| /** |
| * 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 com.twitter.distributedlog.impl; |
| |
| import com.google.common.base.Optional; |
| import com.google.common.collect.Lists; |
| import com.twitter.distributedlog.DistributedLogConfiguration; |
| import com.twitter.distributedlog.ZooKeeperClient; |
| import com.twitter.distributedlog.callback.NamespaceListener; |
| import com.twitter.distributedlog.exceptions.ZKException; |
| import com.twitter.distributedlog.metadata.LogMetadataStore; |
| import com.twitter.distributedlog.util.OrderedScheduler; |
| import com.twitter.util.Future; |
| import com.twitter.util.Promise; |
| import org.apache.zookeeper.AsyncCallback; |
| import org.apache.zookeeper.KeeperException; |
| import org.apache.zookeeper.ZooKeeper; |
| import org.apache.zookeeper.data.Stat; |
| |
| import java.net.URI; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import static com.twitter.distributedlog.impl.BKDLUtils.*; |
| |
| /** |
| * ZooKeeper based log metadata store |
| */ |
| public class ZKLogMetadataStore implements LogMetadataStore { |
| |
| final URI namespace; |
| final Optional<URI> nsOptional; |
| final ZooKeeperClient zkc; |
| final ZKNamespaceWatcher nsWatcher; |
| |
| public ZKLogMetadataStore( |
| DistributedLogConfiguration conf, |
| URI namespace, |
| ZooKeeperClient zkc, |
| OrderedScheduler scheduler) { |
| this.namespace = namespace; |
| this.nsOptional = Optional.of(this.namespace); |
| this.zkc = zkc; |
| this.nsWatcher = new ZKNamespaceWatcher(conf, namespace, zkc, scheduler); |
| } |
| |
| @Override |
| public Future<URI> createLog(String logName) { |
| return Future.value(namespace); |
| } |
| |
| @Override |
| public Future<Optional<URI>> getLogLocation(String logName) { |
| return Future.value(nsOptional); |
| } |
| |
| @Override |
| public Future<Iterator<String>> getLogs() { |
| final Promise<Iterator<String>> promise = new Promise<Iterator<String>>(); |
| final String nsRootPath = namespace.getPath(); |
| try { |
| final ZooKeeper zk = zkc.get(); |
| zk.sync(nsRootPath, new AsyncCallback.VoidCallback() { |
| @Override |
| public void processResult(int syncRc, String syncPath, Object ctx) { |
| if (KeeperException.Code.OK.intValue() == syncRc) { |
| zk.getChildren(nsRootPath, false, new AsyncCallback.Children2Callback() { |
| @Override |
| public void processResult(int rc, String path, Object ctx, List<String> children, Stat stat) { |
| if (KeeperException.Code.OK.intValue() == rc) { |
| List<String> results = Lists.newArrayListWithExpectedSize(children.size()); |
| for (String child : children) { |
| if (!isReservedStreamName(child)) { |
| results.add(child); |
| } |
| } |
| promise.setValue(results.iterator()); |
| } else if (KeeperException.Code.NONODE.intValue() == rc) { |
| List<String> streams = Lists.newLinkedList(); |
| promise.setValue(streams.iterator()); |
| } else { |
| promise.setException(new ZKException("Error reading namespace " + nsRootPath, |
| KeeperException.Code.get(rc))); |
| } |
| } |
| }, null); |
| } else if (KeeperException.Code.NONODE.intValue() == syncRc) { |
| List<String> streams = Lists.newLinkedList(); |
| promise.setValue(streams.iterator()); |
| } else { |
| promise.setException(new ZKException("Error reading namespace " + nsRootPath, |
| KeeperException.Code.get(syncRc))); |
| } |
| } |
| }, null); |
| zkc.get(); |
| } catch (ZooKeeperClient.ZooKeeperConnectionException e) { |
| promise.setException(e); |
| } catch (InterruptedException e) { |
| promise.setException(e); |
| } |
| return promise; |
| } |
| |
| @Override |
| public void registerNamespaceListener(NamespaceListener listener) { |
| this.nsWatcher.registerListener(listener); |
| } |
| } |