| /* |
| * 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.ratis.server; |
| |
| import org.apache.ratis.protocol.RaftPeer; |
| import org.apache.ratis.protocol.RaftPeerId; |
| |
| import java.util.Collection; |
| |
| /** |
| * A configuration is a subset of the members in a {@link org.apache.ratis.protocol.RaftGroup}. |
| * The configuration of a cluster may change from time to time. |
| * This class captures the current configuration and the previous configuration of a cluster. |
| * |
| * The objects of this class are immutable. |
| */ |
| public interface RaftConfiguration { |
| /** |
| * @return the peer corresponding to the given id; |
| * or return null if the peer is not in this configuration. |
| */ |
| RaftPeer getPeer(RaftPeerId id); |
| |
| /** @return all the peers in the current configuration and the previous configuration. */ |
| Collection<RaftPeer> getAllPeers(); |
| |
| /** @return all the peers in the current configuration. */ |
| Collection<RaftPeer> getCurrentPeers(); |
| |
| /** @return all the peers in the previous configuration. */ |
| Collection<RaftPeer> getPreviousPeers(); |
| |
| /** @return the index of the corresponding log entry for the current configuration. */ |
| long getLogEntryIndex(); |
| } |