| /* |
| * 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.twill.internal.zookeeper; |
| |
| import com.google.common.util.concurrent.FutureCallback; |
| import com.google.common.util.concurrent.Futures; |
| import org.apache.twill.internal.zookeeper.RewatchOnExpireWatcher.ActionType; |
| import org.apache.twill.zookeeper.ForwardingZKClient; |
| import org.apache.twill.zookeeper.NodeChildren; |
| import org.apache.twill.zookeeper.NodeData; |
| import org.apache.twill.zookeeper.OperationFuture; |
| import org.apache.twill.zookeeper.ZKClient; |
| import org.apache.zookeeper.Watcher; |
| import org.apache.zookeeper.data.Stat; |
| |
| /** |
| * A {@link ZKClient} that will rewatch automatically when session expired and reconnect. |
| * The rewatch logic is mainly done in {@link RewatchOnExpireWatcher}. |
| */ |
| public final class RewatchOnExpireZKClient extends ForwardingZKClient { |
| |
| public RewatchOnExpireZKClient(ZKClient delegate) { |
| super(delegate); |
| } |
| |
| @Override |
| public OperationFuture<Stat> exists(String path, Watcher watcher) { |
| if (watcher == null) { |
| return super.exists(path, null); |
| } |
| final RewatchOnExpireWatcher wrappedWatcher = new RewatchOnExpireWatcher(this, ActionType.EXISTS, path, watcher); |
| OperationFuture<Stat> result = super.exists(path, wrappedWatcher); |
| Futures.addCallback(result, new FutureCallback<Stat>() { |
| @Override |
| public void onSuccess(Stat result) { |
| wrappedWatcher.setLastResult(result); |
| } |
| |
| @Override |
| public void onFailure(Throwable t) { |
| // No-op |
| } |
| }); |
| return result; |
| } |
| |
| @Override |
| public OperationFuture<NodeChildren> getChildren(String path, Watcher watcher) { |
| if (watcher == null) { |
| return super.getChildren(path, null); |
| } |
| final RewatchOnExpireWatcher wrappedWatcher = new RewatchOnExpireWatcher(this, ActionType.CHILDREN, path, watcher); |
| OperationFuture<NodeChildren> result = super.getChildren(path, wrappedWatcher); |
| Futures.addCallback(result, new FutureCallback<NodeChildren>() { |
| @Override |
| public void onSuccess(NodeChildren result) { |
| wrappedWatcher.setLastResult(result); |
| } |
| |
| @Override |
| public void onFailure(Throwable t) { |
| // No-op |
| } |
| }); |
| return result; |
| } |
| |
| @Override |
| public OperationFuture<NodeData> getData(String path, Watcher watcher) { |
| if (watcher == null) { |
| return super.getData(path, null); |
| } |
| final RewatchOnExpireWatcher wrappedWatcher = new RewatchOnExpireWatcher(this, ActionType.DATA, path, watcher); |
| OperationFuture<NodeData> result = super.getData(path, wrappedWatcher); |
| Futures.addCallback(result, new FutureCallback<NodeData>() { |
| @Override |
| public void onSuccess(NodeData result) { |
| wrappedWatcher.setLastResult(result); |
| } |
| |
| @Override |
| public void onFailure(Throwable t) { |
| // No-op |
| } |
| }); |
| return result; |
| |
| } |
| } |