solr/solrj/src/java/org/apache/solr/common/cloud/LiveNodesPredicate.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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 org.apache.solr.common.cloud;

import java.util.SortedSet;
import java.util.concurrent.TimeUnit;

/**
 * Interface to determine if live nodes matches a required state
 *
 * @see ZkStateReader#waitForLiveNodes(long, TimeUnit, LiveNodesPredicate)
 */
public interface LiveNodesPredicate {

  boolean matches(SortedSet<String> oldLiveNodes, SortedSet<String> newLiveNodes);
}