org.opendaylight.controller.cluster.access.client.BackendInfoResolver Maven / Gradle / Ivy
/*
* 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.controller.cluster.access.client;
import akka.actor.ActorRef;
import java.util.concurrent.CompletionStage;
import java.util.function.Consumer;
import org.eclipse.jdt.annotation.NonNull;
import org.opendaylight.yangtools.concepts.Registration;
/**
* Caching resolver which resolves a cookie to a leader {@link ActorRef}. This class needs to be specialized by the
* client. It is used by {@link ClientActorBehavior} for request dispatch. Results are cached until they are invalidated
* by either the client actor (when a message timeout is detected) and by the specific frontend (on explicit
* invalidation or when updated information becomes available).
*
*
* If the completion stage returned by this interface's methods fails with a
* {@link org.opendaylight.controller.cluster.access.concepts.RequestException}, it will be forwarded to all
* outstanding requests towards the leader. If it fails with a {@link java.util.concurrent.TimeoutException},
* resolution process will be retried. If it fails with any other cause, it will we wrapped as a
* {@link org.opendaylight.controller.cluster.access.concepts.RuntimeRequestException} wrapping that cause.
*
* @author Robert Varga
*/
public abstract class BackendInfoResolver implements AutoCloseable {
/**
* Request resolution of a particular backend identified by a cookie. This request can be satisfied from the cache.
*
* @param cookie Backend cookie
* @return A {@link CompletionStage} resulting in information about the backend
*/
public abstract @NonNull CompletionStage getBackendInfo(@NonNull Long cookie);
/**
* Request re-resolution of a particular backend identified by a cookie, indicating a particular information as
* being stale. If the implementation's cache holds the stale information, it should be purged.
*
* @param cookie Backend cookie
* @param staleInfo Stale backend information
* @return A {@link CompletionStage} resulting in information about the backend
*/
public abstract @NonNull CompletionStage refreshBackendInfo(@NonNull Long cookie,
@NonNull T staleInfo);
/**
* Registers a callback to be notified when BackendInfo that may have been previously obtained is now stale and
* should be refreshed.
*
* @param callback the callback that takes the backend cookie whose BackendInfo is now stale.
* @return a Registration
*/
public abstract @NonNull Registration notifyWhenBackendInfoIsStale(Consumer callback);
public abstract @NonNull String resolveCookieName(Long cookie);
@Override
public void close() {
}
}