| /** |
| * 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.hadoop.fs.viewfs; |
| |
| import java.io.IOException; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FSDataInputStream; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.LocatedFileStatus; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.fs.RemoteIterator; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * An implementation for Apache Hadoop compatible file system based mount-table |
| * file loading. |
| */ |
| public class HCFSMountTableConfigLoader implements MountTableConfigLoader { |
| private static final String REGEX_DOT = "[.]"; |
| private static final Logger LOGGER = |
| LoggerFactory.getLogger(HCFSMountTableConfigLoader.class); |
| private Path mountTable = null; |
| |
| /** |
| * Loads the mount-table configuration from hadoop compatible file system and |
| * add the configuration items to given configuration. Mount-table |
| * configuration format should be suffixed with version number. |
| * Format: mount-table.<versionNumber>.xml |
| * Example: mount-table.1.xml |
| * When user wants to update mount-table, the expectation is to upload new |
| * mount-table configuration file with monotonically increasing integer as |
| * version number. This API loads the highest version number file. We can |
| * also configure single file path directly. |
| * |
| * @param mountTableConfigPath : A directory path where mount-table files |
| * stored or a mount-table file path. We recommend to configure |
| * directory with the mount-table version files. |
| * @param conf : to add the mount table as resource. |
| */ |
| @Override |
| public void load(String mountTableConfigPath, Configuration conf) |
| throws IOException { |
| this.mountTable = new Path(mountTableConfigPath); |
| String scheme = mountTable.toUri().getScheme(); |
| FsGetter fsGetter = new ViewFileSystemOverloadScheme.ChildFsGetter(scheme); |
| try (FileSystem fs = fsGetter.getNewInstance(mountTable.toUri(), conf)) { |
| RemoteIterator<LocatedFileStatus> listFiles = |
| fs.listFiles(mountTable, false); |
| LocatedFileStatus lfs = null; |
| int higherVersion = -1; |
| while (listFiles.hasNext()) { |
| LocatedFileStatus curLfs = listFiles.next(); |
| String cur = curLfs.getPath().getName(); |
| String[] nameParts = cur.split(REGEX_DOT); |
| if (nameParts.length < 2) { |
| logInvalidFileNameFormat(cur); |
| continue; // invalid file name |
| } |
| int curVersion = higherVersion; |
| try { |
| curVersion = Integer.parseInt(nameParts[nameParts.length - 2]); |
| } catch (NumberFormatException nfe) { |
| logInvalidFileNameFormat(cur); |
| continue; |
| } |
| |
| if (curVersion > higherVersion) { |
| higherVersion = curVersion; |
| lfs = curLfs; |
| } |
| } |
| |
| if (lfs == null) { |
| // No valid mount table file found. |
| // TODO: Should we fail? Currently viewfs init will fail if no mount |
| // links anyway. |
| LOGGER.warn("No valid mount-table file exist at: {}. At least one " |
| + "mount-table file should present with the name format: " |
| + "mount-table.<versionNumber>.xml", mountTableConfigPath); |
| return; |
| } |
| // Latest version file. |
| Path latestVersionMountTable = lfs.getPath(); |
| if (LOGGER.isDebugEnabled()) { |
| LOGGER.debug("Loading the mount-table {} into configuration.", |
| latestVersionMountTable); |
| } |
| try (FSDataInputStream open = fs.open(latestVersionMountTable)) { |
| Configuration newConf = new Configuration(false); |
| newConf.addResource(open); |
| // This will add configuration props as resource, instead of stream |
| // itself. So, that stream can be closed now. |
| conf.addResource(newConf); |
| } |
| } |
| } |
| |
| private void logInvalidFileNameFormat(String cur) { |
| LOGGER.warn("Invalid file name format for mount-table version file: {}. " |
| + "The valid file name format is mount-table-name.<versionNumber>.xml", |
| cur); |
| } |
| |
| } |