2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.mdsal.dom.api;
10 import com.google.common.util.concurrent.ListenableFuture;
11 import java.util.concurrent.TimeUnit;
12 import org.checkerframework.checker.index.qual.NonNegative;
13 import org.eclipse.jdt.annotation.NonNull;
14 import org.opendaylight.yangtools.util.concurrent.FluentFutures;
17 * A {@link DOMService} which allows its user to publish top-level (YANG 1.0) {@link DOMNotification}s. It provides two
18 * styles of initiating the notification delivery, similar to {@link java.util.concurrent.BlockingQueue}:
20 * <li>a put-style method which waits until the implementation can accept the notification for delivery, and</li>
21 * <li>an offer-style method, which attempts to enqueue the notification, but allows the caller to specify that it
22 * should never wait, or put an upper bound on how long it is going to wait</li>
25 public interface DOMNotificationPublishService extends DOMService {
27 * Well-known value indicating that the implementation is currently not
28 * able to accept a notification.
30 ListenableFuture<Object> REJECTED = FluentFutures.immediateFailedFluentFuture(
31 new DOMNotificationRejectedException("Unacceptable blocking conditions encountered"));
34 * Publish a notification. The result of this method is a {@link ListenableFuture} which will
35 * complete once the notification has been delivered to all immediate registrants. The type of
36 * the object resulting from the future is not defined and implementations may use it to convey
37 * additional information related to the publishing process.
38 * Abstract subclasses can refine the return type as returning a promise of a more specific
40 * public interface DeliveryStatus { int getListenerCount(); } ListenableFuture<? extends
41 * DeliveryStatus>[ putNotification(DOMNotification notification);
42 * Once the Future succeeds, the resulting object can be queried for traits using instanceof,
44 * // Can block when (for example) the implemention's ThreadPool queue is full Object o =
45 * service.putNotification(notif).get(); if (o instanceof DeliveryStatus) { DeliveryStatus ds =
46 * (DeliveryStatus)o; LOG.debug("Notification was received by {} listeners",
47 * ds.getListenerCount();); } }
48 * In case an implementation is running out of resources, it can block the calling thread until
49 * enough resources become available to accept the notification for processing, or it is
53 * Caution: completion here means that the implementation has completed processing of the
54 * notification. This does not mean that all existing registrants have seen the notification.
55 * Most importantly, the delivery process at other cluster nodes may have not begun yet.
57 * @param notification Notification to be published.
58 * @return A listenable future which will report completion when the service has finished
59 * propagating the notification to its immediate registrants.
60 * @throws InterruptedException if interrupted while waiting
61 * @throws NullPointerException if notification is null.
63 @NonNull ListenableFuture<? extends Object> putNotification(@NonNull DOMNotification notification)
64 throws InterruptedException;
67 * Attempt to publish a notification. The result of this method is a {@link ListenableFuture}
68 * which will complete once the notification has been delivered to all immediate registrants.
69 * The type of the object resulting from the future is not defined and implementations may use
70 * it to convey additional information related to the publishing process. Unlike
71 * {@link #putNotification(DOMNotification)}, this method is guaranteed not to block if the
72 * underlying implementation encounters contention.
74 * @param notification Notification to be published.
75 * @return A listenable future which will report completion when the service has finished
76 * propagating the notification to its immediate registrants, or {@link #REJECTED} if
77 * resource constraints prevent the implementation from accepting the notification for
79 * @throws NullPointerException if notification is null.
81 @NonNull ListenableFuture<? extends Object> offerNotification(@NonNull DOMNotification notification);
84 * Attempt to publish a notification. The result of this method is a {@link ListenableFuture}
85 * which will complete once the notification has been delivered to all immediate registrants.
86 * The type of the object resulting from the future is not defined and implementations may use
87 * it to convey additional information related to the publishing process. Unlike
88 * {@link #putNotification(DOMNotification)}, this method is guaranteed to block more than the
91 * @param notification Notification to be published.
92 * @param timeout how long to wait before giving up, in units of unit
93 * @param unit a TimeUnit determining how to interpret the timeout parameter
94 * @return A listenable future which will report completion when the service has finished
95 * propagating the notification to its immediate registrants, or {@link #REJECTED} if
96 * resource constraints prevent the implementation from accepting the notification for
98 * @throws InterruptedException if interrupted while waiting
99 * @throws NullPointerException if notification or unit is null.
100 * @throws IllegalArgumentException if timeout is negative.
102 @NonNull ListenableFuture<? extends Object> offerNotification(@NonNull DOMNotification notification,
103 @NonNegative long timeout, @NonNull TimeUnit unit) throws InterruptedException;