Java tutorial
/** * 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.curator.framework.imps; import org.apache.curator.RetryLoop; import org.apache.curator.drivers.OperationTrace; import org.apache.curator.framework.api.*; import org.apache.curator.framework.api.transaction.CuratorTransactionBridge; import org.apache.curator.framework.api.transaction.OperationType; import org.apache.curator.framework.api.transaction.TransactionDeleteBuilder; import org.apache.curator.utils.ThreadUtils; import org.apache.curator.utils.ZKPaths; import org.apache.zookeeper.AsyncCallback; import org.apache.zookeeper.KeeperException; import org.apache.zookeeper.Op; import java.util.concurrent.Callable; import java.util.concurrent.Executor; class DeleteBuilderImpl implements DeleteBuilder, BackgroundOperation<String>, ErrorListenerPathable<Void> { private final CuratorFrameworkImpl client; private int version; private Backgrounding backgrounding; private boolean deletingChildrenIfNeeded; private boolean guaranteed; DeleteBuilderImpl(CuratorFrameworkImpl client) { this.client = client; version = -1; backgrounding = new Backgrounding(); deletingChildrenIfNeeded = false; guaranteed = false; } TransactionDeleteBuilder asTransactionDeleteBuilder(final CuratorTransactionImpl curatorTransaction, final CuratorMultiTransactionRecord transaction) { return new TransactionDeleteBuilder() { @Override public CuratorTransactionBridge forPath(String path) throws Exception { String fixedPath = client.fixForNamespace(path); transaction.add(Op.delete(fixedPath, version), OperationType.DELETE, path); return curatorTransaction; } @Override public Pathable<CuratorTransactionBridge> withVersion(int version) { DeleteBuilderImpl.this.withVersion(version); return this; } }; } @Override public ChildrenDeletable guaranteed() { guaranteed = true; return this; } @Override public BackgroundVersionable deletingChildrenIfNeeded() { deletingChildrenIfNeeded = true; return this; } @Override public BackgroundPathable<Void> withVersion(int version) { this.version = version; return this; } @Override public ErrorListenerPathable<Void> inBackground(BackgroundCallback callback, Object context) { backgrounding = new Backgrounding(callback, context); return this; } @Override public ErrorListenerPathable<Void> inBackground(BackgroundCallback callback, Object context, Executor executor) { backgrounding = new Backgrounding(client, callback, context, executor); return this; } @Override public ErrorListenerPathable<Void> inBackground(BackgroundCallback callback) { backgrounding = new Backgrounding(callback); return this; } @Override public ErrorListenerPathable<Void> inBackground(BackgroundCallback callback, Executor executor) { backgrounding = new Backgrounding(client, callback, executor); return this; } @Override public ErrorListenerPathable<Void> inBackground() { backgrounding = new Backgrounding(true); return this; } @Override public ErrorListenerPathable<Void> inBackground(Object context) { backgrounding = new Backgrounding(context); return this; } @Override public Pathable<Void> withUnhandledErrorListener(UnhandledErrorListener listener) { backgrounding = new Backgrounding(backgrounding, listener); return this; } @Override public void performBackgroundOperation(final OperationAndData<String> operationAndData) throws Exception { try { final OperationTrace trace = client.getZookeeperClient() .startAdvancedTracer("DeleteBuilderImpl-Background"); client.getZooKeeper().delete(operationAndData.getData(), version, new AsyncCallback.VoidCallback() { @Override public void processResult(int rc, String path, Object ctx) { trace.setReturnCode(rc).setPath(path).commit(); if ((rc == KeeperException.Code.NOTEMPTY.intValue()) && deletingChildrenIfNeeded) { backgroundDeleteChildrenThenNode(operationAndData); } else { CuratorEvent event = new CuratorEventImpl(client, CuratorEventType.DELETE, rc, path, null, ctx, null, null, null, null, null); client.processBackgroundOperation(operationAndData, event); } } }, backgrounding.getContext()); } catch (Throwable e) { backgrounding.checkError(e); } } private void backgroundDeleteChildrenThenNode(final OperationAndData<String> mainOperationAndData) { BackgroundOperation<String> operation = new BackgroundOperation<String>() { @Override public void performBackgroundOperation(OperationAndData<String> dummy) throws Exception { try { ZKPaths.deleteChildren(client.getZooKeeper(), mainOperationAndData.getData(), false); } catch (KeeperException e) { // ignore } client.queueOperation(mainOperationAndData); } }; OperationAndData<String> parentOperation = new OperationAndData<String>(operation, mainOperationAndData.getData(), null, null, backgrounding.getContext()); client.queueOperation(parentOperation); } @Override public Void forPath(String path) throws Exception { final String unfixedPath = path; path = client.fixForNamespace(path); if (backgrounding.inBackground()) { OperationAndData.ErrorCallback<String> errorCallback = null; if (guaranteed) { errorCallback = new OperationAndData.ErrorCallback<String>() { @Override public void retriesExhausted(OperationAndData<String> operationAndData) { client.getFailedDeleteManager().addFailedDelete(unfixedPath); } }; } client.processBackgroundOperation(new OperationAndData<String>(this, path, backgrounding.getCallback(), errorCallback, backgrounding.getContext()), null); } else { pathInForeground(path, unfixedPath); } return null; } protected int getVersion() { return version; } private void pathInForeground(final String path, String unfixedPath) throws Exception { OperationTrace trace = client.getZookeeperClient().startAdvancedTracer("DeleteBuilderImpl-Foreground"); try { RetryLoop.callWithRetry(client.getZookeeperClient(), new Callable<Void>() { @Override public Void call() throws Exception { try { client.getZooKeeper().delete(path, version); } catch (KeeperException.NotEmptyException e) { if (deletingChildrenIfNeeded) { ZKPaths.deleteChildren(client.getZooKeeper(), path, true); } else { throw e; } } return null; } }); } catch (Exception e) { ThreadUtils.checkInterrupted(e); //Only retry a guaranteed delete if it's a retryable error if ((RetryLoop.isRetryException(e) || (e instanceof InterruptedException)) && guaranteed) { client.getFailedDeleteManager().addFailedDelete(unfixedPath); } throw e; } trace.setPath(path).commit(); } }