| /* |
| * 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.samza.zk; |
| |
| /** |
| * An interface for listening to {@link ZkBarrierForVersionUpgrade} related events |
| */ |
| public interface ZkBarrierListener { |
| /** |
| * Invoked when the root of barrier for a given version is created in Zk |
| * |
| * @param version Version associated with the Barrier |
| */ |
| void onBarrierCreated(String version); |
| |
| /** |
| * Invoked when the data written to the Barrier state changes |
| * |
| * @param version Version associated with the Barrier |
| * @param state {@link org.apache.samza.zk.ZkBarrierForVersionUpgrade.State} value |
| */ |
| void onBarrierStateChanged(String version, ZkBarrierForVersionUpgrade.State state); |
| |
| /** |
| * Invoked when Barrier encounters error |
| * |
| * @param version Version associated with the Barrier |
| * @param t Throwable describing the cause of the barrier error |
| */ |
| void onBarrierError(String version, Throwable t); |
| } |