Implement event notification of resource event

When a resource is registered or unregistered, a resource event is notified

Change-Id: I40e66761966ef2126366424a14bb3193fc850e5a

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.net.newresource;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.event.AbstractEvent;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Describes an event related to a resource.
+ */
+@Beta
+public final class ResourceEvent extends AbstractEvent<ResourceEvent.Type, ResourcePath> {
+
+    /**
+     * Type of resource events.
+     */
+    @Beta
+    public enum Type {
+        /**
+         * Signifies that a new resource has been detected.
+         */
+        RESOURCE_ADDED,
+
+        /**
+         * Signifies that a resource has been removed.
+         */
+        RESOURCE_REMOVED
+    }
+
+    /**
+     * Create a resource event.
+     *
+     * @param type type of resource event
+     * @param subject subject of resource event
+     */
+    public ResourceEvent(Type type, ResourcePath subject) {
+        super(checkNotNull(type), checkNotNull(subject));
+    }
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.net.newresource;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.event.EventListener;
+
+/**
+ * Entity capable of receiving resource related events.
+ */
+@Beta
+public interface ResourceListener extends EventListener<ResourceEvent> {
+}

@@ -17,6 +17,7 @@ package org.onosproject.net.newresource;
 
 import com.google.common.annotations.Beta;
 import com.google.common.collect.ImmutableList;
+import org.onosproject.event.ListenerService;
 
 import java.util.Arrays;
 import java.util.Collection;
@@ -29,7 +30,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
  * Service for allocating/releasing resource(s) and retrieving allocation(s) and availability.
  */
 @Beta
-public interface ResourceService {
+public interface ResourceService extends ListenerService<ResourceEvent, ResourceListener> {
     /**
      * Allocates the specified resource to the specified user.
      *

@@ -16,6 +16,7 @@
 package org.onosproject.net.newresource;
 
 import com.google.common.annotations.Beta;
+import org.onosproject.store.Store;
 
 import java.util.Collection;
 import java.util.List;
@@ -25,7 +26,7 @@ import java.util.Optional;
  * Service for storing resource and consumer information.
  */
 @Beta
-public interface ResourceStore {
+public interface ResourceStore extends Store<ResourceEvent, ResourceStoreDelegate> {
 
     /**
      * Registers the resources in transactional way.

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.net.newresource;
+
+import org.onosproject.store.StoreDelegate;
+
+/**
+ * Resource store delegate abstraction.
+ */
+public interface ResourceStoreDelegate extends StoreDelegate<ResourceEvent> {
+}

@@ -18,16 +18,22 @@ package org.onosproject.net.newresource.impl;
 import com.google.common.annotations.Beta;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
+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.onosproject.event.AbstractListenerManager;
 import org.onosproject.net.newresource.ResourceAdminService;
 import org.onosproject.net.newresource.ResourceAllocation;
 import org.onosproject.net.newresource.ResourceConsumer;
+import org.onosproject.net.newresource.ResourceEvent;
+import org.onosproject.net.newresource.ResourceListener;
 import org.onosproject.net.newresource.ResourceService;
 import org.onosproject.net.newresource.ResourcePath;
 import org.onosproject.net.newresource.ResourceStore;
+import org.onosproject.net.newresource.ResourceStoreDelegate;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -44,11 +50,26 @@ import static com.google.common.base.Preconditions.checkNotNull;
 @Component(immediate = true)
 @Service
 @Beta
-public final class ResourceManager implements ResourceService, ResourceAdminService {
+public final class ResourceManager extends AbstractListenerManager<ResourceEvent, ResourceListener>
+        implements ResourceService, ResourceAdminService {
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected ResourceStore store;
 
+    private final ResourceStoreDelegate delegate = new InternalStoreDelegate();
+
+    @Activate
+    public void activate() {
+        store.setDelegate(delegate);
+        eventDispatcher.addSink(ResourceEvent.class, listenerRegistry);
+    }
+
+    @Deactivate
+    public void deactivate() {
+        store.unsetDelegate(delegate);
+        eventDispatcher.addSink(ResourceEvent.class, listenerRegistry);
+    }
+
     @Override
     public List<ResourceAllocation> allocate(ResourceConsumer consumer,
                                              List<ResourcePath> resources) {
@@ -161,4 +182,11 @@ public final class ResourceManager implements ResourceService, ResourceAdminServ
         List<ResourcePath> resources = Lists.transform(children, x -> ResourcePath.child(parent, x));
         return store.unregister(resources);
     }
+
+    private class InternalStoreDelegate implements ResourceStoreDelegate {
+        @Override
+        public void notify(ResourceEvent event) {
+            post(event);
+        }
+    }
 }

@@ -19,6 +19,7 @@ import com.google.common.collect.ImmutableList;
 import org.onlab.packet.MplsLabel;
 import org.onosproject.net.newresource.ResourceAllocation;
 import org.onosproject.net.newresource.ResourceConsumer;
+import org.onosproject.net.newresource.ResourceListener;
 import org.onosproject.net.newresource.ResourcePath;
 import org.onosproject.net.newresource.ResourceService;
 
@@ -97,4 +98,10 @@ class MockResourceService implements ResourceService {
     public boolean isAvailable(ResourcePath resource) {
         return true;
     }
+
+    @Override
+    public void addListener(ResourceListener listener) {}
+
+    @Override
+    public void removeListener(ResourceListener listener) {}
 }

@@ -22,8 +22,11 @@ import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.apache.felix.scr.annotations.Service;
 import org.onosproject.net.newresource.ResourceConsumer;
+import org.onosproject.net.newresource.ResourceEvent;
 import org.onosproject.net.newresource.ResourcePath;
 import org.onosproject.net.newresource.ResourceStore;
+import org.onosproject.net.newresource.ResourceStoreDelegate;
+import org.onosproject.store.AbstractStore;
 import org.onosproject.store.serializers.KryoNamespaces;
 import org.onosproject.store.service.ConsistentMap;
 import org.onosproject.store.service.Serializer;
@@ -47,6 +50,7 @@ import java.util.stream.Collectors;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onosproject.net.newresource.ResourceEvent.Type.*;
 
 /**
  * Implementation of ResourceStore using TransactionalMap.
@@ -54,7 +58,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 @Component(immediate = true)
 @Service
 @Beta
-public class ConsistentResourceStore implements ResourceStore {
+public class ConsistentResourceStore extends AbstractStore<ResourceEvent, ResourceStoreDelegate>
+        implements ResourceStore {
     private static final Logger log = LoggerFactory.getLogger(ConsistentResourceStore.class);
 
     private static final String CONSUMER_MAP = "onos-resource-consumers";
@@ -116,7 +121,15 @@ public class ConsistentResourceStore implements ResourceStore {
             }
         }
 
-        return tx.commit();
+        boolean success = tx.commit();
+        if (success) {
+            List<ResourceEvent> events = resources.stream()
+                    .filter(x -> x.parent().isPresent())
+                    .map(x -> new ResourceEvent(RESOURCE_ADDED, x))
+                    .collect(Collectors.toList());
+            notifyDelegate(events);
+        }
+        return success;
     }
 
     @Override
@@ -147,7 +160,15 @@ public class ConsistentResourceStore implements ResourceStore {
             }
         }
 
-        return tx.commit();
+        boolean success = tx.commit();
+        if (success) {
+            List<ResourceEvent> events = resources.stream()
+                    .filter(x -> x.parent().isPresent())
+                    .map(x -> new ResourceEvent(RESOURCE_REMOVED, x))
+                    .collect(Collectors.toList());
+            notifyDelegate(events);
+        }
+        return success;
     }
 
     @Override