/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the "Elastic License
 * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
 * Public License v 1"; you may not use this file except in compliance with, at
 * your election, the "Elastic License 2.0", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */

package org.elasticsearch.cluster;

import java.util.function.Consumer;

/**
 * Interface for a class used to gather information about a cluster periodically.
 */
@FunctionalInterface
public interface ClusterInfoService {

    /**
     * @return the latest cluster information
     */
    ClusterInfo getClusterInfo();

    /**
     * Add a listener for new cluster information
     */
    default void addListener(Consumer<ClusterInfo> clusterInfoConsumer) {
        throw new UnsupportedOperationException();
    }
}