1 files changed, 72 insertions, 0 deletions
diff --git a/framework/src/onos/core/api/src/main/java/org/onosproject/store/AbstractStore.java b/framework/src/onos/core/api/src/main/java/org/onosproject/store/AbstractStore.java
new file mode 100644
index 00000000..a3005e45
--- /dev/null
+++ b/framework/src/onos/core/api/src/main/java/org/onosproject/store/AbstractStore.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2014 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.store;
+
+import java.util.List;
+
+import org.onosproject.event.Event;
+
+import static com.google.common.base.Preconditions.checkState;
+
+/**
+ * Base implementation of a store.
+ */
+public class AbstractStore<E extends Event, D extends StoreDelegate<E>>
+        implements Store<E, D> {
+
+    protected D delegate;
+
+    @Override
+    public void setDelegate(D delegate) {
+        checkState(this.delegate == null || this.delegate == delegate,
+                   "Store delegate already set");
+        this.delegate = delegate;
+    }
+
+    @Override
+    public void unsetDelegate(D delegate) {
+        if (this.delegate == delegate) {
+            this.delegate = null;
+        }
+    }
+
+    @Override
+    public boolean hasDelegate() {
+        return delegate != null;
+    }
+
+    /**
+     * Notifies the delegate with the specified event.
+     *
+     * @param event event to delegate
+     */
+    protected void notifyDelegate(E event) {
+        if (delegate != null) {
+            delegate.notify(event);
+        }
+    }
+
+    /**
+     * Notifies the delegate with the specified list of events.
+     *
+     * @param events list of events to delegate
+     */
+    protected void notifyDelegate(List<E> events) {
+        for (E event: events) {
+            notifyDelegate(event);
+        }
+    }
+}