deviceId) {
+        checkNotNull(deviceId, DEVICE_ID_NULL);
+        return store.getDeviceIngressLinks(deviceId);
+    }
+
+    @Override
+    public Set<Link> getLinks(ConnectPoint connectPoint) {
+        checkNotNull(connectPoint, CONNECT_POINT_NULL);
+        return Sets.union(store.getEgressLinks(connectPoint),
+                          store.getIngressLinks(connectPoint));
+    }
+
+    @Override
+    public Set<Link> getEgressLinks(ConnectPoint connectPoint) {
+        checkNotNull(connectPoint, CONNECT_POINT_NULL);
+        return store.getEgressLinks(connectPoint);
+    }
+
+    @Override
+    public Set<Link> getInressLinks(ConnectPoint connectPoint) {
+        checkNotNull(connectPoint, CONNECT_POINT_NULL);
+        return store.getIngressLinks(connectPoint);
+    }
+
+    @Override
+    public Set<Link> getLinks(ConnectPoint src, ConnectPoint dst) {
+        checkNotNull(src, CONNECT_POINT_NULL);
+        checkNotNull(dst, CONNECT_POINT_NULL);
+        return Sets.intersection(store.getEgressLinks(src),
+                                 store.getIngressLinks(dst));
+    }
+
+    @Override
+    public void removeLinks(ConnectPoint connectPoint) {
+        removeLinks(getLinks(connectPoint));
+    }
+
+    @Override
+    public void removeLinks(DeviceId deviceId) {
+        removeLinks(getDeviceLinks(deviceId));
+    }
+
+    @Override
+    public void addListener(LinkListener listener) {
+        listenerRegistry.addListener(listener);
+    }
+
+    @Override
+    public void removeListener(LinkListener listener) {
+        listenerRegistry.removeListener(listener);
+    }
+
     // Personalized link provider service issued to the supplied provider.
     private class InternalLinkProviderService extends AbstractProviderService<LinkProvider>
             implements LinkProviderService {
@@ -66,12 +155,54 @@
 
         @Override
         public void linkDetected(LinkDescription linkDescription) {
+            checkNotNull(linkDescription, LINK_DESC_NULL);
+            checkValidity();
             log.info("Link {} detected", linkDescription);
+            LinkEvent event = store.createOrUpdateLink(provider().id(),
+                                                       linkDescription);
+            post(event);
         }
 
         @Override
         public void linkVanished(LinkDescription linkDescription) {
+            checkNotNull(linkDescription, LINK_DESC_NULL);
+            checkValidity();
             log.info("Link {} vanished", linkDescription);
+            LinkEvent event = store.removeLink(linkDescription.src(),
+                                               linkDescription.dst());
+            post(event);
+        }
+
+        @Override
+        public void linksVanished(ConnectPoint connectPoint) {
+            checkNotNull(connectPoint, "Connect point cannot be null");
+            checkValidity();
+            log.info("Link for connection point {} vanished", connectPoint);
+            removeLinks(getLinks(connectPoint));
+        }
+
+        @Override
+        public void linksVanished(DeviceId deviceId) {
+            checkNotNull(deviceId, DEVICE_ID_NULL);
+            checkValidity();
+            log.info("Link for device {} vanished", deviceId);
+            removeLinks(getDeviceLinks(deviceId));
         }
     }
+
+    // Removes all links in the specified set and emits appropriate events.
+    private void removeLinks(Set<Link> links) {
+        for (Link link : links) {
+            LinkEvent event = store.removeLink(link.src(), link.dst());
+            post(event);
+        }
+    }
+
+    // Posts the specified event to the local event dispatcher.
+    private void post(LinkEvent event) {
+        if (event != null && eventDispatcher != null) {
+            eventDispatcher.post(event);
+        }
+    }
+
 }