io.hekate.core.service.ClusterContext Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of hekate-core Show documentation
Java library for cluster communications and computing.
There is a newer version: 4.1.3
/*
 * Copyright 2020 The Hekate Project
 *
 * The Hekate Project licenses this file to you 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 io.hekate.core.service;

import io.hekate.cluster.ClusterNode;
import io.hekate.cluster.ClusterService;
import io.hekate.cluster.ClusterTopology;
import io.hekate.cluster.event.ClusterChangeEvent;
import io.hekate.cluster.event.ClusterEventListener;
import io.hekate.cluster.event.ClusterEventType;
import io.hekate.cluster.event.ClusterJoinEvent;
import io.hekate.core.Hekate;
import java.util.Set;
import java.util.concurrent.CompletableFuture;

/**
 * Context for {@link ClusterService}.
 *
 * 
 * This interface is attended to provide feedback from {@link ClusterService} to {@link Hekate} instance.
 * Other services can also use this interface in order to obtain current cluster topology or register cluster event listeners.
 * 
 *
 * @see InitializationContext#cluster()
 */
public interface ClusterContext {
    /**
     * Asynchronously notifies this context that {@link ClusterService} has successfully joined the cluster.
     *
     * @param joinOrder Join order of the local node (see {@link ClusterNode#joinOrder()}).
     * @param newTopology Initial topology.
     *
     * @return Future object that gets completed once notification is processed.
     */
    CompletableFuture onJoin(int joinOrder, Set newTopology);

    /**
     * Fires the {@link ClusterChangeEvent}.
     *
     * @param live Nodes that are alive.
     * @param failed Nodes that are known to be failed (i.e. left the cluster abnormally without going through the cluster leave protocol).
     *
     * @return Future object that gets completed after processing the cluster event.
     */
    CompletableFuture onTopologyChange(Set live, Set failed);

    /**
     * Asynchronously notifies on {@link ClusterService} successfully left the cluster.
     */
    void onLeave();

    /**
     * Returns the current cluster topology.
     *
     * @return Current cluster topology.
     */
    ClusterTopology topology();

    /**
     * Synchronously registers the specified cluster event listener.
     *
     * @param listener Cluster listener.
     */
    void addListener(ClusterEventListener listener);

    /**
     * Synchronously registers the specified cluster event listener.
     *
     * @param listener Cluster listener.
     * @param eventTypes Event types to listen for.
     */
    void addListener(ClusterEventListener listener, ClusterEventType... eventTypes);

    /**
     * Asynchronously registers the specified cluster event listener without waiting registration to be completed.
     *
     * @param listener Cluster listener.
     */
    void addListenerAsync(ClusterEventListener listener);

    /**
     * Asynchronously registers the specified cluster event listener without waiting for registration to be completed.
     *
     * @param listener Cluster listener.
     * @param eventTypes Event types to listen for.
     */
    void addListenerAsync(ClusterEventListener listener, ClusterEventType... eventTypes);

    /**
     * Synchronously removes the specified cluster event listener.
     *
     * @param listener Listener to be removed.
     */
    void removeListener(ClusterEventListener listener);
}