| /** |
| * 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.metadata; |
| |
| import com.google.common.base.Optional; |
| |
| import java.net.URI; |
| |
| /** |
| * Log Metadata for Reader |
| */ |
| public class ZKLogMetadataForReader extends ZKLogMetadata { |
| |
| /** |
| * Get the root path to store subscription infos of a log. |
| * |
| * @param uri |
| * namespace of the log |
| * @param logName |
| * name of the log |
| * @param logIdentifier |
| * identifier of the log |
| * @return subscribers root path |
| */ |
| public static String getSubscribersPath(URI uri, String logName, String logIdentifier) { |
| return getLogComponentPath(uri, logName, logIdentifier, SUBSCRIBERS_PATH); |
| } |
| |
| /** |
| * Get the path that stores subscription info for a <code>subscriberId</code> for a <code>log</code>. |
| * |
| * @param uri |
| * namespace of the log |
| * @param logName |
| * name of the log |
| * @param logIdentifier |
| * identifier of the log |
| * @param subscriberId |
| * subscriber id of the log |
| * @return subscriber's path |
| */ |
| public static String getSubscriberPath(URI uri, String logName, String logIdentifier, String subscriberId) { |
| return String.format("%s/%s", getSubscribersPath(uri, logName, logIdentifier), subscriberId); |
| } |
| |
| /** |
| * Create a metadata representation of a log for reader. |
| * |
| * @param uri |
| * namespace to store the log |
| * @param logName |
| * name of the log |
| * @param logIdentifier |
| * identifier of the log |
| * @return metadata representation of a log for reader |
| */ |
| public static ZKLogMetadataForReader of(URI uri, String logName, String logIdentifier) { |
| return new ZKLogMetadataForReader(uri, logName, logIdentifier); |
| } |
| |
| final static String SUBSCRIBERS_PATH = "/subscribers"; |
| |
| /** |
| * metadata representation of a log |
| * |
| * @param uri namespace to store the log |
| * @param logName name of the log |
| * @param logIdentifier identifier of the log |
| */ |
| private ZKLogMetadataForReader(URI uri, String logName, String logIdentifier) { |
| super(uri, logName, logIdentifier); |
| } |
| |
| /** |
| * Get the readlock path for the log or a subscriber of the log. |
| * |
| * @param subscriberId |
| * subscriber id. it is optional. |
| * @return read lock path |
| */ |
| public String getReadLockPath(Optional<String> subscriberId) { |
| if (subscriberId.isPresent()) { |
| return logRootPath + SUBSCRIBERS_PATH + "/" + subscriberId.get() + READ_LOCK_PATH; |
| } else { |
| return logRootPath + READ_LOCK_PATH; |
| } |
| } |
| } |