Refactor DOMNotificationSubscriptionListener(Registry)

[mdsal.git] / dom / mdsal-dom-api / src / main / java / org / opendaylight / mdsal / dom / api / DOMNotificationPublishDemandExtension.java

diff --git a/dom/mdsal-dom-api/src/main/java/org/opendaylight/mdsal/dom/api/DOMNotificationPublishDemandExtension.java b/dom/mdsal-dom-api/src/main/java/org/opendaylight/mdsal/dom/api/DOMNotificationPublishDemandExtension.java
new file mode 100644 (file)
index 0000000..3d9fc0c
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+++ b/dom/mdsal-dom-api/src/main/java/org/opendaylight/mdsal/dom/api/DOMNotificationPublishDemandExtension.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.mdsal.dom.api;
+
+import com.google.common.annotations.Beta;
+import com.google.common.collect.ImmutableSet;
+import java.util.EventListener;
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.opendaylight.yangtools.concepts.Registration;
+import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
+
+/**
+ * A {@link DOMNotificationPublishService.Extension} providing a view into which {@link DOMNotification}s the extended
+ * {@link DOMNotificationPublishService} is interested in receiving. This is typically driven by listener registrations
+ * in the {@link DOMNotificationService} consuming published notifications.
+ */
+@Beta
+@NonNullByDefault
+public interface DOMNotificationPublishDemandExtension extends DOMNotificationPublishService.Extension {
+    /**
+     * Register a new {@link DemandListener}.
+     *
+     * @param listener the listener to register
+     * @return A {@link Registration}
+     * @throws NullPointerException if {@code listener} is {@code null}
+     */
+    Registration registerDemandListener(DemandListener listener);
+
+    /**
+     * Listener for changes in demand for {@link DOMNotification} types. Changes are communnicated via
+     * {@link #onDemandUpdated(ImmutableSet)}, which reports the delta between last reported and current state.
+     */
+    interface DemandListener extends EventListener {
+        /**
+         * Update the view of what {@link DOMNotification}s are in demand.
+         *
+         * @param neededTypes currently-needed notification types
+         */
+        void onDemandUpdated(ImmutableSet<Absolute> neededTypes);
+    }
+}