Split Restconf implementations (draft02 and RFC) - move

[netconf.git] / restconf / restconf-nb-rfc8040 / src / main / java / org / opendaylight / restconf / nb / rfc8040 / streams / listeners / AbstractCommonSubscriber.java

diff --git a/restconf/restconf-nb-rfc8040/src/main/java/org/opendaylight/restconf/nb/rfc8040/streams/listeners/AbstractCommonSubscriber.java b/restconf/restconf-nb-rfc8040/src/main/java/org/opendaylight/restconf/nb/rfc8040/streams/listeners/AbstractCommonSubscriber.java
new file mode 100644 (file)
index 0000000..ea3ad27
--- /dev/null
+++ b/restconf/restconf-nb-rfc8040/src/main/java/org/opendaylight/restconf/nb/rfc8040/streams/listeners/AbstractCommonSubscriber.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2016 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.restconf.nb.rfc8040.streams.listeners;
+
+import com.google.common.eventbus.AsyncEventBus;
+import com.google.common.eventbus.EventBus;
+import io.netty.channel.Channel;
+import io.netty.util.internal.ConcurrentSet;
+import java.util.Set;
+import java.util.concurrent.Executors;
+import org.opendaylight.yangtools.concepts.ListenerRegistration;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Features of subscribing part of both notifications.
+ */
+abstract class AbstractCommonSubscriber extends AbstractQueryParams implements BaseListenerInterface {
+
+    private static final Logger LOG = LoggerFactory.getLogger(AbstractCommonSubscriber.class);
+
+    private final Set<Channel> subscribers = new ConcurrentSet<>();
+    private final EventBus eventBus;
+
+    @SuppressWarnings("rawtypes")
+    private EventBusChangeRecorder eventBusChangeRecorder;
+    @SuppressWarnings("rawtypes")
+    private ListenerRegistration registration;
+
+    /**
+     * Creating {@link EventBus}.
+     */
+    protected AbstractCommonSubscriber() {
+        this.eventBus = new AsyncEventBus(Executors.newSingleThreadExecutor());
+    }
+
+    @Override
+    public final boolean hasSubscribers() {
+        return !this.subscribers.isEmpty();
+    }
+
+    @Override
+    public final Set<Channel> getSubscribers() {
+        return this.subscribers;
+    }
+
+    @Override
+    public final void close() throws Exception {
+        this.registration.close();
+        this.registration = null;
+
+        deleteDataInDS();
+        unregister();
+    }
+
+    /**
+     * Creates event of type {@link EventType#REGISTER}, set {@link Channel}
+     * subscriber to the event and post event into event bus.
+     *
+     * @param subscriber
+     *            Channel
+     */
+    public void addSubscriber(final Channel subscriber) {
+        if (!subscriber.isActive()) {
+            LOG.debug("Channel is not active between websocket server and subscriber {}" + subscriber.remoteAddress());
+        }
+        final Event event = new Event(EventType.REGISTER);
+        event.setSubscriber(subscriber);
+        this.eventBus.post(event);
+    }
+
+    /**
+     * Creates event of type {@link EventType#DEREGISTER}, sets {@link Channel}
+     * subscriber to the event and posts event into event bus.
+     *
+     * @param subscriber subscriber channel
+     */
+    public void removeSubscriber(final Channel subscriber) {
+        LOG.debug("Subscriber {} is removed.", subscriber.remoteAddress());
+        final Event event = new Event(EventType.DEREGISTER);
+        event.setSubscriber(subscriber);
+        this.eventBus.post(event);
+    }
+
+    /**
+     * Sets {@link ListenerRegistration} registration.
+     *
+     * @param registration
+     *            DOMDataChangeListener registration
+     */
+    @SuppressWarnings("rawtypes")
+    public void setRegistration(final ListenerRegistration registration) {
+        this.registration = registration;
+    }
+
+    /**
+     * Checks if {@link ListenerRegistration} registration exist.
+     *
+     * @return True if exist, false otherwise.
+     */
+    public boolean isListening() {
+        return this.registration != null;
+    }
+
+    /**
+     * Creating and registering {@link EventBusChangeRecorder} of specific
+     * listener on {@link EventBus}.
+     *
+     * @param listener
+     *            specific listener of notifications
+     */
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    protected <T extends BaseListenerInterface> void register(final T listener) {
+        this.eventBusChangeRecorder = new EventBusChangeRecorder(listener);
+        this.eventBus.register(this.eventBusChangeRecorder);
+    }
+
+    /**
+     * Post event to event bus.
+     *
+     * @param event
+     *            data of incoming notifications
+     */
+    protected void post(final Event event) {
+        this.eventBus.post(event);
+    }
+
+    /**
+     * Removes all subscribers and unregisters event bus change recorder form
+     * event bus.
+     */
+    protected void unregister() {
+        this.subscribers.clear();
+        this.eventBus.unregister(this.eventBusChangeRecorder);
+    }
+}